/* Low level interface to ptrace, for the remote server for GDB.
- Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
- 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+ Copyright (C) 1995-1996, 1998-2012 Free Software Foundation, Inc.
This file is part of GDB.
#include "server.h"
#include "linux-low.h"
+#include "linux-osdata.h"
+#include "agent.h"
#include <sys/wait.h>
#include <stdio.h>
#include <sys/param.h>
#include <sys/ptrace.h>
+#include "linux-ptrace.h"
+#include "linux-procfs.h"
#include <signal.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/vfs.h>
+#include <sys/uio.h>
#ifndef ELFMAG0
/* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
then ELFMAG0 will have been defined. If it didn't get included by
#define SPUFS_MAGIC 0x23c9b64e
#endif
-#ifndef PTRACE_GETSIGINFO
-# define PTRACE_GETSIGINFO 0x4202
-# define PTRACE_SETSIGINFO 0x4203
+#ifdef HAVE_PERSONALITY
+# include <sys/personality.h>
+# if !HAVE_DECL_ADDR_NO_RANDOMIZE
+# define ADDR_NO_RANDOMIZE 0x0040000
+# endif
#endif
#ifndef O_LARGEFILE
#define O_LARGEFILE 0
#endif
-/* If the system headers did not provide the constants, hard-code the normal
- values. */
-#ifndef PTRACE_EVENT_FORK
-
-#define PTRACE_SETOPTIONS 0x4200
-#define PTRACE_GETEVENTMSG 0x4201
-
-/* options set using PTRACE_SETOPTIONS */
-#define PTRACE_O_TRACESYSGOOD 0x00000001
-#define PTRACE_O_TRACEFORK 0x00000002
-#define PTRACE_O_TRACEVFORK 0x00000004
-#define PTRACE_O_TRACECLONE 0x00000008
-#define PTRACE_O_TRACEEXEC 0x00000010
-#define PTRACE_O_TRACEVFORKDONE 0x00000020
-#define PTRACE_O_TRACEEXIT 0x00000040
-
-/* Wait extended result codes for the above trace options. */
-#define PTRACE_EVENT_FORK 1
-#define PTRACE_EVENT_VFORK 2
-#define PTRACE_EVENT_CLONE 3
-#define PTRACE_EVENT_EXEC 4
-#define PTRACE_EVENT_VFORK_DONE 5
-#define PTRACE_EVENT_EXIT 6
-
-#endif /* PTRACE_EVENT_FORK */
-
-/* We can't always assume that this flag is available, but all systems
- with the ptrace event handlers also have __WALL, so it's safe to use
- in some contexts. */
-#ifndef __WALL
-#define __WALL 0x40000000 /* Wait for any child. */
-#endif
-
#ifndef W_STOPCODE
#define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
#endif
+/* This is the kernel's hard limit. Not to be confused with
+ SIGRTMIN. */
+#ifndef __SIGRTMIN
+#define __SIGRTMIN 32
+#endif
+
#ifdef __UCLIBC__
#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
+/* PTRACE_TEXT_ADDR and friends. */
+#include <asm/ptrace.h>
#define HAS_NOMMU
#endif
#endif
+#ifndef HAVE_ELF32_AUXV_T
+/* Copied from glibc's elf.h. */
+typedef struct
+{
+ uint32_t a_type; /* Entry type */
+ union
+ {
+ uint32_t a_val; /* Integer value */
+ /* We use to have pointer elements added here. We cannot do that,
+ though, since it does not work when using 32-bit definitions
+ on 64-bit platforms and vice versa. */
+ } a_un;
+} Elf32_auxv_t;
+#endif
+
+#ifndef HAVE_ELF64_AUXV_T
+/* Copied from glibc's elf.h. */
+typedef struct
+{
+ uint64_t a_type; /* Entry type */
+ union
+ {
+ uint64_t a_val; /* Integer value */
+ /* We use to have pointer elements added here. We cannot do that,
+ though, since it does not work when using 32-bit definitions
+ on 64-bit platforms and vice versa. */
+ } a_un;
+} Elf64_auxv_t;
+#endif
+
/* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
representation of the thread ID.
struct inferior_list all_lwps;
-/* A list of all unknown processes which receive stop signals. Some other
- process will presumably claim each of these as forked children
- momentarily. */
+/* A list of all unknown processes which receive stop signals. Some
+ other process will presumably claim each of these as forked
+ children momentarily. */
+
+struct simple_pid_list
+{
+ /* The process ID. */
+ int pid;
+
+ /* The status as reported by waitpid. */
+ int status;
+
+ /* Next in chain. */
+ struct simple_pid_list *next;
+};
+struct simple_pid_list *stopped_pids;
+
+/* Trivial list manipulation functions to keep track of a list of new
+ stopped processes. */
+
+static void
+add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
+{
+ struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
+
+ new_pid->pid = pid;
+ new_pid->status = status;
+ new_pid->next = *listp;
+ *listp = new_pid;
+}
+
+static int
+pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
+{
+ struct simple_pid_list **p;
+
+ for (p = listp; *p != NULL; p = &(*p)->next)
+ if ((*p)->pid == pid)
+ {
+ struct simple_pid_list *next = (*p)->next;
+
+ *statusp = (*p)->status;
+ xfree (*p);
+ *p = next;
+ return 1;
+ }
+ return 0;
+}
+
+enum stopping_threads_kind
+ {
+ /* Not stopping threads presently. */
+ NOT_STOPPING_THREADS,
+
+ /* Stopping threads. */
+ STOPPING_THREADS,
-struct inferior_list stopped_pids;
+ /* Stopping and suspending threads. */
+ STOPPING_AND_SUSPENDING_THREADS
+ };
-/* FIXME this is a bit of a hack, and could be removed. */
-int stopping_threads;
+/* This is set while stop_all_lwps is in effect. */
+enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS;
/* FIXME make into a target method? */
int using_threads = 1;
+/* True if we're presently stabilizing threads (moving them out of
+ jump pads). */
+static int stabilizing_threads;
+
/* This flag is true iff we've just created or attached to our first
inferior but it has not stopped yet. As soon as it does, we need
to call the low target's arch_setup callback. Doing this only on
static void linux_resume_one_lwp (struct lwp_info *lwp,
int step, int signal, siginfo_t *info);
static void linux_resume (struct thread_resume *resume_info, size_t n);
-static void stop_all_lwps (void);
+static void stop_all_lwps (int suspend, struct lwp_info *except);
+static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
-static int check_removed_breakpoint (struct lwp_info *event_child);
static void *add_lwp (ptid_t ptid);
static int linux_stopped_by_watchpoint (void);
static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
-static int linux_core_of_thread (ptid_t ptid);
+static void proceed_all_lwps (void);
+static int finish_step_over (struct lwp_info *lwp);
+static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
+static int kill_lwp (unsigned long lwpid, int signo);
+static void linux_enable_event_reporting (int pid);
+
+/* True if the low target can hardware single-step. Such targets
+ don't need a BREAKPOINT_REINSERT_ADDR callback. */
+
+static int
+can_hardware_single_step (void)
+{
+ return (the_low_target.breakpoint_reinsert_addr == NULL);
+}
+
+/* True if the low target supports memory breakpoints. If so, we'll
+ have a GET_PC implementation. */
+
+static int
+supports_breakpoints (void)
+{
+ return (the_low_target.get_pc != NULL);
+}
+
+/* Returns true if this target can support fast tracepoints. This
+ does not mean that the in-process agent has been loaded in the
+ inferior. */
+
+static int
+supports_fast_tracepoints (void)
+{
+ return the_low_target.install_fast_tracepoint_jump_pad != NULL;
+}
struct pending_signals
{
struct pending_signals *prev;
};
-#define PTRACE_ARG3_TYPE void *
-#define PTRACE_ARG4_TYPE void *
-#define PTRACE_XFER_TYPE long
-
#ifdef HAVE_LINUX_REGSETS
static char *disabled_regsets;
static int num_regsets;
/* True if we're currently in async mode. */
#define target_is_async_p() (linux_event_pipe[0] != -1)
-static void send_sigstop (struct inferior_list_entry *entry);
+static void send_sigstop (struct lwp_info *lwp);
static void wait_for_sigstop (struct inferior_list_entry *entry);
-/* Accepts an integer PID; Returns a string representing a file that
- can be opened to get info for the child process.
- Space for the result is malloc'd, caller must free. */
-
-char *
-linux_child_pid_to_exec_file (int pid)
-{
- char *name1, *name2;
-
- name1 = xmalloc (MAXPATHLEN);
- name2 = xmalloc (MAXPATHLEN);
- memset (name2, 0, MAXPATHLEN);
-
- sprintf (name1, "/proc/%d/exe", pid);
- if (readlink (name1, name2, MAXPATHLEN) > 0)
- {
- free (name1);
- return name2;
- }
- else
- {
- free (name2);
- return name1;
- }
-}
-
/* Return non-zero if HEADER is a 64-bit ELF file. */
static int
-elf_64_header_p (const Elf64_Ehdr *header)
+elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine)
{
- return (header->e_ident[EI_MAG0] == ELFMAG0
- && header->e_ident[EI_MAG1] == ELFMAG1
- && header->e_ident[EI_MAG2] == ELFMAG2
- && header->e_ident[EI_MAG3] == ELFMAG3
- && header->e_ident[EI_CLASS] == ELFCLASS64);
+ if (header->e_ident[EI_MAG0] == ELFMAG0
+ && header->e_ident[EI_MAG1] == ELFMAG1
+ && header->e_ident[EI_MAG2] == ELFMAG2
+ && header->e_ident[EI_MAG3] == ELFMAG3)
+ {
+ *machine = header->e_machine;
+ return header->e_ident[EI_CLASS] == ELFCLASS64;
+
+ }
+ *machine = EM_NONE;
+ return -1;
}
/* Return non-zero if FILE is a 64-bit ELF file,
zero if the file is not a 64-bit ELF file,
and -1 if the file is not accessible or doesn't exist. */
-int
-elf_64_file_p (const char *file)
+static int
+elf_64_file_p (const char *file, unsigned int *machine)
{
Elf64_Ehdr header;
int fd;
}
close (fd);
- return elf_64_header_p (&header);
+ return elf_64_header_p (&header, machine);
+}
+
+/* Accepts an integer PID; Returns true if the executable PID is
+ running is a 64-bit ELF file.. */
+
+int
+linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine)
+{
+ char file[MAXPATHLEN];
+
+ sprintf (file, "/proc/%d/exe", pid);
+ return elf_64_file_p (file, machine);
}
static void
return proc;
}
-/* Remove a process from the common process list,
- also freeing all private data. */
-
-static void
-linux_remove_process (struct process_info *process)
-{
- struct process_info_private *priv = process->private;
-
- free (priv->arch_private);
- free (priv);
- remove_process (process);
-}
-
/* Wrapper function for waitpid which handles EINTR, and emulates
__WALL for systems where that is not available. */
{
ptid_t ptid;
unsigned long new_pid;
- int ret, status = W_STOPCODE (SIGSTOP);
+ int ret, status;
ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
/* If we haven't already seen the new PID stop, wait for it now. */
- if (! pull_pid_from_list (&stopped_pids, new_pid))
+ if (!pull_pid_from_list (&stopped_pids, new_pid, &status))
{
/* The new child has a pending SIGSTOP. We can't affect it until it
hits the SIGSTOP, but we're already attached. */
warning ("wait returned unexpected status 0x%x", status);
}
- ptrace (PTRACE_SETOPTIONS, new_pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
+ linux_enable_event_reporting (new_pid);
ptid = ptid_build (pid_of (event_child), new_pid, 0);
new_lwp = (struct lwp_info *) add_lwp (ptid);
before calling linux_resume_one_lwp. */
new_lwp->stopped = 1;
+ /* If we're suspending all threads, leave this one suspended
+ too. */
+ if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS)
+ new_lwp->suspended = 1;
+
/* Normally we will get the pending SIGSTOP. But in some cases
we might get another signal delivered to the group first.
If we do get another signal, be sure not to lose it. */
if (WSTOPSIG (status) == SIGSTOP)
{
- if (! stopping_threads)
+ if (stopping_threads != NOT_STOPPING_THREADS)
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
+ else
linux_resume_one_lwp (new_lwp, 0, 0, NULL);
}
else
{
new_lwp->stop_expected = 1;
- if (stopping_threads)
+
+ if (stopping_threads != NOT_STOPPING_THREADS)
{
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
new_lwp->status_pending_p = 1;
new_lwp->status_pending = status;
}
}
}
-/* This function should only be called if the process got a SIGTRAP.
+/* Return the PC as read from the regcache of LWP, without any
+ adjustment. */
+
+static CORE_ADDR
+get_pc (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
+ struct regcache *regcache;
+ CORE_ADDR pc;
+
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ regcache = get_thread_regcache (current_inferior, 1);
+ pc = (*the_low_target.get_pc) (regcache);
+
+ if (debug_threads)
+ fprintf (stderr, "pc is 0x%lx\n", (long) pc);
+
+ current_inferior = saved_inferior;
+ return pc;
+}
+
+/* This function should only be called if LWP got a SIGTRAP.
The SIGTRAP could mean several things.
On i386, where decr_pc_after_break is non-zero:
instruction. */
static CORE_ADDR
-get_stop_pc (void)
+get_stop_pc (struct lwp_info *lwp)
{
- struct regcache *regcache = get_thread_regcache (current_inferior, 1);
- CORE_ADDR stop_pc = (*the_low_target.get_pc) (regcache);
+ CORE_ADDR stop_pc;
+
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ stop_pc = get_pc (lwp);
- if (! get_thread_lwp (current_inferior)->stepping
- && WSTOPSIG (get_thread_lwp (current_inferior)->last_status) == SIGTRAP)
+ if (WSTOPSIG (lwp->last_status) == SIGTRAP
+ && !lwp->stepping
+ && !lwp->stopped_by_watchpoint
+ && lwp->last_status >> 16 == 0)
stop_pc -= the_low_target.decr_pc_after_break;
if (debug_threads)
static int
linux_create_inferior (char *program, char **allargs)
{
+#ifdef HAVE_PERSONALITY
+ int personality_orig = 0, personality_set = 0;
+#endif
struct lwp_info *new_lwp;
int pid;
ptid_t ptid;
+#ifdef HAVE_PERSONALITY
+ if (disable_randomization)
+ {
+ errno = 0;
+ personality_orig = personality (0xffffffff);
+ if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
+ {
+ personality_set = 1;
+ personality (personality_orig | ADDR_NO_RANDOMIZE);
+ }
+ if (errno != 0 || (personality_set
+ && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
+ warning ("Error disabling address space randomization: %s",
+ strerror (errno));
+ }
+#endif
+
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
pid = vfork ();
#else
{
ptrace (PTRACE_TRACEME, 0, 0, 0);
-#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
+#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN + 1, SIG_DFL);
#endif
setpgid (0, 0);
+ /* If gdbserver is connected to gdb via stdio, redirect the inferior's
+ stdout to stderr so that inferior i/o doesn't corrupt the connection.
+ Also, redirect stdin to /dev/null. */
+ if (remote_connection_is_stdio ())
+ {
+ close (0);
+ open ("/dev/null", O_RDONLY);
+ dup2 (2, 1);
+ if (write (2, "stdin/stdout redirected\n",
+ sizeof ("stdin/stdout redirected\n") - 1) < 0)
+ /* Errors ignored. */;
+ }
+
execv (program, allargs);
if (errno == ENOENT)
execvp (program, allargs);
_exit (0177);
}
+#ifdef HAVE_PERSONALITY
+ if (personality_set)
+ {
+ errno = 0;
+ personality (personality_orig);
+ if (errno != 0)
+ warning ("Error restoring address space randomization: %s",
+ strerror (errno));
+ }
+#endif
+
linux_add_process (pid, 0);
ptid = ptid_build (pid, pid, 0);
if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
{
+ struct buffer buffer;
+
if (!initial)
{
/* If we fail to attach to an LWP, just warn. */
fflush (stderr);
return;
}
- else
- /* If we fail to attach to a process, report an error. */
- error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
- strerror (errno), errno);
+
+ /* If we fail to attach to a process, report an error. */
+ buffer_init (&buffer);
+ linux_ptrace_attach_warnings (lwpid, &buffer);
+ buffer_grow_str0 (&buffer, "");
+ error ("%sCannot attach to lwp %ld: %s (%d)", buffer_finish (&buffer),
+ lwpid, strerror (errno), errno);
}
if (initial)
- /* NOTE/FIXME: This lwp might have not been the tgid. */
+ /* If lwp is the tgid, we handle adding existing threads later.
+ Otherwise we just add lwp without bothering about any other
+ threads. */
ptid = ptid_build (lwpid, lwpid, 0);
else
{
ptrace call on this LWP. */
new_lwp->must_set_ptrace_flags = 1;
+ if (linux_proc_pid_is_stopped (lwpid))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Attached to a stopped process\n");
+
+ /* The process is definitely stopped. It is in a job control
+ stop, unless the kernel predates the TASK_STOPPED /
+ TASK_TRACED distinction, in which case it might be in a
+ ptrace stop. Make sure it is in a ptrace stop; from there we
+ can kill it, signal it, et cetera.
+
+ First make sure there is a pending SIGSTOP. Since we are
+ already attached, the process can not transition from stopped
+ to running without a PTRACE_CONT; so we know this signal will
+ go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
+ probably already in the queue (unless this kernel is old
+ enough to use TASK_STOPPED for ptrace stops); but since
+ SIGSTOP is not an RT signal, it can only be queued once. */
+ kill_lwp (lwpid, SIGSTOP);
+
+ /* Finally, resume the stopped process. This will deliver the
+ SIGSTOP (or a higher priority signal, just like normal
+ PTRACE_ATTACH), which we'll catch later on. */
+ ptrace (PTRACE_CONT, lwpid, 0, 0);
+ }
+
/* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
brings it to a halt.
1) gdbserver has already attached to the process and is being notified
of a new thread that is being created.
- In this case we should ignore that SIGSTOP and resume the process.
- This is handled below by setting stop_expected = 1.
+ In this case we should ignore that SIGSTOP and resume the
+ process. This is handled below by setting stop_expected = 1,
+ and the fact that add_thread sets last_resume_kind ==
+ resume_continue.
2) This is the first thread (the process thread), and we're attaching
to it via attach_inferior.
In this case we want the process thread to stop.
- This is handled by having linux_attach clear stop_expected after
- we return.
- ??? If the process already has several threads we leave the other
- threads running.
+ This is handled by having linux_attach set last_resume_kind ==
+ resume_stop after we return.
+
+ If the pid we are attaching to is also the tgid, we attach to and
+ stop all the existing threads. Otherwise, we attach to pid and
+ ignore any other threads in the same group as this pid.
