/* 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 Free Software Foundation, Inc.
+ 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
This file is part of GDB.
#include <pwd.h>
#include <sys/types.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
+ gdb_proc_service.h then including it will likely introduce a duplicate
+ definition of elf_fpregset_t. */
+#include <elf.h>
+#endif
+
+#ifndef SPUFS_MAGIC
+#define SPUFS_MAGIC 0x23c9b64e
+#endif
#ifndef PTRACE_GETSIGINFO
# define PTRACE_GETSIGINFO 0x4202
#define __WALL 0x40000000 /* Wait for any child. */
#endif
+#ifndef W_STOPCODE
+#define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
+#endif
+
#ifdef __UCLIBC__
#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
#define HAS_NOMMU
representation of the thread ID.
``all_lwps'' is keyed by the process ID - which on Linux is (presently)
- the same as the LWP ID. */
+ the same as the LWP ID.
+
+ ``all_processes'' is keyed by the "overall process ID", which
+ GNU/Linux calls tgid, "thread group ID". */
struct inferior_list all_lwps;
/* FIXME make into a target method? */
int using_threads = 1;
-static int thread_db_active;
-static int must_set_ptrace_flags;
-
-/* This flag is true iff we've just created or attached to a new inferior
- but it has not stopped yet. As soon as it does, we need to call the
- low target's arch_setup callback. */
+/* 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
+ the first inferior avoids reinializing the architecture on every
+ inferior, and avoids messing with the register caches of the
+ already running inferiors. NOTE: this assumes all inferiors under
+ control of gdbserver have the same architecture. */
static int new_inferior;
-static void linux_resume_one_lwp (struct inferior_list_entry *entry,
+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);
+static void linux_resume (struct thread_resume *resume_info, size_t n);
static void stop_all_lwps (void);
-static int linux_wait_for_event (struct thread_info *child);
-static int check_removed_breakpoint (struct lwp_info *event_child);
-static void *add_lwp (unsigned long pid);
-static int my_waitpid (int pid, int *status, int flags);
+static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
+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 void unstop_all_lwps (struct lwp_info *except);
+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);
+
+/* 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);
+}
struct pending_signals
{
struct pending_signals *prev;
};
-#define PTRACE_ARG3_TYPE long
+#define PTRACE_ARG3_TYPE void *
+#define PTRACE_ARG4_TYPE void *
#define PTRACE_XFER_TYPE long
#ifdef HAVE_LINUX_REGSETS
static int num_regsets;
#endif
-#define pid_of(proc) ((proc)->head.id)
+/* The read/write ends of the pipe registered as waitable file in the
+ event loop. */
+static int linux_event_pipe[2] = { -1, -1 };
+
+/* 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 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)
+{
+ 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);
+}
+
+/* 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)
+{
+ Elf64_Ehdr header;
+ int fd;
+
+ fd = open (file, O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ if (read (fd, &header, sizeof (header)) != sizeof (header))
+ {
+ close (fd);
+ return 0;
+ }
+ close (fd);
+
+ return elf_64_header_p (&header);
+}
+
+static void
+delete_lwp (struct lwp_info *lwp)
+{
+ remove_thread (get_lwp_thread (lwp));
+ remove_inferior (&all_lwps, &lwp->head);
+ free (lwp->arch_private);
+ free (lwp);
+}
+
+/* Add a process to the common process list, and set its private
+ data. */
+
+static struct process_info *
+linux_add_process (int pid, int attached)
+{
+ struct process_info *proc;
+
+ /* Is this the first process? If so, then set the arch. */
+ if (all_processes.head == NULL)
+ new_inferior = 1;
+
+ proc = add_process (pid, attached);
+ proc->private = xcalloc (1, sizeof (*proc->private));
+
+ if (the_low_target.new_process != NULL)
+ proc->private->arch_private = the_low_target.new_process ();
+
+ return proc;
+}
+
+/* Wrapper function for waitpid which handles EINTR, and emulates
+ __WALL for systems where that is not available. */
+
+static int
+my_waitpid (int pid, int *status, int flags)
+{
+ int ret, out_errno;
+
+ if (debug_threads)
+ fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
+
+ if (flags & __WALL)
+ {
+ sigset_t block_mask, org_mask, wake_mask;
+ int wnohang;
+
+ wnohang = (flags & WNOHANG) != 0;
+ flags &= ~(__WALL | __WCLONE);
+ flags |= WNOHANG;
+
+ /* Block all signals while here. This avoids knowing about
+ LinuxThread's signals. */
+ sigfillset (&block_mask);
+ sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
+
+ /* ... except during the sigsuspend below. */
+ sigemptyset (&wake_mask);
+
+ while (1)
+ {
+ /* Since all signals are blocked, there's no need to check
+ for EINTR here. */
+ ret = waitpid (pid, status, flags);
+ out_errno = errno;
+
+ if (ret == -1 && out_errno != ECHILD)
+ break;
+ else if (ret > 0)
+ break;
+
+ if (flags & __WCLONE)
+ {
+ /* We've tried both flavors now. If WNOHANG is set,
+ there's nothing else to do, just bail out. */
+ if (wnohang)
+ break;
+
+ if (debug_threads)
+ fprintf (stderr, "blocking\n");
-/* FIXME: Delete eventually. */
-#define inferior_pid (pid_of (get_thread_lwp (current_inferior)))
+ /* Block waiting for signals. */
+ sigsuspend (&wake_mask);
+ }
+
+ flags ^= __WCLONE;
+ }
+
+ sigprocmask (SIG_SETMASK, &org_mask, NULL);
+ }
+ else
+ {
+ do
+ ret = waitpid (pid, status, flags);
+ while (ret == -1 && errno == EINTR);
+ out_errno = errno;
+ }
+
+ if (debug_threads)
+ fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
+ pid, flags, status ? *status : -1, ret);
+
+ errno = out_errno;
+ return ret;
+}
+
+/* Handle a GNU/Linux extended wait response. If we see a clone
+ event, we need to add the new LWP to our list (and not report the
+ trap to higher layers). */
static void
handle_extended_wait (struct lwp_info *event_child, int wstat)
if (event == PTRACE_EVENT_CLONE)
{
+ ptid_t ptid;
unsigned long new_pid;
int ret, status = W_STOPCODE (SIGSTOP);
- ptrace (PTRACE_GETEVENTMSG, inferior_pid, 0, &new_pid);
+ 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))
warning ("wait returned unexpected status 0x%x", status);
}
- ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE);
+ ptrace (PTRACE_SETOPTIONS, new_pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
- new_lwp = (struct lwp_info *) add_lwp (new_pid);
- add_thread (new_pid, new_lwp, new_pid);
- new_thread_notify (thread_id_to_gdb_id (new_lwp->lwpid));
+ ptid = ptid_build (pid_of (event_child), new_pid, 0);
+ new_lwp = (struct lwp_info *) add_lwp (ptid);
+ add_thread (ptid, new_lwp);
+
+ /* Either we're going to immediately resume the new thread
+ or leave it stopped. linux_resume_one_lwp is a nop if it
+ thinks the thread is currently running, so set this first
+ before calling linux_resume_one_lwp. */
+ new_lwp->stopped = 1;
/* Normally we will get the pending SIGSTOP. But in some cases
we might get another signal delivered to the group first.
if (WSTOPSIG (status) == SIGSTOP)
{
if (stopping_threads)
- new_lwp->stopped = 1;
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
else
- ptrace (PTRACE_CONT, new_pid, 0, 0);
+ linux_resume_one_lwp (new_lwp, 0, 0, NULL);
}
else
{
new_lwp->stop_expected = 1;
+
if (stopping_threads)
{
- new_lwp->stopped = 1;
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
new_lwp->status_pending_p = 1;
new_lwp->status_pending = status;
}
else
/* Pass the signal on. This is what GDB does - except
shouldn't we really report it instead? */
- ptrace (PTRACE_CONT, new_pid, 0, WSTOPSIG (status));
+ linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
}
/* Always resume the current thread. If we are stopping
threads, it will have a pending SIGSTOP; we may as well
collect it now. */
- linux_resume_one_lwp (&event_child->head,
- event_child->stepping, 0, NULL);
+ linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
}
}
-/* 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)
{
- CORE_ADDR stop_pc = (*the_low_target.get_pc) ();
+ CORE_ADDR stop_pc;
- if (get_thread_lwp (current_inferior)->stepping)
- return stop_pc;
- else
- return stop_pc - the_low_target.decr_pc_after_break;
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ stop_pc = get_pc (lwp);
+
+ 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)
+ fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
+
+ return stop_pc;
}
static void *
-add_lwp (unsigned long pid)
+add_lwp (ptid_t ptid)
{
struct lwp_info *lwp;
lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
memset (lwp, 0, sizeof (*lwp));
- lwp->head.id = pid;
- lwp->lwpid = pid;
+ lwp->head.id = ptid;
+
+ if (the_low_target.new_thread != NULL)
+ lwp->arch_private = the_low_target.new_thread ();
add_inferior_to_list (&all_lwps, &lwp->head);
static int
linux_create_inferior (char *program, char **allargs)
{
- void *new_lwp;
+ struct lwp_info *new_lwp;
int pid;
+ ptid_t ptid;
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
pid = vfork ();
{
ptrace (PTRACE_TRACEME, 0, 0, 0);
+#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN + 1, SIG_DFL);
+#endif
setpgid (0, 0);
_exit (0177);
}
- new_lwp = add_lwp (pid);
- add_thread (pid, new_lwp, pid);
- must_set_ptrace_flags = 1;
- new_inferior = 1;
+ linux_add_process (pid, 0);
+
+ ptid = ptid_build (pid, pid, 0);
+ new_lwp = add_lwp (ptid);
+ add_thread (ptid, new_lwp);
+ new_lwp->must_set_ptrace_flags = 1;
return pid;
}
/* Attach to an inferior process. */
-void
-linux_attach_lwp (unsigned long pid)
+static void
+linux_attach_lwp_1 (unsigned long lwpid, int initial)
{
+ ptid_t ptid;
struct lwp_info *new_lwp;
- if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
+ if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
{
- if (all_threads.head != NULL)
+ if (!initial)
{
/* If we fail to attach to an LWP, just warn. */
- fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", pid,
+ fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
strerror (errno), errno);
fflush (stderr);
return;
}
else
/* If we fail to attach to a process, report an error. */
- error ("Cannot attach to process %ld: %s (%d)\n", pid,
+ error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
strerror (errno), errno);
}
- /* FIXME: This intermittently fails.
