/* 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 Free Software Foundation, Inc.
+ 2006, 2007, 2008 Free Software Foundation, Inc.
This file is part of GDB.
#include <sys/wait.h>
#include <stdio.h>
#include <sys/param.h>
-#include <sys/dir.h>
#include <sys/ptrace.h>
-#include <sys/user.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/syscall.h>
+#include <sched.h>
+#include <ctype.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <dirent.h>
#ifndef PTRACE_GETSIGINFO
# define PTRACE_GETSIGINFO 0x4202
# define PTRACE_SETSIGINFO 0x4203
#endif
+#ifndef O_LARGEFILE
+#define O_LARGEFILE 0
+#endif
+
+/* If the system headers did not provide the constants, hard-code the normal
+ values. */
+#ifndef PTRACE_EVENT_FORK
+
+#define PTRACE_SETOPTIONS 0x4200
+#define PTRACE_GETEVENTMSG 0x4201
+
+/* options set using PTRACE_SETOPTIONS */
+#define PTRACE_O_TRACESYSGOOD 0x00000001
+#define PTRACE_O_TRACEFORK 0x00000002
+#define PTRACE_O_TRACEVFORK 0x00000004
+#define PTRACE_O_TRACECLONE 0x00000008
+#define PTRACE_O_TRACEEXEC 0x00000010
+#define PTRACE_O_TRACEVFORKDONE 0x00000020
+#define PTRACE_O_TRACEEXIT 0x00000040
+
+/* Wait extended result codes for the above trace options. */
+#define PTRACE_EVENT_FORK 1
+#define PTRACE_EVENT_VFORK 2
+#define PTRACE_EVENT_CLONE 3
+#define PTRACE_EVENT_EXEC 4
+#define PTRACE_EVENT_VFORK_DONE 5
+#define PTRACE_EVENT_EXIT 6
+
+#endif /* PTRACE_EVENT_FORK */
+
+/* We can't always assume that this flag is available, but all systems
+ with the ptrace event handlers also have __WALL, so it's safe to use
+ in some contexts. */
+#ifndef __WALL
+#define __WALL 0x40000000 /* Wait for any child. */
+#endif
+
#ifdef __UCLIBC__
#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
#define HAS_NOMMU
#endif
#endif
-/* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead,
- however. This requires changing the ID in place when we go from !using_threads
- to using_threads, immediately.
+/* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
+ representation of the thread ID.
``all_processes'' is keyed by the process ID - which on Linux is (presently)
the same as the LWP ID. */
struct inferior_list all_processes;
+/* A list of all unknown processes which receive stop signals. Some other
+ process will presumably claim each of these as forked children
+ momentarily. */
+
+struct inferior_list stopped_pids;
+
/* FIXME this is a bit of a hack, and could be removed. */
int stopping_threads;
/* FIXME make into a target method? */
-int using_threads;
+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. */
+static int new_inferior;
static void linux_resume_one_process (struct inferior_list_entry *entry,
int step, int signal, siginfo_t *info);
static void stop_all_processes (void);
static int linux_wait_for_event (struct thread_info *child);
static int check_removed_breakpoint (struct process_info *event_child);
+static void *add_process (unsigned long pid);
+static int my_waitpid (int pid, int *status, int flags);
struct pending_signals
{
#define PTRACE_XFER_TYPE long
#ifdef HAVE_LINUX_REGSETS
-static int use_regsets_p = 1;
+static char *disabled_regsets;
+static int num_regsets;
#endif
#define pid_of(proc) ((proc)->head.id)
/* FIXME: Delete eventually. */
#define inferior_pid (pid_of (get_thread_process (current_inferior)))
+static void
+handle_extended_wait (struct process_info *event_child, int wstat)
+{
+ int event = wstat >> 16;
+ struct process_info *new_process;
+
+ if (event == PTRACE_EVENT_CLONE)
+ {
+ unsigned long new_pid;
+ int ret, status = W_STOPCODE (SIGSTOP);
+
+ ptrace (PTRACE_GETEVENTMSG, inferior_pid, 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))
+ {
+ /* The new child has a pending SIGSTOP. We can't affect it until it
+ hits the SIGSTOP, but we're already attached. */
+
+ ret = my_waitpid (new_pid, &status, __WALL);
+
+ if (ret == -1)
+ perror_with_name ("waiting for new child");
+ else if (ret != new_pid)
+ warning ("wait returned unexpected PID %d", ret);
+ else if (!WIFSTOPPED (status))
+ warning ("wait returned unexpected status 0x%x", status);
+ }
+
+ ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE);
+
+ new_process = (struct process_info *) add_process (new_pid);
+ add_thread (new_pid, new_process, new_pid);
+ new_thread_notify (thread_id_to_gdb_id (new_process->lwpid));
+
+ /* Normally we will get the pending SIGSTOP. But in some cases
+ we might get another signal delivered to the group first.