3) GDB is connecting to gdbserver and is requesting an enumeration of all
existing threads.
because we are guaranteed that the add_lwp call above added us to the
end of the list, and so the new thread has not yet reached
wait_for_sigstop (but will). */
- if (! stopping_threads)
- new_lwp->stop_expected = 1;
+ new_lwp->stop_expected = 1;
}
void
linux_attach_lwp_1 (lwpid, 0);
}
-int
+/* Attach to PID. If PID is the tgid, attach to it and all
+ of its threads. */
+
+static int
linux_attach (unsigned long pid)
{
- struct lwp_info *lwp;
-
+ /* Attach to PID. We will check for other threads
+ soon. */
linux_attach_lwp_1 (pid, 1);
-
linux_add_process (pid, 1);
if (!non_stop)
{
- /* Don't ignore the initial SIGSTOP if we just attached to this
- process. It will be collected by wait shortly. */
- lwp = (struct lwp_info *) find_inferior_id (&all_lwps,
- ptid_build (pid, pid, 0));
- lwp->stop_expected = 0;
+ struct thread_info *thread;
+
+ /* Don't ignore the initial SIGSTOP if we just attached to this
+ process. It will be collected by wait shortly. */
+ thread = find_thread_ptid (ptid_build (pid, pid, 0));
+ thread->last_resume_kind = resume_stop;
+ }
+
+ if (linux_proc_get_tgid (pid) == pid)
+ {
+ DIR *dir;
+ char pathname[128];
+
+ sprintf (pathname, "/proc/%ld/task", pid);
+
+ dir = opendir (pathname);
+
+ if (!dir)
+ {
+ fprintf (stderr, "Could not open /proc/%ld/task.\n", pid);
+ fflush (stderr);
+ }
+ else
+ {
+ /* At this point we attached to the tgid. Scan the task for
+ existing threads. */
+ unsigned long lwp;
+ int new_threads_found;
+ int iterations = 0;
+ struct dirent *dp;
+
+ while (iterations < 2)
+ {
+ new_threads_found = 0;
+ /* Add all the other threads. While we go through the
+ threads, new threads may be spawned. Cycle through
+ the list of threads until we have done two iterations without
+ finding new threads. */
+ while ((dp = readdir (dir)) != NULL)
+ {
+ /* Fetch one lwp. */
+ lwp = strtoul (dp->d_name, NULL, 10);
+
+ /* Is this a new thread? */
+ if (lwp
+ && find_thread_ptid (ptid_build (pid, lwp, 0)) == NULL)
+ {
+ linux_attach_lwp_1 (lwp, 0);
+ new_threads_found++;
+
+ if (debug_threads)
+ fprintf (stderr, "\
+Found and attached to new lwp %ld\n", lwp);
+ }
+ }
+
+ if (!new_threads_found)
+ iterations++;
+ else
+ iterations = 0;
+
+ rewinddir (dir);
+ }
+ closedir (dir);
+ }
}
return 0;
second_thread_of_pid_p, &counter) == NULL);
}
-/* Kill the inferior lwp. */
+/* Kill LWP. */
+
+static void
+linux_kill_one_lwp (struct lwp_info *lwp)
+{
+ int pid = lwpid_of (lwp);
+
+ /* PTRACE_KILL is unreliable. After stepping into a signal handler,
+ there is no signal context, and ptrace(PTRACE_KILL) (or
+ ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
+ ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
+ alternative is to kill with SIGKILL. We only need one SIGKILL
+ per process, not one for each thread. But since we still support
+ linuxthreads, and we also support debugging programs using raw
+ clone without CLONE_THREAD, we send one for each thread. For
+ years, we used PTRACE_KILL only, so we're being a bit paranoid
+ about some old kernels where PTRACE_KILL might work better
+ (dubious if there are any such, but that's why it's paranoia), so
+ we try SIGKILL first, PTRACE_KILL second, and so we're fine
+ everywhere. */
+
+ errno = 0;
+ kill (pid, SIGKILL);
+ if (debug_threads)
+ fprintf (stderr,
+ "LKL: kill (SIGKILL) %s, 0, 0 (%s)\n",
+ target_pid_to_str (ptid_of (lwp)),
+ errno ? strerror (errno) : "OK");
+
+ errno = 0;
+ ptrace (PTRACE_KILL, pid, 0, 0);
+ if (debug_threads)
+ fprintf (stderr,
+ "LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
+ target_pid_to_str (ptid_of (lwp)),
+ errno ? strerror (errno) : "OK");
+}
+
+/* Callback for `find_inferior'. Kills an lwp of a given process,
+ except the leader. */
static int
-linux_kill_one_lwp (struct inferior_list_entry *entry, void *args)
+kill_one_lwp_callback (struct inferior_list_entry *entry, void *args)
{
struct thread_info *thread = (struct thread_info *) entry;
struct lwp_info *lwp = get_thread_lwp (thread);
return 0;
}
- /* If we're killing a running inferior, make sure it is stopped
- first, as PTRACE_KILL will not work otherwise. */
- if (!lwp->stopped)
- send_sigstop (&lwp->head);
-
do
{
- ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
+ linux_kill_one_lwp (lwp);
/* Make sure it died. The loop is most likely unnecessary. */
pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
{
struct process_info *process;
struct lwp_info *lwp;
- struct thread_info *thread;
int wstat;
int lwpid;
if (process == NULL)
return -1;
- find_inferior (&all_threads, linux_kill_one_lwp, &pid);
+ /* If we're killing a running inferior, make sure it is stopped
+ first, as PTRACE_KILL will not work otherwise. */
+ stop_all_lwps (0, NULL);
+
+ find_inferior (&all_threads, kill_one_lwp_callback , &pid);
/* See the comment in linux_kill_one_lwp. We did not kill the first
thread in the list, so do so now. */
lwp = find_lwp_pid (pid_to_ptid (pid));
- thread = get_lwp_thread (lwp);
- if (debug_threads)
- fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
- lwpid_of (lwp), pid);
+ if (lwp == NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr, "lk_1: cannot find lwp %ld, for pid: %d\n",
+ lwpid_of (lwp), pid);
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
+ lwpid_of (lwp), pid);
- /* If we're killing a running inferior, make sure it is stopped
- first, as PTRACE_KILL will not work otherwise. */
- if (!lwp->stopped)
- send_sigstop (&lwp->head);
+ do
+ {
+ linux_kill_one_lwp (lwp);
- do
- {
- ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
+ /* Make sure it died. The loop is most likely unnecessary. */
+ lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
+ } while (lwpid > 0 && WIFSTOPPED (wstat));
+ }
- /* Make sure it died. The loop is most likely unnecessary. */
- lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
- } while (lwpid > 0 && WIFSTOPPED (wstat));
+ the_target->mourn (process);
-#ifdef USE_THREAD_DB
- thread_db_free (process, 0);
-#endif
- delete_lwp (lwp);
- linux_remove_process (process);
+ /* Since we presently can only stop all lwps of all processes, we
+ need to unstop lwps of other processes. */
+ unstop_all_lwps (0, NULL);
return 0;
}
+/* Get pending signal of THREAD, for detaching purposes. This is the
+ signal the thread last stopped for, which we need to deliver to the
+ thread when detaching, otherwise, it'd be suppressed/lost. */
+
static int
-linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
+get_detach_signal (struct thread_info *thread)
{
- struct thread_info *thread = (struct thread_info *) entry;
- struct lwp_info *lwp = get_thread_lwp (thread);
- int pid = * (int *) args;
+ enum gdb_signal signo = GDB_SIGNAL_0;
+ int status;
+ struct lwp_info *lp = get_thread_lwp (thread);
- if (ptid_get_pid (entry->id) != pid)
- return 0;
+ if (lp->status_pending_p)
+ status = lp->status_pending;
+ else
+ {
+ /* If the thread had been suspended by gdbserver, and it stopped
+ cleanly, then it'll have stopped with SIGSTOP. But we don't
+ want to deliver that SIGSTOP. */
+ if (thread->last_status.kind != TARGET_WAITKIND_STOPPED
+ || thread->last_status.value.sig == GDB_SIGNAL_0)
+ return 0;
- /* If we're detaching from a running inferior, make sure it is
- stopped first, as PTRACE_DETACH will not work otherwise. */
- if (!lwp->stopped)
+ /* Otherwise, we may need to deliver the signal we
+ intercepted. */
+ status = lp->last_status;
+ }
+
+ if (!WIFSTOPPED (status))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s hasn't stopped: no pending signal\n",
+ target_pid_to_str (ptid_of (lp)));
+ return 0;
+ }
+
+ /* Extended wait statuses aren't real SIGTRAPs. */
+ if (WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
{
- int lwpid = lwpid_of (lwp);
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s had stopped with extended "
+ "status: no pending signal\n",
+ target_pid_to_str (ptid_of (lp)));
+ return 0;
+ }
- stopping_threads = 1;
- send_sigstop (&lwp->head);
+ signo = gdb_signal_from_host (WSTOPSIG (status));
- /* If this detects a new thread through a clone event, the new
- thread is appended to the end of the lwp list, so we'll
- eventually detach from it. */
- wait_for_sigstop (&lwp->head);
- stopping_threads = 0;
+ if (program_signals_p && !program_signals[signo])
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s had signal %s, but it is in nopass state\n",
+ target_pid_to_str (ptid_of (lp)),
+ gdb_signal_to_string (signo));
+ return 0;
+ }
+ else if (!program_signals_p
+ /* If we have no way to know which signals GDB does not
+ want to have passed to the program, assume
+ SIGTRAP/SIGINT, which is GDB's default. */
+ && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s had signal %s, "
+ "but we don't know if we should pass it. Default to not.\n",
+ target_pid_to_str (ptid_of (lp)),
+ gdb_signal_to_string (signo));
+ return 0;
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s has pending signal %s: delivering it.\n",
+ target_pid_to_str (ptid_of (lp)),
+ gdb_signal_to_string (signo));
- /* If LWP exits while we're trying to stop it, there's nothing
- left to do. */
- lwp = find_lwp_pid (pid_to_ptid (lwpid));
- if (lwp == NULL)
- return 0;
+ return WSTOPSIG (status);
}
+}
+
+static int
+linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
+{
+ struct thread_info *thread = (struct thread_info *) entry;
+ struct lwp_info *lwp = get_thread_lwp (thread);
+ int pid = * (int *) args;
+ int sig;
- /* Make sure the process isn't stopped at a breakpoint that's
- no longer there. */
- check_removed_breakpoint (lwp);
+ if (ptid_get_pid (entry->id) != pid)
+ return 0;
- /* If this process is stopped but is expecting a SIGSTOP, then make
- sure we take care of that now. This isn't absolutely guaranteed
- to collect the SIGSTOP, but is fairly likely to. */
+ /* If there is a pending SIGSTOP, get rid of it. */
if (lwp->stop_expected)
{
- int wstat;
- /* Clear stop_expected, so that the SIGSTOP will be reported. */
+ if (debug_threads)
+ fprintf (stderr,
+ "Sending SIGCONT to %s\n",
+ target_pid_to_str (ptid_of (lwp)));
+
+ kill_lwp (lwpid_of (lwp), SIGCONT);
lwp->stop_expected = 0;
- if (lwp->stopped)
- linux_resume_one_lwp (lwp, 0, 0, NULL);
- linux_wait_for_event (lwp->head.id, &wstat, __WALL);
}
/* Flush any pending changes to the process's registers. */
regcache_invalidate_one ((struct inferior_list_entry *)
get_lwp_thread (lwp));
- /* Finally, let it resume. */
- ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
+ /* Pass on any pending signal for this thread. */
+ sig = get_detach_signal (thread);
- delete_lwp (lwp);
- return 0;
-}
-
-static int
-any_thread_of (struct inferior_list_entry *entry, void *args)
-{
- int *pid_p = args;
-
- if (ptid_get_pid (entry->id) == *pid_p)
- return 1;
+ /* Finally, let it resume. */
+ if (the_low_target.prepare_to_resume != NULL)
+ the_low_target.prepare_to_resume (lwp);
+ if (ptrace (PTRACE_DETACH, lwpid_of (lwp), 0,
+ (PTRACE_ARG4_TYPE) (long) sig) < 0)
+ error (_("Can't detach %s: %s"),
+ target_pid_to_str (ptid_of (lwp)),
+ strerror (errno));
+ delete_lwp (lwp);
return 0;
}
if (process == NULL)
return -1;
+ /* Stop all threads before detaching. First, ptrace requires that
+ the thread is stopped to sucessfully detach. Second, thread_db
+ may need to uninstall thread event breakpoints from memory, which
+ only works with a stopped process anyway. */
+ stop_all_lwps (0, NULL);
+
#ifdef USE_THREAD_DB
- thread_db_free (process, 1);
+ thread_db_detach (process);
#endif
- current_inferior =
- (struct thread_info *) find_inferior (&all_threads, any_thread_of, &pid);
+ /* Stabilize threads (move out of jump pads). */
+ stabilize_threads ();
- delete_all_breakpoints ();
find_inferior (&all_threads, linux_detach_one_lwp, &pid);
- linux_remove_process (process);
+
+ the_target->mourn (process);
+
+ /* Since we presently can only stop all lwps of all processes, we
+ need to unstop lwps of other processes. */
+ unstop_all_lwps (0, NULL);
+ return 0;
+}
+
+/* Remove all LWPs that belong to process PROC from the lwp list. */
+
+static int
+delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct process_info *process = proc;
+
+ if (pid_of (lwp) == pid_of (process))
+ delete_lwp (lwp);
+
return 0;
}
+static void
+linux_mourn (struct process_info *process)
+{
+ struct process_info_private *priv;
+
+#ifdef USE_THREAD_DB
+ thread_db_mourn (process);
+#endif
+
+ find_inferior (&all_lwps, delete_lwp_callback, process);
+
+ /* Freeing all private data. */
+ priv = process->private;
+ free (priv->arch_private);
+ free (priv);
+ process->private = NULL;
+
+ remove_process (process);
+}
+
static void
linux_join (int pid)
{
int status, ret;
- struct process_info *process;
-
- process = find_process_pid (pid);
- if (process == NULL)
- return;
do {
ret = my_waitpid (pid, &status, 0);
return 0;
}
-/* Return nonzero if this process stopped at a breakpoint which
- no longer appears to be inserted. Also adjust the PC
- appropriately to resume where the breakpoint used to be. */
-static int
-check_removed_breakpoint (struct lwp_info *event_child)
-{
- CORE_ADDR stop_pc;
- struct thread_info *saved_inferior;
- struct regcache *regcache;
-
- if (event_child->pending_is_breakpoint == 0)
- return 0;
-
- if (debug_threads)
- fprintf (stderr, "Checking for breakpoint in lwp %ld.\n",
- lwpid_of (event_child));
-
- saved_inferior = current_inferior;
- current_inferior = get_lwp_thread (event_child);
- regcache = get_thread_regcache (current_inferior, 1);
- stop_pc = get_stop_pc ();
-
- /* If the PC has changed since we stopped, then we shouldn't do
- anything. This happens if, for instance, GDB handled the
- decr_pc_after_break subtraction itself. */
- if (stop_pc != event_child->pending_stop_pc)
- {
- if (debug_threads)
- fprintf (stderr, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
- event_child->pending_stop_pc);
-
- event_child->pending_is_breakpoint = 0;
- current_inferior = saved_inferior;
- return 0;
- }
-
- /* If the breakpoint is still there, we will report hitting it. */
- if ((*the_low_target.breakpoint_at) (stop_pc))
- {
- if (debug_threads)
- fprintf (stderr, "Ignoring, breakpoint is still present.\n");
- current_inferior = saved_inferior;
- return 0;
- }
-
- if (debug_threads)
- fprintf (stderr, "Removed breakpoint.\n");
-
- /* For decr_pc_after_break targets, here is where we perform the
- decrement. We go immediately from this function to resuming,
- and can not safely call get_stop_pc () again. */
- if (the_low_target.set_pc != NULL)
- {
- if (debug_threads)
- fprintf (stderr, "Set pc to 0x%lx\n", (long) stop_pc);
- (*the_low_target.set_pc) (regcache, stop_pc);
- }
-
- /* We consumed the pending SIGTRAP. */
- event_child->pending_is_breakpoint = 0;
- event_child->status_pending_p = 0;
- event_child->status_pending = 0;
-
- current_inferior = saved_inferior;
- return 1;
-}
-
-/* Return 1 if this lwp has an interesting status pending. This
- function may silently resume an inferior lwp. */
+/* Return 1 if this lwp has an interesting status pending. */
static int
-status_pending_p (struct inferior_list_entry *entry, void *arg)
+status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
{
struct lwp_info *lwp = (struct lwp_info *) entry;
ptid_t ptid = * (ptid_t *) arg;
+ struct thread_info *thread;
/* Check if we're only interested in events from a specific process
or its lwps. */
&& ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
return 0;
- if (lwp->status_pending_p && !lwp->suspended)
- if (check_removed_breakpoint (lwp))
- {
- /* This thread was stopped at a breakpoint, and the breakpoint
- is now gone. We were told to continue (or step...) all threads,
- so GDB isn't trying to single-step past this breakpoint.
- So instead of reporting the old SIGTRAP, pretend we got to
- the breakpoint just after it was removed instead of just
- before; resume the process. */
- linux_resume_one_lwp (lwp, 0, 0, NULL);
- return 0;
- }
+ thread = get_lwp_thread (lwp);
+
+ /* If we got a `vCont;t', but we haven't reported a stop yet, do
+ report any status pending the LWP may have. */
+ if (thread->last_resume_kind == resume_stop
+ && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
+ return 0;
- return (lwp->status_pending_p && !lwp->suspended);
+ return lwp->status_pending_p;
}
static int
was reported to us by the kernel. Save its PID. */
if (child == NULL && WIFSTOPPED (*wstatp))
{
- add_pid_to_list (&stopped_pids, ret);
+ add_to_pid_list (&stopped_pids, ret, *wstatp);
goto retry;
}
else if (child == NULL)
goto retry;
child->stopped = 1;
- child->pending_is_breakpoint = 0;
child->last_status = *wstatp;
new_inferior = 0;
}
+ /* Fetch the possibly triggered data watchpoint info and store it in
+ CHILD.
+
+ On some archs, like x86, that use debug registers to set
+ watchpoints, it's possible that the way to know which watched
+ address trapped, is to check the register that is used to select
+ which address to watch. Problem is, between setting the
+ watchpoint and reading back which data address trapped, the user
+ may change the set of watchpoints, and, as a consequence, GDB
+ changes the debug registers in the inferior. To avoid reading
+ back a stale stopped-data-address when that happens, we cache in
+ LP the fact that a watchpoint trapped, and the corresponding data
+ address, as soon as we see CHILD stop with a SIGTRAP. If GDB
+ changes the debug registers meanwhile, we have the cached data we
+ can rely on. */
+
+ if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP)
+ {
+ if (the_low_target.stopped_by_watchpoint == NULL)
+ {
+ child->stopped_by_watchpoint = 0;
+ }
+ else
+ {
+ struct thread_info *saved_inferior;
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (child);
+
+ child->stopped_by_watchpoint
+ = the_low_target.stopped_by_watchpoint ();
+
+ if (child->stopped_by_watchpoint)
+ {
+ if (the_low_target.stopped_data_address != NULL)
+ child->stopped_data_address
+ = the_low_target.stopped_data_address ();
+ else
+ child->stopped_data_address = 0;
+ }
+
+ current_inferior = saved_inferior;
+ }
+ }
+
+ /* Store the STOP_PC, with adjustment applied. This depends on the
+ architecture being defined already (so that CHILD has a valid
+ regcache), and on LAST_STATUS being set (to check for SIGTRAP or
+ not). */
+ if (WIFSTOPPED (*wstatp))
+ child->stop_pc = get_stop_pc (child);
+
if (debug_threads
&& WIFSTOPPED (*wstatp)
&& the_low_target.get_pc != NULL)
{
struct thread_info *saved_inferior = current_inferior;
- struct regcache *regcache = get_thread_regcache (current_inferior, 1);
+ struct regcache *regcache;
CORE_ADDR pc;
- current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, child->head.id);
+ current_inferior = get_lwp_thread (child);
+ regcache = get_thread_regcache (current_inferior, 1);
pc = (*the_low_target.get_pc) (regcache);
fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
current_inferior = saved_inferior;
return child;
}
-/* Wait for an event from child PID. If PID is -1, wait for any
- child. Store the stop status through the status pointer WSTAT.
- OPTIONS is passed to the waitpid call. Return 0 if no child stop
- event was found and OPTIONS contains WNOHANG. Return the PID of
- the stopped child otherwise. */
+/* This function should only be called if the LWP got a SIGTRAP.
+
+ Handle any tracepoint steps or hits. Return true if a tracepoint
+ event was handled, 0 otherwise. */
static int
-linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options)
+handle_tracepoints (struct lwp_info *lwp)
{
- CORE_ADDR stop_pc;
- struct lwp_info *event_child = NULL;
- int bp_status;
- struct lwp_info *requested_child = NULL;
+ struct thread_info *tinfo = get_lwp_thread (lwp);
+ int tpoint_related_event = 0;
- /* Check for a lwp with a pending status. */
- /* It is possible that the user changed the pending task's registers since
- it stopped. We correctly handle the change of PC if we hit a breakpoint
- (in check_removed_breakpoint); signals should be reported anyway. */
+ /* If this tracepoint hit causes a tracing stop, we'll immediately
+ uninsert tracepoints. To do this, we temporarily pause all
+ threads, unpatch away, and then unpause threads. We need to make
+ sure the unpausing doesn't resume LWP too. */
+ lwp->suspended++;
- if (ptid_equal (ptid, minus_one_ptid)
- || ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid))
- {
- event_child = (struct lwp_info *)
- find_inferior (&all_lwps, status_pending_p, &ptid);
- if (debug_threads && event_child)
- fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
- }
- else
- {
- requested_child = find_lwp_pid (ptid);
- if (requested_child->status_pending_p
- && !check_removed_breakpoint (requested_child))
- event_child = requested_child;
- }
+ /* And we need to be sure that any all-threads-stopping doesn't try
+ to move threads out of the jump pads, as it could deadlock the
+ inferior (LWP could be in the jump pad, maybe even holding the
+ lock.) */
- if (event_child != NULL)
+ /* Do any necessary step collect actions. */
+ tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
+
+ tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
+
+ /* See if we just hit a tracepoint and do its main collect
+ actions. */
+ tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
+
+ lwp->suspended--;
+
+ gdb_assert (lwp->suspended == 0);
+ gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
+
+ if (tpoint_related_event)
{
if (debug_threads)
- fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
- lwpid_of (event_child), event_child->status_pending);
- *wstat = event_child->status_pending;
- event_child->status_pending_p = 0;
- event_child->status_pending = 0;
- current_inferior = get_lwp_thread (event_child);
- return lwpid_of (event_child);
+ fprintf (stderr, "got a tracepoint event\n");
+ return 1;
}
- /* We only enter this loop if no process has a pending wait status. Thus
- any action taken in response to a wait status inside this loop is
- responding as soon as we detect the status, not after any pending
- events. */
- while (1)
- {
- event_child = linux_wait_for_lwp (ptid, wstat, options);
+ return 0;
+}
- if ((options & WNOHANG) && event_child == NULL)
- return 0;
+/* Convenience wrapper. Returns true if LWP is presently collecting a
+ fast tracepoint. */
- if (event_child == NULL)
- error ("event from unknown child");
+static int
+linux_fast_tracepoint_collecting (struct lwp_info *lwp,
+ struct fast_tpoint_collect_status *status)
+{
+ CORE_ADDR thread_area;
- current_inferior = get_lwp_thread (event_child);
+ if (the_low_target.get_thread_area == NULL)
+ return 0;
- /* Check for thread exit. */
- if (! WIFSTOPPED (*wstat))
+ /* Get the thread area address. This is used to recognize which
+ thread is which when tracing with the in-process agent library.
