#endif
#include <sys/ptrace.h>
#include "linux-nat.h"
+#include "linux-ptrace.h"
#include "linux-fork.h"
#include "gdbthread.h"
#include "gdbcmd.h"
#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 */
-
/* Unlike other extended result codes, WSTOPSIG (status) on
PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but
instead SIGTRAP with bit 7 set. */
#define SYSCALL_SIGTRAP (SIGTRAP | 0x80)
-/* 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
- here. */
-#ifndef __WALL
-#define __WALL 0x40000000 /* Wait for any child. */
-#endif
-
-#ifndef PTRACE_GETSIGINFO
-# define PTRACE_GETSIGINFO 0x4202
-# define PTRACE_SETSIGINFO 0x4203
-#endif
-
/* The single-threaded native GNU/Linux target_ops. We save a pointer for
the use of the multi-threaded target. */
static struct target_ops *linux_ops;
value);
}
-static int debug_linux_nat_async = 0;
-static void
-show_debug_linux_nat_async (struct ui_file *file, int from_tty,
- struct cmd_list_element *c, const char *value)
-{
- fprintf_filtered (file,
- _("Debugging of GNU/Linux async lwp module is %s.\n"),
- value);
-}
-
static int disable_randomization = 1;
static void
static int linux_supports_tracevforkdone_flag = -1;
-/* Async mode support. */
-
-/* Zero if the async mode, although enabled, is masked, which means
- linux_nat_wait should behave as if async mode was off. */
-static int linux_nat_async_mask_value = 1;
-
/* Stores the current used ptrace() options. */
static int current_ptrace_options = 0;
+/* Async mode support. */
+
/* The read/write ends of the pipe registered as waitable file in the
event loop. */
static int linux_nat_event_pipe[2] = { -1, -1 };
(enum inferior_event_type event_type,
void *context),
void *context);
-static int linux_nat_async_mask (int mask);
static int kill_lwp (int lwpid, int signo);
static int stop_callback (struct lwp_info *lp, void *data);
return !linux_supports_tracefork (pid);
}
+static int
+linux_child_remove_fork_catchpoint (int pid)
+{
+ return 0;
+}
+
static int
linux_child_insert_vfork_catchpoint (int pid)
{
return !linux_supports_tracefork (pid);
}
+static int
+linux_child_remove_vfork_catchpoint (int pid)
+{
+ return 0;
+}
+
static int
linux_child_insert_exec_catchpoint (int pid)
{
return !linux_supports_tracefork (pid);
}
+static int
+linux_child_remove_exec_catchpoint (int pid)
+{
+ return 0;
+}
+
static int
linux_child_set_syscall_catchpoint (int pid, int needed, int any_count,
int table_size, int *table)
{
sigprocmask (SIG_SETMASK, prev_mask, NULL);
}
+
+/* Mask of signals to pass directly to the inferior. */
+static sigset_t pass_mask;
+
+/* Update signals to pass to the inferior. */
+static void
+linux_nat_pass_signals (int numsigs, unsigned char *pass_signals)
+{
+ int signo;
+
+ sigemptyset (&pass_mask);
+
+ for (signo = 1; signo < NSIG; signo++)
+ {
+ int target_signo = target_signal_from_host (signo);
+ if (target_signo < numsigs && pass_signals[target_signo])
+ sigaddset (&pass_mask, signo);
+ }
+}
+
\f
/* Prototypes for local functions. */
status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
if (!WIFSTOPPED (status))
- return -1;
+ {
+ restore_child_signals_mask (&prev_mask);
+ return -1;
+ }
lp = add_lwp (ptid);
lp->stopped = 1;
}
#endif /* HAVE_PERSONALITY */
+ /* Make sure we report all signals during startup. */
+ linux_nat_pass_signals (0, NULL);
+
linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
#ifdef HAVE_PERSONALITY
int status;
ptid_t ptid;
+ /* Make sure we report all signals during attach. */
+ linux_nat_pass_signals (0, NULL);
+