+ If we do, be sure not to lose it. */
+ if (WSTOPSIG (status) == SIGSTOP)
+ {
+ if (stopping_threads)
+ new_process->stopped = 1;
+ else
+ ptrace (PTRACE_CONT, new_pid, 0, 0);
+ }
+ else
+ {
+ new_process->stop_expected = 1;
+ if (stopping_threads)
+ {
+ new_process->stopped = 1;
+ new_process->status_pending_p = 1;
+ new_process->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));
+ }
+
+ /* 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_process (&event_child->head,
+ event_child->stepping, 0, NULL);
+ }
+}
+
/* This function should only be called if the process got a SIGTRAP.
The SIGTRAP could mean several things.
{
struct process_info *process;
- process = (struct process_info *) malloc (sizeof (*process));
+ process = (struct process_info *) xmalloc (sizeof (*process));
memset (process, 0, sizeof (*process));
process->head.id = pid;
-
- /* Default to tid == lwpid == pid. */
- process->tid = pid;
process->lwpid = pid;
add_inferior_to_list (&all_processes, &process->head);
new_process = add_process (pid);
add_thread (pid, new_process, pid);
+ must_set_ptrace_flags = 1;
+ new_inferior = 1;
return pid;
}
/* Attach to an inferior process. */
void
-linux_attach_lwp (unsigned long pid, unsigned long tid)
+linux_attach_lwp (unsigned long pid)
{
struct process_info *new_process;
if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
{
- fprintf (stderr, "Cannot attach to process %ld: %s (%d)\n", pid,
+ if (all_threads.head != NULL)
+ {
+ /* If we fail to attach to an LWP, just warn. */
+ fprintf (stderr, "Cannot attach to process %ld: %s (%d)\n", pid,
+ 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,
strerror (errno), errno);
- fflush (stderr);
-
- /* If we fail to attach to an LWP, just return. */
- if (!using_threads)
- _exit (0177);
- return;
}
+ ptrace (PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACECLONE);
+
new_process = (struct process_info *) add_process (pid);
- add_thread (tid, new_process, pid);
+ add_thread (pid, new_process, pid);
+ new_thread_notify (thread_id_to_gdb_id (new_process->lwpid));
/* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
brings it to a halt. We should ignore that SIGSTOP and resume the process
{
struct process_info *process;
- linux_attach_lwp (pid, pid);
+ linux_attach_lwp (pid);
/* Don't ignore the initial SIGSTOP if we just attached to this process.