+ We don't read anything from the address, and treat it as opaque;
+ it's the address itself that we assume is unique per-thread. */
+ if ((*the_low_target.get_thread_area) (lwpid_of (lwp), &thread_area) == -1)
+ return 0;
+
+ return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
+}
+
+/* The reason we resume in the caller, is because we want to be able
+ to pass lwp->status_pending as WSTAT, and we need to clear
+ status_pending_p before resuming, otherwise, linux_resume_one_lwp
+ refuses to resume. */
+
+static int
+maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
+{
+ struct thread_info *saved_inferior;
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ if ((wstat == NULL
+ || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
+ && supports_fast_tracepoints ()
+ && agent_loaded_p ())
+ {
+ struct fast_tpoint_collect_status status;
+ int r;
+
+ if (debug_threads)
+ fprintf (stderr, "\
+Checking whether LWP %ld needs to move out of the jump pad.\n",
+ lwpid_of (lwp));
+
+ r = linux_fast_tracepoint_collecting (lwp, &status);
+
+ if (wstat == NULL
+ || (WSTOPSIG (*wstat) != SIGILL
+ && WSTOPSIG (*wstat) != SIGFPE
+ && WSTOPSIG (*wstat) != SIGSEGV
+ && WSTOPSIG (*wstat) != SIGBUS))
{
- if (debug_threads)
- fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
+ lwp->collecting_fast_tracepoint = r;
- /* If the last thread is exiting, just return. */
- if (last_thread_of_process_p (current_inferior))
+ if (r != 0)
{
+ if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
+ {
+ /* Haven't executed the original instruction yet.
+ Set breakpoint there, and wait till it's hit,
+ then single-step until exiting the jump pad. */
+ lwp->exit_jump_pad_bkpt
+ = set_breakpoint_at (status.adjusted_insn_addr, NULL);
+ }
+
if (debug_threads)
- fprintf (stderr, "LWP %ld is last lwp of process\n",
- lwpid_of (event_child));
- return lwpid_of (event_child);
+ fprintf (stderr, "\
+Checking whether LWP %ld needs to move out of the jump pad...it does\n",
+ lwpid_of (lwp));
+ current_inferior = saved_inferior;
+
+ return 1;
}
+ }
+ else
+ {
+ /* If we get a synchronous signal while collecting, *and*
+ while executing the (relocated) original instruction,
+ reset the PC to point at the tpoint address, before
+ reporting to GDB. Otherwise, it's an IPA lib bug: just
+ report the signal to GDB, and pray for the best. */
- delete_lwp (event_child);
+ lwp->collecting_fast_tracepoint = 0;
- if (!non_stop)
+ if (r != 0
+ && (status.adjusted_insn_addr <= lwp->stop_pc
+ && lwp->stop_pc < status.adjusted_insn_addr_end))
{
- current_inferior = (struct thread_info *) all_threads.head;
- if (debug_threads)
- fprintf (stderr, "Current inferior is now %ld\n",
- lwpid_of (get_thread_lwp (current_inferior)));
+ siginfo_t info;
+ struct regcache *regcache;
+
+ /* The si_addr on a few signals references the address
+ of the faulting instruction. Adjust that as
+ well. */
+ if ((WSTOPSIG (*wstat) == SIGILL
+ || WSTOPSIG (*wstat) == SIGFPE
+ || WSTOPSIG (*wstat) == SIGBUS
+ || WSTOPSIG (*wstat) == SIGSEGV)
+ && ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &info) == 0
+ /* Final check just to make sure we don't clobber
+ the siginfo of non-kernel-sent signals. */
+ && (uintptr_t) info.si_addr == lwp->stop_pc)
+ {
+ info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
+ ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &info);
+ }
+
+ regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
+ (*the_low_target.set_pc) (regcache, status.tpoint_addr);
+ lwp->stop_pc = status.tpoint_addr;
+
+ /* Cancel any fast tracepoint lock this thread was
+ holding. */
+ force_unlock_trace_buffer ();
}
- else
+
+ if (lwp->exit_jump_pad_bkpt != NULL)
{
- current_inferior = NULL;
if (debug_threads)
- fprintf (stderr, "Current inferior is now <NULL>\n");
- }
+ fprintf (stderr,
+ "Cancelling fast exit-jump-pad: removing bkpt. "
+ "stopping all threads momentarily.\n");
- /* If we were waiting for this particular child to do something...
- well, it did something. */
- if (requested_child != NULL)
- return lwpid_of (event_child);
+ stop_all_lwps (1, lwp);
+ cancel_breakpoints ();
- /* Wait for a more interesting event. */
- continue;
- }
+ delete_breakpoint (lwp->exit_jump_pad_bkpt);
+ lwp->exit_jump_pad_bkpt = NULL;
- if (event_child->must_set_ptrace_flags)
- {
- ptrace (PTRACE_SETOPTIONS, lwpid_of (event_child),
- 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
- event_child->must_set_ptrace_flags = 0;
- }
+ unstop_all_lwps (1, lwp);
- if (WIFSTOPPED (*wstat)
- && WSTOPSIG (*wstat) == SIGSTOP
- && event_child->stop_expected)
- {
- if (debug_threads)
- fprintf (stderr, "Expected stop.\n");
- event_child->stop_expected = 0;
- linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
- continue;
+ gdb_assert (lwp->suspended >= 0);
+ }
}
+ }
- if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
- && *wstat >> 16 != 0)
- {
- handle_extended_wait (event_child, *wstat);
- continue;
- }
+ if (debug_threads)
+ fprintf (stderr, "\
+Checking whether LWP %ld needs to move out of the jump pad...no\n",
+ lwpid_of (lwp));
- /* If GDB is not interested in this signal, don't stop other
- threads, and don't report it to GDB. Just resume the
- inferior right away. We do this for threading-related
- signals as well as any that GDB specifically requested we
- ignore. But never ignore SIGSTOP if we sent it ourselves,
- and do not ignore signals when stepping - they may require
- special handling to skip the signal handler. */
- /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
- thread library? */
- if (WIFSTOPPED (*wstat)
- && !event_child->stepping
- && (
-#if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
- (current_process ()->private->thread_db != NULL
- && (WSTOPSIG (*wstat) == __SIGRTMIN
- || WSTOPSIG (*wstat) == __SIGRTMIN + 1))
- ||
-#endif
- (pass_signals[target_signal_from_host (WSTOPSIG (*wstat))]
- && (WSTOPSIG (*wstat) != SIGSTOP || !stopping_threads))))
- {
- siginfo_t info, *info_p;
+ current_inferior = saved_inferior;
+ return 0;
+}
- if (debug_threads)
- fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
- WSTOPSIG (*wstat), lwpid_of (event_child));
+/* Enqueue one signal in the "signals to report later when out of the
+ jump pad" list. */
- if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
- info_p = &info;
- else
- info_p = NULL;
- linux_resume_one_lwp (event_child,
- event_child->stepping,
- WSTOPSIG (*wstat), info_p);
- continue;
- }
+static void
+enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
+{
+ struct pending_signals *p_sig;
+
+ if (debug_threads)
+ fprintf (stderr, "\
+Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat), lwpid_of (lwp));
- /* If this event was not handled above, and is not a SIGTRAP,
- report it. SIGILL and SIGSEGV are also treated as traps in case
- a breakpoint is inserted at the current PC. */
- if (!WIFSTOPPED (*wstat)
- || (WSTOPSIG (*wstat) != SIGTRAP && WSTOPSIG (*wstat) != SIGILL
- && WSTOPSIG (*wstat) != SIGSEGV))
- return lwpid_of (event_child);
+ if (debug_threads)
+ {
+ struct pending_signals *sig;
- /* If this target does not support breakpoints, we simply report the
- signal; it's of no concern to us. */
- if (the_low_target.get_pc == NULL)
- return lwpid_of (event_child);
+ for (sig = lwp->pending_signals_to_report;
+ sig != NULL;
+ sig = sig->prev)
+ fprintf (stderr,
+ " Already queued %d\n",
+ sig->signal);
- stop_pc = get_stop_pc ();
+ fprintf (stderr, " (no more currently queued signals)\n");
+ }
- /* Only handle SIGILL or SIGSEGV if we've hit a recognized
- breakpoint. */
- if (WSTOPSIG (*wstat) != SIGTRAP
- && (event_child->stepping
- || ! (*the_low_target.breakpoint_at) (stop_pc)))
- return lwpid_of (event_child);
+ /* Don't enqueue non-RT signals if they are already in the deferred
+ queue. (SIGSTOP being the easiest signal to see ending up here
+ twice) */
+ if (WSTOPSIG (*wstat) < __SIGRTMIN)
+ {
+ struct pending_signals *sig;
- /* bp_reinsert will only be set if we were single-stepping.
- Notice that we will resume the process after hitting
- a gdbserver breakpoint; single-stepping to/over one
- is not supported (yet). */
- if (event_child->bp_reinsert != 0)
+ for (sig = lwp->pending_signals_to_report;
+ sig != NULL;
+ sig = sig->prev)
{
- if (debug_threads)
- fprintf (stderr, "Reinserted breakpoint.\n");
- reinsert_breakpoint (event_child->bp_reinsert);
- event_child->bp_reinsert = 0;
-
- /* Clear the single-stepping flag and SIGTRAP as we resume. */
- linux_resume_one_lwp (event_child, 0, 0, NULL);
- continue;
+ if (sig->signal == WSTOPSIG (*wstat))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Not requeuing already queued non-RT signal %d"
+ " for LWP %ld\n",
+ sig->signal,
+ lwpid_of (lwp));
+ return;
+ }
}
+ }
- bp_status = check_breakpoints (stop_pc);
+ p_sig = xmalloc (sizeof (*p_sig));
+ p_sig->prev = lwp->pending_signals_to_report;
+ p_sig->signal = WSTOPSIG (*wstat);
+ memset (&p_sig->info, 0, sizeof (siginfo_t));
+ ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
- if (bp_status != 0)
- {
- if (debug_threads)
- fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+ lwp->pending_signals_to_report = p_sig;
+}
- /* We hit one of our own breakpoints. We mark it as a pending
- breakpoint, so that check_removed_breakpoint () will do the PC
- adjustment for us at the appropriate time. */
- event_child->pending_is_breakpoint = 1;
- event_child->pending_stop_pc = stop_pc;
-
- /* We may need to put the breakpoint back. We continue in the event
- loop instead of simply replacing the breakpoint right away,
- in order to not lose signals sent to the thread that hit the
- breakpoint. Unfortunately this increases the window where another
- thread could sneak past the removed breakpoint. For the current
- use of server-side breakpoints (thread creation) this is
- acceptable; but it needs to be considered before this breakpoint
- mechanism can be used in more general ways. For some breakpoints
- it may be necessary to stop all other threads, but that should
- be avoided where possible.
-
- If breakpoint_reinsert_addr is NULL, that means that we can
- use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
- mark it for reinsertion, and single-step.
-
- Otherwise, call the target function to figure out where we need
- our temporary breakpoint, create it, and continue executing this
- process. */
+/* Dequeue one signal from the "signals to report later when out of
+ the jump pad" list. */
- /* NOTE: we're lifting breakpoints in non-stop mode. This
- is currently only used for thread event breakpoints, so
- it isn't that bad as long as we have PTRACE_EVENT_CLONE
- events. */
- if (bp_status == 2)
- /* No need to reinsert. */
- linux_resume_one_lwp (event_child, 0, 0, NULL);
- else if (the_low_target.breakpoint_reinsert_addr == NULL)
- {
- event_child->bp_reinsert = stop_pc;
- uninsert_breakpoint (stop_pc);
- linux_resume_one_lwp (event_child, 1, 0, NULL);
- }
- else
- {
- reinsert_breakpoint_by_bp
- (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
- linux_resume_one_lwp (event_child, 0, 0, NULL);
- }
+static int
+dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
+{
+ if (lwp->pending_signals_to_report != NULL)
+ {
+ struct pending_signals **p_sig;
- continue;
- }
+ p_sig = &lwp->pending_signals_to_report;
+ while ((*p_sig)->prev != NULL)
+ p_sig = &(*p_sig)->prev;
+
+ *wstat = W_STOPCODE ((*p_sig)->signal);
+ if ((*p_sig)->info.si_signo != 0)
+ ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
+ free (*p_sig);
+ *p_sig = NULL;
if (debug_threads)
- fprintf (stderr, "Hit a non-gdbserver breakpoint.\n");
+ fprintf (stderr, "Reporting deferred signal %d for LWP %ld.\n",
+ WSTOPSIG (*wstat), lwpid_of (lwp));
+
+ if (debug_threads)
+ {
+ struct pending_signals *sig;
+
+ for (sig = lwp->pending_signals_to_report;
+ sig != NULL;
+ sig = sig->prev)
+ fprintf (stderr,
+ " Still queued %d\n",
+ sig->signal);
+
+ fprintf (stderr, " (no more queued signals)\n");
+ }
+
+ return 1;
+ }
+
+ return 0;
+}
- /* If we were single-stepping, we definitely want to report the
- SIGTRAP. Although the single-step operation has completed,
- do not clear clear the stepping flag yet; we need to check it
- in wait_for_sigstop. */
- if (event_child->stepping)
- return lwpid_of (event_child);
+/* Arrange for a breakpoint to be hit again later. We don't keep the
+ SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
+ will handle the current event, eventually we will resume this LWP,
+ and this breakpoint will trap again. */
+
+static int
+cancel_breakpoint (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
+
+ /* There's nothing to do if we don't support breakpoints. */
+ if (!supports_breakpoints ())
+ return 0;
+
+ /* breakpoint_at reads from current inferior. */
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "CB: Push back breakpoint for %s\n",
+ target_pid_to_str (ptid_of (lwp)));
- /* A SIGTRAP that we can't explain. It may have been a breakpoint.
- Check if it is a breakpoint, and if so mark the process information
- accordingly. This will handle both the necessary fiddling with the
- PC on decr_pc_after_break targets and suppressing extra threads
- hitting a breakpoint if two hit it at once and then GDB removes it
- after the first is reported. Arguably it would be better to report
- multiple threads hitting breakpoints simultaneously, but the current
- remote protocol does not allow this. */
- if ((*the_low_target.breakpoint_at) (stop_pc))
+ /* Back up the PC if necessary. */
+ if (the_low_target.decr_pc_after_break)
{
- event_child->pending_is_breakpoint = 1;
- event_child->pending_stop_pc = stop_pc;
+ struct regcache *regcache
+ = get_thread_regcache (current_inferior, 1);
+ (*the_low_target.set_pc) (regcache, lwp->stop_pc);
}
- return lwpid_of (event_child);
+ current_inferior = saved_inferior;
+ return 1;
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "CB: No breakpoint found at %s for [%s]\n",
+ paddress (lwp->stop_pc),
+ target_pid_to_str (ptid_of (lwp)));
}
- /* NOTREACHED */
+ current_inferior = saved_inferior;
return 0;
}
+/* When the event-loop is doing a step-over, this points at the thread
+ being stepped. */
+ptid_t step_over_bkpt;
+
+/* Wait for an event from child PID. If PID is -1, wait for any
+ child. Store the stop status through the status pointer WSTAT.
+ OPTIONS is passed to the waitpid call. Return 0 if no child stop
+ event was found and OPTIONS contains WNOHANG. Return the PID of
+ the stopped child otherwise. */
+
static int
linux_wait_for_event (ptid_t ptid, int *wstat, int options)
{
+ struct lwp_info *event_child, *requested_child;
ptid_t wait_ptid;
+ event_child = NULL;
+ requested_child = NULL;
+
+ /* Check for a lwp with a pending status. */
+
+ if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
+ {
+ event_child = (struct lwp_info *)
+ find_inferior (&all_lwps, status_pending_p_callback, &ptid);
+ if (debug_threads && event_child)
+ fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
+ }
+ else
+ {
+ requested_child = find_lwp_pid (ptid);
+
+ if (stopping_threads == NOT_STOPPING_THREADS
+ && requested_child->status_pending_p
+ && requested_child->collecting_fast_tracepoint)
+ {
+ enqueue_one_deferred_signal (requested_child,
+ &requested_child->status_pending);
+ requested_child->status_pending_p = 0;
+ requested_child->status_pending = 0;
+ linux_resume_one_lwp (requested_child, 0, 0, NULL);
+ }
+
+ if (requested_child->suspended
+ && requested_child->status_pending_p)
+ fatal ("requesting an event out of a suspended child?");
+
+ if (requested_child->status_pending_p)
+ event_child = requested_child;
+ }
+
+ if (event_child != NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
+ lwpid_of (event_child), event_child->status_pending);
+ *wstat = event_child->status_pending;
+ event_child->status_pending_p = 0;
+ event_child->status_pending = 0;
+ current_inferior = get_lwp_thread (event_child);
+ return lwpid_of (event_child);
+ }
+
if (ptid_is_pid (ptid))
{
/* A request to wait for a specific tgid. This is not possible
else
wait_ptid = ptid;
+ /* We only enter this loop if no process has a pending wait status. Thus
+ any action taken in response to a wait status inside this loop is
+ responding as soon as we detect the status, not after any pending
+ events. */
while (1)
{
- int event_pid;
-
- event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options);
+ event_child = linux_wait_for_lwp (wait_ptid, wstat, options);
- if (event_pid > 0
- && ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid)
+ if ((options & WNOHANG) && event_child == NULL)
{
- struct lwp_info *event_child = find_lwp_pid (pid_to_ptid (event_pid));
+ if (debug_threads)
+ fprintf (stderr, "WNOHANG set, no event found\n");
+ return 0;
+ }
+
+ if (event_child == NULL)
+ error ("event from unknown child");
+ if (ptid_is_pid (ptid)
+ && ptid_get_pid (ptid) != ptid_get_pid (ptid_of (event_child)))
+ {
if (! WIFSTOPPED (*wstat))
mark_lwp_dead (event_child, *wstat);
else
event_child->status_pending_p = 1;
event_child->status_pending = *wstat;
}
+ continue;
}
- else
- return event_pid;
+
+ current_inferior = get_lwp_thread (event_child);
+
+ /* Check for thread exit. */
+ if (! WIFSTOPPED (*wstat))
+ {
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
+
+ /* If the last thread is exiting, just return. */
+ if (last_thread_of_process_p (current_inferior))
+ {
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld is last lwp of process\n",
+ lwpid_of (event_child));
+ return lwpid_of (event_child);
+ }
+
+ if (!non_stop)
+ {
+ current_inferior = (struct thread_info *) all_threads.head;
+ if (debug_threads)
+ fprintf (stderr, "Current inferior is now %ld\n",
+ lwpid_of (get_thread_lwp (current_inferior)));
+ }
+ else
+ {
+ current_inferior = NULL;
+ if (debug_threads)
+ fprintf (stderr, "Current inferior is now <NULL>\n");
+ }
+
+ /* If we were waiting for this particular child to do something...
