1 /* Wrapper implementation for waitpid for GNU/Linux (LWP layer).
3 Copyright (C) 2001-2014 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "nat/linux-nat.h"
28 #include "nat/linux-waitpid.h"
33 /* Print debugging output based on the format string FORMAT and
37 linux_debug (const char *format, ...)
43 va_start (args, format);
44 vfprintf (stderr, format, args);
48 /* GDB-specific debugging output. */
52 /* Convert wait status STATUS to a string. Used for printing debug
56 status_to_str (int status)
60 if (WIFSTOPPED (status))
62 if (WSTOPSIG (status) == SYSCALL_SIGTRAP)
63 snprintf (buf, sizeof (buf), "%s (stopped at syscall)",
66 snprintf (buf, sizeof (buf), "%s (stopped)",
67 strsignal (WSTOPSIG (status)));
69 else if (WIFSIGNALED (status))
70 snprintf (buf, sizeof (buf), "%s (terminated)",
71 strsignal (WTERMSIG (status)));
73 snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
78 /* Wrapper function for waitpid which handles EINTR, and emulates
79 __WALL for systems where that is not available. */
82 my_waitpid (int pid, int *status, int flags)
86 linux_debug ("my_waitpid (%d, 0x%x)\n", pid, flags);
90 sigset_t block_mask, org_mask, wake_mask;
93 wnohang = (flags & WNOHANG) != 0;
94 flags &= ~(__WALL | __WCLONE);
97 /* Block all signals while here. This avoids knowing about
98 LinuxThread's signals. */
99 sigfillset (&block_mask);
100 sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
102 /* ... except during the sigsuspend below. */
103 sigemptyset (&wake_mask);
107 /* Since all signals are blocked, there's no need to check
109 ret = waitpid (pid, status, flags);
112 if (ret == -1 && out_errno != ECHILD)
117 if (flags & __WCLONE)
119 /* We've tried both flavors now. If WNOHANG is set,
120 there's nothing else to do, just bail out. */
124 linux_debug ("blocking\n");
126 /* Block waiting for signals. */
127 sigsuspend (&wake_mask);
132 sigprocmask (SIG_SETMASK, &org_mask, NULL);
137 ret = waitpid (pid, status, flags);
138 while (ret == -1 && errno == EINTR);
142 linux_debug ("my_waitpid (%d, 0x%x): status(%x), %d\n",
143 pid, flags, status ? *status : -1, ret);