- We need to wait for SIGSTOP first. */
- ptrace (PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACECLONE);
+ if (initial)
+ /* NOTE/FIXME: This lwp might have not been the tgid. */
+ ptid = ptid_build (lwpid, lwpid, 0);
+ else
+ {
+ /* Note that extracting the pid from the current inferior is
+ safe, since we're always called in the context of the same
+ process as this new thread. */
+ int pid = pid_of (get_thread_lwp (current_inferior));
+ ptid = ptid_build (pid, lwpid, 0);
+ }
+
+ new_lwp = (struct lwp_info *) add_lwp (ptid);
+ add_thread (ptid, new_lwp);
- new_lwp = (struct lwp_info *) add_lwp (pid);
- add_thread (pid, new_lwp, pid);
- new_thread_notify (thread_id_to_gdb_id (new_lwp->lwpid));
+ /* We need to wait for SIGSTOP before being able to make the next
+ ptrace call on this LWP. */
+ new_lwp->must_set_ptrace_flags = 1;
/* 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.
+ This is handled by having linux_attach set last_resume_kind ==
+ resume_stop after we return.
??? If the process already has several threads we leave the other
threads running.
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 (unsigned long lwpid)
+{
+ linux_attach_lwp_1 (lwpid, 0);
}
int
linux_attach (unsigned long pid)
{
- struct lwp_info *lwp;
+ linux_attach_lwp_1 (pid, 1);
+ linux_add_process (pid, 1);
+
+ if (!non_stop)
+ {
+ struct thread_info *thread;
- linux_attach_lwp (pid);
+ /* 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;
+ }
- /* 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, pid);
- lwp->stop_expected = 0;
+ return 0;
+}
+
+struct counter
+{
+ int pid;
+ int count;
+};
+
+static int
+second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
+{
+ struct counter *counter = args;
- new_inferior = 1;
+ if (ptid_get_pid (entry->id) == counter->pid)
+ {
+ if (++counter->count > 1)
+ return 1;
+ }
return 0;
}
-/* Kill the inferior process. Make us have no inferior. */
+static int
+last_thread_of_process_p (struct thread_info *thread)
+{
+ ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
+ int pid = ptid_get_pid (ptid);
+ struct counter counter = { pid , 0 };
+
+ return (find_inferior (&all_threads,
+ second_thread_of_pid_p, &counter) == NULL);
+}
+
+/* Kill the inferior lwp. */
-static void
-linux_kill_one_lwp (struct inferior_list_entry *entry)
+static int
+linux_kill_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 wstat;
+ int pid = * (int *) args;
+
+ if (ptid_get_pid (entry->id) != pid)
+ return 0;
/* We avoid killing the first thread here, because of a Linux kernel (at
least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
the children get a chance to be reaped, it will remain a zombie
forever. */
- if (entry == all_threads.head)
- return;
+
+ if (lwpid_of (lwp) == pid)
+ {
+ if (debug_threads)
+ fprintf (stderr, "lkop: is last of process %s\n",
+ target_pid_to_str (entry->id));
+ 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, pid_of (lwp), 0, 0);
+ ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
/* Make sure it died. The loop is most likely unnecessary. */
- wstat = linux_wait_for_event (thread);
- } while (WIFSTOPPED (wstat));
+ pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
+ } while (pid > 0 && WIFSTOPPED (wstat));
+
+ return 0;
}
-static void
-linux_kill (void)
+static int
+linux_kill (int pid)
{
- struct thread_info *thread = (struct thread_info *) all_threads.head;
+ struct process_info *process;
struct lwp_info *lwp;
+ struct thread_info *thread;
int wstat;
+ int lwpid;
- if (thread == NULL)
- return;
+ process = find_process_pid (pid);
+ if (process == NULL)
+ return -1;
- for_each_inferior (&all_threads, linux_kill_one_lwp);
+ find_inferior (&all_threads, linux_kill_one_lwp, &pid);
/* See the comment in linux_kill_one_lwp. We did not kill the first
thread in the list, so do so now. */
- lwp = get_thread_lwp (thread);
+ 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 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, pid_of (lwp), 0, 0);
+ ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
/* Make sure it died. The loop is most likely unnecessary. */
- wstat = linux_wait_for_event (thread);
- } while (WIFSTOPPED (wstat));
+ lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
+ } while (lwpid > 0 && WIFSTOPPED (wstat));
- clear_inferiors ();
- free (all_lwps.head);
- all_lwps.head = all_lwps.tail = NULL;
+ delete_lwp (lwp);
+
+ the_target->mourn (process);
+ return 0;
}
-static void
-linux_detach_one_lwp (struct inferior_list_entry *entry)
+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;
+
+ if (ptid_get_pid (entry->id) != pid)
+ return 0;
- /* Make sure the process isn't stopped at a breakpoint that's
- no longer there. */
- check_removed_breakpoint (lwp);
+ /* If we're detaching from a running inferior, make sure it is
+ stopped first, as PTRACE_DETACH will not work otherwise. */
+ if (!lwp->stopped)
+ {
+ int lwpid = lwpid_of (lwp);
+
+ stopping_threads = 1;
+ send_sigstop (&lwp->head);
+
+ /* 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 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;
+ }
/* 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 (lwp->stop_expected)
{
+ int wstat;
/* Clear stop_expected, so that the SIGSTOP will be reported. */
lwp->stop_expected = 0;
if (lwp->stopped)
- linux_resume_one_lwp (&lwp->head, 0, 0, NULL);
- linux_wait_for_event (thread);
+ 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. */
get_lwp_thread (lwp));
/* Finally, let it resume. */
- ptrace (PTRACE_DETACH, pid_of (lwp), 0, 0);
+ ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
+
+ delete_lwp (lwp);
+ return 0;
}
static int
-linux_detach (void)
+any_thread_of (struct inferior_list_entry *entry, void *args)
{
+ int *pid_p = args;
+
+ if (ptid_get_pid (entry->id) == *pid_p)
+ return 1;
+
+ return 0;
+}
+
+static int
+linux_detach (int pid)
+{
+ struct process_info *process;
+
+ process = find_process_pid (pid);
+ if (process == NULL)
+ return -1;
+
+#ifdef USE_THREAD_DB
+ thread_db_detach (process);
+#endif
+
+ current_inferior =
+ (struct thread_info *) find_inferior (&all_threads, any_thread_of, &pid);
+
delete_all_breakpoints ();
- for_each_inferior (&all_threads, linux_detach_one_lwp);
- clear_inferiors ();
- free (all_lwps.head);
- all_lwps.head = all_lwps.tail = NULL;
+ find_inferior (&all_threads, linux_detach_one_lwp, &pid);
+
+ the_target->mourn (process);
return 0;
}
static void
-linux_join (void)
+linux_mourn (struct process_info *process)
+{
+ struct process_info_private *priv;
+
+#ifdef USE_THREAD_DB
+ thread_db_mourn (process);
+#endif
+
+ /* Freeing all private data. */
+ priv = process->private;
+ free (priv->arch_private);
+ free (priv);
+ process->private = NULL;
+}
+
+static void
+linux_join (int pid)
{
- extern unsigned long signal_pid;
int status, ret;
+ struct process_info *process;
+
+ process = find_process_pid (pid);
+ if (process == NULL)
+ return;
do {
- ret = waitpid (signal_pid, &status, 0);
+ ret = my_waitpid (pid, &status, 0);
if (WIFEXITED (status) || WIFSIGNALED (status))
break;
} while (ret != -1 || errno != ECHILD);
/* Return nonzero if the given thread is still alive. */
static int
-linux_thread_alive (unsigned long lwpid)
+linux_thread_alive (ptid_t ptid)
{
- if (find_inferior_id (&all_threads, lwpid) != NULL)
- return 1;
+ struct lwp_info *lwp = find_lwp_pid (ptid);
+
+ /* We assume we always know if a thread exits. If a whole process
+ exited but we still haven't been able to report it to GDB, we'll
+ hold on to the last lwp of the dead process. */
+ if (lwp != NULL)
+ return !lwp->dead;
else
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. */
+/* Return 1 if this lwp has an interesting status pending. */
static int
-check_removed_breakpoint (struct lwp_info *event_child)
+status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
{
- CORE_ADDR stop_pc;
- struct thread_info *saved_inferior;
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ ptid_t ptid = * (ptid_t *) arg;
+ struct thread_info *thread = get_lwp_thread (lwp);
- if (event_child->pending_is_breakpoint == 0)
+ /* Check if we're only interested in events from a specific process
+ or its lwps. */
+ if (!ptid_equal (minus_one_ptid, ptid)
+ && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
return 0;
- if (debug_threads)
- fprintf (stderr, "Checking for breakpoint in lwp %ld.\n",
- event_child->lwpid);
-
- saved_inferior = current_inferior;
- current_inferior = get_lwp_thread (event_child);
-
- stop_pc = get_stop_pc ();
+ thread = get_lwp_thread (lwp);
- /* 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);
+ /* 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_STOPPED)
+ return 0;
- event_child->pending_is_breakpoint = 0;
- current_inferior = saved_inferior;
- return 0;
- }
+ return lwp->status_pending_p;
+}
- /* 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;
- }
+static int
+same_lwp (struct inferior_list_entry *entry, void *data)
+{
+ ptid_t ptid = *(ptid_t *) data;
+ int lwp;
- if (debug_threads)
- fprintf (stderr, "Removed breakpoint.\n");
+ if (ptid_get_lwp (ptid) != 0)
+ lwp = ptid_get_lwp (ptid);
+ else
+ lwp = ptid_get_pid (ptid);
- /* 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)
- (*the_low_target.set_pc) (stop_pc);
+ if (ptid_get_lwp (entry->id) == lwp)
+ return 1;
- /* We consumed the pending SIGTRAP. */
- event_child->pending_is_breakpoint = 0;