+ well, it did something. */
+ if (requested_child != NULL)
+ {
+ int lwpid = lwpid_of (event_child);
+
+ /* Cancel the step-over operation --- the thread that
+ started it is gone. */
+ if (finish_step_over (event_child))
+ unstop_all_lwps (1, event_child);
+ delete_lwp (event_child);
+ return lwpid;
+ }
+
+ delete_lwp (event_child);
+
+ /* Wait for a more interesting event. */
+ continue;
+ }
+
+ if (event_child->must_set_ptrace_flags)
+ {
+ linux_enable_event_reporting (lwpid_of (event_child));
+ event_child->must_set_ptrace_flags = 0;
+ }
+
+ if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
+ && *wstat >> 16 != 0)
+ {
+ handle_extended_wait (event_child, *wstat);
+ continue;
+ }
+
+ if (WIFSTOPPED (*wstat)
+ && WSTOPSIG (*wstat) == SIGSTOP
+ && event_child->stop_expected)
+ {
+ int should_stop;
+
+ if (debug_threads)
+ fprintf (stderr, "Expected stop.\n");
+ event_child->stop_expected = 0;
+
+ should_stop = (current_inferior->last_resume_kind == resume_stop
+ || stopping_threads != NOT_STOPPING_THREADS);
+
+ if (!should_stop)
+ {
+ linux_resume_one_lwp (event_child,
+ event_child->stepping, 0, NULL);
+ continue;
+ }
+ }
+
+ return lwpid_of (event_child);
+ }
+
+ /* NOTREACHED */
+ return 0;
+}
+
+/* Count the LWP's that have had events. */
+
+static int
+count_events_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ int *count = data;
+
+ gdb_assert (count != NULL);
+
+ /* Count only resumed LWPs that have a SIGTRAP event pending that
+ should be reported to GDB. */
+ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && thread->last_resume_kind != resume_stop
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !breakpoint_inserted_here (lp->stop_pc))
+ (*count)++;
+
+ return 0;
+}
+
+/* Select the LWP (if any) that is currently being single-stepped. */
+
+static int
+select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+
+ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && thread->last_resume_kind == resume_step
+ && lp->status_pending_p)
+ return 1;
+ else
+ return 0;
+}
+
+/* Select the Nth LWP that has had a SIGTRAP event that should be
+ reported to GDB. */
+
+static int
+select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ int *selector = data;
+
+ gdb_assert (selector != NULL);
+
+ /* Select only resumed LWPs that have a SIGTRAP event pending. */
+ if (thread->last_resume_kind != resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !breakpoint_inserted_here (lp->stop_pc))
+ if ((*selector)-- == 0)
+ return 1;
+
+ return 0;
+}
+
+static int
+cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ struct lwp_info *event_lp = data;
+
+ /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
+ if (lp == event_lp)
+ return 0;
+
+ /* If a LWP other than the LWP that we're reporting an event for has
+ hit a GDB breakpoint (as opposed to some random trap signal),
+ then just arrange for it to hit it again later. We don't keep
+ the SIGTRAP status and don't forward the SIGTRAP signal to the
+ LWP. We will handle the current event, eventually we will resume
+ all LWPs, and this one will get its breakpoint trap again.
+
+ If we do not do this, then we run the risk that the user will
+ delete or disable the breakpoint, but the LWP will have already
+ tripped on it. */
+
+ if (thread->last_resume_kind != resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !lp->stepping
+ && !lp->stopped_by_watchpoint
+ && cancel_breakpoint (lp))
+ /* Throw away the SIGTRAP. */
+ lp->status_pending_p = 0;
+
+ return 0;
+}
+
+static void
+linux_cancel_breakpoints (void)
+{
+ find_inferior (&all_lwps, cancel_breakpoints_callback, NULL);
+}
+
+/* Select one LWP out of those that have events pending. */
+
+static void
+select_event_lwp (struct lwp_info **orig_lp)
+{
+ int num_events = 0;
+ int random_selector;
+ struct lwp_info *event_lp;
+
+ /* Give preference to any LWP that is being single-stepped. */
+ event_lp
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ select_singlestep_lwp_callback, NULL);
+ if (event_lp != NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "SEL: Select single-step %s\n",
+ target_pid_to_str (ptid_of (event_lp)));
+ }
+ else
+ {
+ /* No single-stepping LWP. Select one at random, out of those
+ which have had SIGTRAP events. */
+
+ /* First see how many SIGTRAP events we have. */
+ find_inferior (&all_lwps, count_events_callback, &num_events);
+
+ /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
+ random_selector = (int)
+ ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
+
+ if (debug_threads && num_events > 1)
+ fprintf (stderr,
+ "SEL: Found %d SIGTRAP events, selecting #%d\n",
+ num_events, random_selector);
+
+ event_lp = (struct lwp_info *) find_inferior (&all_lwps,
+ select_event_lwp_callback,
+ &random_selector);
+ }
+
+ if (event_lp != NULL)
+ {
+ /* Switch the event LWP. */
+ *orig_lp = event_lp;
+ }
+}
+
+/* Decrement the suspend count of an LWP. */
+
+static int
+unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ /* Ignore EXCEPT. */
+ if (lwp == except)
+ return 0;
+
+ lwp->suspended--;
+
+ gdb_assert (lwp->suspended >= 0);
+ return 0;
+}
+
+/* Decrement the suspend count of all LWPs, except EXCEPT, if non
+ NULL. */
+
+static void
+unsuspend_all_lwps (struct lwp_info *except)
+{
+ find_inferior (&all_lwps, unsuspend_one_lwp, except);
+}
+
+static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
+static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
+ void *data);
+static int lwp_running (struct inferior_list_entry *entry, void *data);
+static ptid_t linux_wait_1 (ptid_t ptid,
+ struct target_waitstatus *ourstatus,
+ int target_options);
+
+/* Stabilize threads (move out of jump pads).
+
+ If a thread is midway collecting a fast tracepoint, we need to
+ finish the collection and move it out of the jump pad before
+ reporting the signal.
+
+ This avoids recursion while collecting (when a signal arrives
+ midway, and the signal handler itself collects), which would trash
+ the trace buffer. In case the user set a breakpoint in a signal
+ handler, this avoids the backtrace showing the jump pad, etc..
+ Most importantly, there are certain things we can't do safely if
+ threads are stopped in a jump pad (or in its callee's). For
+ example:
+
+ - starting a new trace run. A thread still collecting the
+ previous run, could trash the trace buffer when resumed. The trace
+ buffer control structures would have been reset but the thread had
+ no way to tell. The thread could even midway memcpy'ing to the
+ buffer, which would mean that when resumed, it would clobber the
+ trace buffer that had been set for a new run.
+
+ - we can't rewrite/reuse the jump pads for new tracepoints
+ safely. Say you do tstart while a thread is stopped midway while
+ collecting. When the thread is later resumed, it finishes the
+ collection, and returns to the jump pad, to execute the original
+ instruction that was under the tracepoint jump at the time the
+ older run had been started. If the jump pad had been rewritten
+ since for something else in the new run, the thread would now
+ execute the wrong / random instructions. */
+
+static void
+linux_stabilize_threads (void)
+{
+ struct thread_info *save_inferior;
+ struct lwp_info *lwp_stuck;
+
+ lwp_stuck
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ stuck_in_jump_pad_callback, NULL);
+ if (lwp_stuck != NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr, "can't stabilize, LWP %ld is stuck in jump pad\n",
+ lwpid_of (lwp_stuck));
+ return;
+ }
+
+ save_inferior = current_inferior;
+
+ stabilizing_threads = 1;
+
+ /* Kick 'em all. */
+ for_each_inferior (&all_lwps, move_out_of_jump_pad_callback);
+
+ /* Loop until all are stopped out of the jump pads. */
+ while (find_inferior (&all_lwps, lwp_running, NULL) != NULL)
+ {
+ struct target_waitstatus ourstatus;
+ struct lwp_info *lwp;
+ int wstat;
+
+ /* Note that we go through the full wait even loop. While
+ moving threads out of jump pad, we need to be able to step
+ over internal breakpoints and such. */
+ linux_wait_1 (minus_one_ptid, &ourstatus, 0);
+
+ if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
+ {
+ lwp = get_thread_lwp (current_inferior);
+
+ /* Lock it. */
+ lwp->suspended++;
+
+ if (ourstatus.value.sig != GDB_SIGNAL_0
+ || current_inferior->last_resume_kind == resume_stop)
+ {
+ wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig));
+ enqueue_one_deferred_signal (lwp, &wstat);
+ }
+ }
+ }
+
+ find_inferior (&all_lwps, unsuspend_one_lwp, NULL);
+
+ stabilizing_threads = 0;
+
+ current_inferior = save_inferior;
+
+ if (debug_threads)
+ {
+ lwp_stuck
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ stuck_in_jump_pad_callback, NULL);
+ if (lwp_stuck != NULL)
+ fprintf (stderr, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
+ lwpid_of (lwp_stuck));
}
}
struct target_waitstatus *ourstatus, int target_options)
{
int w;
- struct thread_info *thread = NULL;
- struct lwp_info *lwp = NULL;
+ struct lwp_info *event_child;
int options;
int pid;
+ int step_over_finished;
+ int bp_explains_trap;
+ int maybe_internal_trap;
+ int report_to_gdb;
+ int trace_event;
/* Translate generic target options into linux options. */
options = __WALL;
options |= WNOHANG;
retry:
+ bp_explains_trap = 0;
+ trace_event = 0;
ourstatus->kind = TARGET_WAITKIND_IGNORE;
/* If we were only supposed to resume one thread, only wait for
&& !ptid_equal (cont_thread, null_ptid)
&& !ptid_equal (cont_thread, minus_one_ptid))
{
+ struct thread_info *thread;
+
thread = (struct thread_info *) find_inferior_id (&all_threads,
cont_thread);
ptid = cont_thread;
}
- pid = linux_wait_for_event (ptid, &w, options);
+ if (ptid_equal (step_over_bkpt, null_ptid))
+ pid = linux_wait_for_event (ptid, &w, options);
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n",
+ target_pid_to_str (step_over_bkpt));
+ pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
+ }
+
if (pid == 0) /* only if TARGET_WNOHANG */
return null_ptid;
- lwp = get_thread_lwp (current_inferior);
+ event_child = get_thread_lwp (current_inferior);
/* If we are waiting for a particular child, and it exited,
linux_wait_for_event will return its exit status. Similarly if
{
if (WIFEXITED (w) || WIFSIGNALED (w))
{
- int pid = pid_of (lwp);
- struct process_info *process = find_process_pid (pid);
-
-#ifdef USE_THREAD_DB
- thread_db_free (process, 0);
-#endif
- delete_lwp (lwp);
- linux_remove_process (process);
-
- current_inferior = NULL;
-
if (WIFEXITED (w))
{
ourstatus->kind = TARGET_WAITKIND_EXITED;
ourstatus->value.integer = WEXITSTATUS (w);
if (debug_threads)
- fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
+ fprintf (stderr,
+ "\nChild exited with retcode = %x \n",
+ WEXITSTATUS (w));
}
else
{
ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
- ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
+ ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w));
if (debug_threads)
- fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
+ fprintf (stderr,
+ "\nChild terminated with signal = %x \n",
+ WTERMSIG (w));
}
- return pid_to_ptid (pid);
+ return ptid_of (event_child);
}
}
else
goto retry;
}
- /* In all-stop, stop all threads. Be careful to only do this if
- we're about to report an event to GDB. */
- if (!non_stop)
- stop_all_lwps ();
+ /* If this event was not handled before, and is not a SIGTRAP, we
+ report it. SIGILL and SIGSEGV are also treated as traps in case
+ a breakpoint is inserted at the current PC. If this target does
+ not support internal breakpoints at all, we also report the
+ SIGTRAP without further processing; it's of no concern to us. */
+ maybe_internal_trap
+ = (supports_breakpoints ()
+ && (WSTOPSIG (w) == SIGTRAP
+ || ((WSTOPSIG (w) == SIGILL
+ || WSTOPSIG (w) == SIGSEGV)
+ && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
+
+ if (maybe_internal_trap)
+ {
+ /* Handle anything that requires bookkeeping before deciding to
+ report the event or continue waiting. */
+
+ /* First check if we can explain the SIGTRAP with an internal
+ breakpoint, or if we should possibly report the event to GDB.
+ Do this before anything that may remove or insert a
+ breakpoint. */
+ bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
+
+ /* We have a SIGTRAP, possibly a step-over dance has just
+ finished. If so, tweak the state machine accordingly,
+ reinsert breakpoints and delete any reinsert (software
+ single-step) breakpoints. */
+ step_over_finished = finish_step_over (event_child);
+
+ /* Now invoke the callbacks of any internal breakpoints there. */
+ check_breakpoints (event_child->stop_pc);
+
+ /* Handle tracepoint data collecting. This may overflow the
+ trace buffer, and cause a tracing stop, removing
+ breakpoints. */
+ trace_event = handle_tracepoints (event_child);
+
+ if (bp_explains_trap)
+ {
+ /* If we stepped or ran into an internal breakpoint, we've
+ already handled it. So next time we resume (from this
+ PC), we should step over it. */
+ if (debug_threads)
+ fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+
+ if (breakpoint_here (event_child->stop_pc))
+ event_child->need_step_over = 1;
+ }
+ }
+ else
+ {
+ /* We have some other signal, possibly a step-over dance was in
+ progress, and it should be cancelled too. */
+ step_over_finished = finish_step_over (event_child);
+ }
+
+ /* We have all the data we need. Either report the event to GDB, or
+ resume threads and keep waiting for more. */
+
+ /* If we're collecting a fast tracepoint, finish the collection and
+ move out of the jump pad before delivering a signal. See
+ linux_stabilize_threads. */
+
+ if (WIFSTOPPED (w)
+ && WSTOPSIG (w) != SIGTRAP
+ && supports_fast_tracepoints ()
+ && agent_loaded_p ())
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Got signal %d for LWP %ld. Check if we need "
+ "to defer or adjust it.\n",
+ WSTOPSIG (w), lwpid_of (event_child));
+
+ /* Allow debugging the jump pad itself. */
+ if (current_inferior->last_resume_kind != resume_step
+ && maybe_move_out_of_jump_pad (event_child, &w))
+ {
+ enqueue_one_deferred_signal (event_child, &w);
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Signal %d for LWP %ld deferred (in jump pad)\n",
+ WSTOPSIG (w), lwpid_of (event_child));
+
+ linux_resume_one_lwp (event_child, 0, 0, NULL);
+ goto retry;
+ }
+ }
+
+ if (event_child->collecting_fast_tracepoint)
+ {
+ if (debug_threads)
+ fprintf (stderr, "\
+LWP %ld was trying to move out of the jump pad (%d). \
+Check if we're already there.\n",
+ lwpid_of (event_child),
+ event_child->collecting_fast_tracepoint);
+
+ trace_event = 1;
+
+ event_child->collecting_fast_tracepoint
+ = linux_fast_tracepoint_collecting (event_child, NULL);
+
+ if (event_child->collecting_fast_tracepoint != 1)
+ {
+ /* No longer need this breakpoint. */
+ if (event_child->exit_jump_pad_bkpt != NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "No longer need exit-jump-pad bkpt; removing it."
+ "stopping all threads momentarily.\n");
+
+ /* Other running threads could hit this breakpoint.
+ We don't handle moribund locations like GDB does,
+ instead we always pause all threads when removing
+ breakpoints, so that any step-over or
+ decr_pc_after_break adjustment is always taken
+ care of while the breakpoint is still
+ inserted. */
+ stop_all_lwps (1, event_child);
+ cancel_breakpoints ();
+
+ delete_breakpoint (event_child->exit_jump_pad_bkpt);
+ event_child->exit_jump_pad_bkpt = NULL;
+
+ unstop_all_lwps (1, event_child);
+
+ gdb_assert (event_child->suspended >= 0);
+ }
+ }
+
+ if (event_child->collecting_fast_tracepoint == 0)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "fast tracepoint finished "
+ "collecting successfully.\n");
+
+ /* We may have a deferred signal to report. */
+ if (dequeue_one_deferred_signal (event_child, &w))
+ {
+ if (debug_threads)
+ fprintf (stderr, "dequeued one signal.\n");
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "no deferred signals.\n");
+
+ if (stabilizing_threads)
+ {
+ ourstatus->kind = TARGET_WAITKIND_STOPPED;
+ ourstatus->value.sig = GDB_SIGNAL_0;
+ return ptid_of (event_child);
+ }
+ }
+ }
+ }
+
+ /* Check whether GDB would be interested in this event. */
+
+ /* If GDB is not interested in this signal, don't stop other
+ threads, and don't report it to GDB. Just resume the inferior
+ right away. We do this for threading-related signals as well as
+ any that GDB specifically requested we ignore. But never ignore
+ SIGSTOP if we sent it ourselves, and do not ignore signals when
+ stepping - they may require special handling to skip the signal
+ handler. */
+ /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
+ thread library? */
+ if (WIFSTOPPED (w)
+ && current_inferior->last_resume_kind != resume_step
+ && (
+#if defined (USE_THREAD_DB) && !defined (__ANDROID__)
+ (current_process ()->private->thread_db != NULL
+ && (WSTOPSIG (w) == __SIGRTMIN
+ || WSTOPSIG (w) == __SIGRTMIN + 1))
+ ||
+#endif
+ (pass_signals[gdb_signal_from_host (WSTOPSIG (w))]
+ && !(WSTOPSIG (w) == SIGSTOP
+ && current_inferior->last_resume_kind == resume_stop))))
+ {
+ siginfo_t info, *info_p;
+
+ if (debug_threads)
+ fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
+ WSTOPSIG (w), lwpid_of (event_child));
+
+ if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
+ info_p = &info;
+ else
+ info_p = NULL;
+ linux_resume_one_lwp (event_child, event_child->stepping,
+ WSTOPSIG (w), info_p);
+ goto retry;
+ }
+
+ /* If GDB wanted this thread to single step, we always want to
+ report the SIGTRAP, and let GDB handle it. Watchpoints should
+ always be reported. So should signals we can't explain. A
+ SIGTRAP we can't explain could be a GDB breakpoint --- we may or
+ not support Z0 breakpoints. If we do, we're be able to handle
+ GDB breakpoints on top of internal breakpoints, by handling the
+ internal breakpoint and still reporting the event to GDB. If we
+ don't, we're out of luck, GDB won't see the breakpoint hit. */
+ report_to_gdb = (!maybe_internal_trap
+ || current_inferior->last_resume_kind == resume_step
+ || event_child->stopped_by_watchpoint
+ || (!step_over_finished
+ && !bp_explains_trap && !trace_event)
+ || (gdb_breakpoint_here (event_child->stop_pc)
+ && gdb_condition_true_at_breakpoint (event_child->stop_pc)));
+
+ /* We found no reason GDB would want us to stop. We either hit one
+ of our own breakpoints, or finished an internal step GDB
+ shouldn't know about. */
+ if (!report_to_gdb)
+ {
+ if (debug_threads)
+ {
+ if (bp_explains_trap)
+ fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+ if (step_over_finished)
+ fprintf (stderr, "Step-over finished.\n");
+ if (trace_event)
+ fprintf (stderr, "Tracepoint event.\n");
+ }
+
+ /* We're not reporting this breakpoint to GDB, so apply the
+ decr_pc_after_break adjustment to the inferior's regcache
+ ourselves. */
+
+ if (the_low_target.set_pc != NULL)
+ {
+ struct regcache *regcache
+ = get_thread_regcache (get_lwp_thread (event_child), 1);
+ (*the_low_target.set_pc) (regcache, event_child->stop_pc);
+ }
+
+ /* We may have finished stepping over a breakpoint. If so,
+ we've stopped and suspended all LWPs momentarily except the
+ stepping one. This is where we resume them all again. We're
+ going to keep waiting, so use proceed, which handles stepping
+ over the next breakpoint. */
+ if (debug_threads)
+ fprintf (stderr, "proceeding all threads.\n");
+
+ if (step_over_finished)
+ unsuspend_all_lwps (event_child);
+
+ proceed_all_lwps ();
+ goto retry;
+ }
+
+ if (debug_threads)
+ {
+ if (current_inferior->last_resume_kind == resume_step)
+ fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
+ if (event_child->stopped_by_watchpoint)
+ fprintf (stderr, "Stopped by watchpoint.\n");
+ if (gdb_breakpoint_here (event_child->stop_pc))
+ fprintf (stderr, "Stopped by GDB breakpoint.\n");
+ if (debug_threads)
+ fprintf (stderr, "Hit a non-gdbserver trap event.\n");
+ }
+
+ /* Alright, we're going to report a stop. */
+
+ if (!non_stop && !stabilizing_threads)
+ {
+ /* In all-stop, stop all threads. */
+ stop_all_lwps (0, NULL);
+
+ /* If we're not waiting for a specific LWP, choose an event LWP
+ from among those that have had events. Giving equal priority
+ to all LWPs that have had events helps prevent
+ starvation. */
+ if (ptid_equal (ptid, minus_one_ptid))
+ {
+ event_child->status_pending_p = 1;
+ event_child->status_pending = w;
+
+ select_event_lwp (&event_child);
+
+ event_child->status_pending_p = 0;
+ w = event_child->status_pending;
+ }
+
+ /* Now that we've selected our final event LWP, cancel any
+ breakpoints in other LWPs that have hit a GDB breakpoint.
