/* GNU/Linux native-dependent code common to multiple platforms.
- Copyright (C) 2001-2016 Free Software Foundation, Inc.
+ Copyright (C) 2001-2017 Free Software Foundation, Inc.
This file is part of GDB.
return lwp->stop_reason;
}
+/* See nat/linux-nat.h. */
+
+int
+lwp_is_stepping (struct lwp_info *lwp)
+{
+ return lwp->step;
+}
+
\f
/* Trivial list manipulation functions to keep track of a list of
new stopped processes. */
static int stop_wait_callback (struct lwp_info *lp, void *data);
static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
+static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp);
\f
/* We need to wait for a stop before being able to make the
next ptrace call on this LWP. */
lp->must_set_ptrace_flags = 1;
+
+ /* So that wait collects the SIGSTOP. */
+ lp->resumed = 1;
+
+ /* Also add the LWP to gdb's thread list, in case a
+ matching libthread_db is not found (or the process uses
+ raw clone). */
+ add_thread (lp->ptid);
+ set_running (lp->ptid, 1);
+ set_executing (lp->ptid, 1);
}
return 1;
int exit_code = WEXITSTATUS (status);
target_terminal_ours ();
- target_mourn_inferior ();
+ target_mourn_inferior (inferior_ptid);
if (exit_code == 0)
error (_("Unable to attach: program exited normally."));
else
enum gdb_signal signo;
target_terminal_ours ();
- target_mourn_inferior ();
+ target_mourn_inferior (inferior_ptid);
signo = gdb_signal_from_host (WTERMSIG (status));
error (_("Unable to attach: program terminated with signal "
target_async (1);
}
-/* Get pending status of LP. */
+/* Get pending signal of THREAD as a host signal number, for detaching
+ purposes. This is the signal the thread last stopped for, which we
+ need to deliver to the thread when detaching, otherwise, it'd be
+ suppressed/lost. */
+
static int
-get_pending_status (struct lwp_info *lp, int *status)
+get_detach_signal (struct lwp_info *lp)
{
enum gdb_signal signo = GDB_SIGNAL_0;
}
}
- *status = 0;
-
if (signo == GDB_SIGNAL_0)
{
if (debug_linux_nat)
}
else
{
- *status = W_STOPCODE (gdb_signal_to_host (signo));
-
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
"GPT: lwp %s has pending signal %s\n",
target_pid_to_str (lp->ptid),
gdb_signal_to_string (signo));
+
+ return gdb_signal_to_host (signo);
}
return 0;
}
-static int
-detach_callback (struct lwp_info *lp, void *data)
+/* Detach from LP. If SIGNO_P is non-NULL, then it points to the
+ signal number that should be passed to the LWP when detaching.
+ Otherwise pass any pending signal the LWP may have, if any. */
+
+static void
+detach_one_lwp (struct lwp_info *lp, int *signo_p)
{
+ int lwpid = ptid_get_lwp (lp->ptid);
+ int signo;
+
gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
if (debug_linux_nat && lp->status)
"DC: Sending SIGCONT to %s\n",
target_pid_to_str (lp->ptid));
- kill_lwp (ptid_get_lwp (lp->ptid), SIGCONT);
+ kill_lwp (lwpid, SIGCONT);
lp->signalled = 0;
}
- /* We don't actually detach from the LWP that has an id equal to the
- overall process id just yet. */
- if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
+ if (signo_p == NULL)
{
- int status = 0;
-
/* Pass on any pending signal for this LWP. */
- get_pending_status (lp, &status);
+ signo = get_detach_signal (lp);
+ }
+ else
+ signo = *signo_p;
+ /* Preparing to resume may try to write registers, and fail if the
+ lwp is zombie. If that happens, ignore the error. We'll handle
+ it below, when detach fails with ESRCH. */
+ TRY
+ {
if (linux_nat_prepare_to_resume != NULL)
linux_nat_prepare_to_resume (lp);
- errno = 0;
- if (ptrace (PTRACE_DETACH, ptid_get_lwp (lp->ptid), 0,
- WSTOPSIG (status)) < 0)
- error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
- safe_strerror (errno));
+ }
+ CATCH (ex, RETURN_MASK_ERROR)
+ {
+ if (!check_ptrace_stopped_lwp_gone (lp))
+ throw_exception (ex);
+ }
+ END_CATCH
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "PTRACE_DETACH (%s, %s, 0) (OK)\n",
- target_pid_to_str (lp->ptid),
- strsignal (WSTOPSIG (status)));
+ if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0)
+ {
+ int save_errno = errno;
+
+ /* We know the thread exists, so ESRCH must mean the lwp is
+ zombie. This can happen if one of the already-detached
+ threads exits the whole thread group. In that case we're
+ still attached, and must reap the lwp. */
+ if (save_errno == ESRCH)
+ {
+ int ret, status;
- delete_lwp (lp->ptid);
+ ret = my_waitpid (lwpid, &status, __WALL);
+ if (ret == -1)
+ {
+ warning (_("Couldn't reap LWP %d while detaching: %s"),
+ lwpid, strerror (errno));
+ }
+ else if (!WIFEXITED (status) && !WIFSIGNALED (status))
+ {
+ warning (_("Reaping LWP %d while detaching "
+ "returned unexpected status 0x%x"),
+ lwpid, status);
+ }
+ }
+ else
+ {
+ error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
+ safe_strerror (save_errno));
+ }
}
+ else if (debug_linux_nat)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "PTRACE_DETACH (%s, %s, 0) (OK)\n",
+ target_pid_to_str (lp->ptid),
+ strsignal (signo));
+ }
+
+ delete_lwp (lp->ptid);
+}
+static int
+detach_callback (struct lwp_info *lp, void *data)
+{
+ /* We don't actually detach from the thread group leader just yet.