linux_ops->to_attach (ops, args, from_tty);
/* The ptrace base target adds the main thread with (pid,0,0)
if (lp->status && WIFSTOPPED (lp->status))
{
- enum target_signal saved_signo;
- struct inferior *inf;
-
- inf = find_inferior_pid (ptid_get_pid (lp->ptid));
- gdb_assert (inf);
- saved_signo = target_signal_from_host (WSTOPSIG (lp->status));
-
- /* Defer to common code if we're gaining control of the
- inferior. */
- if (inf->control.stop_soon == NO_STOP_QUIETLY
- && signal_stop_state (saved_signo) == 0
- && signal_print_state (saved_signo) == 0
- && signal_pass_state (saved_signo) == 1)
+ if (!lp->step
+ && WSTOPSIG (lp->status)
+ && sigismember (&pass_mask, WSTOPSIG (lp->status)))
{
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
/* FIXME: What should we do if we are supposed to continue
this thread with a signal? */
gdb_assert (signo == TARGET_SIGNAL_0);
- signo = saved_signo;
+ signo = target_signal_from_host (WSTOPSIG (lp->status));
lp->status = 0;
}
}
if (event == PTRACE_EVENT_FORK
&& linux_fork_checkpointing_p (GET_PID (lp->ptid)))
{
- struct fork_info *fp;
-
/* Handle checkpointing by linux-fork.c here as a special
case. We don't want the follow-fork-mode or 'catch fork'
to interfere with this. */
detach_breakpoints (new_pid);
/* Retain child fork in ptrace (stopped) state. */
- fp = find_fork_pid (new_pid);
- if (!fp)
- fp = add_fork (new_pid);
+ if (!find_fork_pid (new_pid))
+ add_fork (new_pid);
/* Report as spurious, so that infrun doesn't want to follow
this fork. We're actually doing an infcall in
_("unknown ptrace event %d"), event);
}
+/* Return non-zero if LWP is a zombie. */
+
+static int
+linux_lwp_is_zombie (long lwp)
+{
+ char buffer[MAXPATHLEN];
+ FILE *procfile;
+ int retval = 0;
+
+ xsnprintf (buffer, sizeof (buffer), "/proc/%ld/status", lwp);
+ procfile = fopen (buffer, "r");
+ if (procfile == NULL)
+ {
+ warning (_("unable to open /proc file '%s'"), buffer);
+ return 0;
+ }
+ while (fgets (buffer, sizeof (buffer), procfile) != NULL)
+ if (strcmp (buffer, "State:\tZ (zombie)\n") == 0)
+ {
+ retval = 1;
+ break;
+ }
+ fclose (procfile);
+
+ return retval;
+}
+
/* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
exited. */
wait_lwp (struct lwp_info *lp)
{
pid_t pid;
- int status;
+ int status = 0;
int thread_dead = 0;
+ sigset_t prev_mask;
gdb_assert (!lp->stopped);
gdb_assert (lp->status == 0);
- pid = my_waitpid (GET_LWP (lp->ptid), &status, 0);
- if (pid == -1 && errno == ECHILD)
+ /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
+ block_child_signals (&prev_mask);
+
+ for (;;)
{
- pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
+ /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
+ was right and we should just call sigsuspend. */
+
+ pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG);
if (pid == -1 && errno == ECHILD)
+ pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG);
+ if (pid != 0)
+ break;
+
+ /* Bugs 10970, 12702.
+ Thread group leader may have exited in which case we'll lock up in
+ waitpid if there are other threads, even if they are all zombies too.
+ Basically, we're not supposed to use waitpid this way.
+ __WCLONE is not applicable for the leader so we can't use that.
+ LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
+ process; it gets ESRCH both for the zombie and for running processes.
+
+ As a workaround, check if we're waiting for the thread group leader and
+ if it's a zombie, and avoid calling waitpid if it is.
+
+ This is racy, what if the tgl becomes a zombie right after we check?