- event_child->status_pending_p = 0;
- event_child->status_pending = 0;
+ return 0;
+}
- current_inferior = saved_inferior;
- return 1;
+struct lwp_info *
+find_lwp_pid (ptid_t ptid)
+{
+ return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
}
-/* Return 1 if this lwp has an interesting status pending. This
- function may silently resume an inferior lwp. */
-static int
-status_pending_p (struct inferior_list_entry *entry, void *dummy)
+static struct lwp_info *
+linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
{
- struct lwp_info *lwp = (struct lwp_info *) entry;
+ int ret;
+ int to_wait_for = -1;
+ struct lwp_info *child = NULL;
- if (lwp->status_pending_p)
- 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->head, 0, 0, NULL);
- return 0;
- }
-
- return lwp->status_pending_p;
-}
+ if (debug_threads)
+ fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
-static void
-linux_wait_for_lwp (struct lwp_info **childp, int *wstatp)
-{
- int ret;
- int to_wait_for = -1;
+ if (ptid_equal (ptid, minus_one_ptid))
+ to_wait_for = -1; /* any child */
+ else
+ to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
- if (*childp != NULL)
- to_wait_for = (*childp)->lwpid;
+ options |= __WALL;
retry:
- while (1)
- {
- ret = waitpid (to_wait_for, wstatp, WNOHANG);
-
- if (ret == -1)
- {
- if (errno != ECHILD)
- perror_with_name ("waitpid");
- }
- else if (ret > 0)
- break;
-
- ret = waitpid (to_wait_for, wstatp, WNOHANG | __WCLONE);
- if (ret == -1)
- {
- if (errno != ECHILD)
- perror_with_name ("waitpid (WCLONE)");
- }
- else if (ret > 0)
- break;
-
- usleep (1000);
- }
+ ret = my_waitpid (to_wait_for, wstatp, options);
+ if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
+ return NULL;
+ else if (ret == -1)
+ perror_with_name ("waitpid");
if (debug_threads
&& (!WIFSTOPPED (*wstatp)
&& WSTOPSIG (*wstatp) != 33)))
fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
- if (to_wait_for == -1)
- *childp = (struct lwp_info *) find_inferior_id (&all_lwps, ret);
+ child = find_lwp_pid (pid_to_ptid (ret));
/* If we didn't find a process, one of two things presumably happened:
- A process we started and then detached from has exited. Ignore it.
- A process we are controlling has forked and the new child's stop
was reported to us by the kernel. Save its PID. */
- if (*childp == NULL && WIFSTOPPED (*wstatp))
+ if (child == NULL && WIFSTOPPED (*wstatp))
{
add_pid_to_list (&stopped_pids, ret);
goto retry;
}
- else if (*childp == NULL)
+ else if (child == NULL)
goto retry;
- (*childp)->stopped = 1;
- (*childp)->pending_is_breakpoint = 0;
+ child->stopped = 1;
- (*childp)->last_status = *wstatp;
+ child->last_status = *wstatp;
/* Architecture-specific setup after inferior is running.
This needs to happen after we have attached to the inferior
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))
+ && WIFSTOPPED (*wstatp)
+ && the_low_target.get_pc != NULL)
{
struct thread_info *saved_inferior = current_inferior;
- current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, (*childp)->lwpid);
- /* For testing only; i386_stop_pc prints out a diagnostic. */
- if (the_low_target.get_pc != NULL)
- get_stop_pc ();
+ struct regcache *regcache;
+ CORE_ADDR pc;
+
+ 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;
}
+/* 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 (struct thread_info *child)
+handle_tracepoints (struct lwp_info *lwp)
{
- CORE_ADDR stop_pc;
- struct lwp_info *event_child;
- int wstat;
- int bp_status;
+ struct thread_info *tinfo = get_lwp_thread (lwp);
+ int tpoint_related_event = 0;
+
+ /* 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.) */
+
+ /* Do any necessary step collect actions. */
+ tpoint_related_event |= tracepoint_finished_step (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);
- /* Check for a process 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 (child == NULL)
+ if (tpoint_related_event)
+ {
+ if (debug_threads)
+ fprintf (stderr, "got a tracepoint event\n");
+ return 1;
+ }
+
+ return 0;
+}
+
+/* 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)));
+
+ /* Back up the PC if necessary. */
+ if (the_low_target.decr_pc_after_break)
+ {
+ struct regcache *regcache
+ = get_thread_regcache (current_inferior, 1);
+ (*the_low_target.set_pc) (regcache, lwp->stop_pc);
+ }
+
+ 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)));
+ }
+
+ 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_1 (ptid_t ptid, int *wstat, int options)
+{
+ struct lwp_info *event_child, *requested_child;
+
+ event_child = NULL;
+ requested_child = NULL;
+
+ /* Check for a lwp with a pending status. */
+
+ 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, NULL);
+ find_inferior (&all_lwps, status_pending_p_callback, &ptid);
if (debug_threads && event_child)
- fprintf (stderr, "Got a pending child %ld\n", event_child->lwpid);
+ fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
}
else
{
- event_child = get_thread_lwp (child);
- if (event_child->status_pending_p
- && check_removed_breakpoint (event_child))
- event_child = NULL;
+ requested_child = find_lwp_pid (ptid);
+
+ if (requested_child->status_pending_p)
+ event_child = requested_child;
}
if (event_child != NULL)
{
- if (event_child->status_pending_p)
- {
- if (debug_threads)
- fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
- event_child->lwpid, 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 wstat;
- }
+ 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);
}
/* We only enter this loop if no process has a pending wait status. Thus
events. */
while (1)
{
- if (child == NULL)
- event_child = NULL;
- else
- event_child = get_thread_lwp (child);
+ event_child = linux_wait_for_lwp (ptid, wstat, options);
- linux_wait_for_lwp (&event_child, &wstat);
+ if ((options & WNOHANG) && event_child == NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr, "WNOHANG set, no event found\n");
+ return 0;
+ }
if (event_child == NULL)
error ("event from unknown child");
- current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, event_child->lwpid);
+ current_inferior = get_lwp_thread (event_child);
/* Check for thread exit. */
- if (! WIFSTOPPED (wstat))
+ if (! WIFSTOPPED (*wstat))
{
if (debug_threads)
- fprintf (stderr, "LWP %ld exiting\n", event_child->head.id);
+ fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
/* If the last thread is exiting, just return. */
- if (all_threads.head == all_threads.tail)
- return wstat;
-
- dead_thread_notify (thread_id_to_gdb_id (event_child->lwpid));
+ 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);
+ }
- remove_inferior (&all_lwps, &event_child->head);
- free (event_child);
- remove_thread (current_inferior);
- current_inferior = (struct thread_info *) all_threads.head;
+ 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 (child != NULL)
- return wstat;
+ 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 (event_child);
+ delete_lwp (event_child);
+ return lwpid;
+ }
+
+ delete_lwp (event_child);
/* Wait for a more interesting event. */
continue;
}
- if (WIFSTOPPED (wstat)
- && WSTOPSIG (wstat) == SIGSTOP
- && event_child->stop_expected)
+ if (event_child->must_set_ptrace_flags)
{
- if (debug_threads)
- fprintf (stderr, "Expected stop.\n");
- event_child->stop_expected = 0;
- linux_resume_one_lwp (&event_child->head,
- event_child->stepping, 0, NULL);
- continue;
+ ptrace (PTRACE_SETOPTIONS, lwpid_of (event_child),
+ 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
+ event_child->must_set_ptrace_flags = 0;
}
- if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
- && wstat >> 16 != 0)
+ if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
+ && *wstat >> 16 != 0)
{
- handle_extended_wait (event_child, wstat);
+ handle_extended_wait (event_child, *wstat);
continue;
}
special handling to skip the signal handler. */
/* FIXME drow/2002-06-09: Get signal numbers from the inferior's
thread library? */
- if (WIFSTOPPED (wstat)
+ if (WIFSTOPPED (*wstat)
&& !event_child->stepping
&& (
-#ifdef USE_THREAD_DB
- (thread_db_active && (WSTOPSIG (wstat) == __SIGRTMIN
- || WSTOPSIG (wstat) == __SIGRTMIN + 1))
+#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))))
+ (pass_signals[target_signal_from_host (WSTOPSIG (*wstat))]
+ && !(WSTOPSIG (*wstat) == SIGSTOP
+ && event_child->stop_expected))))
{
siginfo_t info, *info_p;
if (debug_threads)
fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
- WSTOPSIG (wstat), event_child->head.id);
+ WSTOPSIG (*wstat), lwpid_of (event_child));
- if (ptrace (PTRACE_GETSIGINFO, event_child->lwpid, 0, &info) == 0)
+ if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
info_p = &info;
else
info_p = NULL;
- linux_resume_one_lwp (&event_child->head,
- event_child->stepping,
- WSTOPSIG (wstat), info_p);
+ linux_resume_one_lwp (event_child, event_child->stepping,
+ WSTOPSIG (*wstat), info_p);
continue;
}
- /* If this event was not handled above, and is not a SIGTRAP, report
- it. */
- if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP)
- return wstat;
-
- /* If this target does not support breakpoints, we simply report the
- SIGTRAP; it's of no concern to us. */
- if (the_low_target.get_pc == NULL)
- return wstat;
-
- stop_pc = get_stop_pc ();
-
- /* 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)
+ if (WIFSTOPPED (*wstat)
+ && WSTOPSIG (*wstat) == SIGSTOP
+ && event_child->stop_expected)
{
+ int should_stop;
+
if (debug_threads)
