/* GNU/Linux native-dependent code common to multiple platforms.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
Free Software Foundation, Inc.
This file is part of GDB.
struct simple_pid_list
{
int pid;
+ int status;
struct simple_pid_list *next;
};
struct simple_pid_list *stopped_pids;
/* Trivial list manipulation functions to keep track of a list of
new stopped processes. */
static void
-add_to_pid_list (struct simple_pid_list **listp, int pid)
+add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
{
struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
new_pid->pid = pid;
+ new_pid->status = status;
new_pid->next = *listp;
*listp = new_pid;
}
static int
-pull_pid_from_list (struct simple_pid_list **listp, int pid)
+pull_pid_from_list (struct simple_pid_list **listp, int pid, int *status)
{
struct simple_pid_list **p;
if ((*p)->pid == pid)
{
struct simple_pid_list *next = (*p)->next;
+ *status = (*p)->status;
xfree (*p);
*p = next;
return 1;
return 0;
}
-void
-linux_record_stopped_pid (int pid)
+static void
+linux_record_stopped_pid (int pid, int status)
{
- add_to_pid_list (&stopped_pids, pid);
+ add_to_pid_list (&stopped_pids, pid, status);
}
\f
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
return 0;
}
-ptid_t
-linux_handle_extended_wait (int pid, int status,
- struct target_waitstatus *ourstatus)
-{
- int event = status >> 16;
-
- if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
- || event == PTRACE_EVENT_CLONE)
- {
- unsigned long new_pid;
- int ret;
-
- ptrace (PTRACE_GETEVENTMSG, 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,
- (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
- if (ret == -1)
- perror_with_name (_("waiting for new child"));
- else if (ret != new_pid)
- internal_error (__FILE__, __LINE__,
- _("wait returned unexpected PID %d"), ret);
- else if (!WIFSTOPPED (status) || WSTOPSIG (status) != SIGSTOP)
- internal_error (__FILE__, __LINE__,
- _("wait returned unexpected status 0x%x"), status);
- }
-
- if (event == PTRACE_EVENT_FORK)
- ourstatus->kind = TARGET_WAITKIND_FORKED;
- else if (event == PTRACE_EVENT_VFORK)
- ourstatus->kind = TARGET_WAITKIND_VFORKED;
- else
- ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
-
- ourstatus->value.related_pid = new_pid;
- return inferior_ptid;
- }
-
- if (event == PTRACE_EVENT_EXEC)
- {
- ourstatus->kind = TARGET_WAITKIND_EXECD;
- ourstatus->value.execd_pathname
- = xstrdup (child_pid_to_exec_file (pid));
-
- if (linux_parent_pid)
- {
- detach_breakpoints (linux_parent_pid);
- ptrace (PTRACE_DETACH, linux_parent_pid, 0, 0);
-
- linux_parent_pid = 0;
- }
-
- return inferior_ptid;
- }
-
- internal_error (__FILE__, __LINE__,
- _("unknown ptrace event %d"), event);
-}
-
\f
void
child_insert_fork_catchpoint (int pid)
/* Attach to the LWP specified by PID. If VERBOSE is non-zero, print
a message telling the user that a new LWP has been added to the
- process. */
+ process. Return 0 if successful or -1 if the new LWP could not
+ be attached. */
-void
+int
lin_lwp_attach_lwp (ptid_t ptid, int verbose)
{
- struct lwp_info *lp, *found_lp;
+ struct lwp_info *lp;
gdb_assert (is_lwp (ptid));
sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
}
- if (verbose)
- printf_filtered (_("[New %s]\n"), target_pid_to_str (ptid));
-
- found_lp = lp = find_lwp_pid (ptid);
- if (lp == NULL)
- lp = add_lwp (ptid);
+ lp = find_lwp_pid (ptid);
/* We assume that we're already attached to any LWP that has an id
equal to the overall process id, and to any LWP that is already
and we've had PID wraparound since we last tried to stop all threads,
this assumption might be wrong; fortunately, this is very unlikely
to happen. */
- if (GET_LWP (ptid) != GET_PID (ptid) && found_lp == NULL)
+ if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
{
pid_t pid;
int status;
if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
- error (_("Can't attach %s: %s"), target_pid_to_str (ptid),
- safe_strerror (errno));
+ {
+ /* If we fail to attach to the thread, issue a warning,
+ but continue. One way this can happen is if thread
+ creation is interrupted; as of Linux 2.6.19, a kernel
+ bug may place threads in the thread list and then fail
+ to create them. */
+ warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
+ safe_strerror (errno));
+ return -1;
+ }
+
+ if (lp == NULL)
+ lp = add_lwp (ptid);
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
{
/* We assume that the LWP representing the original process is
already stopped. Mark it as stopped in the data structure
- that the linux ptrace layer uses to keep track of threads.