+ Therefore always use WNOHANG with sigsuspend - it is equivalent to
+ waiting waitpid but the linux_lwp_is_zombie is safe this way. */
+
+ if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)
+ && linux_lwp_is_zombie (GET_LWP (lp->ptid)))
{
- /* The thread has previously exited. We need to delete it
- now because, for some vendor 2.4 kernels with NPTL
- support backported, there won't be an exit event unless
- it is the main thread. 2.6 kernels will report an exit
- event for each thread that exits, as expected. */
thread_dead = 1;
if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
+ fprintf_unfiltered (gdb_stdlog,
+ "WL: Thread group leader %s vanished.\n",
target_pid_to_str (lp->ptid));
+ break;
}
+
+ /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
+ get invoked despite our caller had them intentionally blocked by
+ block_child_signals. This is sensitive only to the loop of
+ linux_nat_wait_1 and there if we get called my_waitpid gets called
+ again before it gets to sigsuspend so we can safely let the handlers
+ get executed here. */
+
+ sigsuspend (&suspend_mask);
+ }
+
+ restore_child_signals_mask (&prev_mask);
+
+ if (pid == -1 && errno == ECHILD)
+ {
+ /* The thread has previously exited. We need to delete it
+ now because, for some vendor 2.4 kernels with NPTL
+ support backported, there won't be an exit event unless
+ it is the main thread. 2.6 kernels will report an exit
+ event for each thread that exits, as expected. */
+ thread_dead = 1;
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
+ target_pid_to_str (lp->ptid));
}
if (!thread_dead)
if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
{
/* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
- or a a pending process exit. Note that `W_EXITCODE(0,0) ==
+ or a pending process exit. Note that `W_EXITCODE(0,0) ==
0', so a clean process exit can not be stored pending in
lp->status, it is indistinguishable from
no-pending-status. */
int status = 0;
pid_t pid;
- if (debug_linux_nat_async)
+ if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
/* The first time we get here after starting a new inferior, we may
{
ourstatus->kind = TARGET_WAITKIND_IGNORE;
- if (debug_linux_nat_async)
+ if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
restore_child_signals_mask (&prev_mask);
/* No interesting event. */
ourstatus->kind = TARGET_WAITKIND_IGNORE;
- if (debug_linux_nat_async)
+ if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
restore_child_signals_mask (&prev_mask);
/* No interesting event for PID yet. */
ourstatus->kind = TARGET_WAITKIND_IGNORE;
- if (debug_linux_nat_async)
+ if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
restore_child_signals_mask (&prev_mask);
if (WIFSTOPPED (status))
{
enum target_signal signo = target_signal_from_host (WSTOPSIG (status));
- struct inferior *inf;
-
- inf = find_inferior_pid (ptid_get_pid (lp->ptid));
- gdb_assert (inf);
- /* Defer to common code if we get a signal while
- single-stepping, since that may need special care, e.g. to
- skip the signal handler, or, if we're gaining control of the
- inferior. */
+ /* When using hardware single-step, we need to report every signal.
+ Otherwise, signals in pass_mask may be short-circuited. */
if (!lp->step
- && inf->control.stop_soon == NO_STOP_QUIETLY
- && signal_stop_state (signo) == 0
- && signal_print_state (signo) == 0
- && signal_pass_state (signo) == 1)
+ && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)))
{
/* FIMXE: kettenis/2001-06-06: Should we resume all threads
here? It is not clear we should. GDB may not expect
else
store_waitstatus (ourstatus, status);
- if (debug_linux_nat_async)
+ if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
restore_child_signals_mask (&prev_mask);
static int
kill_callback (struct lwp_info *lp, void *data)
{
+ /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
+
+ errno = 0;
+ kill (GET_LWP (lp->ptid), SIGKILL);
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
+ target_pid_to_str (lp->ptid),
+ errno ? safe_strerror (errno) : "OK");
+
+ /* Some kernels ignore even SIGKILL for processes under ptrace. */
+
errno = 0;
ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
if (debug_linux_nat)
static int
linux_thread_alive (ptid_t ptid)
{
- int err;
+ int err, tmp_errno;
gdb_assert (is_lwp (ptid));
running thread errors out claiming that the thread doesn't
exist. */
err = kill_lwp (GET_LWP (ptid), 0);
-
+ tmp_errno = errno;
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
"LLTA: KILL(SIG0) %s (%s)\n",
target_pid_to_str (ptid),
- err ? safe_strerror (err) : "OK");
+ err ? safe_strerror (tmp_errno) : "OK");
if (err != 0)
return 0;
if (get_exec_file (0))
{
- strncpy (fname, strrchr (get_exec_file (0), '/') + 1, sizeof (fname));
+ strncpy (fname, lbasename (get_exec_file (0)), sizeof (fname));
strncpy (psargs, get_exec_file (0), sizeof (psargs));
if (get_inferior_args ())
{
if ((f = fopen (pathname, "r")) != NULL)
{
- size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
+ size_t length = fread (cmd, 1, sizeof (cmd) - 1, f);
- if (len > 0)
+ if (length > 0)
{
int i;
- for (i = 0; i < len; i++)
+ for (i = 0; i < length; i++)
if (cmd[i] == '\0')
cmd[i] = ' ';
- cmd[len] = '\0';
+ cmd[length] = '\0';
obstack_xml_printf (
&obstack,
linux_target_install_ops (struct target_ops *t)
{
t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
+ t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
+ t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
+ t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
t->to_post_startup_inferior = linux_child_post_startup_inferior;
/* NOTE: palves 2008-03-21: We're only async when the user requests
it explicitly with the "set target-async" command.