+ If the thread group exits, we must reap the zombie clone lwps
+ before we're able to reap the leader. */
+ if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
+ detach_one_lwp (lp, NULL);
return 0;
}
linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
{
int pid;
- int status;
struct lwp_info *main_lwp;
pid = ptid_get_pid (inferior_ptid);
main_lwp = find_lwp_pid (pid_to_ptid (pid));
- /* Pass on any pending signal for the last LWP. */
- if ((args == NULL || *args == '\0')
- && get_pending_status (main_lwp, &status) != -1
- && WIFSTOPPED (status))
- {
- char *tem;
-
- /* Put the signal number in ARGS so that inf_ptrace_detach will
- pass it along with PTRACE_DETACH. */
- tem = (char *) alloca (8);
- xsnprintf (tem, 8, "%d", (int) WSTOPSIG (status));
- args = tem;
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "LND: Sending signal %s to %s\n",
- args,
- target_pid_to_str (main_lwp->ptid));
- }
-
- if (linux_nat_prepare_to_resume != NULL)
- linux_nat_prepare_to_resume (main_lwp);
- delete_lwp (main_lwp->ptid);
-
if (forks_exist_p ())
{
/* Multi-fork case. The current inferior_ptid is being detached
linux_fork_detach (args, from_tty);
}
else
- linux_ops->to_detach (ops, args, from_tty);
+ {
+ int signo;
+
+ target_announce_detach (from_tty);
+
+ /* Pass on any pending signal for the last LWP, unless the user
+ requested detaching with a different signal (most likely 0,
+ meaning, discard the signal). */
+ if (args != NULL)
+ signo = atoi (args);
+ else
+ signo = get_detach_signal (main_lwp);
+
+ detach_one_lwp (main_lwp, &signo);
+
+ inf_ptrace_detach_success (ops);
+ }
+ delete_lwp (main_lwp->ptid);
}
/* Resume execution of the inferior process. If STEP is nonzero,
iterate_over_lwps (ptid, kill_wait_callback, NULL);
}
- target_mourn_inferior ();
+ target_mourn_inferior (inferior_ptid);
}
static void
return linux_proc_pid_to_exec_file (pid);
}
-/* Implement the to_xfer_partial interface for memory reads using the /proc
- filesystem. Because we can use a single read() call for /proc, this
- can be much more efficient than banging away at PTRACE_PEEKTEXT,
- but it doesn't support writes. */
+/* Implement the to_xfer_partial target method using /proc/<pid>/mem.
+ Because we can use a single read/write call, this can be much more
+ efficient than banging away at PTRACE_PEEKTEXT. */
static enum target_xfer_status
linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
int fd;
char filename[64];
- if (object != TARGET_OBJECT_MEMORY || !readbuf)
+ if (object != TARGET_OBJECT_MEMORY)
return TARGET_XFER_EOF;
/* Don't bother for one word. */
thread. That requires some juggling, but is even faster. */
xsnprintf (filename, sizeof filename, "/proc/%d/mem",
ptid_get_pid (inferior_ptid));
- fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0);
+ fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY)
+ | O_LARGEFILE), 0);
if (fd == -1)
return TARGET_XFER_EOF;
- /* 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). */
+ /* Use pread64/pwrite64 if available, since they save a syscall and can
+ handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
+ debugging a SPARC64 application). */
#ifdef HAVE_PREAD64
- if (pread64 (fd, readbuf, len, offset) != len)
+ ret = (readbuf ? pread64 (fd, readbuf, len, offset)
+ : pwrite64 (fd, writebuf, len, offset));
#else
- if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
+ ret = lseek (fd, offset, SEEK_SET);
+ if (ret != -1)
+ ret = (readbuf ? read (fd, readbuf, len)
+ : write (fd, writebuf, len));
#endif
- ret = 0;
- else
- ret = len;
close (fd);
- if (ret == 0)
+ if (ret == -1 || ret == 0)
return TARGET_XFER_EOF;
else
{
gdb_assert (arg != NULL);
/* Unpause all */
- target_resume (*ptid, 0, GDB_SIGNAL_0);
+ target_continue_no_signal (*ptid);
}
static VEC(static_tracepoint_marker_p) *
static int
linux_nat_can_async_p (struct target_ops *ops)
{
- /* 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. */
+ /* We're always async, unless the user explicitly prevented it with the
+ "maint set target-async" command. */
return target_async_permitted;
}
if (!async_terminal_is_ours)
return;
- delete_file_handler (input_fd);
async_terminal_is_ours = 0;
set_sigint_trap ();
}
return;
clear_sigint_trap ();
- add_file_handler (input_fd, stdin_event_handler, 0);
async_terminal_is_ours = 1;
}
projects / deliverable / binutils-gdb.git / blobdiff