It will be collected by wait shortly. */
process = (struct process_info *) find_inferior_id (&all_processes, pid);
process->stop_expected = 0;
+ new_inferior = 1;
+
return 0;
}
/* Make sure it died. The loop is most likely unnecessary. */
wstat = linux_wait_for_event (thread);
} while (WIFSTOPPED (wstat));
+
+ clear_inferiors ();
+ free (all_processes.head);
+ all_processes.head = all_processes.tail = NULL;
}
static void
delete_all_breakpoints ();
for_each_inferior (&all_threads, linux_detach_one_process);
clear_inferiors ();
+ free (all_processes.head);
+ all_processes.head = all_processes.tail = NULL;
return 0;
}
/* Return nonzero if the given thread is still alive. */
static int
-linux_thread_alive (unsigned long tid)
+linux_thread_alive (unsigned long lwpid)
{
- if (find_inferior_id (&all_threads, tid) != NULL)
+ if (find_inferior_id (&all_threads, lwpid) != NULL)
return 1;
else
return 0;
if (*childp != NULL)
to_wait_for = (*childp)->lwpid;
+retry:
while (1)
{
ret = waitpid (to_wait_for, wstatp, WNOHANG);
if (to_wait_for == -1)
*childp = (struct process_info *) find_inferior_id (&all_processes, 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))
+ {
+ add_pid_to_list (&stopped_pids, ret);
+ goto retry;
+ }
+ else if (*childp == NULL)
+ goto retry;
+
(*childp)->stopped = 1;
(*childp)->pending_is_breakpoint = 0;
(*childp)->last_status = *wstatp;
+ /* Architecture-specific setup after inferior is running.
+ This needs to happen after we have attached to the inferior
+ and it is stopped for the first time, but before we access
+ any inferior registers. */
+ if (new_inferior)
+ {
+ the_low_target.arch_setup ();
+#ifdef HAVE_LINUX_REGSETS
+ memset (disabled_regsets, 0, num_regsets);
+#endif
+ new_inferior = 0;
+ }
+
if (debug_threads
&& WIFSTOPPED (*wstatp))
{
+ struct thread_info *saved_inferior = current_inferior;
current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, (*childp)->tid);
+ 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 ();
+ current_inferior = saved_inferior;
}
}
CORE_ADDR stop_pc;
struct process_info *event_child;
int wstat;
+ int bp_status;
/* Check for a process with a pending status. */
/* It is possible that the user changed the pending task's registers since
error ("event from unknown child");
current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, event_child->tid);
+ find_inferior_id (&all_threads, event_child->lwpid);
/* Check for thread exit. */
- if (using_threads && ! WIFSTOPPED (wstat))
+ if (! WIFSTOPPED (wstat))
{
if (debug_threads)
- fprintf (stderr, "Thread %ld (LWP %ld) exiting\n",
- event_child->tid, event_child->head.id);
+ fprintf (stderr, "LWP %ld exiting\n", event_child->head.id);
/* If the last thread is exiting, just return. */
if (all_threads.head == all_threads.tail)
return wstat;
- dead_thread_notify (event_child->tid);
+ dead_thread_notify (thread_id_to_gdb_id (event_child->lwpid));
remove_inferior (&all_processes, &event_child->head);
free (event_child);
continue;
}
- if (using_threads
- && WIFSTOPPED (wstat)
+ if (WIFSTOPPED (wstat)
&& WSTOPSIG (wstat) == SIGSTOP
&& event_child->stop_expected)
{
continue;
}
+ if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
+ && wstat >> 16 != 0)
+ {
+ handle_extended_wait (event_child, wstat);
+ continue;
+ }
+
/* If GDB is not interested in this signal, don't stop other
threads, and don't report it to GDB. Just resume the
inferior right away. We do this for threading-related
thread library? */
if (WIFSTOPPED (wstat)
&& !event_child->stepping
- && ((using_threads && (WSTOPSIG (wstat) == __SIGRTMIN
- || WSTOPSIG (wstat) == __SIGRTMIN + 1))
- || (pass_signals[target_signal_from_host (WSTOPSIG (wstat))]