- fprintf (stderr, "Reinserted breakpoint.\n");
- reinsert_breakpoint (event_child->bp_reinsert);
- event_child->bp_reinsert = 0;
+ fprintf (stderr, "Expected stop.\n");
+ event_child->stop_expected = 0;
- /* Clear the single-stepping flag and SIGTRAP as we resume. */
- linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
- continue;
+ should_stop = (current_inferior->last_resume_kind == resume_stop
+ || stopping_threads);
+
+ if (!should_stop)
+ {
+ linux_resume_one_lwp (event_child,
+ event_child->stepping, 0, NULL);
+ continue;
+ }
}
- bp_status = check_breakpoints (stop_pc);
+ return lwpid_of (event_child);
+ }
+
+ /* NOTREACHED */
+ return 0;
+}
+
+static int
+linux_wait_for_event (ptid_t ptid, int *wstat, int options)
+{
+ ptid_t wait_ptid;
- if (bp_status != 0)
+ if (ptid_is_pid (ptid))
+ {
+ /* A request to wait for a specific tgid. This is not possible
+ with waitpid, so instead, we wait for any child, and leave
+ children we're not interested in right now with a pending
+ status to report later. */
+ wait_ptid = minus_one_ptid;
+ }
+ else
+ wait_ptid = ptid;
+
+ while (1)
+ {
+ int event_pid;
+
+ event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options);
+
+ if (event_pid > 0
+ && ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid)
{
- if (debug_threads)
- fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+ struct lwp_info *event_child = find_lwp_pid (pid_to_ptid (event_pid));
- /* 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. */
- if (bp_status == 2)
- /* No need to reinsert. */
- linux_resume_one_lwp (&event_child->head, 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->head, 1, 0, NULL);
- }
+ if (! WIFSTOPPED (*wstat))
+ mark_lwp_dead (event_child, *wstat);
else
{
- reinsert_breakpoint_by_bp
- (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
- linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
+ event_child->status_pending_p = 1;
+ event_child->status_pending = *wstat;
}
-
- continue;
}
+ else
+ return event_pid;
+ }
+}
+
+
+/* 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;
+}
+
+/* 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, "Hit a non-gdbserver breakpoint.\n");
-
- /* If we were single-stepping, we definitely want to report the
- SIGTRAP. The single-step operation has completed, so also
- clear the stepping flag; in general this does not matter,
- because the SIGTRAP will be reported to the client, which
- will give us a new action for this thread, but clear it for
- consistency anyway. It's safe to clear the stepping flag
- because the only consumer of get_stop_pc () after this point
- is check_removed_breakpoint, and pending_is_breakpoint is not
- set. It might be wiser to use a step_completed flag instead. */
- if (event_child->stepping)
- {
- event_child->stepping = 0;
- return wstat;
- }
+ 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. */
- /* 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))
- {
- event_child->pending_is_breakpoint = 1;
- event_child->pending_stop_pc = stop_pc;
- }
+ /* 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);
- return wstat;
+ event_lp = (struct lwp_info *) find_inferior (&all_lwps,
+ select_event_lwp_callback,
+ &random_selector);
}
- /* NOTREACHED */
- return 0;
+ if (event_lp != NULL)
+ {
+ /* Switch the event LWP. */
+ *orig_lp = event_lp;
+ }
+}
+
+/* Set this inferior LWP's state as "want-stopped". We won't resume
+ this LWP until the client gives us another action for it. */
+
+static void
+gdb_wants_lwp_stopped (struct inferior_list_entry *entry)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lwp);
+
+ /* Most threads are stopped implicitly (all-stop); tag that with
+ signal 0. The thread being explicitly reported stopped to the
+ client, gets it's status fixed up afterwards. */
+ thread->last_status.kind = TARGET_WAITKIND_STOPPED;
+ thread->last_status.value.sig = TARGET_SIGNAL_0;
+
+ thread->last_resume_kind = resume_stop;
+}
+
+/* Set all LWP's states as "want-stopped". */
+
+static void
+gdb_wants_all_stopped (void)
+{
+ for_each_inferior (&all_lwps, gdb_wants_lwp_stopped);
}
/* Wait for process, returns status. */
-static unsigned char
-linux_wait (char *status)
+static ptid_t
+linux_wait_1 (ptid_t ptid,
+ struct target_waitstatus *ourstatus, int target_options)
{
int w;
- struct thread_info *child = 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;
+ if (target_options & TARGET_WNOHANG)
+ options |= WNOHANG;
retry:
+ ourstatus->kind = TARGET_WAITKIND_IGNORE;
+
/* If we were only supposed to resume one thread, only wait for
that thread - if it's still alive. If it died, however - which
can happen if we're coming from the thread death case below -
then we need to make sure we restart the other threads. We could
pick a thread at random or restart all; restarting all is less
arbitrary. */
- if (cont_thread != 0 && cont_thread != -1)
+ if (!non_stop
+ && !ptid_equal (cont_thread, null_ptid)
+ && !ptid_equal (cont_thread, minus_one_ptid))
{
- child = (struct thread_info *) find_inferior_id (&all_threads,
- cont_thread);
+ struct thread_info *thread;
+
+ thread = (struct thread_info *) find_inferior_id (&all_threads,
+ cont_thread);
/* No stepping, no signal - unless one is pending already, of course. */
- if (child == NULL)
+ if (thread == NULL)
{
struct thread_resume resume_info;
- resume_info.thread = -1;
- resume_info.step = resume_info.sig = resume_info.leave_stopped = 0;
- linux_resume (&resume_info);
+ resume_info.thread = minus_one_ptid;
+ resume_info.kind = resume_continue;
+ resume_info.sig = 0;
+ linux_resume (&resume_info, 1);
}
+ else
+ ptid = cont_thread;
}
- w = linux_wait_for_event (child);
- stop_all_lwps ();
-
- if (must_set_ptrace_flags)
+ if (ptid_equal (step_over_bkpt, null_ptid))
+ pid = linux_wait_for_event (ptid, &w, options);
+ else
{
- ptrace (PTRACE_SETOPTIONS, inferior_pid, 0, PTRACE_O_TRACECLONE);
- must_set_ptrace_flags = 0;
+ 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;
+
+ 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
the last child exited. If this is not the last child, however,
Report the exit status of the last thread to exit. This matches
LinuxThreads' behavior. */
- if (all_threads.head == all_threads.tail)
+ if (last_thread_of_process_p (current_inferior))
{
- if (WIFEXITED (w))
- {
- fprintf (stderr, "\nChild exited with retcode = %x \n",
- WEXITSTATUS (w));
- *status = 'W';
- clear_inferiors ();
- free (all_lwps.head);
- all_lwps.head = all_lwps.tail = NULL;
- return WEXITSTATUS (w);
- }
- else if (!WIFSTOPPED (w))
+ if (WIFEXITED (w) || WIFSIGNALED (w))
{
- fprintf (stderr, "\nChild terminated with signal = %x \n",
- WTERMSIG (w));
- *status = 'X';
- clear_inferiors ();
- free (all_lwps.head);
- all_lwps.head = all_lwps.tail = NULL;
- return target_signal_from_host (WTERMSIG (w));
+ delete_lwp (event_child);
+
+ 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));
+ }
+ else
+ {
+ ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
+ ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
+
+ if (debug_threads)
+ fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
+
+ }
+
+ return pid_to_ptid (pid);
}
}
else
goto retry;
}
- *status = 'T';
- return target_signal_from_host (WSTOPSIG (w));
+ /* 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);
+
+ trace_event = 0;
+ }
+
+ /* We have all the data we need. Either report the event to GDB, or
+ resume threads and keep waiting for more. */
+
+ /* Check If GDB would be interested in this event. 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));
+
+ /* 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've finished stepping over a breakpoint. We've stopped 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");
+ 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)
+ {
+ /* In all-stop, stop all threads. */
+ stop_all_lwps ();
+
+ /* 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);
+ }
+ 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 (event_child);
+ }
+
+ ourstatus->kind = TARGET_WAITKIND_STOPPED;
+
+ /* Do this before the gdb_wants_all_stopped calls below, since they
+ always set last_resume_kind to resume_stop. */
+ 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;
+ }
+ 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. */
+ ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
+ }
+ else
+ {
+ ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
+ }
+
+ gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
+
+ if (!non_stop)
+ {
+ /* From GDB's perspective, all-stop mode always stops all
+ threads implicitly. Tag all threads as "want-stopped". */
+ gdb_wants_all_stopped ();
+ }
+ else
+ {
+ /* We're reporting this LWP as stopped. Update it's
+ "want-stopped" state to what the client wants, until it gets
+ a new resume action. */
+ gdb_wants_lwp_stopped (&event_child->head);
+ }
+
+ if (debug_threads)
+ fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
+ target_pid_to_str (ptid_of (event_child)),
+ ourstatus->kind,
+ ourstatus->value.sig);
+
+ get_lwp_thread (event_child)->last_status = *ourstatus;
+ return ptid_of (event_child);
+}
+
+/* Get rid of any pending event in the pipe. */
+static void
+async_file_flush (void)
+{
+ int ret;
+ char buf;
+
+ do
+ ret = read (linux_event_pipe[0], &buf, 1);
+ while (ret >= 0 || (ret == -1 && errno == EINTR));
+}
+
+/* Put something in the pipe, so the event loop wakes up. */
+static void