- Note that this won't have already been done since the main
- thread will have, we assume, been stopped by an attach from a
- different layer. */
+ that the GNU/linux ptrace layer uses to keep track of
+ threads. Note that this won't have already been done since
+ the main thread will have, we assume, been stopped by an
+ attach from a different layer. */
+ if (lp == NULL)
+ lp = add_lwp (ptid);
lp->stopped = 1;
}
+
+ if (verbose)
+ printf_filtered (_("[New %s]\n"), target_pid_to_str (ptid));
+
+ return 0;
}
static void
return kill (lwpid, signo);
}
-/* Handle a GNU/Linux extended wait response. Most of the work we
- just pass off to linux_handle_extended_wait, but if it reports a
- clone event we need to add the new LWP to our list (and not report
- the trap to higher layers). This function returns non-zero if
- the event should be ignored and we should wait again. If STOPPING
- is true, the new LWP remains stopped, otherwise it is continued. */
+/* 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). This function returns non-zero if the
+ event should be ignored and we should wait again. If STOPPING is
+ true, the new LWP remains stopped, otherwise it is continued. */
static int
-linux_nat_handle_extended (struct lwp_info *lp, int status, int stopping)
+linux_handle_extended_wait (struct lwp_info *lp, int status,
+ int stopping)
{
- linux_handle_extended_wait (GET_LWP (lp->ptid), status,
- &lp->waitstatus);
+ int pid = GET_LWP (lp->ptid);
+ struct target_waitstatus *ourstatus = &lp->waitstatus;
+ struct lwp_info *new_lp = NULL;
+ int event = status >> 16;
- /* TARGET_WAITKIND_SPURIOUS is used to indicate clone events. */
- if (lp->waitstatus.kind == TARGET_WAITKIND_SPURIOUS)
+ if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
+ || event == PTRACE_EVENT_CLONE)
{
- struct lwp_info *new_lp;
- new_lp = add_lwp (BUILD_LWP (lp->waitstatus.value.related_pid,
- GET_PID (inferior_ptid)));
- new_lp->cloned = 1;
+ unsigned long new_pid;
+ int ret;
- if (stopping)
- new_lp->stopped = 1;
+ ptrace (PTRACE_GETEVENTMSG, 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, &status))
+ {
+ /* 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,
+ (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
+ if (ret == -1)
+ perror_with_name (_("waiting for new child"));
+ else if (ret != new_pid)
+ internal_error (__FILE__, __LINE__,
+ _("wait returned unexpected PID %d"), ret);
+ else if (!WIFSTOPPED (status))
+ internal_error (__FILE__, __LINE__,
+ _("wait returned unexpected status 0x%x"), status);
+ }
+
+ ourstatus->value.related_pid = new_pid;
+
+ if (event == PTRACE_EVENT_FORK)
+ ourstatus->kind = TARGET_WAITKIND_FORKED;
+ else if (event == PTRACE_EVENT_VFORK)
+ ourstatus->kind = TARGET_WAITKIND_VFORKED;
else
- ptrace (PTRACE_CONT, lp->waitstatus.value.related_pid, 0, 0);
+ {
+ ourstatus->kind = TARGET_WAITKIND_IGNORE;
+ new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (inferior_ptid)));
+ new_lp->cloned = 1;
- lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
+ if (WSTOPSIG (status) != SIGSTOP)
+ {
+ /* This can happen if someone starts sending signals to
+ the new thread before it gets a chance to run, which
+ have a lower number than SIGSTOP (e.g. SIGUSR1).