- && (WSTOPSIG (wstat) != SIGSTOP
- || !event_child->sigstop_sent))))
+ && (
+#ifdef USE_THREAD_DB
+ (thread_db_active && (WSTOPSIG (wstat) == __SIGRTMIN
+ || WSTOPSIG (wstat) == __SIGRTMIN + 1))
+ ||
+#endif
+ (pass_signals[target_signal_from_host (WSTOPSIG (wstat))]
+ && (WSTOPSIG (wstat) != SIGSTOP || !stopping_threads))))
{
siginfo_t info, *info_p;
if (debug_threads)
- fprintf (stderr, "Ignored signal %d for %ld (LWP %ld).\n",
- WSTOPSIG (wstat), event_child->tid,
- event_child->head.id);
+ fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
+ WSTOPSIG (wstat), event_child->head.id);
if (ptrace (PTRACE_GETSIGINFO, event_child->lwpid, 0, &info) == 0)
info_p = &info;
continue;
}
- if (debug_threads)
- fprintf (stderr, "Hit a (non-reinsert) breakpoint.\n");
+ bp_status = check_breakpoints (stop_pc);
- if (check_breakpoints (stop_pc) != 0)
+ if (bp_status != 0)
{
+ if (debug_threads)
+ fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+
/* 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;
- /* Now we need to put the breakpoint back. We continue in the event
+ /* 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
Otherwise, call the target function to figure out where we need
our temporary breakpoint, create it, and continue executing this
process. */
- if (the_low_target.breakpoint_reinsert_addr == NULL)
+ if (bp_status == 2)
+ /* No need to reinsert. */
+ linux_resume_one_process (&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);
continue;
}
+ 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,
}
}
- enable_async_io ();
- unblock_async_io ();
w = linux_wait_for_event (child);
stop_all_processes ();
- disable_async_io ();
+
+ if (must_set_ptrace_flags)
+ {
+ ptrace (PTRACE_SETOPTIONS, inferior_pid, 0, PTRACE_O_TRACECLONE);
+ must_set_ptrace_flags = 0;
+ }
/* If we are waiting for a particular child, and it exited,
linux_wait_for_event will return its exit status. Similarly if
fprintf (stderr, "Sending sigstop to process %ld\n", process->head.id);
kill_lwp (process->head.id, SIGSTOP);
- process->sigstop_sent = 1;
}
static void
saved_inferior = current_inferior;
saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
thread = (struct thread_info *) find_inferior_id (&all_threads,
- process->tid);
+ process->lwpid);
wstat = linux_wait_for_event (thread);
/* If we stopped with a non-SIGSTOP signal, save it for later
&& WSTOPSIG (wstat) != SIGSTOP)
{
if (debug_threads)
- fprintf (stderr, "Process %ld (thread %ld) "
- "stopped with non-sigstop status %06x\n",
- process->lwpid, process->tid, wstat);
+ fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
+ process->lwpid, wstat);
process->status_pending_p = 1;
process->status_pending = wstat;
process->stop_expected = 1;
|| process->bp_reinsert != 0))
{
struct pending_signals *p_sig;
- p_sig = malloc (sizeof (*p_sig));
+ p_sig = xmalloc (sizeof (*p_sig));
p_sig->prev = process->pending_signals;
p_sig->signal = signal;
if (info == NULL)
current_inferior = saved_inferior;
if (errno)
- perror_with_name ("ptrace");
+ {
+ /* ESRCH from ptrace either means that the thread was already
+ running (an error) or that it is gone (a race condition). If
+ it's gone, we will get a notification the next time we wait,
+ so we can ignore the error. We could differentiate these
+ two, but it's tricky without waiting; the thread still exists
+ as a zombie, so sending it signal 0 would succeed. So just
+ ignore ESRCH. */
+ if (errno == ESRCH)
+ return;
+
+ perror_with_name ("ptrace");
+ }
}
static struct thread_resume *resume_ptr;
if (process->resume->sig != 0)
{
struct pending_signals *p_sig;
- p_sig = malloc (sizeof (*p_sig));
+ p_sig = xmalloc (sizeof (*p_sig));