+ See the comment in cancel_breakpoints_callback to find out
+ why. */
+ find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
+
+ /* If we were going a step-over, all other threads but the stepping one
+ had been paused in start_step_over, with their suspend counts
+ incremented. We don't want to do a full unstop/unpause, because we're
+ in all-stop mode (so we want threads stopped), but we still need to
+ unsuspend the other threads, to decrement their `suspended' count
+ back. */
+ if (step_over_finished)
+ unsuspend_all_lwps (event_child);
+
+ /* Stabilize threads (move out of jump pads). */
+ stabilize_threads ();
+ }
+ else
+ {
+ /* If we just finished a step-over, then all threads had been
+ momentarily paused. In all-stop, that's fine, we want
+ threads stopped by now anyway. In non-stop, we need to
+ re-resume threads that GDB wanted to be running. */
+ if (step_over_finished)
+ unstop_all_lwps (1, event_child);
+ }
ourstatus->kind = TARGET_WAITKIND_STOPPED;
- if (lwp->suspended && WSTOPSIG (w) == SIGSTOP)
+ if (current_inferior->last_resume_kind == resume_stop
+ && WSTOPSIG (w) == SIGSTOP)
{
/* A thread that has been requested to stop by GDB with vCont;t,
and it stopped cleanly, so report as SIG0. The use of
SIGSTOP is an implementation detail. */
- ourstatus->value.sig = TARGET_SIGNAL_0;
+ ourstatus->value.sig = GDB_SIGNAL_0;
}
- else if (lwp->suspended && WSTOPSIG (w) != SIGSTOP)
+ else if (current_inferior->last_resume_kind == resume_stop
+ && WSTOPSIG (w) != SIGSTOP)
{
/* A thread that has been requested to stop by GDB with vCont;t,
- but, it stopped for other reasons. Set stop_expected so the
- pending SIGSTOP is ignored and the LWP is resumed. */
- lwp->stop_expected = 1;
- ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
+ but, it stopped for other reasons. */
+ ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
}
else
{
- ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
+ ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
}
+ gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
+
if (debug_threads)
fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
- target_pid_to_str (lwp->head.id),
+ target_pid_to_str (ptid_of (event_child)),
ourstatus->kind,
ourstatus->value.sig);
- return lwp->head.id;
+ return ptid_of (event_child);
}
/* Get rid of any pending event in the pipe. */
return kill (lwpid, signo);
}
+void
+linux_stop_lwp (struct lwp_info *lwp)
+{
+ send_sigstop (lwp);
+}
+
static void
-send_sigstop (struct inferior_list_entry *entry)
+send_sigstop (struct lwp_info *lwp)
{
- struct lwp_info *lwp = (struct lwp_info *) entry;
int pid;
- if (lwp->stopped)
- return;
-
pid = lwpid_of (lwp);
/* If we already have a pending stop signal for this process, don't
if (debug_threads)
fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
- /* We clear the stop_expected flag so that wait_for_sigstop
- will receive the SIGSTOP event (instead of silently resuming and
- waiting again). It'll be reset below. */
- lwp->stop_expected = 0;
return;
}
if (debug_threads)
fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
+ lwp->stop_expected = 1;
kill_lwp (pid, SIGSTOP);
}
+static int
+send_sigstop_callback (struct inferior_list_entry *entry, void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ /* Ignore EXCEPT. */
+ if (lwp == except)
+ return 0;
+
+ if (lwp->stopped)
+ return 0;
+
+ send_sigstop (lwp);
+ return 0;
+}
+
+/* Increment the suspend count of an LWP, and stop it, if not stopped
+ yet. */
+static int
+suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
+ void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ /* Ignore EXCEPT. */
+ if (lwp == except)
+ return 0;
+
+ lwp->suspended++;
+
+ return send_sigstop_callback (entry, except);
+}
+
static void
mark_lwp_dead (struct lwp_info *lwp, int wstat)
{
lwp->status_pending_p = 1;
lwp->status_pending = wstat;
- /* So that check_removed_breakpoint doesn't try to figure out if
- this is stopped at a breakpoint. */
- lwp->pending_is_breakpoint = 0;
-
/* Prevent trying to stop it. */
lwp->stopped = 1;
int wstat;
ptid_t saved_tid;
ptid_t ptid;
+ int pid;
if (lwp->stopped)
- return;
+ {
+ if (debug_threads)
+ fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
+ lwpid_of (lwp));
+ return;
+ }
saved_inferior = current_inferior;
if (saved_inferior != NULL)
ptid = lwp->head.id;
- linux_wait_for_event (ptid, &wstat, __WALL);
+ if (debug_threads)
+ fprintf (stderr, "wait_for_sigstop: pulling one event\n");
+
+ pid = linux_wait_for_event (ptid, &wstat, __WALL);
/* If we stopped with a non-SIGSTOP signal, save it for later
and record the pending SIGSTOP. If the process exited, just
return. */
- if (WIFSTOPPED (wstat)
- && WSTOPSIG (wstat) != SIGSTOP)
+ if (WIFSTOPPED (wstat))
{
if (debug_threads)
- fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
- lwpid_of (lwp), wstat);
-
- /* Do not leave a pending single-step finish to be reported to
- the client. The client will give us a new action for this
- thread, possibly a continue request --- otherwise, the client
- would consider this pending SIGTRAP reported later a spurious
- signal. */
- if (WSTOPSIG (wstat) == SIGTRAP
- && lwp->stepping
- && !linux_stopped_by_watchpoint ())
+ fprintf (stderr, "LWP %ld stopped with signal %d\n",
+ lwpid_of (lwp), WSTOPSIG (wstat));
+
+ if (WSTOPSIG (wstat) != SIGSTOP)
{
if (debug_threads)
- fprintf (stderr, " single-step SIGTRAP ignored\n");
- }
- else
- {
+ fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
+ lwpid_of (lwp), wstat);
+
lwp->status_pending_p = 1;
lwp->status_pending = wstat;
}
- lwp->stop_expected = 1;
}
- else if (!WIFSTOPPED (wstat))
+ else
{
if (debug_threads)
- fprintf (stderr, "Process %ld exited while stopping LWPs\n",
- lwpid_of (lwp));
+ fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
+
+ lwp = find_lwp_pid (pid_to_ptid (pid));
+ if (lwp)
+ {
+ /* Leave this status pending for the next time we're able to
+ report it. In the mean time, we'll report this lwp as
+ dead to GDB, so GDB doesn't try to read registers and
+ memory from it. This can only happen if this was the
+ last thread of the process; otherwise, PID is removed
+ from the thread tables before linux_wait_for_event
+ returns. */
+ mark_lwp_dead (lwp, wstat);
+ }
+ }
+
+ if (saved_inferior == NULL || linux_thread_alive (saved_tid))
+ current_inferior = saved_inferior;
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "Previously current thread died.\n");
+
+ if (non_stop)
+ {
+ /* We can't change the current inferior behind GDB's back,
+ otherwise, a subsequent command may apply to the wrong
+ process. */
+ current_inferior = NULL;
+ }
+ else
+ {
+ /* Set a valid thread as current. */
+ set_desired_inferior (0);
+ }
+ }
+}
+
+/* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
+ move it out, because we need to report the stop event to GDB. For
+ example, if the user puts a breakpoint in the jump pad, it's
+ because she wants to debug it. */
+
+static int
+stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lwp);
+
+ gdb_assert (lwp->suspended == 0);
+ gdb_assert (lwp->stopped);
+
+ /* Allow debugging the jump pad, gdb_collect, etc.. */
+ return (supports_fast_tracepoints ()
+ && agent_loaded_p ()
+ && (gdb_breakpoint_here (lwp->stop_pc)
+ || lwp->stopped_by_watchpoint
+ || thread->last_resume_kind == resume_step)
+ && linux_fast_tracepoint_collecting (lwp, NULL));
+}
+
+static void
+move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lwp);
+ int *wstat;
- /* Leave this status pending for the next time we're able to
- report it. In the mean time, we'll report this lwp as dead
- to GDB, so GDB doesn't try to read registers and memory from
- it. */
- mark_lwp_dead (lwp, wstat);
- }
+ gdb_assert (lwp->suspended == 0);
+ gdb_assert (lwp->stopped);
- if (saved_inferior == NULL || linux_thread_alive (saved_tid))
- current_inferior = saved_inferior;
- else
+ wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
+
+ /* Allow debugging the jump pad, gdb_collect, etc. */
+ if (!gdb_breakpoint_here (lwp->stop_pc)
+ && !lwp->stopped_by_watchpoint
+ && thread->last_resume_kind != resume_step
+ && maybe_move_out_of_jump_pad (lwp, wstat))
{
if (debug_threads)
- fprintf (stderr, "Previously current thread died.\n");
+ fprintf (stderr,
+ "LWP %ld needs stabilizing (in jump pad)\n",
+ lwpid_of (lwp));
- if (non_stop)
- {
- /* We can't change the current inferior behind GDB's back,
- otherwise, a subsequent command may apply to the wrong
- process. */
- current_inferior = NULL;
- }
- else
+ if (wstat)
{
- /* Set a valid thread as current. */
- set_desired_inferior (0);
+ lwp->status_pending_p = 0;
+ enqueue_one_deferred_signal (lwp, wstat);
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Signal %d for LWP %ld deferred "
+ "(in jump pad)\n",
+ WSTOPSIG (*wstat), lwpid_of (lwp));
}
+
+ linux_resume_one_lwp (lwp, 0, 0, NULL);
}
+ else
+ lwp->suspended++;
+}
+
+static int
+lwp_running (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ if (lwp->dead)
+ return 0;
+ if (lwp->stopped)
+ return 0;
+ return 1;
}
+/* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
+ If SUSPEND, then also increase the suspend count of every LWP,
+ except EXCEPT. */
+
static void
-stop_all_lwps (void)
+stop_all_lwps (int suspend, struct lwp_info *except)
{
- stopping_threads = 1;
- for_each_inferior (&all_lwps, send_sigstop);
+ /* Should not be called recursively. */
+ gdb_assert (stopping_threads == NOT_STOPPING_THREADS);
+
+ stopping_threads = (suspend
+ ? STOPPING_AND_SUSPENDING_THREADS
+ : STOPPING_THREADS);
+
+ if (suspend)
+ find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except);
+ else
+ find_inferior (&all_lwps, send_sigstop_callback, except);
for_each_inferior (&all_lwps, wait_for_sigstop);
- stopping_threads = 0;
+ stopping_threads = NOT_STOPPING_THREADS;
}
/* Resume execution of the inferior process.
int step, int signal, siginfo_t *info)
{
struct thread_info *saved_inferior;
+ int fast_tp_collecting;
if (lwp->stopped == 0)
return;
+ fast_tp_collecting = lwp->collecting_fast_tracepoint;
+
+ gdb_assert (!stabilizing_threads || fast_tp_collecting);
+
+ /* Cancel actions that rely on GDB not changing the PC (e.g., the
+ user used the "jump" command, or "set $pc = foo"). */
+ if (lwp->stop_pc != get_pc (lwp))
+ {
+ /* Collecting 'while-stepping' actions doesn't make sense
+ anymore. */
+ release_while_stepping_state_list (get_lwp_thread (lwp));
+ }
+
/* If we have pending signals or status, and a new signal, enqueue the
signal. Also enqueue the signal if we are waiting to reinsert a
breakpoint; it will be picked up again below. */
if (signal != 0
- && (lwp->status_pending_p || lwp->pending_signals != NULL
- || lwp->bp_reinsert != 0))
+ && (lwp->status_pending_p
+ || lwp->pending_signals != NULL
+ || lwp->bp_reinsert != 0
+ || fast_tp_collecting))
{
struct pending_signals *p_sig;
p_sig = xmalloc (sizeof (*p_sig));
lwp->pending_signals = p_sig;
}
- if (lwp->status_pending_p && !check_removed_breakpoint (lwp))
- return;
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
+ " has pending status\n",
+ lwpid_of (lwp), step ? "step" : "continue", signal,
+ lwp->stop_expected ? "expected" : "not expected");
+ return;
+ }
saved_inferior = current_inferior;
current_inferior = get_lwp_thread (lwp);
if (lwp->bp_reinsert != 0)
{
if (debug_threads)
- fprintf (stderr, " pending reinsert at %08lx", (long)lwp->bp_reinsert);
- if (step == 0)
- fprintf (stderr, "BAD - reinserting but not stepping.\n");
- step = 1;
+ fprintf (stderr, " pending reinsert at 0x%s\n",
+ paddress (lwp->bp_reinsert));
+
+ if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
+ {
+ if (fast_tp_collecting == 0)
+ {
+ if (step == 0)
+ fprintf (stderr, "BAD - reinserting but not stepping.\n");
+ if (lwp->suspended)
+ fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
+ lwp->suspended);
+ }
+
+ step = 1;
+ }
+
+ /* Postpone any pending signal. It was enqueued above. */
+ signal = 0;
+ }
+
+ if (fast_tp_collecting == 1)
+ {
+ if (debug_threads)
+ fprintf (stderr, "\
+lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
+ lwpid_of (lwp));
+
+ /* Postpone any pending signal. It was enqueued above. */
+ signal = 0;
+ }
+ else if (fast_tp_collecting == 2)
+ {
+ if (debug_threads)
+ fprintf (stderr, "\
+lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
+ lwpid_of (lwp));
+
+ if (can_hardware_single_step ())
+ step = 1;
+ else
+ fatal ("moving out of jump pad single-stepping"
+ " not implemented on this target");
/* Postpone any pending signal. It was enqueued above. */
signal = 0;
}
- check_removed_breakpoint (lwp);
+ /* If we have while-stepping actions in this thread set it stepping.
+ If we have a signal to deliver, it may or may not be set to
+ SIG_IGN, we don't know. Assume so, and allow collecting
+ while-stepping into a signal handler. A possible smart thing to
+ do would be to set an internal breakpoint at the signal return
+ address, continue, and carry on catching this while-stepping
+ action only when that breakpoint is hit. A future
+ enhancement. */
+ if (get_lwp_thread (lwp)->while_stepping != NULL
+ && can_hardware_single_step ())
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "lwp %ld has a while-stepping action -> forcing step.\n",
+ lwpid_of (lwp));
+ step = 1;
+ }
if (debug_threads && the_low_target.get_pc != NULL)
{
fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
}
- /* If we have pending signals, consume one unless we are trying to reinsert
- a breakpoint. */
- if (lwp->pending_signals != NULL && lwp->bp_reinsert == 0)
+ /* If we have pending signals, consume one unless we are trying to
+ reinsert a breakpoint or we're trying to finish a fast tracepoint
+ collect. */
+ if (lwp->pending_signals != NULL
+ && lwp->bp_reinsert == 0
+ && fast_tp_collecting == 0)
{
struct pending_signals **p_sig;
get_lwp_thread (lwp));
errno = 0;
lwp->stopped = 0;
+ lwp->stopped_by_watchpoint = 0;
lwp->stepping = step;
ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
/* Coerce to a uintptr_t first to avoid potential gcc warning
|| (ptid_get_lwp (ptid) == -1
&& (ptid_get_pid (ptid) == pid_of (lwp))))
{
+ if (r->resume[ndx].kind == resume_stop
+ && thread->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr, "already %s LWP %ld at GDB's request\n",
+ thread->last_status.kind == TARGET_WAITKIND_STOPPED
+ ? "stopped"
+ : "stopping",
+ lwpid_of (lwp));
+
+ continue;
+ }
+
lwp->resume = &r->resume[ndx];
+ thread->last_resume_kind = lwp->resume->kind;
+
+ /* If we had a deferred signal to report, dequeue one now.
+ This can happen if LWP gets more than one signal while
+ trying to get out of a jump pad. */
+ if (lwp->stopped
+ && !lwp->status_pending_p
+ && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
+ {
+ lwp->status_pending_p = 1;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Dequeueing deferred signal %d for LWP %ld, "
+ "leaving status pending.\n",
+ WSTOPSIG (lwp->status_pending), lwpid_of (lwp));
+ }
+
return 0;
}
}
if (lwp->resume == NULL)
return 0;
- /* If this thread has a removed breakpoint, we won't have any
- events to report later, so check now. check_removed_breakpoint
- may clear status_pending_p. We avoid calling check_removed_breakpoint
- for any thread that we are not otherwise going to resume - this
- lets us preserve stopped status when two threads hit a breakpoint.
- GDB removes the breakpoint to single-step a particular thread
- past it, then re-inserts it and resumes all threads. We want
- to report the second thread without resuming it in the interim. */
if (lwp->status_pending_p)
- check_removed_breakpoint (lwp);
+ * (int *) flag_p = 1;
+
+ return 0;
+}
+
+/* Return 1 if this lwp that GDB wants running is stopped at an
+ internal breakpoint that we need to step over. It assumes that any
+ required STOP_PC adjustment has already been propagated to the
+ inferior's regcache. */
+
+static int
+need_step_over_p (struct inferior_list_entry *entry, void *dummy)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread;
+ struct thread_info *saved_inferior;
+ CORE_ADDR pc;
+
+ /* LWPs which will not be resumed are not interesting, because we
+ might not wait for them next time through linux_wait. */
+
+ if (!lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, not stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ thread = get_lwp_thread (lwp);
+
+ if (thread->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ gdb_assert (lwp->suspended >= 0);
+
+ if (lwp->suspended)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, suspended\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ if (!lwp->need_step_over)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? No\n", lwpid_of (lwp));
+ }
if (lwp->status_pending_p)
- * (int *) flag_p = 1;
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, has pending status.\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
+ or we have. */
+ pc = get_pc (lwp);
+
+ /* If the PC has changed since we stopped, then don't do anything,
+ and let the breakpoint/tracepoint be hit. This happens if, for
+ instance, GDB handled the decr_pc_after_break subtraction itself,
+ GDB is OOL stepping this thread, or the user has issued a "jump"
+ command, or poked thread's registers herself. */
+ if (pc != lwp->stop_pc)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Cancelling, PC was changed. "
+ "Old stop_pc was 0x%s, PC is now 0x%s\n",
+ lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
+
+ lwp->need_step_over = 0;
+ return 0;
+ }
+
+ saved_inferior = current_inferior;
+ current_inferior = thread;
+
+ /* We can only step over breakpoints we know about. */
+ if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
+ {
+ /* Don't step over a breakpoint that GDB expects to hit
+ though. If the condition is being evaluated on the target's side
+ and it evaluate to false, step over this breakpoint as well. */
+ if (gdb_breakpoint_here (pc)
+ && gdb_condition_true_at_breakpoint (pc))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? yes, but found"
+ " GDB breakpoint at 0x%s; skipping step over\n",
+ lwpid_of (lwp), paddress (pc));
+
+ current_inferior = saved_inferior;
+ return 0;
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? yes, "
+ "found breakpoint at 0x%s\n",
+ lwpid_of (lwp), paddress (pc));
+
+ /* We've found an lwp that needs stepping over --- return 1 so
+ that find_inferior stops looking. */
+ current_inferior = saved_inferior;
+
+ /* If the step over is cancelled, this is set again. */
+ lwp->need_step_over = 0;
+ return 1;
+ }
+ }
+
+ current_inferior = saved_inferior;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
+ lwpid_of (lwp), paddress (pc));
return 0;
}
+/* Start a step-over operation on LWP. When LWP stopped at a
+ breakpoint, to make progress, we need to remove the breakpoint out
+ of the way. If we let other threads run while we do that, they may
+ pass by the breakpoint location and miss hitting it. To avoid
+ that, a step-over momentarily stops all threads while LWP is
+ single-stepped while the breakpoint is temporarily uninserted from
+ the inferior. When the single-step finishes, we reinsert the
+ breakpoint, and let all threads that are supposed to be running,
+ run again.