Someday, linux will always be async. */
- if (!target_async_permitted)
- return 0;
-
- /* See target.h/target_async_mask. */
- return linux_nat_async_mask_value;
+ return target_async_permitted;
}
/* target_can_async_p implementation. */
/* NOTE: palves 2008-03-21: We're only async when the user requests
it explicitly with the "set target-async" command.
Someday, linux will always be async. */
- if (!target_async_permitted)
- return 0;
-
- /* See target.h/target_async_mask. */
- return linux_nat_async_mask_value;
+ return target_async_permitted;
}
static int
return linux_multi_process;
}
-/* target_async_mask implementation. */
-
-static int
-linux_nat_async_mask (int new_mask)
-{
- int curr_mask = linux_nat_async_mask_value;
-
- if (curr_mask != new_mask)
- {
- if (new_mask == 0)
- {
- linux_nat_async (NULL, 0);
- linux_nat_async_mask_value = new_mask;
- }
- else
- {
- linux_nat_async_mask_value = new_mask;
-
- /* If we're going out of async-mask in all-stop, then the
- inferior is stopped. The next resume will call
- target_async. In non-stop, the target event source
- should be always registered in the event loop. Do so
- now. */
- if (non_stop)
- linux_nat_async (inferior_event_handler, 0);
- }
- }
-
- return curr_mask;
-}
-
static int async_terminal_is_ours = 1;
/* target_terminal_inferior implementation. */
{
int old_errno = errno;
- if (debug_linux_nat_async)
- fprintf_unfiltered (gdb_stdlog, "sigchld\n");
+ if (debug_linux_nat)
+ ui_file_write_async_safe (gdb_stdlog,
+ "sigchld\n", sizeof ("sigchld\n") - 1);
if (signo == SIGCHLD
&& linux_nat_event_pipe[0] != -1)
linux_nat_async (void (*callback) (enum inferior_event_type event_type,
void *context), void *context)
{
- if (linux_nat_async_mask_value == 0 || !target_async_permitted)
- internal_error (__FILE__, __LINE__,
- "Calling target_async when async is masked");
-
if (callback != NULL)
{
async_client_callback = callback;
if (target_is_async_p ())
target_async (NULL, 0);
- /* Reset the async_masking. */
- linux_nat_async_mask_value = 1;
-
if (linux_ops->to_close)
linux_ops->to_close (quitting);
}
t->to_detach = linux_nat_detach;
t->to_resume = linux_nat_resume;
t->to_wait = linux_nat_wait;
+ t->to_pass_signals = linux_nat_pass_signals;
t->to_xfer_partial = linux_nat_xfer_partial;
t->to_kill = linux_nat_kill;
t->to_mourn_inferior = linux_nat_mourn_inferior;
t->to_is_async_p = linux_nat_is_async_p;
t->to_supports_non_stop = linux_nat_supports_non_stop;
t->to_async = linux_nat_async;
- t->to_async_mask = linux_nat_async_mask;
t->to_terminal_inferior = linux_nat_terminal_inferior;
t->to_terminal_ours = linux_nat_terminal_ours;
t->to_close = linux_nat_close;
show_debug_linux_nat,
&setdebuglist, &showdebuglist);
- add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance,
- &debug_linux_nat_async, _("\
-Set debugging of GNU/Linux async lwp module."), _("\
-Show debugging of GNU/Linux async lwp module."), _("\
-Enables printf debugging output."),
- NULL,
- show_debug_linux_nat_async,
- &setdebuglist, &showdebuglist);
-
/* Save this mask as the default. */
sigprocmask (SIG_SETMASK, NULL, &normal_mask);
projects / deliverable / binutils-gdb.git / blobdiff