p_sig->prev = process->pending_signals;
p_sig->signal = process->resume->sig;
memset (&p_sig->info, 0, sizeof (siginfo_t));
if (pending_flag)
for_each_inferior (&all_threads, linux_queue_one_thread);
else
- {
- block_async_io ();
- enable_async_io ();
- for_each_inferior (&all_threads, linux_continue_one_thread);
- }
+ for_each_inferior (&all_threads, linux_continue_one_thread);
}
#ifdef HAVE_LINUX_USRREGS
goto error_exit;
}
}
- if (the_low_target.left_pad_xfer
- && register_size (regno) < sizeof (PTRACE_XFER_TYPE))
- supply_register (regno, (buf + sizeof (PTRACE_XFER_TYPE)
- - register_size (regno)));
+
+ if (the_low_target.supply_ptrace_register)
+ the_low_target.supply_ptrace_register (regno, buf);
else
supply_register (regno, buf);
& - sizeof (PTRACE_XFER_TYPE);
buf = alloca (size);
memset (buf, 0, size);
- if (the_low_target.left_pad_xfer
- && register_size (regno) < sizeof (PTRACE_XFER_TYPE))
- collect_register (regno, (buf + sizeof (PTRACE_XFER_TYPE)
- - register_size (regno)));
+
+ if (the_low_target.collect_ptrace_register)
+ the_low_target.collect_ptrace_register (regno, buf);
else
collect_register (regno, buf);
+
for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
{
errno = 0;
*(PTRACE_XFER_TYPE *) (buf + i));
if (errno != 0)
{
+ /* At this point, ESRCH should mean the process is already gone,
+ in which case we simply ignore attempts to change its registers.
+ See also the related comment in linux_resume_one_process. */
+ if (errno == ESRCH)
+ return;
+
if ((*the_low_target.cannot_store_register) (regno) == 0)
{
char *err = strerror (errno);
void *buf;
int res;
- if (regset->size == 0)
+ if (regset->size == 0 || disabled_regsets[regset - target_regsets])
{
regset ++;
continue;
}
- buf = malloc (regset->size);
+ buf = xmalloc (regset->size);
+#ifndef __sparc__
res = ptrace (regset->get_request, inferior_pid, 0, buf);
+#else
+ res = ptrace (regset->get_request, inferior_pid, buf, 0);
+#endif
if (res < 0)
{
if (errno == EIO)
{
- /* If we get EIO on the first regset, do not try regsets again.
- If we get EIO on a later regset, disable that regset. */
- if (regset == target_regsets)
- {
- use_regsets_p = 0;
- return -1;
- }
- else
- {
- regset->size = 0;
- continue;
- }
+ /* If we get EIO on a regset, do not try it again for
+ this process. */
+ disabled_regsets[regset - target_regsets] = 1;
+ continue;
}
else
{
void *buf;
int res;
- if (regset->size == 0)
+ if (regset->size == 0 || disabled_regsets[regset - target_regsets])
{
regset ++;
continue;
}
- buf = malloc (regset->size);
+ buf = xmalloc (regset->size);
/* 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. */
+#ifndef __sparc__
res = ptrace (regset->get_request, inferior_pid, 0, buf);
+#else
+ res = ptrace (regset->get_request, inferior_pid, buf, 0);
+#endif
if (res == 0)
{
regset->fill_function (buf);
/* Only now do we write the register set. */
- res = ptrace (regset->set_request, inferior_pid, 0, buf);
+#ifndef __sparc__
+ res = ptrace (regset->set_request, inferior_pid, 0, buf);
+#else
+ res = ptrace (regset->set_request, inferior_pid, buf, 0);
+#endif
}
if (res < 0)
{
if (errno == EIO)
{
- /* If we get EIO on the first regset, do not try regsets again.
- If we get EIO on a later regset, disable that regset. */
- if (regset == target_regsets)
- {
- use_regsets_p = 0;
- return -1;
- }
- else
- {
- regset->size = 0;
- continue;
- }
+ /* If we get EIO on a regset, do not try it again for
+ this process. */
+ disabled_regsets[regset - target_regsets] = 1;
+ continue;
+ }
+ else if (errno == ESRCH)
+ {
+ /* At this point, ESRCH should mean the process is already gone,
+ in which case we simply ignore attempts to change its registers.