+
+ On targets that don't support hardware single-step, we don't
+ currently support full software single-stepping. Instead, we only
+ support stepping over the thread event breakpoint, by asking the
+ low target where to place a reinsert breakpoint. Since this
+ routine assumes the breakpoint being stepped over is a thread event
+ breakpoint, it usually assumes the return address of the current
+ function is a good enough place to set the reinsert breakpoint. */
+
+static int
+start_step_over (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
+ CORE_ADDR pc;
+ int step;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Starting step-over on LWP %ld. Stopping all threads\n",
+ lwpid_of (lwp));
+
+ stop_all_lwps (1, lwp);
+ gdb_assert (lwp->suspended == 0);
+
+ if (debug_threads)
+ fprintf (stderr, "Done stopping all threads for step-over.\n");
+
+ /* Note, we should always reach here with an already adjusted PC,
+ either by GDB (if we're resuming due to GDB's request), or by our
+ caller, if we just finished handling an internal breakpoint GDB
+ shouldn't care about. */
+ pc = get_pc (lwp);
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ lwp->bp_reinsert = pc;
+ uninsert_breakpoints_at (pc);
+ uninsert_fast_tracepoint_jumps_at (pc);
+
+ if (can_hardware_single_step ())
+ {
+ step = 1;
+ }
+ else
+ {
+ CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
+ set_reinsert_breakpoint (raddr);
+ step = 0;
+ }
+
+ current_inferior = saved_inferior;
+
+ linux_resume_one_lwp (lwp, step, 0, NULL);
+
+ /* Require next event from this LWP. */
+ step_over_bkpt = lwp->head.id;
+ return 1;
+}
+
+/* Finish a step-over. Reinsert the breakpoint we had uninserted in
+ start_step_over, if still there, and delete any reinsert
+ breakpoints we've set, on non hardware single-step targets. */
+
+static int
+finish_step_over (struct lwp_info *lwp)
+{
+ if (lwp->bp_reinsert != 0)
+ {
+ if (debug_threads)
+ fprintf (stderr, "Finished step over.\n");
+
+ /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
+ may be no breakpoint to reinsert there by now. */
+ reinsert_breakpoints_at (lwp->bp_reinsert);
+ reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
+
+ lwp->bp_reinsert = 0;
+
+ /* Delete any software-single-step reinsert breakpoints. No
+ longer needed. We don't have to worry about other threads
+ hitting this trap, and later not being able to explain it,
+ because we were stepping over a breakpoint, and we hold all
+ threads but LWP stopped while doing that. */
+ if (!can_hardware_single_step ())
+ delete_reinsert_breakpoints ();
+
+ step_over_bkpt = null_ptid;
+ return 1;
+ }
+ else
+ return 0;
+}
+
/* This function is called once per thread. We check the thread's resume
request, which will tell us whether to resume, step, or leave the thread
stopped; and what signal, if any, it should be sent.
struct lwp_info *lwp;
struct thread_info *thread;
int step;
- int pending_flag = * (int *) arg;
+ int leave_all_stopped = * (int *) arg;
+ int leave_pending;
thread = (struct thread_info *) entry;
lwp = get_thread_lwp (thread);
if (lwp->resume->kind == resume_stop)
{
if (debug_threads)
- fprintf (stderr, "suspending LWP %ld\n", lwpid_of (lwp));
+ fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
if (!lwp->stopped)
{
if (debug_threads)
- fprintf (stderr, "running -> suspending LWP %ld\n", lwpid_of (lwp));
+ fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
- lwp->suspended = 1;
- send_sigstop (&lwp->head);
+ /* Stop the thread, and wait for the event asynchronously,
+ through the event loop. */
+ send_sigstop (lwp);
}
else
{
if (debug_threads)
- {
- if (lwp->suspended)
- fprintf (stderr, "already stopped/suspended LWP %ld\n",
- lwpid_of (lwp));
- else
- fprintf (stderr, "already stopped/not suspended LWP %ld\n",
- lwpid_of (lwp));
- }
-
- /* Make sure we leave the LWP suspended, so we don't try to
- resume it without GDB telling us to. FIXME: The LWP may
- have been stopped in an internal event that was not meant
- to be notified back to GDB (e.g., gdbserver breakpoint),
- so we should be reporting a stop event in that case
- too. */
- lwp->suspended = 1;
+ fprintf (stderr, "already stopped LWP %ld\n",
+ lwpid_of (lwp));
+
+ /* The LWP may have been stopped in an internal event that
+ was not meant to be notified back to GDB (e.g., gdbserver
+ breakpoint), so we should be reporting a stop event in
+ this case too. */
+
+ /* If the thread already has a pending SIGSTOP, this is a
+ no-op. Otherwise, something later will presumably resume
+ the thread and this will cause it to cancel any pending
+ operation, due to last_resume_kind == resume_stop. If
+ the thread already has a pending status to report, we
+ will still report it the next time we wait - see
+ status_pending_p_callback. */
+
+ /* If we already have a pending signal to report, then
+ there's no need to queue a SIGSTOP, as this means we're
+ midway through moving the LWP out of the jumppad, and we
+ will report the pending signal as soon as that is
+ finished. */
+ if (lwp->pending_signals_to_report == NULL)
+ send_sigstop (lwp);
}
/* For stop requests, we're done. */
lwp->resume = NULL;
+ thread->last_status.kind = TARGET_WAITKIND_IGNORE;
return 0;
}
- else
- lwp->suspended = 0;
/* If this thread which is about to be resumed has a pending status,
then don't resume any threads - we can just report the pending
status. Make sure to queue any signals that would otherwise be
sent. In all-stop mode, we do this decision based on if *any*
- thread has a pending status. */
- if (non_stop)
- resume_status_pending_p (&lwp->head, &pending_flag);
+ thread has a pending status. If there's a thread that needs the
+ step-over-breakpoint dance, then don't resume any other thread
+ but that particular one. */
+ leave_pending = (lwp->status_pending_p || leave_all_stopped);
- if (!pending_flag)
+ if (!leave_pending)
{
if (debug_threads)
fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
- if (ptid_equal (lwp->resume->thread, minus_one_ptid)
- && lwp->stepping
- && lwp->pending_is_breakpoint)
- step = 1;
- else
- step = (lwp->resume->kind == resume_step);
-
+ step = (lwp->resume->kind == resume_step);
linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
}
else
&& WSTOPSIG (lwp->last_status) == lwp->resume->sig)
ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
- lwp->pending_signals = p_sig;
- }
+ lwp->pending_signals = p_sig;
+ }
+ }
+
+ thread->last_status.kind = TARGET_WAITKIND_IGNORE;
+ lwp->resume = NULL;
+ return 0;
+}
+
+static void
+linux_resume (struct thread_resume *resume_info, size_t n)
+{
+ struct thread_resume_array array = { resume_info, n };
+ struct lwp_info *need_step_over = NULL;
+ int any_pending;
+ int leave_all_stopped;
+
+ find_inferior (&all_threads, linux_set_resume_request, &array);
+
+ /* If there is a thread which would otherwise be resumed, which has
+ a pending status, then don't resume any threads - we can just
+ report the pending status. Make sure to queue any signals that
+ would otherwise be sent. In non-stop mode, we'll apply this
+ logic to each thread individually. We consume all pending events
+ before considering to start a step-over (in all-stop). */
+ any_pending = 0;
+ if (!non_stop)
+ find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
+
+ /* If there is a thread which would otherwise be resumed, which is
+ stopped at a breakpoint that needs stepping over, then don't
+ resume any threads - have it step over the breakpoint with all
+ other threads stopped, then resume all threads again. Make sure
+ to queue any signals that would otherwise be delivered or
+ queued. */
+ if (!any_pending && supports_breakpoints ())
+ need_step_over
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ need_step_over_p, NULL);
+
+ leave_all_stopped = (need_step_over != NULL || any_pending);
+
+ if (debug_threads)
+ {
+ if (need_step_over != NULL)
+ fprintf (stderr, "Not resuming all, need step over\n");
+ else if (any_pending)
+ fprintf (stderr,
+ "Not resuming, all-stop and found "
+ "an LWP with pending status\n");
+ else
+ fprintf (stderr, "Resuming, no pending status or step over needed\n");
+ }
+
+ /* Even if we're leaving threads stopped, queue all signals we'd
+ otherwise deliver. */
+ find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
+
+ if (need_step_over)
+ start_step_over (need_step_over);
+}
+
+/* This function is called once per thread. We check the thread's
+ last resume request, which will tell us whether to resume, step, or
+ leave the thread stopped. Any signal the client requested to be
+ delivered has already been enqueued at this point.
+
+ If any thread that GDB wants running is stopped at an internal
+ breakpoint that needs stepping over, we start a step-over operation
+ on that particular thread, and leave all others stopped. */
+
+static int
+proceed_one_lwp (struct inferior_list_entry *entry, void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread;
+ int step;
+
+ if (lwp == except)
+ return 0;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
+
+ if (!lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
+ return 0;
}
- lwp->resume = NULL;
- return 0;
-}
+ thread = get_lwp_thread (lwp);
-static void
-linux_resume (struct thread_resume *resume_info, size_t n)
-{
- int pending_flag;
- struct thread_resume_array array = { resume_info, n };
+ if (thread->last_resume_kind == resume_stop
+ && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
+ {
+ if (debug_threads)
+ fprintf (stderr, " client wants LWP to remain %ld stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
- find_inferior (&all_threads, linux_set_resume_request, &array);
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
- /* If there is a thread which would otherwise be resumed, which
- has a pending status, then don't resume any threads - we can just
- report the pending status. Make sure to queue any signals
- that would otherwise be sent. In non-stop mode, we'll apply this
- logic to each thread individually. */
- pending_flag = 0;
- if (!non_stop)
- find_inferior (&all_lwps, resume_status_pending_p, &pending_flag);
+ gdb_assert (lwp->suspended >= 0);
- if (debug_threads)
+ if (lwp->suspended)
{
- if (pending_flag)
- fprintf (stderr, "Not resuming, pending status\n");
- else
- fprintf (stderr, "Resuming, no pending status\n");
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
+ return 0;
}
- find_inferior (&all_threads, linux_resume_one_thread, &pending_flag);
-}
+ if (thread->last_resume_kind == resume_stop
+ && lwp->pending_signals_to_report == NULL
+ && lwp->collecting_fast_tracepoint == 0)
+ {
+ /* We haven't reported this LWP as stopped yet (otherwise, the
+ last_status.kind check above would catch it, and we wouldn't
+ reach here. This LWP may have been momentarily paused by a
+ stop_all_lwps call while handling for example, another LWP's
+ step-over. In that case, the pending expected SIGSTOP signal
+ that was queued at vCont;t handling time will have already
+ been consumed by wait_for_sigstop, and so we need to requeue
+ another one here. Note that if the LWP already has a SIGSTOP
+ pending, this is a no-op. */
-#ifdef HAVE_LINUX_USRREGS
+ if (debug_threads)
+ fprintf (stderr,
+ "Client wants LWP %ld to stop. "
+ "Making sure it has a SIGSTOP pending\n",
+ lwpid_of (lwp));
-int
-register_addr (int regnum)
+ send_sigstop (lwp);
+ }
+
+ step = thread->last_resume_kind == resume_step;
+ linux_resume_one_lwp (lwp, step, 0, NULL);
+ return 0;
+}
+
+static int
+unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
{
- int addr;
+ struct lwp_info *lwp = (struct lwp_info *) entry;
- if (regnum < 0 || regnum >= the_low_target.num_regs)
- error ("Invalid register number %d.", regnum);
+ if (lwp == except)
+ return 0;
- addr = the_low_target.regmap[regnum];
+ lwp->suspended--;
+ gdb_assert (lwp->suspended >= 0);
- return addr;
+ return proceed_one_lwp (entry, except);
}
-/* Fetch one register. */
+/* When we finish a step-over, set threads running again. If there's
+ another thread that may need a step-over, now's the time to start
+ it. Eventually, we'll move all threads past their breakpoints. */
+
static void
-fetch_register (struct regcache *regcache, int regno)
+proceed_all_lwps (void)
{
- CORE_ADDR regaddr;
- int i, size;
- char *buf;
- int pid;
-
- if (regno >= the_low_target.num_regs)
- return;
- if ((*the_low_target.cannot_fetch_register) (regno))
- return;
+ struct lwp_info *need_step_over;
- regaddr = register_addr (regno);
- if (regaddr == -1)
- return;
+ /* If there is a thread which would otherwise be resumed, which is
+ stopped at a breakpoint that needs stepping over, then don't
+ resume any threads - have it step over the breakpoint with all
+ other threads stopped, then resume all threads again. */
- pid = lwpid_of (get_thread_lwp (current_inferior));
- size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
- & - sizeof (PTRACE_XFER_TYPE));
- buf = alloca (size);
- for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
+ if (supports_breakpoints ())
{
- errno = 0;
- *(PTRACE_XFER_TYPE *) (buf + i) =
- ptrace (PTRACE_PEEKUSER, pid,
- /* Coerce to a uintptr_t first to avoid potential gcc warning
- of coercing an 8 byte integer to a 4 byte pointer. */
- (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
- regaddr += sizeof (PTRACE_XFER_TYPE);
- if (errno != 0)
+ need_step_over
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ need_step_over_p, NULL);
+
+ if (need_step_over != NULL)
{
- /* Warning, not error, in case we are attached; sometimes the
- kernel doesn't let us at the registers. */
- char *err = strerror (errno);
- char *msg = alloca (strlen (err) + 128);
- sprintf (msg, "reading register %d: %s", regno, err);
- error (msg);
- goto error_exit;
+ if (debug_threads)
+ fprintf (stderr, "proceed_all_lwps: found "
+ "thread %ld needing a step-over\n",
+ lwpid_of (need_step_over));
+
+ start_step_over (need_step_over);
+ return;
}
}
- if (the_low_target.supply_ptrace_register)
- the_low_target.supply_ptrace_register (regcache, regno, buf);
- else
- supply_register (regcache, regno, buf);
+ if (debug_threads)
+ fprintf (stderr, "Proceeding, no step-over needed\n");
-error_exit:;
+ find_inferior (&all_lwps, proceed_one_lwp, NULL);
}
-/* Fetch all registers, or just one, from the child process. */
-static void
-usr_fetch_inferior_registers (struct regcache *regcache, int regno)
-{
- if (regno == -1)
- for (regno = 0; regno < the_low_target.num_regs; regno++)
- fetch_register (regcache, regno);
- else
- fetch_register (regcache, regno);
-}
+/* Stopped LWPs that the client wanted to be running, that don't have
+ pending statuses, are set to run again, except for EXCEPT, if not
+ NULL. This undoes a stop_all_lwps call. */
-/* Store our register values back into the inferior.
- If REGNO is -1, do this for all registers.
- Otherwise, REGNO specifies which register (so we can save time). */
static void
-usr_store_inferior_registers (struct regcache *regcache, int regno)
+unstop_all_lwps (int unsuspend, struct lwp_info *except)
{
- CORE_ADDR regaddr;
- int i, size;
- char *buf;
- int pid;
-
- if (regno >= 0)
+ if (debug_threads)
{
- if (regno >= the_low_target.num_regs)
- return;
-
- if ((*the_low_target.cannot_store_register) (regno) == 1)
- return;
-
- regaddr = register_addr (regno);
- if (regaddr == -1)
- return;
- errno = 0;
- size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
- & - sizeof (PTRACE_XFER_TYPE);
- buf = alloca (size);
- memset (buf, 0, size);
-
- if (the_low_target.collect_ptrace_register)
- the_low_target.collect_ptrace_register (regcache, regno, buf);
+ if (except)
+ fprintf (stderr,
+ "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
else
- collect_register (regcache, regno, buf);
-
- pid = lwpid_of (get_thread_lwp (current_inferior));
- for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
- {
- errno = 0;
- ptrace (PTRACE_POKEUSER, pid,
- /* Coerce to a uintptr_t first to avoid potential gcc warning
- about coercing an 8 byte integer to a 4 byte pointer. */
- (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
- (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
- if (errno != 0)
- {
- /* At this point, ESRCH should mean the process is
- already gone, in which case we simply ignore attempts
- to change its registers. See also the related
- comment in linux_resume_one_lwp. */
- if (errno == ESRCH)
- return;
-
- if ((*the_low_target.cannot_store_register) (regno) == 0)
- {
- char *err = strerror (errno);
- char *msg = alloca (strlen (err) + 128);
- sprintf (msg, "writing register %d: %s",
- regno, err);
- error (msg);
- return;
- }
- }
- regaddr += sizeof (PTRACE_XFER_TYPE);
- }
+ fprintf (stderr,
+ "unstopping all lwps\n");
}
+
+ if (unsuspend)
+ find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except);
else
- for (regno = 0; regno < the_low_target.num_regs; regno++)
- usr_store_inferior_registers (regcache, regno);
+ find_inferior (&all_lwps, proceed_one_lwp, except);
}
-#endif /* HAVE_LINUX_USRREGS */
-
#ifdef HAVE_LINUX_REGSETS
+#define use_linux_regsets 1
+
static int
regsets_fetch_inferior_registers (struct regcache *regcache)
{
struct regset_info *regset;
int saw_general_regs = 0;
int pid;
+ struct iovec iov;
regset = target_regsets;
pid = lwpid_of (get_thread_lwp (current_inferior));
while (regset->size >= 0)
{
- void *buf;
- int res;
+ void *buf, *data;
+ int nt_type, res;
if (regset->size == 0 || disabled_regsets[regset - target_regsets])
{
}
buf = xmalloc (regset->size);
+
+ nt_type = regset->nt_type;
+ if (nt_type)
+ {
+ iov.iov_base = buf;
+ iov.iov_len = regset->size;
+ data = (void *) &iov;
+ }
+ else
+ data = buf;
+
#ifndef __sparc__
- res = ptrace (regset->get_request, pid, 0, buf);
+ res = ptrace (regset->get_request, pid,
+ (PTRACE_ARG3_TYPE) (long) nt_type, data);
#else
- res = ptrace (regset->get_request, pid, buf, 0);
+ res = ptrace (regset->get_request, pid, data, nt_type);
#endif
if (res < 0)
{
struct regset_info *regset;
int saw_general_regs = 0;
int pid;
+ struct iovec iov;
regset = target_regsets;
pid = lwpid_of (get_thread_lwp (current_inferior));
while (regset->size >= 0)
{
- void *buf;
- int res;
+ void *buf, *data;
+ int nt_type, res;
if (regset->size == 0 || disabled_regsets[regset - target_regsets])
{
/* First fill the buffer with the current register set contents,
in case there are any items in the kernel's regset that are
not in gdbserver's regcache. */
+
+ nt_type = regset->nt_type;
+ if (nt_type)
+ {
+ iov.iov_base = buf;
+ iov.iov_len = regset->size;
+ data = (void *) &iov;
+ }
+ else
+ data = buf;
+
#ifndef __sparc__
- res = ptrace (regset->get_request, pid, 0, buf);
+ res = ptrace (regset->get_request, pid,
+ (PTRACE_ARG3_TYPE) (long) nt_type, data);
#else
- res = ptrace (regset->get_request, pid, buf, 0);
+ res = ptrace (regset->get_request, pid, data, nt_type);
#endif
if (res == 0)
/* Then overlay our cached registers on that. */
regset->fill_function (regcache, buf);
- /* Only now do we write the register set. */
-#ifndef __sparc__
- res = ptrace (regset->set_request, pid, 0, buf);
-#else
- res = ptrace (regset->set_request, pid, buf, 0);
-#endif
- }
+ /* Only now do we write the register set. */
+#ifndef __sparc__
+ res = ptrace (regset->set_request, pid,
+ (PTRACE_ARG3_TYPE) (long) nt_type, data);
+#else
+ res = ptrace (regset->set_request, pid, data, nt_type);
+#endif
+ }
+
+ if (res < 0)
+ {
+ if (errno == EIO)
+ {
+ /* If we get EIO on a regset, do not try it again for
+ this process. */
+ disabled_regsets[regset - target_regsets] = 1;
+ free (buf);
+ continue;
+ }
+ else if (errno == ESRCH)
+ {
+ /* At this point, ESRCH should mean the process is
+ already gone, in which case we simply ignore attempts
+ to change its registers. See also the related
+ comment in linux_resume_one_lwp. */
+ free (buf);
+ return 0;
+ }
+ else
+ {
+ perror ("Warning: ptrace(regsets_store_inferior_registers)");
+ }
+ }
+ else if (regset->type == GENERAL_REGS)
+ saw_general_regs = 1;
+ regset ++;
+ free (buf);
+ }
+ if (saw_general_regs)
+ return 0;
+ else
+ return 1;
+}
+
+#else /* !HAVE_LINUX_REGSETS */
+
+#define use_linux_regsets 0
+#define regsets_fetch_inferior_registers(regcache) 1
+#define regsets_store_inferior_registers(regcache) 1
+
+#endif
+
+/* Return 1 if register REGNO is supported by one of the regset ptrace
+ calls or 0 if it has to be transferred individually. */
+
+static int
+linux_register_in_regsets (int regno)
+{
+ unsigned char mask = 1 << (regno % 8);
+ size_t index = regno / 8;
+
+ return (use_linux_regsets
+ && (the_low_target.regset_bitmap == NULL
+ || (the_low_target.regset_bitmap[index] & mask) != 0));
+}
+
+#ifdef HAVE_LINUX_USRREGS
+
+int
+register_addr (int regnum)
+{
+ int addr;
+
+ if (regnum < 0 || regnum >= the_low_target.num_regs)
+ error ("Invalid register number %d.", regnum);
+
+ addr = the_low_target.regmap[regnum];
+
+ return addr;
+}
+
+/* Fetch one register. */
+static void
+fetch_register (struct regcache *regcache, int regno)
+{
+ CORE_ADDR regaddr;
+ int i, size;
+ char *buf;
+ int pid;
+
+ if (regno >= the_low_target.num_regs)
+ return;
+ if ((*the_low_target.cannot_fetch_register) (regno))
+ return;
+
+ regaddr = register_addr (regno);
+ if (regaddr == -1)
+ return;
+
+ size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
+ & -sizeof (PTRACE_XFER_TYPE));
+ buf = alloca (size);
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
+ {
+ errno = 0;
+ *(PTRACE_XFER_TYPE *) (buf + i) =
+ ptrace (PTRACE_PEEKUSER, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ of coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
+ regaddr += sizeof (PTRACE_XFER_TYPE);
+ if (errno != 0)
+ error ("reading register %d: %s", regno, strerror (errno));
+ }
+
+ if (the_low_target.supply_ptrace_register)
+ the_low_target.supply_ptrace_register (regcache, regno, buf);
+ else
+ supply_register (regcache, regno, buf);
+}
+
+/* Store one register. */
+static void
+store_register (struct regcache *regcache, int regno)
+{
+ CORE_ADDR regaddr;
+ int i, size;
+ char *buf;
+ int pid;
+
+ if (regno >= the_low_target.num_regs)
+ return;
+ if ((*the_low_target.cannot_store_register) (regno))
+ return;
+
+ regaddr = register_addr (regno);
+ if (regaddr == -1)
+ return;
+
+ size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
+ & -sizeof (PTRACE_XFER_TYPE));
+ buf = alloca (size);
+ memset (buf, 0, size);
- if (res < 0)
+ if (the_low_target.collect_ptrace_register)
+ the_low_target.collect_ptrace_register (regcache, regno, buf);
+ else
+ collect_register (regcache, regno, buf);
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
+ {
+ errno = 0;
+ ptrace (PTRACE_POKEUSER, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
+ (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
+ if (errno != 0)
{
- if (errno == EIO)
- {
- /* If we get EIO on a regset, do not try it again for
- this process. */
- disabled_regsets[regset - target_regsets] = 1;
- free (buf);
- continue;
- }
- else if (errno == ESRCH)
- {
- /* At this point, ESRCH should mean the process is
- already gone, in which case we simply ignore attempts
- to change its registers. See also the related
- comment in linux_resume_one_lwp. */
- free (buf);
- return 0;
- }
- else
- {
- perror ("Warning: ptrace(regsets_store_inferior_registers)");
- }
+ /* At this point, ESRCH should mean the process is
+ already gone, in which case we simply ignore attempts
+ to change its registers. See also the related
+ comment in linux_resume_one_lwp. */
+ if (errno == ESRCH)
+ return;
+
+ if ((*the_low_target.cannot_store_register) (regno) == 0)
+ error ("writing register %d: %s", regno, strerror (errno));
}
- else if (regset->type == GENERAL_REGS)
- saw_general_regs = 1;
- regset ++;
- free (buf);
+ regaddr += sizeof (PTRACE_XFER_TYPE);
+ }
+}
+
+/* Fetch all registers, or just one, from the child process.