+async_file_mark (void)
+{
+ int ret;
+
+ async_file_flush ();
+
+ do
+ ret = write (linux_event_pipe[1], "+", 1);
+ while (ret == 0 || (ret == -1 && errno == EINTR));
+
+ /* Ignore EAGAIN. If the pipe is full, the event loop will already
+ be awakened anyway. */
}
-/* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
- thread groups are in use, we need to use tkill. */
+static ptid_t
+linux_wait (ptid_t ptid,
+ struct target_waitstatus *ourstatus, int target_options)
+{
+ ptid_t event_ptid;
+
+ if (debug_threads)
+ fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
+
+ /* Flush the async file first. */
+ if (target_is_async_p ())
+ async_file_flush ();
+
+ event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
+
+ /* If at least one stop was reported, there may be more. A single
+ SIGCHLD can signal more than one child stop. */
+ if (target_is_async_p ()
+ && (target_options & TARGET_WNOHANG) != 0
+ && !ptid_equal (event_ptid, null_ptid))
+ async_file_mark ();
+
+ return event_ptid;
+}
+
+/* Send a signal to an LWP. */
static int
kill_lwp (unsigned long lwpid, int signo)
{
- static int tkill_failed;
+ /* Use tkill, if possible, in case we are using nptl threads. If tkill
+ fails, then we are not using nptl threads and we should be using kill. */
- errno = 0;
+#ifdef __NR_tkill
+ {
+ static int tkill_failed;
-#ifdef SYS_tkill
- if (!tkill_failed)
- {
- int ret = syscall (SYS_tkill, lwpid, signo);
- if (errno != ENOSYS)
- return ret;
- errno = 0;
- tkill_failed = 1;
- }
+ if (!tkill_failed)
+ {
+ int ret;
+
+ errno = 0;
+ ret = syscall (__NR_tkill, lwpid, signo);
+ if (errno != ENOSYS)
+ return ret;
+ tkill_failed = 1;
+ }
+ }
#endif
return kill (lwpid, signo);
send_sigstop (struct inferior_list_entry *entry)
{
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
send another. */
if (lwp->stop_expected)
{
if (debug_threads)
- fprintf (stderr, "Have pending sigstop for lwp %ld\n",
- lwp->lwpid);
+ 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 %ld\n", lwp->head.id);
+ fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
+
+ lwp->stop_expected = 1;
+ kill_lwp (pid, SIGSTOP);
+}
+
+static void
+mark_lwp_dead (struct lwp_info *lwp, int wstat)
+{
+ /* It's dead, really. */
+ lwp->dead = 1;
- kill_lwp (lwp->head.id, SIGSTOP);
+ /* Store the exit status for later. */
+ lwp->status_pending_p = 1;
+ lwp->status_pending = wstat;
+
+ /* Prevent trying to stop it. */
+ lwp->stopped = 1;
+
+ /* No further stops are expected from a dead lwp. */
+ lwp->stop_expected = 0;
}
static void
wait_for_sigstop (struct inferior_list_entry *entry)
{
struct lwp_info *lwp = (struct lwp_info *) entry;
- struct thread_info *saved_inferior, *thread;
+ struct thread_info *saved_inferior;
int wstat;
- unsigned long saved_tid;
+ 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;
- saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
- thread = (struct thread_info *) find_inferior_id (&all_threads,
- lwp->lwpid);
- wstat = linux_wait_for_event (thread);
+ if (saved_inferior != NULL)
+ saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
+ else
+ saved_tid = null_ptid; /* avoid bogus unused warning */
+
+ ptid = lwp->head.id;
+
+ 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",
- lwp->lwpid, wstat);
- lwp->status_pending_p = 1;
- lwp->status_pending = wstat;
- lwp->stop_expected = 1;
+ fprintf (stderr, "LWP %ld stopped with signal %d\n",
+ lwpid_of (lwp), WSTOPSIG (wstat));
+
+ if (WSTOPSIG (wstat) != SIGSTOP)
+ {
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
+ lwpid_of (lwp), wstat);
+
+ lwp->status_pending_p = 1;
+ lwp->status_pending = wstat;
+ }
}
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
- if (linux_thread_alive (saved_tid))
+ 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");
- /* Set a valid thread as current. */
- set_desired_inferior (0);
+ 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);
+ }
}
}
If SIGNAL is nonzero, give it that signal. */
static void
-linux_resume_one_lwp (struct inferior_list_entry *entry,
+linux_resume_one_lwp (struct lwp_info *lwp,
int step, int signal, siginfo_t *info)
{
- struct lwp_info *lwp = (struct lwp_info *) entry;
struct thread_info *saved_inferior;
if (lwp->stopped == 0)
return;
+ /* 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. */
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 (debug_threads)
fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
- inferior_pid, step ? "step" : "continue", signal,
+ lwpid_of (lwp), step ? "step" : "continue", signal,
lwp->stop_expected ? "expected" : "not expected");
/* This bit needs some thinking about. If we get a signal that
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 (step == 0)
+ fprintf (stderr, "BAD - reinserting but not stepping.\n");
+
+ step = 1;
+ }
/* 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, " ");
- (*the_low_target.get_pc) ();
+ struct regcache *regcache = get_thread_regcache (current_inferior, 1);
+ CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
+ fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
}
/* If we have pending signals, consume one unless we are trying to reinsert
signal = (*p_sig)->signal;
if ((*p_sig)->info.si_signo != 0)
- ptrace (PTRACE_SETSIGINFO, lwp->lwpid, 0, &(*p_sig)->info);
+ ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
free (*p_sig);
*p_sig = NULL;
}
+ if (the_low_target.prepare_to_resume != NULL)
+ the_low_target.prepare_to_resume (lwp);
+
regcache_invalidate_one ((struct inferior_list_entry *)
get_lwp_thread (lwp));
errno = 0;
lwp->stopped = 0;
+ lwp->stopped_by_watchpoint = 0;
lwp->stepping = step;
- ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwp->lwpid, 0, signal);
+ ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ of coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG4_TYPE) (uintptr_t) signal);
current_inferior = saved_inferior;
if (errno)
}
}
-static struct thread_resume *resume_ptr;
+struct thread_resume_array
+{
+ struct thread_resume *resume;
+ size_t n;
+};
/* This function is called once per thread. We look up the thread
in RESUME_PTR, and mark the thread with a pointer to the appropriate
This algorithm is O(threads * resume elements), but resume elements
is small (and will remain small at least until GDB supports thread
suspension). */
-static void
-linux_set_resume_request (struct inferior_list_entry *entry)
+static int
+linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
{
struct lwp_info *lwp;
struct thread_info *thread;
int ndx;
+ struct thread_resume_array *r;
thread = (struct thread_info *) entry;
lwp = get_thread_lwp (thread);
+ r = arg;
+
+ for (ndx = 0; ndx < r->n; ndx++)
+ {
+ ptid_t ptid = r->resume[ndx].thread;
+ if (ptid_equal (ptid, minus_one_ptid)
+ || ptid_equal (ptid, entry->id)
+ || (ptid_is_pid (ptid)
+ && (ptid_get_pid (ptid) == pid_of (lwp)))
+ || (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;
+ return 0;
+ }
+ }
- ndx = 0;
- while (resume_ptr[ndx].thread != -1 && resume_ptr[ndx].thread != entry->id)
- ndx++;
+ /* No resume action for this thread. */
+ lwp->resume = NULL;
- lwp->resume = &resume_ptr[ndx];
+ 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. For threads which
- we aren't explicitly told otherwise, we preserve the stepping flag; this
- is used for stepping over gdbserver-placed breakpoints. */
-static void
-linux_continue_one_thread (struct inferior_list_entry *entry)
+/* Set *FLAG_P if this lwp has an interesting status pending. */
+static int
+resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
{
- struct lwp_info *lwp;
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ /* LWPs which will not be resumed are not interesting, because
+ we might not wait for them next time through linux_wait. */
+ if (lwp->resume == NULL)
+ return 0;
+
+ if (lwp->status_pending_p)
+ * (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;
+ }
+
+ 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)
+ {
+ 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))
+ {
+ /* Don't step over a breakpoint that GDB expects to hit
+ though. */
+ if (gdb_breakpoint_here (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;
- thread = (struct thread_info *) entry;
- lwp = get_thread_lwp (thread);
+ if (debug_threads)
+ fprintf (stderr,
+ "Starting step-over on LWP %ld. Stopping all threads\n",
+ lwpid_of (lwp));
- if (lwp->resume->leave_stopped)
- return;
+ stop_all_lwps ();
+
+ 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);
- if (lwp->resume->thread == -1)
- step = lwp->stepping || lwp->resume->step;
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ lwp->bp_reinsert = pc;
+ uninsert_breakpoints_at (pc);
+
+ if (can_hardware_single_step ())
+ {
+ step = 1;
+ }
else
- step = lwp->resume->step;
+ {
+ CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
+ set_reinsert_breakpoint (raddr);
+ step = 0;
+ }
+
+ current_inferior = saved_inferior;
- linux_resume_one_lwp (&lwp->head, step, lwp->resume->sig, NULL);
+ linux_resume_one_lwp (lwp, step, 0, NULL);
- lwp->resume = 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);
+
+ 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. We queue any needed
- signals, since we won't actually resume. We already have a pending event
- to report, so we don't need to preserve any step requests; they should
- be re-issued if necessary. */
+ stopped; and what signal, if any, it should be sent.