+ See also the related comment in linux_resume_one_process. */
+ return 0;
}
else
{
linux_fetch_registers (int regno)
{
#ifdef HAVE_LINUX_REGSETS
- if (use_regsets_p)
- {
- if (regsets_fetch_inferior_registers () == 0)
- return;
- }
+ if (regsets_fetch_inferior_registers () == 0)
+ return;
#endif
#ifdef HAVE_LINUX_USRREGS
usr_fetch_inferior_registers (regno);
linux_store_registers (int regno)
{
#ifdef HAVE_LINUX_REGSETS
- if (use_regsets_p)
- {
- if (regsets_store_inferior_registers () == 0)
- return;
- }
+ if (regsets_store_inferior_registers () == 0)
+ return;
#endif
#ifdef HAVE_LINUX_USRREGS
usr_store_inferior_registers (regno);
/* Allocate buffer of that many longwords. */
register PTRACE_XFER_TYPE *buffer
= (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+ int fd;
+ char filename[64];
+
+ /* 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);
+ fd = open (filename, O_RDONLY | O_LARGEFILE);
+ if (fd == -1)
+ goto no_proc;
+
+ /* If pread64 is available, use it. It's faster if the kernel
+ supports it (only one syscall), and it's 64-bit safe even on
+ 32-bit platforms (for instance, SPARC debugging a SPARC64
+ application). */
+#ifdef HAVE_PREAD64
+ if (pread64 (fd, myaddr, len, memaddr) != len)
+#else
+ if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, memaddr, len) != len)
+#endif
+ {
+ close (fd);
+ goto no_proc;
+ }
+
+ close (fd);
+ return 0;
+ }
+ no_proc:
/* Read all the longwords */
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
{
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
/* Allocate buffer of that many longwords. */
register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
- extern int errno;
if (debug_threads)
{
return 0;
}
+static int linux_supports_tracefork_flag;
+
+/* Helper functions for linux_test_for_tracefork, called via clone (). */
+
+static int
+linux_tracefork_grandchild (void *arg)
+{
+ _exit (0);
+}
+
+#define STACK_SIZE 4096
+
+static int
+linux_tracefork_child (void *arg)
+{
+ ptrace (PTRACE_TRACEME, 0, 0, 0);
+ kill (getpid (), SIGSTOP);
+#ifdef __ia64__
+ __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
+ CLONE_VM | SIGCHLD, NULL);
+#else
+ 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);
+
+ return ret;
+}
+
+/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
+ sure that we can enable the option, and that it had the desired
+ effect. */
+
+static void
+linux_test_for_tracefork (void)
+{
+ int child_pid, ret, status;
+ long second_pid;
+ char *stack = xmalloc (STACK_SIZE * 4);
+
+ linux_supports_tracefork_flag = 0;
+
+ /* 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
+ child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
+ CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
+#endif
+ if (child_pid == -1)
+ perror_with_name ("clone");
+
+ ret = my_waitpid (child_pid, &status, 0);
+ if (ret == -1)
+ perror_with_name ("waitpid");
+ else if (ret != child_pid)
+ error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
+ if (! WIFSTOPPED (status))
+ error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
+
+ ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
+ if (ret != 0)
+ {
+ ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
+ if (ret != 0)
+ {
+ warning ("linux_test_for_tracefork: failed to kill child");
+ return;
+ }
+
+ ret = my_waitpid (child_pid, &status, 0);
+ if (ret != child_pid)
+ warning ("linux_test_for_tracefork: failed to wait for killed child");
+ else if (!WIFSIGNALED (status))
+ warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
+ "killed child", status);