+ If REGNO is -1, do this for all registers, skipping any that are
+ assumed to have been retrieved by regsets_fetch_inferior_registers,
+ unless ALL is non-zero.
+ Otherwise, REGNO specifies which register (so we can save time). */
+static void
+usr_fetch_inferior_registers (struct regcache *regcache, int regno, int all)
+{
+ if (regno == -1)
+ {
+ for (regno = 0; regno < the_low_target.num_regs; regno++)
+ if (all || !linux_register_in_regsets (regno))
+ fetch_register (regcache, regno);
}
- if (saw_general_regs)
- return 0;
else
- return 1;
- return 0;
+ fetch_register (regcache, regno);
+}
+
+/* Store our register values back into the inferior.
+ If REGNO is -1, do this for all registers, skipping any that are
+ assumed to have been saved by regsets_store_inferior_registers,
+ unless ALL is non-zero.
+ Otherwise, REGNO specifies which register (so we can save time). */
+static void
+usr_store_inferior_registers (struct regcache *regcache, int regno, int all)
+{
+ if (regno == -1)
+ {
+ for (regno = 0; regno < the_low_target.num_regs; regno++)
+ if (all || !linux_register_in_regsets (regno))
+ store_register (regcache, regno);
+ }
+ else
+ store_register (regcache, regno);
}
-#endif /* HAVE_LINUX_REGSETS */
+#else /* !HAVE_LINUX_USRREGS */
+
+#define usr_fetch_inferior_registers(regcache, regno, all) do {} while (0)
+#define usr_store_inferior_registers(regcache, regno, all) do {} while (0)
+
+#endif
void
linux_fetch_registers (struct regcache *regcache, int regno)
{
-#ifdef HAVE_LINUX_REGSETS
- if (regsets_fetch_inferior_registers (regcache) == 0)
- return;
-#endif
-#ifdef HAVE_LINUX_USRREGS
- usr_fetch_inferior_registers (regcache, regno);
-#endif
+ int use_regsets;
+ int all = 0;
+
+ if (regno == -1)
+ {
+ if (the_low_target.fetch_register != NULL)
+ for (regno = 0; regno < the_low_target.num_regs; regno++)
+ (*the_low_target.fetch_register) (regcache, regno);
+
+ all = regsets_fetch_inferior_registers (regcache);
+ usr_fetch_inferior_registers (regcache, -1, all);
+ }
+ else
+ {
+ if (the_low_target.fetch_register != NULL
+ && (*the_low_target.fetch_register) (regcache, regno))
+ return;
+
+ use_regsets = linux_register_in_regsets (regno);
+ if (use_regsets)
+ all = regsets_fetch_inferior_registers (regcache);
+ if (!use_regsets || all)
+ usr_fetch_inferior_registers (regcache, regno, 1);
+ }
}
void
linux_store_registers (struct regcache *regcache, int regno)
{
-#ifdef HAVE_LINUX_REGSETS
- if (regsets_store_inferior_registers (regcache) == 0)
- return;
-#endif
-#ifdef HAVE_LINUX_USRREGS
- usr_store_inferior_registers (regcache, regno);
-#endif
+ int use_regsets;
+ int all = 0;
+
+ if (regno == -1)
+ {
+ all = regsets_store_inferior_registers (regcache);
+ usr_store_inferior_registers (regcache, regno, all);
+ }
+ else
+ {
+ use_regsets = linux_register_in_regsets (regno);
+ if (use_regsets)
+ all = regsets_store_inferior_registers (regcache);
+ if (!use_regsets || all)
+ usr_store_inferior_registers (regcache, regno, 1);
+ }
}
static int
linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
{
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
+ register PTRACE_XFER_TYPE *buffer;
+ register CORE_ADDR addr;
+ register int count;
+ char filename[64];
register int i;
- /* Round starting address down to longword boundary. */
- register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
- /* Round ending address up; get number of longwords that makes. */
- register int count
- = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
- / sizeof (PTRACE_XFER_TYPE);
- /* Allocate buffer of that many longwords. */
- register PTRACE_XFER_TYPE *buffer
- = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+ int ret;
int fd;
- char filename[64];
- int pid = lwpid_of (get_thread_lwp (current_inferior));
/* Try using /proc. Don't bother for one word. */
if (len >= 3 * sizeof (long))
{
+ int bytes;
+
/* We could keep this file open and cache it - possibly one per
thread. That requires some juggling, but is even faster. */
sprintf (filename, "/proc/%d/mem", pid);
32-bit platforms (for instance, SPARC debugging a SPARC64
application). */
#ifdef HAVE_PREAD64
- if (pread64 (fd, myaddr, len, memaddr) != len)
+ bytes = pread64 (fd, myaddr, len, memaddr);
#else
- if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
+ bytes = -1;
+ if (lseek (fd, memaddr, SEEK_SET) != -1)
+ bytes = read (fd, myaddr, len);
#endif
- {
- close (fd);
- goto no_proc;
- }
close (fd);
- return 0;
+ if (bytes == len)
+ return 0;
+
+ /* Some data was read, we'll try to get the rest with ptrace. */
+ if (bytes > 0)
+ {
+ memaddr += bytes;
+ myaddr += bytes;
+ len -= bytes;
+ }
}
no_proc:
+ /* Round starting address down to longword boundary. */
+ addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
+ /* Round ending address up; get number of longwords that makes. */
+ count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
+ / sizeof (PTRACE_XFER_TYPE));
+ /* Allocate buffer of that many longwords. */
+ buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+
/* Read all the longwords */
+ errno = 0;
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
{
- errno = 0;
/* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
about coercing an 8 byte integer to a 4 byte pointer. */
buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
(PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
if (errno)
- return errno;
+ break;
}
+ ret = errno;
/* Copy appropriate bytes out of the buffer. */
- memcpy (myaddr,
- (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
- len);
+ if (i > 0)
+ {
+ i *= sizeof (PTRACE_XFER_TYPE);
+ i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1);
+ memcpy (myaddr,
+ (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
+ i < len ? i : len);
+ }
- return 0;
+ return ret;
}
-/* Copy LEN bytes of data from debugger memory at MYADDR
- to inferior's memory at MEMADDR.
- On failure (cannot write the inferior)
+/* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
+ memory at MEMADDR. On failure (cannot write to the inferior)
returns the value of errno. */
static int
register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
/* Round ending address up; get number of longwords that makes. */
register int count
- = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
+ = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
+ / sizeof (PTRACE_XFER_TYPE);
+
/* Allocate buffer of that many longwords. */
- register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+ register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
+ alloca (count * sizeof (PTRACE_XFER_TYPE));
+
int pid = lwpid_of (get_thread_lwp (current_inferior));
if (debug_threads)
/* Fill start and end extra bytes of buffer with existing memory data. */
+ errno = 0;
/* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
about coercing an 8 byte integer to a 4 byte pointer. */
buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
(PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
+ if (errno)
+ return errno;
if (count > 1)
{
+ errno = 0;
buffer[count - 1]
= ptrace (PTRACE_PEEKTEXT, pid,
/* Coerce to a uintptr_t first to avoid potential gcc warning
(PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
* sizeof (PTRACE_XFER_TYPE)),
0);
+ if (errno)
+ return errno;
}
- /* Copy data to be written over corresponding part of buffer */
+ /* Copy data to be written over corresponding part of buffer. */
- memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
+ memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
+ myaddr, len);
/* Write the entire buffer. */
return 0;
}
+/* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
static int linux_supports_tracefork_flag;
+static void
+linux_enable_event_reporting (int pid)
+{
+ if (!linux_supports_tracefork_flag)
+ return;
+
+ ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
+}
+
/* Helper functions for linux_test_for_tracefork, called via clone (). */
static int
{
ptrace (PTRACE_TRACEME, 0, 0, 0);
kill (getpid (), SIGSTOP);
+
+#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
+
+ if (fork () == 0)
+ linux_tracefork_grandchild (NULL);
+
+#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
#ifdef __ia64__
__clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
CLONE_VM | SIGCHLD, NULL);
#else
- clone (linux_tracefork_grandchild, arg + STACK_SIZE,
+ clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE,
CLONE_VM | SIGCHLD, NULL);
#endif
+
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
_exit (0);
}
{
int child_pid, ret, status;
long second_pid;
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
char *stack = xmalloc (STACK_SIZE * 4);
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
linux_supports_tracefork_flag = 0;
+#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
+
+ child_pid = fork ();
+ if (child_pid == 0)
+ linux_tracefork_child (NULL);
+
+#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
/* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
#ifdef __ia64__
child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
-#else
+#else /* !__ia64__ */
child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
-#endif
+#endif /* !__ia64__ */
+
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
if (child_pid == -1)
perror_with_name ("clone");
}
while (WIFSTOPPED (status));
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
free (stack);
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
}
if (proc->private->thread_db != NULL)
return;
+ /* If the kernel supports tracing forks then it also supports tracing
+ clones, and then we don't need to use the magic thread event breakpoint
+ to learn about threads. */
thread_db_init (!linux_supports_tracefork_flag);
#endif
}
int fd, n;
int pid = lwpid_of (get_thread_lwp (current_inferior));
- snprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
+ xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
fd = open (filename, O_RDONLY);
if (fd < 0)
static int
linux_stopped_by_watchpoint (void)
{
- if (the_low_target.stopped_by_watchpoint != NULL)
- return the_low_target.stopped_by_watchpoint ();
- else
- return 0;
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+
+ return lwp->stopped_by_watchpoint;
}
static CORE_ADDR
linux_stopped_data_address (void)
{
- if (the_low_target.stopped_data_address != NULL)
- return the_low_target.stopped_data_address ();
- else
- return 0;
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+
+ return lwp->stopped_data_address;
}
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
+#if ! (defined(PT_TEXT_ADDR) \
+ || defined(PT_DATA_ADDR) \
+ || defined(PT_TEXT_END_ADDR))
#if defined(__mcoldfire__)
/* These should really be defined in the kernel's ptrace.h header. */
#define PT_TEXT_ADDR 49*4
#define PT_DATA_ADDR 50*4
#define PT_TEXT_END_ADDR 51*4
+#elif defined(BFIN)
+#define PT_TEXT_ADDR 220
+#define PT_TEXT_END_ADDR 224
+#define PT_DATA_ADDR 228
+#elif defined(__TMS320C6X__)
+#define PT_TEXT_ADDR (0x10000*4)
+#define PT_DATA_ADDR (0x10004*4)
+#define PT_TEXT_END_ADDR (0x10008*4)
+#endif
#endif
/* Under uClinux, programs are loaded at non-zero offsets, which we need
}
#endif
-static int
-compare_ints (const void *xa, const void *xb)
-{
- int a = *(const int *)xa;
- int b = *(const int *)xb;
-
- return a - b;
-}
-
-static int *
-unique (int *b, int *e)
-{
- int *d = b;
- while (++b != e)
- if (*d != *b)
- *++d = *b;
- return ++d;
-}
-
-/* Given PID, iterates over all threads in that process.
-
- Information about each thread, in a format suitable for qXfer:osdata:thread
- is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
- initialized, and the caller is responsible for finishing and appending '\0'
- to it.
-
- The list of cores that threads are running on is assigned to *CORES, if it
- is not NULL. If no cores are found, *CORES will be set to NULL. Caller
- should free *CORES. */
-
-static void
-list_threads (int pid, struct buffer *buffer, char **cores)
-{
- int count = 0;
- int allocated = 10;
- int *core_numbers = xmalloc (sizeof (int) * allocated);
- char pathname[128];
- DIR *dir;
- struct dirent *dp;
- struct stat statbuf;
-
- sprintf (pathname, "/proc/%d/task", pid);
- if (stat (pathname, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
- {
- dir = opendir (pathname);
- if (!dir)
- {
- free (core_numbers);
- return;
- }
-
- while ((dp = readdir (dir)) != NULL)
- {
- unsigned long lwp = strtoul (dp->d_name, NULL, 10);
-
- if (lwp != 0)
- {
- unsigned core = linux_core_of_thread (ptid_build (pid, lwp, 0));
-
- if (core != -1)
- {
- char s[sizeof ("4294967295")];
- sprintf (s, "%u", core);
-
- if (count == allocated)
- {
- allocated *= 2;
- core_numbers = realloc (core_numbers,
- sizeof (int) * allocated);
- }
- core_numbers[count++] = core;
- if (buffer)
- buffer_xml_printf (buffer,
- "<item>"
- "<column name=\"pid\">%d</column>"
- "<column name=\"tid\">%s</column>"
- "<column name=\"core\">%s</column>"
- "</item>", pid, dp->d_name, s);
- }
- else
- {
- if (buffer)
- buffer_xml_printf (buffer,
- "<item>"
- "<column name=\"pid\">%d</column>"
- "<column name=\"tid\">%s</column>"
- "</item>", pid, dp->d_name);
- }
- }
- }
- }
-
- if (cores)
- {
- *cores = NULL;
- if (count > 0)
- {
- struct buffer buffer2;
- int *b;
- int *e;
- qsort (core_numbers, count, sizeof (int), compare_ints);
-
- /* Remove duplicates. */
- b = core_numbers;
- e = unique (b, core_numbers + count);
-
- buffer_init (&buffer2);
-
- for (b = core_numbers; b != e; ++b)
- {
- char number[sizeof ("4294967295")];
- sprintf (number, "%u", *b);
- buffer_xml_printf (&buffer2, "%s%s",
- (b == core_numbers) ? "" : ",", number);
- }
- buffer_grow_str0 (&buffer2, "");
-
- *cores = buffer_finish (&buffer2);
- }
- }
- free (core_numbers);
-}
-
-static void
-show_process (int pid, const char *username, struct buffer *buffer)
-{
- char pathname[128];
- FILE *f;
- char cmd[MAXPATHLEN + 1];
-
- sprintf (pathname, "/proc/%d/cmdline", pid);
-
- if ((f = fopen (pathname, "r")) != NULL)
- {
- size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
- if (len > 0)
- {
- char *cores = 0;
- int i;
- for (i = 0; i < len; i++)
- if (cmd[i] == '\0')
- cmd[i] = ' ';
- cmd[len] = '\0';
-
- buffer_xml_printf (buffer,
- "<item>"
- "<column name=\"pid\">%d</column>"
- "<column name=\"user\">%s</column>"
- "<column name=\"command\">%s</column>",
- pid,
- username,
- cmd);
-
- /* This only collects core numbers, and does not print threads. */
- list_threads (pid, NULL, &cores);
-
- if (cores)
- {
- buffer_xml_printf (buffer,
- "<column name=\"cores\">%s</column>", cores);
- free (cores);
- }
-
- buffer_xml_printf (buffer, "</item>");
- }
- fclose (f);
- }
-}
-
static int
linux_qxfer_osdata (const char *annex,
unsigned char *readbuf, unsigned const char *writebuf,
CORE_ADDR offset, int len)
{
- /* We make the process list snapshot when the object starts to be
- read. */
- static const char *buf;
- static long len_avail = -1;
- static struct buffer buffer;
- int processes = 0;
- int threads = 0;
-
- DIR *dirp;
-
- if (strcmp (annex, "processes") == 0)
- processes = 1;
- else if (strcmp (annex, "threads") == 0)
- threads = 1;
- else
- return 0;
-
- if (!readbuf || writebuf)
- return 0;
-
- if (offset == 0)
- {
- if (len_avail != -1 && len_avail != 0)
- buffer_free (&buffer);
- len_avail = 0;
- buf = NULL;
- buffer_init (&buffer);
- if (processes)
- buffer_grow_str (&buffer, "<osdata type=\"processes\">");
- else if (threads)
- buffer_grow_str (&buffer, "<osdata type=\"threads\">");
-
- dirp = opendir ("/proc");
- if (dirp)
- {
- struct dirent *dp;
- while ((dp = readdir (dirp)) != NULL)
- {
- struct stat statbuf;
- char procentry[sizeof ("/proc/4294967295")];
-
- if (!isdigit (dp->d_name[0])
- || strlen (dp->d_name) > sizeof ("4294967295") - 1)
- continue;
-
- sprintf (procentry, "/proc/%s", dp->d_name);
- if (stat (procentry, &statbuf) == 0
- && S_ISDIR (statbuf.st_mode))
- {
- int pid = (int) strtoul (dp->d_name, NULL, 10);
-
- if (processes)
- {
- struct passwd *entry = getpwuid (statbuf.st_uid);
- show_process (pid, entry ? entry->pw_name : "?", &buffer);
- }
- else if (threads)
- {
- list_threads (pid, &buffer, NULL);
- }
- }
- }
-
- closedir (dirp);
- }
- buffer_grow_str0 (&buffer, "</osdata>\n");
- buf = buffer_finish (&buffer);
- len_avail = strlen (buf);
- }
-
- if (offset >= len_avail)
- {
- /* Done. Get rid of the data. */
- buffer_free (&buffer);
- buf = NULL;
- len_avail = 0;
- return 0;
- }
-
- if (len > len_avail - offset)
- len = len_avail - offset;
- memcpy (readbuf, buf + offset, len);
-
- return len;
+ return linux_common_xfer_osdata (annex, readbuf, offset, len);
}
/* Convert a native/host siginfo object, into/from the siginfo in the
layout of the inferiors' architecture. */
static void
-siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
+siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction)
{
int done = 0;
if (!done)
{
if (direction == 1)
- memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
+ memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
else
- memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
+ memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
}
}
unsigned const char *writebuf, CORE_ADDR offset, int len)
{
int pid;
- struct siginfo siginfo;
- char inf_siginfo[sizeof (struct siginfo)];
+ siginfo_t siginfo;
+ char inf_siginfo[sizeof (siginfo_t)];
if (current_inferior == NULL)
return -1;
readbuf != NULL ? "Reading" : "Writing",
pid);
- if (offset > sizeof (siginfo))
+ if (offset >= sizeof (siginfo))
return -1;
if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
int old_errno = errno;
if (debug_threads)
- /* fprintf is not async-signal-safe, so call write directly. */
- write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
+ {
+ do
+ {
+ /* fprintf is not async-signal-safe, so call write
+ directly. */
+ if (write (2, "sigchld_handler\n",
+ sizeof ("sigchld_handler\n") - 1) < 0)
+ break; /* just ignore */
+ } while (0);
+ }
if (target_is_async_p ())