-static void
-linux_queue_one_thread (struct inferior_list_entry *entry)
+ For threads which we aren't explicitly told otherwise, we preserve
+ the stepping flag; this is used for stepping over gdbserver-placed
+ breakpoints.
+
+ If pending_flags was set in any thread, we queue any needed
+ signals, since we won't actually resume. We already have a pending
+ event to report, so we don't need to preserve any step requests;
+ they should be re-issued if necessary. */
+
+static int
+linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
{
struct lwp_info *lwp;
struct thread_info *thread;
+ int step;
+ int leave_all_stopped = * (int *) arg;
+ int leave_pending;
thread = (struct thread_info *) entry;
lwp = get_thread_lwp (thread);
- if (lwp->resume->leave_stopped)
- return;
+ if (lwp->resume == NULL)
+ return 0;
- /* If we have a new signal, enqueue the signal. */
- if (lwp->resume->sig != 0)
+ if (lwp->resume->kind == resume_stop)
{
- struct pending_signals *p_sig;
- p_sig = xmalloc (sizeof (*p_sig));
- p_sig->prev = lwp->pending_signals;
- p_sig->signal = lwp->resume->sig;
- memset (&p_sig->info, 0, sizeof (siginfo_t));
+ if (debug_threads)
+ fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
- /* If this is the same signal we were previously stopped by,
- make sure to queue its siginfo. We can ignore the return
- value of ptrace; if it fails, we'll skip
- PTRACE_SETSIGINFO. */
- if (WIFSTOPPED (lwp->last_status)
- && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
- ptrace (PTRACE_GETSIGINFO, lwp->lwpid, 0, &p_sig->info);
+ if (!lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
- lwp->pending_signals = p_sig;
+ /* Stop the thread, and wait for the event asynchronously,
+ through the event loop. */
+ send_sigstop (&lwp->head);
+ }
+ else
+ {
+ if (debug_threads)
+ 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. */
+ send_sigstop (&lwp->head);
+ }
+
+ /* For stop requests, we're done. */
+ lwp->resume = NULL;
+ thread->last_status.kind = TARGET_WAITKIND_IGNORE;
+ return 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 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 (!leave_pending)
+ {
+ if (debug_threads)
+ fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
+
+ step = (lwp->resume->kind == resume_step);
+ linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
+
+ /* If we have a new signal, enqueue the signal. */
+ if (lwp->resume->sig != 0)
+ {
+ struct pending_signals *p_sig;
+ p_sig = xmalloc (sizeof (*p_sig));
+ p_sig->prev = lwp->pending_signals;
+ p_sig->signal = lwp->resume->sig;
+ memset (&p_sig->info, 0, sizeof (siginfo_t));
+
+ /* If this is the same signal we were previously stopped by,
+ make sure to queue its siginfo. We can ignore the return
+ value of ptrace; if it fails, we'll skip
+ PTRACE_SETSIGINFO. */
+ if (WIFSTOPPED (lwp->last_status)
+ && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
+ ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
+
+ lwp->pending_signals = p_sig;
+ }
}
+ thread->last_status.kind = TARGET_WAITKIND_IGNORE;
lwp->resume = NULL;
+ return 0;
}
-/* Set DUMMY if this process has an interesting status pending. */
-static int
-resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
+static void
+linux_resume (struct thread_resume *resume_info, size_t n)
{
- struct lwp_info *lwp = (struct lwp_info *) entry;
+ 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);
- /* Processes which will not be resumed are not interesting, because
- we might not wait for them next time through linux_wait. */
- if (lwp->resume->leave_stopped)
- return 0;
+ 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");
+ }
- /* 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);
+ /* 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 void
+proceed_one_lwp (struct inferior_list_entry *entry)
+{
+ struct lwp_info *lwp;
+ struct thread_info *thread;
+ int step;
+
+ lwp = (struct lwp_info *) entry;
+
+ 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;
+ }
+
+ thread = get_lwp_thread (lwp);
+
+ if (thread->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr, " client wants LWP %ld stopped\n", lwpid_of (lwp));
+ return;
+ }
if (lwp->status_pending_p)
- * (int *) flag_p = 1;
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
+ lwpid_of (lwp));
+ return;
+ }
- return 0;
+ if (lwp->suspended)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
+ return;
+ }
+
+ step = thread->last_resume_kind == resume_step;
+ linux_resume_one_lwp (lwp, step, 0, NULL);
}
+/* 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
-linux_resume (struct thread_resume *resume_info)
+proceed_all_lwps (void)
{
- int pending_flag;
+ struct lwp_info *need_step_over;
+
+ /* 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. */
+
+ if (supports_breakpoints ())
+ {
+ need_step_over
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ need_step_over_p, NULL);
+
+ if (need_step_over != NULL)
+ {
+ 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;
+ }
+ }
- /* Yes, the use of a global here is rather ugly. */
- resume_ptr = resume_info;
+ if (debug_threads)
+ fprintf (stderr, "Proceeding, no step-over needed\n");
- for_each_inferior (&all_threads, linux_set_resume_request);
+ for_each_inferior (&all_lwps, proceed_one_lwp);
+}
- /* 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. */
- pending_flag = 0;
- find_inferior (&all_lwps, resume_status_pending_p, &pending_flag);
+/* 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. */
+static void
+unstop_all_lwps (struct lwp_info *except)
+{
if (debug_threads)
{
- if (pending_flag)
- fprintf (stderr, "Not resuming, pending status\n");
+ if (except)
+ fprintf (stderr,
+ "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
else
- fprintf (stderr, "Resuming, no pending status\n");
+ fprintf (stderr,
+ "unstopping all lwps\n");
}
- if (pending_flag)
- for_each_inferior (&all_threads, linux_queue_one_thread);
- else
- for_each_inferior (&all_threads, linux_continue_one_thread);
+ /* Make sure proceed_one_lwp doesn't try to resume this thread. */
+ if (except != NULL)
+ ++except->suspended;
+
+ for_each_inferior (&all_lwps, proceed_one_lwp);
+
+ if (except != NULL)
+ --except->suspended;
}
#ifdef HAVE_LINUX_USRREGS
/* Fetch one register. */
static void
-fetch_register (int regno)
+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;
regaddr = register_addr (regno);
if (regaddr == -1)
return;
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
& - sizeof (PTRACE_XFER_TYPE));
buf = alloca (size);
{
errno = 0;
*(PTRACE_XFER_TYPE *) (buf + i) =
- ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0);
+ 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)
- {
- /* 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;
- }
+ error ("reading register %d: %s", regno, strerror (errno));
}
if (the_low_target.supply_ptrace_register)
- the_low_target.supply_ptrace_register (regno, buf);
+ the_low_target.supply_ptrace_register (regcache, regno, buf);
else
- supply_register (regno, buf);
-
-error_exit:;
+ supply_register (regcache, regno, buf);
}
/* Fetch all registers, or just one, from the child process. */
static void
-usr_fetch_inferior_registers (int regno)
+usr_fetch_inferior_registers (struct regcache *regcache, int regno)
{
- if (regno == -1 || regno == 0)
+ if (regno == -1)
for (regno = 0; regno < the_low_target.num_regs; regno++)
- fetch_register (regno);
+ fetch_register (regcache, regno);
else
- fetch_register (regno);
+ fetch_register (regcache, regno);
}
/* 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 (int regno)
+usr_store_inferior_registers (struct regcache *regcache, int regno)
{
CORE_ADDR regaddr;
int i, size;
char *buf;
+ int pid;
if (regno >= 0)
{
memset (buf, 0, size);
if (the_low_target.collect_ptrace_register)
- the_low_target.collect_ptrace_register (regno, buf);
+ the_low_target.collect_ptrace_register (regcache, regno, buf);
else
- collect_register (regno, buf);
+ 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, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
- *(PTRACE_XFER_TYPE *) (buf + i));
+ 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
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;
- }
+ error ("writing register %d: %s", regno, strerror (errno));
}
regaddr += sizeof (PTRACE_XFER_TYPE);
}
}
else
for (regno = 0; regno < the_low_target.num_regs; regno++)
- usr_store_inferior_registers (regno);
+ usr_store_inferior_registers (regcache, regno);
}
#endif /* HAVE_LINUX_USRREGS */