+ This is an unlikely case, and harder to handle for
+ fork / vfork than for clone, so we do not try - but
+ we handle it for clone events here. We'll send
+ the other signal on to the thread below. */
+
+ new_lp->signalled = 1;
+ }
+ else
+ status = 0;
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "LLHE: Got clone event from LWP %ld, resuming\n",
- GET_LWP (lp->ptid));
- ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
+ if (stopping)
+ new_lp->stopped = 1;
+ else
+ {
+ new_lp->resumed = 1;
+ ptrace (PTRACE_CONT, lp->waitstatus.value.related_pid, 0,
+ status ? WSTOPSIG (status) : 0);
+ }
- return 1;
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LHEW: Got clone event from LWP %ld, resuming\n",
+ GET_LWP (lp->ptid));
+ ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
+
+ return 1;
+ }
+
+ return 0;
}
- return 0;
+ if (event == PTRACE_EVENT_EXEC)
+ {
+ ourstatus->kind = TARGET_WAITKIND_EXECD;
+ ourstatus->value.execd_pathname
+ = xstrdup (child_pid_to_exec_file (pid));
+
+ if (linux_parent_pid)
+ {
+ detach_breakpoints (linux_parent_pid);
+ ptrace (PTRACE_DETACH, linux_parent_pid, 0, 0);
+
+ linux_parent_pid = 0;
+ }
+
+ return 0;
+ }
+
+ internal_error (__FILE__, __LINE__,
+ _("unknown ptrace event %d"), event);
}
/* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
fprintf_unfiltered (gdb_stdlog,
"WL: Handling extended status 0x%06x\n",
status);
- if (linux_nat_handle_extended (lp, status, 1))
+ if (linux_handle_extended_wait (lp, status, 1))
return wait_lwp (lp);
}
lp->status = 0;
}
- while (linux_nat_has_pending (GET_LWP (lp->ptid), &pending, flush_mask))
+ /* While there is a pending signal we would like to flush, continue
+ the inferior and collect another signal. But if there's already
+ a saved status that we don't want to flush, we can't resume the
+ inferior - if it stopped for some other reason we wouldn't have
+ anywhere to save the new status. In that case, we must leave the
+ signal unflushed (and possibly generate an extra SIGINT stop).
+ That's much less bad than losing a signal. */
+ while (lp->status == 0
+ && linux_nat_has_pending (GET_LWP (lp->ptid), &pending, flush_mask))
{
int ret;
from waitpid before or after the event is. */
if (WIFSTOPPED (status) && !lp)
{
- linux_record_stopped_pid (lwpid);
+ linux_record_stopped_pid (lwpid, status);
status = 0;
continue;
}
fprintf_unfiltered (gdb_stdlog,
"LLW: Handling extended status 0x%06x\n",
status);
- if (linux_nat_handle_extended (lp, status, 0))
+ if (linux_handle_extended_wait (lp, status, 0))
{
status = 0;
continue;
target_pid_to_str (ptid),
errno ? safe_strerror (errno) : "OK");
- /* Not every Linux target implements PTRACE_PEEKUSER.
- But we can handle that case gracefully since ptrace
- will first do a lookup for the process based upon the
- passed-in pid. If that fails we will get either -ESRCH
- or -EPERM, otherwise the child exists and is alive. */
+ /* Not every Linux kernel implements PTRACE_PEEKUSER. But we can
+ handle that case gracefully since ptrace will first do a lookup
+ for the process based upon the passed-in pid. If that fails we
+ will get either -ESRCH or -EPERM, otherwise the child exists and
+ is alive. */
if (errno == ESRCH || errno == EPERM)
return 0;
size, paddr_nz (addr),
read ? 'r' : ' ',
write ? 'w' : ' ', exec ? 'x' : ' ');
- if (filename && filename[0])
+ if (filename[0])
fprintf_filtered (gdb_stdout, " for %s", filename);
fprintf_filtered (gdb_stdout, "\n");
}
if (cmdline_f || all)
{
sprintf (fname1, "/proc/%lld/cmdline", pid);
- if ((procfile = fopen (fname1, "r")) > 0)
+ if ((procfile = fopen (fname1, "r")) != NULL)
{
fgets (buffer, sizeof (buffer), procfile);
printf_filtered ("cmdline = '%s'\n", buffer);
if (mappings_f || all)
{
sprintf (fname1, "/proc/%lld/maps", pid);
- if ((procfile = fopen (fname1, "r")) > 0)
+ if ((procfile = fopen (fname1, "r")) != NULL)
{
long long addr, endaddr, size, offset, inode;
char permissions[8], device[8], filename[MAXPATHLEN];
if (status_f || all)
{
sprintf (fname1, "/proc/%lld/status", pid);
- if ((procfile = fopen (fname1, "r")) > 0)
+ if ((procfile = fopen (fname1, "r")) != NULL)
{
while (fgets (buffer, sizeof (buffer), procfile) != NULL)
puts_filtered (buffer);
if (stat_f || all)
{
sprintf (fname1, "/proc/%lld/stat", pid);
- if ((procfile = fopen (fname1, "r")) > 0)
+ if ((procfile = fopen (fname1, "r")) != NULL)
{
int itmp;
char ctmp;
projects / deliverable / binutils-gdb.git / blobdiff