async_file_mark (); /* trigger a linux_wait */
{
int previous = (linux_event_pipe[0] != -1);
+ if (debug_threads)
+ fprintf (stderr, "linux_async (%d), previous=%d\n",
+ enable, previous);
+
if (previous != enable)
{
sigset_t mask;
}
static int
-linux_supports_multi_process (void)
+linux_supports_multi_process (void)
+{
+ return 1;
+}
+
+static int
+linux_supports_disable_randomization (void)
+{
+#ifdef HAVE_PERSONALITY
+ return 1;
+#else
+ return 0;
+#endif
+}
+
+static int
+linux_supports_agent (void)
{
return 1;
}
-
/* Enumerate spufs IDs for process PID. */
static int
spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
return ret;
}
+#if defined PT_GETDSBT || defined PTRACE_GETFDPIC
+struct target_loadseg
+{
+ /* Core address to which the segment is mapped. */
+ Elf32_Addr addr;
+ /* VMA recorded in the program header. */
+ Elf32_Addr p_vaddr;
+ /* Size of this segment in memory. */
+ Elf32_Word p_memsz;
+};
+
+# if defined PT_GETDSBT
+struct target_loadmap
+{
+ /* Protocol version number, must be zero. */
+ Elf32_Word version;
+ /* Pointer to the DSBT table, its size, and the DSBT index. */
+ unsigned *dsbt_table;
+ unsigned dsbt_size, dsbt_index;
+ /* Number of segments in this map. */
+ Elf32_Word nsegs;
+ /* The actual memory map. */
+ struct target_loadseg segs[/*nsegs*/];
+};
+# define LINUX_LOADMAP PT_GETDSBT
+# define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
+# define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
+# else
+struct target_loadmap
+{
+ /* Protocol version number, must be zero. */
+ Elf32_Half version;
+ /* Number of segments in this map. */
+ Elf32_Half nsegs;
+ /* The actual memory map. */
+ struct target_loadseg segs[/*nsegs*/];
+};
+# define LINUX_LOADMAP PTRACE_GETFDPIC
+# define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
+# define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
+# endif
+
static int
-linux_core_of_thread (ptid_t ptid)
+linux_read_loadmap (const char *annex, CORE_ADDR offset,
+ unsigned char *myaddr, unsigned int len)
{
- char filename[sizeof ("/proc//task//stat")
- + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
- + 1];
- FILE *f;
- char *content = NULL;
- char *p;
- char *ts = 0;
- int content_read = 0;
- int i;
- int core;
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
+ int addr = -1;
+ struct target_loadmap *data = NULL;
+ unsigned int actual_length, copy_length;
+
+ if (strcmp (annex, "exec") == 0)
+ addr = (int) LINUX_LOADMAP_EXEC;
+ else if (strcmp (annex, "interp") == 0)
+ addr = (int) LINUX_LOADMAP_INTERP;
+ else
+ return -1;
+
+ if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
+ return -1;
+
+ if (data == NULL)
+ return -1;
+
+ actual_length = sizeof (struct target_loadmap)
+ + sizeof (struct target_loadseg) * data->nsegs;
- sprintf (filename, "/proc/%d/task/%ld/stat",
- ptid_get_pid (ptid), ptid_get_lwp (ptid));
- f = fopen (filename, "r");
- if (!f)
+ if (offset < 0 || offset > actual_length)
return -1;
- for (;;)
+ copy_length = actual_length - offset < len ? actual_length - offset : len;
+ memcpy (myaddr, (char *) data + offset, copy_length);
+ return copy_length;
+}
+#else
+# define linux_read_loadmap NULL
+#endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
+
+static void
+linux_process_qsupported (const char *query)
+{
+ if (the_low_target.process_qsupported != NULL)
+ the_low_target.process_qsupported (query);
+}
+
+static int
+linux_supports_tracepoints (void)
+{
+ if (*the_low_target.supports_tracepoints == NULL)
+ return 0;
+
+ return (*the_low_target.supports_tracepoints) ();
+}
+
+static CORE_ADDR
+linux_read_pc (struct regcache *regcache)
+{
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ return (*the_low_target.get_pc) (regcache);
+}
+
+static void
+linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+ gdb_assert (the_low_target.set_pc != NULL);
+
+ (*the_low_target.set_pc) (regcache, pc);
+}
+
+static int
+linux_thread_stopped (struct thread_info *thread)
+{
+ return get_thread_lwp (thread)->stopped;
+}
+
+/* This exposes stop-all-threads functionality to other modules. */
+
+static void
+linux_pause_all (int freeze)
+{
+ stop_all_lwps (freeze, NULL);
+}
+
+/* This exposes unstop-all-threads functionality to other gdbserver
+ modules. */
+
+static void
+linux_unpause_all (int unfreeze)
+{
+ unstop_all_lwps (unfreeze, NULL);
+}
+
+static int
+linux_prepare_to_access_memory (void)
+{
+ /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
+ running LWP. */
+ if (non_stop)
+ linux_pause_all (1);
+ return 0;
+}
+
+static void
+linux_done_accessing_memory (void)
+{
+ /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
+ running LWP. */
+ if (non_stop)
+ linux_unpause_all (1);
+}
+
+static int
+linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
+ CORE_ADDR collector,
+ CORE_ADDR lockaddr,
+ ULONGEST orig_size,
+ CORE_ADDR *jump_entry,
+ CORE_ADDR *trampoline,
+ ULONGEST *trampoline_size,
+ unsigned char *jjump_pad_insn,
+ ULONGEST *jjump_pad_insn_size,
+ CORE_ADDR *adjusted_insn_addr,
+ CORE_ADDR *adjusted_insn_addr_end,
+ char *err)
+{
+ return (*the_low_target.install_fast_tracepoint_jump_pad)
+ (tpoint, tpaddr, collector, lockaddr, orig_size,
+ jump_entry, trampoline, trampoline_size,
+ jjump_pad_insn, jjump_pad_insn_size,
+ adjusted_insn_addr, adjusted_insn_addr_end,
+ err);
+}
+
+static struct emit_ops *
+linux_emit_ops (void)
+{
+ if (the_low_target.emit_ops != NULL)
+ return (*the_low_target.emit_ops) ();
+ else
+ return NULL;
+}
+
+static int
+linux_get_min_fast_tracepoint_insn_len (void)
+{
+ return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
+}
+
+/* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
+
+static int
+get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
+ CORE_ADDR *phdr_memaddr, int *num_phdr)
+{
+ char filename[PATH_MAX];
+ int fd;
+ const int auxv_size = is_elf64
+ ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
+ char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
+
+ xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
+
+ fd = open (filename, O_RDONLY);
+ if (fd < 0)
+ return 1;
+
+ *phdr_memaddr = 0;
+ *num_phdr = 0;
+ while (read (fd, buf, auxv_size) == auxv_size
+ && (*phdr_memaddr == 0 || *num_phdr == 0))
+ {
+ if (is_elf64)
+ {
+ Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
+
+ switch (aux->a_type)
+ {
+ case AT_PHDR:
+ *phdr_memaddr = aux->a_un.a_val;
+ break;
+ case AT_PHNUM:
+ *num_phdr = aux->a_un.a_val;
+ break;
+ }
+ }
+ else
+ {
+ Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
+
+ switch (aux->a_type)
+ {
+ case AT_PHDR:
+ *phdr_memaddr = aux->a_un.a_val;
+ break;
+ case AT_PHNUM:
+ *num_phdr = aux->a_un.a_val;
+ break;
+ }
+ }
+ }
+
+ close (fd);
+
+ if (*phdr_memaddr == 0 || *num_phdr == 0)
+ {
+ warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
+ "phdr_memaddr = %ld, phdr_num = %d",
+ (long) *phdr_memaddr, *num_phdr);
+ return 2;
+ }
+
+ return 0;
+}
+
+/* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
+
+static CORE_ADDR
+get_dynamic (const int pid, const int is_elf64)
+{
+ CORE_ADDR phdr_memaddr, relocation;
+ int num_phdr, i;
+ unsigned char *phdr_buf;
+ const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
+
+ if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
+ return 0;
+
+ gdb_assert (num_phdr < 100); /* Basic sanity check. */
+ phdr_buf = alloca (num_phdr * phdr_size);
+
+ if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
+ return 0;
+
+ /* Compute relocation: it is expected to be 0 for "regular" executables,
+ non-zero for PIE ones. */
+ relocation = -1;
+ for (i = 0; relocation == -1 && i < num_phdr; i++)
+ if (is_elf64)
+ {
+ Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
+
+ if (p->p_type == PT_PHDR)
+ relocation = phdr_memaddr - p->p_vaddr;
+ }
+ else
+ {
+ Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
+
+ if (p->p_type == PT_PHDR)
+ relocation = phdr_memaddr - p->p_vaddr;
+ }
+
+ if (relocation == -1)
+ {
+ /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
+ any real world executables, including PIE executables, have always
+ PT_PHDR present. PT_PHDR is not present in some shared libraries or
+ in fpc (Free Pascal 2.4) binaries but neither of those have a need for
+ or present DT_DEBUG anyway (fpc binaries are statically linked).
+
+ Therefore if there exists DT_DEBUG there is always also PT_PHDR.
+
+ GDB could find RELOCATION also from AT_ENTRY - e_entry. */
+
+ return 0;
+ }
+
+ for (i = 0; i < num_phdr; i++)
+ {
+ if (is_elf64)
+ {
+ Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
+
+ if (p->p_type == PT_DYNAMIC)
+ return p->p_vaddr + relocation;
+ }
+ else
+ {
+ Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
+
+ if (p->p_type == PT_DYNAMIC)
+ return p->p_vaddr + relocation;
+ }
+ }
+
+ return 0;
+}
+
+/* Return &_r_debug in the inferior, or -1 if not present. Return value
+ can be 0 if the inferior does not yet have the library list initialized.
+ We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
+ DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
+
+static CORE_ADDR
+get_r_debug (const int pid, const int is_elf64)
+{
+ CORE_ADDR dynamic_memaddr;
+ const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
+ unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
+ CORE_ADDR map = -1;
+
+ dynamic_memaddr = get_dynamic (pid, is_elf64);
+ if (dynamic_memaddr == 0)
+ return map;
+
+ while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
{
- int n;
- content = realloc (content, content_read + 1024);
- n = fread (content + content_read, 1, 1024, f);
- content_read += n;
- if (n < 1024)
+ if (is_elf64)
+ {
+ Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
+#ifdef DT_MIPS_RLD_MAP
+ union
+ {
+ Elf64_Xword map;
+ unsigned char buf[sizeof (Elf64_Xword)];
+ }
+ rld_map;
+
+ if (dyn->d_tag == DT_MIPS_RLD_MAP)
+ {
+ if (linux_read_memory (dyn->d_un.d_val,
+ rld_map.buf, sizeof (rld_map.buf)) == 0)
+ return rld_map.map;
+ else
+ break;
+ }
+#endif /* DT_MIPS_RLD_MAP */
+
+ if (dyn->d_tag == DT_DEBUG && map == -1)
+ map = dyn->d_un.d_val;
+
+ if (dyn->d_tag == DT_NULL)
+ break;
+ }
+ else
{
- content[content_read] = '\0';
- break;
+ Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
+#ifdef DT_MIPS_RLD_MAP
+ union
+ {
+ Elf32_Word map;
+ unsigned char buf[sizeof (Elf32_Word)];
+ }
+ rld_map;
+
+ if (dyn->d_tag == DT_MIPS_RLD_MAP)
+ {
+ if (linux_read_memory (dyn->d_un.d_val,
+ rld_map.buf, sizeof (rld_map.buf)) == 0)
+ return rld_map.map;
+ else
+ break;
+ }
+#endif /* DT_MIPS_RLD_MAP */
+
+ if (dyn->d_tag == DT_DEBUG && map == -1)
+ map = dyn->d_un.d_val;
+
+ if (dyn->d_tag == DT_NULL)
+ break;
}
+
+ dynamic_memaddr += dyn_size;
+ }
+
+ return map;
+}
+
+/* Read one pointer from MEMADDR in the inferior. */
+
+static int
+read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
+{
+ int ret;
+
+ /* Go through a union so this works on either big or little endian
+ hosts, when the inferior's pointer size is smaller than the size
+ of CORE_ADDR. It is assumed the inferior's endianness is the
+ same of the superior's. */
+ union
+ {
+ CORE_ADDR core_addr;
+ unsigned int ui;
+ unsigned char uc;
+ } addr;
+
+ ret = linux_read_memory (memaddr, &addr.uc, ptr_size);
+ if (ret == 0)
+ {
+ if (ptr_size == sizeof (CORE_ADDR))
+ *ptr = addr.core_addr;
+ else if (ptr_size == sizeof (unsigned int))
+ *ptr = addr.ui;
+ else
+ gdb_assert_not_reached ("unhandled pointer size");
+ }
+ return ret;
+}
+
+struct link_map_offsets
+ {
+ /* Offset and size of r_debug.r_version. */
+ int r_version_offset;
+
+ /* Offset and size of r_debug.r_map. */
+ int r_map_offset;
+
+ /* Offset to l_addr field in struct link_map. */
+ int l_addr_offset;
+
+ /* Offset to l_name field in struct link_map. */
+ int l_name_offset;
+
+ /* Offset to l_ld field in struct link_map. */
+ int l_ld_offset;
+
+ /* Offset to l_next field in struct link_map. */
+ int l_next_offset;
+
+ /* Offset to l_prev field in struct link_map. */
+ int l_prev_offset;
+ };
+
+/* Construct qXfer:libraries-svr4:read reply. */
+
+static int
+linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
+ unsigned const char *writebuf,
+ CORE_ADDR offset, int len)
+{
+ char *document;
+ unsigned document_len;
+ struct process_info_private *const priv = current_process ()->private;
+ char filename[PATH_MAX];
+ int pid, is_elf64;
+
+ static const struct link_map_offsets lmo_32bit_offsets =
+ {
+ 0, /* r_version offset. */
+ 4, /* r_debug.r_map offset. */
+ 0, /* l_addr offset in link_map. */
+ 4, /* l_name offset in link_map. */
+ 8, /* l_ld offset in link_map. */
+ 12, /* l_next offset in link_map. */
+ 16 /* l_prev offset in link_map. */
+ };
+
+ static const struct link_map_offsets lmo_64bit_offsets =
+ {
+ 0, /* r_version offset. */
+ 8, /* r_debug.r_map offset. */
+ 0, /* l_addr offset in link_map. */
+ 8, /* l_name offset in link_map. */
+ 16, /* l_ld offset in link_map. */
+ 24, /* l_next offset in link_map. */
+ 32 /* l_prev offset in link_map. */
+ };
+ const struct link_map_offsets *lmo;
+ unsigned int machine;
+
+ if (writebuf != NULL)
+ return -2;
+ if (readbuf == NULL)
+ return -1;
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
+ is_elf64 = elf_64_file_p (filename, &machine);
+ lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
+
+ if (priv->r_debug == 0)
+ priv->r_debug = get_r_debug (pid, is_elf64);
+
+ /* We failed to find DT_DEBUG. Such situation will not change for this
+ inferior - do not retry it. Report it to GDB as E01, see for the reasons
+ at the GDB solib-svr4.c side. */
+ if (priv->r_debug == (CORE_ADDR) -1)
+ return -1;
+
+ if (priv->r_debug == 0)
+ {
+ document = xstrdup ("<library-list-svr4 version=\"1.0\"/>\n");
}
+ else
+ {
+ int allocated = 1024;
+ char *p;
+ const int ptr_size = is_elf64 ? 8 : 4;
+ CORE_ADDR lm_addr, lm_prev, l_name, l_addr, l_ld, l_next, l_prev;
+ int r_version, header_done = 0;
+
+ document = xmalloc (allocated);
+ strcpy (document, "<library-list-svr4 version=\"1.0\"");
+ p = document + strlen (document);
+
+ r_version = 0;
+ if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
+ (unsigned char *) &r_version,
+ sizeof (r_version)) != 0
+ || r_version != 1)
+ {
+ warning ("unexpected r_debug version %d", r_version);
+ goto done;
+ }
+
+ if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
+ &lm_addr, ptr_size) != 0)
+ {
+ warning ("unable to read r_map from 0x%lx",
+ (long) priv->r_debug + lmo->r_map_offset);
+ goto done;
+ }
+
+ lm_prev = 0;
+ while (read_one_ptr (lm_addr + lmo->l_name_offset,
+ &l_name, ptr_size) == 0
+ && read_one_ptr (lm_addr + lmo->l_addr_offset,
+ &l_addr, ptr_size) == 0
+ && read_one_ptr (lm_addr + lmo->l_ld_offset,
+ &l_ld, ptr_size) == 0
+ && read_one_ptr (lm_addr + lmo->l_prev_offset,
+ &l_prev, ptr_size) == 0
+ && read_one_ptr (lm_addr + lmo->l_next_offset,
+ &l_next, ptr_size) == 0)
+ {
+ unsigned char libname[PATH_MAX];
+
+ if (lm_prev != l_prev)
+ {
+ warning ("Corrupted shared library list: 0x%lx != 0x%lx",
+ (long) lm_prev, (long) l_prev);
+ break;
+ }
+
+ /* Not checking for error because reading may stop before
+ we've got PATH_MAX worth of characters. */
+ libname[0] = '\0';
+ linux_read_memory (l_name, libname, sizeof (libname) - 1);
+ libname[sizeof (libname) - 1] = '\0';
+ if (libname[0] != '\0')
+ {
+ /* 6x the size for xml_escape_text below. */
+ size_t len = 6 * strlen ((char *) libname);
+ char *name;
+
+ if (!header_done)
+ {
+ /* Terminate `<library-list-svr4'. */
+ *p++ = '>';
+ header_done = 1;
+ }
+
+ while (allocated < p - document + len + 200)
+ {
+ /* Expand to guarantee sufficient storage. */
+ uintptr_t document_len = p - document;
+
+ document = xrealloc (document, 2 * allocated);
+ allocated *= 2;
+ p = document + document_len;
+ }
+
+ name = xml_escape_text ((char *) libname);
+ p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
+ "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
+ name, (unsigned long) lm_addr,
+ (unsigned long) l_addr, (unsigned long) l_ld);
+ free (name);
+ }
+ else if (lm_prev == 0)
+ {
+ sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
+ p = p + strlen (p);
+ }
- p = strchr (content, '(');
- p = strchr (p, ')') + 2; /* skip ")" and a whitespace. */
+ if (l_next == 0)
+ break;
- p = strtok_r (p, " ", &ts);
- for (i = 0; i != 36; ++i)
- p = strtok_r (NULL, " ", &ts);
+ lm_prev = lm_addr;
+ lm_addr = l_next;
+ }
+ done:
+ if (!header_done)
+ {
+ /* Empty list; terminate `<library-list-svr4'. */
+ strcpy (p, "/>");
+ }
+ else
+ strcpy (p, "</library-list-svr4>");
+ }
- if (sscanf (p, "%d", &core) == 0)
- core = -1;
+ document_len = strlen (document);
+ if (offset < document_len)
+ document_len -= offset;
+ else
+ document_len = 0;
+ if (len > document_len)
+ len = document_len;
- free (content);
- fclose (f);
+ memcpy (readbuf, document + offset, len);
+ xfree (document);
- return core;
+ return len;
}
static struct target_ops linux_target_ops = {
linux_attach,
linux_kill,
linux_detach,
+ linux_mourn,
linux_join,
linux_thread_alive,
linux_resume,
linux_wait,
linux_fetch_registers,
linux_store_registers,
+ linux_prepare_to_access_memory,
+ linux_done_accessing_memory,
linux_read_memory,
linux_write_memory,
linux_look_up_symbols,
#else
NULL,
#endif
- linux_core_of_thread
+ linux_common_core_of_thread,
+ linux_read_loadmap,
+ linux_process_qsupported,
+ linux_supports_tracepoints,
+ linux_read_pc,
+ linux_write_pc,
+ linux_thread_stopped,
+ NULL,
+ linux_pause_all,
+ linux_unpause_all,
+ linux_cancel_breakpoints,
+ linux_stabilize_threads,
+ linux_install_fast_tracepoint_jump_pad,
+ linux_emit_ops,
+ linux_supports_disable_randomization,
+ linux_get_min_fast_tracepoint_insn_len,
+ linux_qxfer_libraries_svr4,
+ linux_supports_agent,
};
static void
{
/* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
to find what the cancel signal actually is. */
-#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
+#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN+1, SIG_IGN);
#endif
}
projects / deliverable / binutils-gdb.git / blobdiff