#ifdef HAVE_LINUX_REGSETS
static int
-regsets_fetch_inferior_registers ()
+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, inferior_pid, 0, buf);
+ res = ptrace (regset->get_request, pid, nt_type, data);
#else
- res = ptrace (regset->get_request, inferior_pid, buf, 0);
+ res = ptrace (regset->get_request, pid, data, nt_type);
#endif
if (res < 0)
{
/* 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
{
char s[256];
- sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
- inferior_pid);
+ sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
+ pid);
perror (s);
}
}
else if (regset->type == GENERAL_REGS)
saw_general_regs = 1;
- regset->store_function (buf);
+ regset->store_function (regcache, buf);
regset ++;
+ free (buf);
}
if (saw_general_regs)
return 0;
}
static int
-regsets_store_inferior_registers ()
+regsets_store_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])
{
/* 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, inferior_pid, 0, buf);
+ res = ptrace (regset->get_request, pid, nt_type, data);
#else
- res = ptrace (regset->get_request, inferior_pid, buf, 0);
+ res = ptrace (regset->get_request, pid, &iov, data);
#endif
if (res == 0)
{
/* Then overlay our cached registers on that. */
- regset->fill_function (buf);
+ regset->fill_function (regcache, buf);
/* Only now do we write the register set. */
#ifndef __sparc__
- res = ptrace (regset->set_request, inferior_pid, 0, buf);
+ res = ptrace (regset->set_request, pid, nt_type, data);
#else
- res = ptrace (regset->set_request, inferior_pid, buf, 0);
+ res = ptrace (regset->set_request, pid, data, nt_type);
#endif
}
/* 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)
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
void
-linux_fetch_registers (int regno)
+linux_fetch_registers (struct regcache *regcache, int regno)
{
#ifdef HAVE_LINUX_REGSETS
- if (regsets_fetch_inferior_registers () == 0)
+ if (regsets_fetch_inferior_registers (regcache) == 0)
return;
#endif
#ifdef HAVE_LINUX_USRREGS
- usr_fetch_inferior_registers (regno);
+ usr_fetch_inferior_registers (regcache, regno);
#endif
}
void
-linux_store_registers (int regno)
+linux_store_registers (struct regcache *regcache, int regno)
{
#ifdef HAVE_LINUX_REGSETS
- if (regsets_store_inferior_registers () == 0)
+ if (regsets_store_inferior_registers (regcache) == 0)
return;
#endif
#ifdef HAVE_LINUX_USRREGS
- usr_store_inferior_registers (regno);
+ usr_store_inferior_registers (regcache, regno);
#endif
}
= (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
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))
{
/* We could keep this file open and cache it - possibly one per
thread. That requires some juggling, but is even faster. */
- sprintf (filename, "/proc/%ld/mem", inferior_pid);
+ sprintf (filename, "/proc/%d/mem", pid);
fd = open (filename, O_RDONLY | O_LARGEFILE);
if (fd == -1)
goto no_proc;
#ifdef HAVE_PREAD64
if (pread64 (fd, myaddr, len, memaddr) != len)
#else
- if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, memaddr, len) != len)
+ if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
#endif
{
close (fd);
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
{
errno = 0;
- buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
- (PTRACE_ARG3_TYPE) addr, 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;
}
return 0;
}
-/* 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
= (((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 pid = lwpid_of (get_thread_lwp (current_inferior));
if (debug_threads)
{
- fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr);
+ /* Dump up to four bytes. */
+ unsigned int val = * (unsigned int *) myaddr;
+ if (len == 1)
+ val = val & 0xff;
+ else if (len == 2)
+ val = val & 0xffff;
+ else if (len == 3)
+ val = val & 0xffffff;
+ fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
+ val, (long)memaddr);
}
/* Fill start and end extra bytes of buffer with existing memory data. */
- buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
- (PTRACE_ARG3_TYPE) addr, 0);
+ 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, inferior_pid,
- (PTRACE_ARG3_TYPE) (addr + (count - 1)
- * sizeof (PTRACE_XFER_TYPE)),
+ = ptrace (PTRACE_PEEKTEXT, 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) (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);
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
{
errno = 0;
- ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]);
+ ptrace (PTRACE_POKETEXT, 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) addr,
+ (PTRACE_ARG4_TYPE) buffer[i]);
if (errno)
return errno;
}
return 0;
}
+/* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
static int linux_supports_tracefork_flag;
/* Helper functions for linux_test_for_tracefork, called via clone (). */
{
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);
clone (linux_tracefork_grandchild, arg + STACK_SIZE,
CLONE_VM | SIGCHLD, NULL);
#endif
- _exit (0);
-}
-/* Wrapper function for waitpid which handles EINTR. */
-
-static int
-my_waitpid (int pid, int *status, int flags)
-{
- int ret;
- do
- {
- ret = waitpid (pid, status, flags);
- }
- while (ret == -1 && errno == EINTR);
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
- return ret;
+ _exit (0);
}
/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
{
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");
if (! WIFSTOPPED (status))
error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
- ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
+ ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
+ (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
if (ret != 0)
{
ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
}
while (WIFSTOPPED (status));
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
free (stack);
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
}
linux_look_up_symbols (void)
{
#ifdef USE_THREAD_DB
- if (thread_db_active)
+ struct process_info *proc = current_process ();
+
+ if (proc->private->thread_db != NULL)
return;
- thread_db_active = thread_db_init (!linux_supports_tracefork_flag);
+ /* 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
}
{
extern unsigned long signal_pid;
- if (cont_thread != 0 && cont_thread != -1)
+ if (!ptid_equal (cont_thread, null_ptid)
+ && !ptid_equal (cont_thread, minus_one_ptid))
{
struct lwp_info *lwp;
+ int lwpid;
lwp = get_thread_lwp (current_inferior);
- kill_lwp (lwp->lwpid, SIGINT);
+ lwpid = lwpid_of (lwp);
+ kill_lwp (lwpid, SIGINT);
}
else
kill_lwp (signal_pid, SIGINT);
{
char filename[PATH_MAX];
int fd, n;
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
- snprintf (filename, sizeof filename, "/proc/%ld/auxv", inferior_pid);
+ snprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
fd = open (filename, O_RDONLY);
if (fd < 0)
return n;
}
-/* These watchpoint related wrapper functions simply pass on the function call
- if the target has registered a corresponding function. */
+/* These breakpoint and watchpoint related wrapper functions simply
+ pass on the function call if the target has registered a
+ corresponding function. */
static int
-linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
+linux_insert_point (char type, CORE_ADDR addr, int len)
{
- if (the_low_target.insert_watchpoint != NULL)
- return the_low_target.insert_watchpoint (type, addr, len);
+ if (the_low_target.insert_point != NULL)
+ return the_low_target.insert_point (type, addr, len);
else
/* Unsupported (see target.h). */
return 1;
}
static int
-linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
+linux_remove_point (char type, CORE_ADDR addr, int len)
{
- if (the_low_target.remove_watchpoint != NULL)
- return the_low_target.remove_watchpoint (type, addr, len);
+ if (the_low_target.remove_point != NULL)
+ return the_low_target.remove_point (type, addr, len);
else
/* Unsupported (see target.h). */
return 1;
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)
unsigned long text, text_end, data;
- int pid = get_thread_lwp (current_inferior)->head.id;
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
errno = 0;
}
#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,
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)
+ if (strcmp (annex, "processes") == 0)
+ processes = 1;
+ else if (strcmp (annex, "threads") == 0)
+ threads = 1;
+ else
return 0;
if (!readbuf || writebuf)
len_avail = 0;
buf = NULL;
buffer_init (&buffer);
- buffer_grow_str (&buffer, "<osdata type=\"processes\">");
+ if (processes)