+
+ return;
+ }
+
+ ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to resume child");
+
+ ret = my_waitpid (child_pid, &status, 0);
+
+ if (ret == child_pid && WIFSTOPPED (status)
+ && status >> 16 == PTRACE_EVENT_FORK)
+ {
+ second_pid = 0;
+ ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
+ if (ret == 0 && second_pid != 0)
+ {
+ int second_status;
+
+ linux_supports_tracefork_flag = 1;
+ my_waitpid (second_pid, &second_status, 0);
+ ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to kill second child");
+ my_waitpid (second_pid, &status, 0);
+ }
+ }
+ else
+ warning ("linux_test_for_tracefork: unexpected result from waitpid "
+ "(%d, status 0x%x)", ret, status);
+
+ do
+ {
+ ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to kill child");
+ my_waitpid (child_pid, &status, 0);
+ }
+ while (WIFSTOPPED (status));
+
+ free (stack);
+}
+
+
static void
linux_look_up_symbols (void)
{
#ifdef USE_THREAD_DB
- if (using_threads)
+ if (thread_db_active)
return;
- using_threads = thread_db_init ();
+ thread_db_active = thread_db_init (!linux_supports_tracefork_flag);
#endif
}
}
#endif
-static const char *
-linux_arch_string (void)
+static int
+linux_qxfer_osdata (const char *annex,
+ unsigned char *readbuf, unsigned const char *writebuf,
+ CORE_ADDR offset, int len)
{
- return the_low_target.arch_string;
+ /* We make the process list snapshot when the object starts to be
+ read. */
+ static const char *buf;
+ static long len_avail = -1;
+ static struct buffer buffer;
+
+ DIR *dirp;
+
+ if (strcmp (annex, "processes") != 0)
+ return 0;
+
+ if (!readbuf || writebuf)
+ return 0;
+
+ if (offset == 0)
+ {
+ if (len_avail != -1 && len_avail != 0)
+ buffer_free (&buffer);
+ len_avail = 0;
+ buf = NULL;
+ buffer_init (&buffer);
+ buffer_grow_str (&buffer, "<osdata type=\"processes\">");
+
+ dirp = opendir ("/proc");
+ if (dirp)
+ {
+ struct dirent *dp;
+ while ((dp = readdir (dirp)) != NULL)
+ {
+ struct stat statbuf;
+ char procentry[sizeof ("/proc/4294967295")];
+
+ if (!isdigit (dp->d_name[0])
+ || strlen (dp->d_name) > sizeof ("4294967295") - 1)
+ continue;
+
+ sprintf (procentry, "/proc/%s", dp->d_name);
+ if (stat (procentry, &statbuf) == 0
+ && S_ISDIR (statbuf.st_mode))
+ {
+ char pathname[128];
+ FILE *f;
+ char cmd[MAXPATHLEN + 1];
+ struct passwd *entry;
+
+ sprintf (pathname, "/proc/%s/cmdline", dp->d_name);
+ entry = getpwuid (statbuf.st_uid);
+
+ if ((f = fopen (pathname, "r")) != NULL)
+ {
+ 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);
+ }
+ }
+ }
+
+ closedir (dirp);
+ }
+ buffer_grow_str0 (&buffer, "</osdata>\n");
+ buf = buffer_finish (&buffer);
+ len_avail = strlen (buf);
+ }
+
+ if (offset >= len_avail)
+ {
+ /* Done. Get rid of the data. */
+ buffer_free (&buffer);
+ buf = NULL;
+ len_avail = 0;
+ return 0;
+ }
+
+ if (len > len_avail - offset)
+ len = len_avail - offset;
+ memcpy (readbuf, buf + offset, len);
+
+ return len;
}
static struct target_ops linux_target_ops = {
#else
NULL,
#endif
- linux_arch_string,
+ NULL,
+ hostio_last_error_from_errno,
+ linux_qxfer_osdata,
};
static void
void
initialize_low (void)
{
- using_threads = 0;
+ thread_db_active = 0;
set_target_ops (&linux_target_ops);
set_breakpoint_data (the_low_target.breakpoint,
the_low_target.breakpoint_len);
- init_registers ();
linux_init_signals ();
+ linux_test_for_tracefork ();
+#ifdef HAVE_LINUX_REGSETS
+ for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
+ ;
+ disabled_regsets = xmalloc (num_regsets);
+#endif
}
projects / deliverable / binutils-gdb.git / blobdiff