+ buffer_grow_str (&buffer, "<osdata type=\"processes\">");
+ else if (threads)
+ buffer_grow_str (&buffer, "<osdata type=\"threads\">");
dirp = opendir ("/proc");
if (dirp)
if (stat (procentry, &statbuf) == 0
&& S_ISDIR (statbuf.st_mode))
{
- char pathname[128];
- FILE *f;
- char cmd[MAXPATHLEN + 1];
- struct passwd *entry;
+ int pid = (int) strtoul (dp->d_name, NULL, 10);
- sprintf (pathname, "/proc/%s/cmdline", dp->d_name);
- entry = getpwuid (statbuf.st_uid);
-
- if ((f = fopen (pathname, "r")) != NULL)
+ if (processes)
+ {
+ struct passwd *entry = getpwuid (statbuf.st_uid);
+ show_process (pid, entry ? entry->pw_name : "?", &buffer);
+ }
+ else if (threads)
{
- size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
- if (len > 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\">%s</column>"
- "<column name=\"user\">%s</column>"
- "<column name=\"command\">%s</column>"
- "</item>",
- dp->d_name,
- entry ? entry->pw_name : "?",
- cmd);
- }
- fclose (f);
+ list_threads (pid, &buffer, NULL);
}
}
}
return 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)
+{
+ int done = 0;
+
+ if (the_low_target.siginfo_fixup != NULL)
+ done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
+
+ /* If there was no callback, or the callback didn't do anything,
+ then just do a straight memcpy. */
+ if (!done)
+ {
+ if (direction == 1)
+ memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
+ else
+ memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
+ }
+}
+
static int
linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
unsigned const char *writebuf, CORE_ADDR offset, int len)
{
+ int pid;
struct siginfo siginfo;
- long pid = -1;
+ char inf_siginfo[sizeof (struct siginfo)];
if (current_inferior == NULL)
return -1;
- pid = pid_of (get_thread_lwp (current_inferior));
+ pid = lwpid_of (get_thread_lwp (current_inferior));
if (debug_threads)
- fprintf (stderr, "%s siginfo for lwp %ld.\n",
+ fprintf (stderr, "%s siginfo for lwp %d.\n",
readbuf != NULL ? "Reading" : "Writing",
pid);
if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
return -1;
+ /* When GDBSERVER is built as a 64-bit application, ptrace writes into
+ SIGINFO an object with 64-bit layout. Since debugging a 32-bit
+ inferior with a 64-bit GDBSERVER should look the same as debugging it
+ with a 32-bit GDBSERVER, we need to convert it. */
+ siginfo_fixup (&siginfo, inf_siginfo, 0);
+
if (offset + len > sizeof (siginfo))
len = sizeof (siginfo) - offset;
if (readbuf != NULL)
- memcpy (readbuf, (char *) &siginfo + offset, len);
+ memcpy (readbuf, inf_siginfo + offset, len);
else
{
- memcpy ((char *) &siginfo + offset, writebuf, len);
+ memcpy (inf_siginfo + offset, writebuf, len);
+
+ /* Convert back to ptrace layout before flushing it out. */
+ siginfo_fixup (&siginfo, inf_siginfo, 1);
+
if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
return -1;
}
return len;
}
+/* SIGCHLD handler that serves two purposes: In non-stop/async mode,
+ so we notice when children change state; as the handler for the
+ sigsuspend in my_waitpid. */
+
+static void
+sigchld_handler (int signo)
+{
+ 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);
+
+ if (target_is_async_p ())
+ async_file_mark (); /* trigger a linux_wait */
+
+ errno = old_errno;
+}
+
+static int
+linux_supports_non_stop (void)
+{
+ return 1;
+}
+
+static int
+linux_async (int enable)
+{
+ 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;
+ sigemptyset (&mask);
+ sigaddset (&mask, SIGCHLD);
+
+ sigprocmask (SIG_BLOCK, &mask, NULL);
+
+ if (enable)
+ {
+ if (pipe (linux_event_pipe) == -1)
+ fatal ("creating event pipe failed.");
+
+ fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
+ fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
+
+ /* Register the event loop handler. */
+ add_file_handler (linux_event_pipe[0],
+ handle_target_event, NULL);
+
+ /* Always trigger a linux_wait. */
+ async_file_mark ();
+ }
+ else
+ {
+ delete_file_handler (linux_event_pipe[0]);
+
+ close (linux_event_pipe[0]);
+ close (linux_event_pipe[1]);
+ linux_event_pipe[0] = -1;
+ linux_event_pipe[1] = -1;
+ }
+
+ sigprocmask (SIG_UNBLOCK, &mask, NULL);
+ }
+
+ return previous;
+}
+
+static int
+linux_start_non_stop (int nonstop)
+{
+ /* Register or unregister from event-loop accordingly. */
+ linux_async (nonstop);
+ return 0;
+}
+
+static int
+linux_supports_multi_process (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)
+{
+ int pos = 0;
+ int written = 0;
+ char path[128];
+ DIR *dir;
+ struct dirent *entry;
+
+ sprintf (path, "/proc/%ld/fd", pid);
+ dir = opendir (path);
+ if (!dir)
+ return -1;
+
+ rewinddir (dir);
+ while ((entry = readdir (dir)) != NULL)
+ {
+ struct stat st;
+ struct statfs stfs;
+ int fd;
+
+ fd = atoi (entry->d_name);
+ if (!fd)
+ continue;
+
+ sprintf (path, "/proc/%ld/fd/%d", pid, fd);
+ if (stat (path, &st) != 0)
+ continue;
+ if (!S_ISDIR (st.st_mode))
+ continue;
+
+ if (statfs (path, &stfs) != 0)
+ continue;
+ if (stfs.f_type != SPUFS_MAGIC)
+ continue;
+
+ if (pos >= offset && pos + 4 <= offset + len)
+ {
+ *(unsigned int *)(buf + pos - offset) = fd;
+ written += 4;
+ }
+ pos += 4;
+ }
+
+ closedir (dir);
+ return written;
+}
+
+/* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
+ object type, using the /proc file system. */
+static int
+linux_qxfer_spu (const char *annex, unsigned char *readbuf,
+ unsigned const char *writebuf,
+ CORE_ADDR offset, int len)
+{
+ long pid = lwpid_of (get_thread_lwp (current_inferior));
+ char buf[128];
+ int fd = 0;
+ int ret = 0;
+
+ if (!writebuf && !readbuf)
+ return -1;
+
+ if (!*annex)
+ {
+ if (!readbuf)
+ return -1;
+ else
+ return spu_enumerate_spu_ids (pid, readbuf, offset, len);
+ }
+
+ sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
+ fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
+ if (fd <= 0)
+ return -1;
+
+ if (offset != 0
+ && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
+ {
+ close (fd);
+ return 0;
+ }
+
+ if (writebuf)
+ ret = write (fd, writebuf, (size_t) len);
+ else
+ ret = read (fd, readbuf, (size_t) len);
+
+ close (fd);
+ return ret;
+}
+
+static int
+linux_core_of_thread (ptid_t ptid)
+{
+ 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;
+
+ sprintf (filename, "/proc/%d/task/%ld/stat",
+ ptid_get_pid (ptid), ptid_get_lwp (ptid));
+ f = fopen (filename, "r");
+ if (!f)
+ return -1;
+
+ for (;;)
+ {
+ int n;
+ content = realloc (content, content_read + 1024);
+ n = fread (content + content_read, 1, 1024, f);
+ content_read += n;
+ if (n < 1024)
+ {
+ content[content_read] = '\0';
+ break;
+ }
+ }
+
+ p = strchr (content, '(');
+ p = strchr (p, ')') + 2; /* skip ")" and a whitespace. */
+
+ p = strtok_r (p, " ", &ts);
+ for (i = 0; i != 36; ++i)
+ p = strtok_r (NULL, " ", &ts);
+
+ if (sscanf (p, "%d", &core) == 0)
+ core = -1;
+
+ free (content);
+ fclose (f);
+
+ return core;
+}
+
+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 (void)
+{
+ stop_all_lwps ();
+}
+
static struct target_ops linux_target_ops = {
linux_create_inferior,
linux_attach,
linux_kill,
linux_detach,
+ linux_mourn,
linux_join,
linux_thread_alive,
linux_resume,
linux_look_up_symbols,
linux_request_interrupt,
linux_read_auxv,
- linux_insert_watchpoint,
- linux_remove_watchpoint,
+ linux_insert_point,
+ linux_remove_point,
linux_stopped_by_watchpoint,
linux_stopped_data_address,
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
#else
NULL,
#endif
- NULL,
+ linux_qxfer_spu,
hostio_last_error_from_errno,
linux_qxfer_osdata,
linux_xfer_siginfo,
+ linux_supports_non_stop,
+ linux_async,
+ linux_start_non_stop,
+ linux_supports_multi_process,
+#ifdef USE_THREAD_DB
+ thread_db_handle_monitor_command,
+#else
+ NULL,
+#endif
+ linux_core_of_thread,
+ linux_process_qsupported,
+ linux_supports_tracepoints,
+ linux_read_pc,
+ linux_write_pc,
+ linux_thread_stopped,
+ linux_pause_all
};
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. */
signal (__SIGRTMIN+1, SIG_IGN);
+#endif
}
void
initialize_low (void)
{
- thread_db_active = 0;
+ struct sigaction sigchld_action;
+ memset (&sigchld_action, 0, sizeof (sigchld_action));
set_target_ops (&linux_target_ops);
set_breakpoint_data (the_low_target.breakpoint,
the_low_target.breakpoint_len);
;
disabled_regsets = xmalloc (num_regsets);
#endif
+
+ sigchld_action.sa_handler = sigchld_handler;
+ sigemptyset (&sigchld_action.sa_mask);
+ sigchld_action.sa_flags = SA_RESTART;
+ sigaction (SIGCHLD, &sigchld_action, NULL);
}
projects / deliverable / binutils-gdb.git / blobdiff