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96d7229d LM |
1 | /* Wrapper implementation for waitpid for GNU/Linux (LWP layer). |
2 | ||
ecd75fc8 | 3 | Copyright (C) 2001-2014 Free Software Foundation, Inc. |
96d7229d LM |
4 | |
5 | This file is part of GDB. | |
6 | ||
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. | |
11 | ||
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. | |
16 | ||
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/>. */ | |
19 | ||
20 | #ifdef GDBSERVER | |
21 | #include "server.h" | |
22 | #else | |
23 | #include "defs.h" | |
24 | #include "signal.h" | |
25 | #endif | |
26 | ||
125f8a3d GB |
27 | #include "linux-nat.h" |
28 | #include "linux-waitpid.h" | |
96d7229d LM |
29 | #include "gdb_wait.h" |
30 | ||
31 | /* Print debugging output based on the format string FORMAT and | |
32 | its parameters. */ | |
33 | ||
34 | static inline void | |
35 | linux_debug (const char *format, ...) | |
36 | { | |
37 | #ifdef GDBSERVER | |
38 | if (debug_threads) | |
39 | { | |
40 | va_list args; | |
41 | va_start (args, format); | |
42 | vfprintf (stderr, format, args); | |
96d7229d LM |
43 | va_end (args); |
44 | } | |
45 | #else | |
46 | /* GDB-specific debugging output. */ | |
47 | #endif | |
48 | } | |
49 | ||
d632a097 PA |
50 | /* Convert wait status STATUS to a string. Used for printing debug |
51 | messages only. */ | |
52 | ||
53 | char * | |
54 | status_to_str (int status) | |
55 | { | |
56 | static char buf[64]; | |
57 | ||
58 | if (WIFSTOPPED (status)) | |
59 | { | |
60 | if (WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
61 | snprintf (buf, sizeof (buf), "%s (stopped at syscall)", | |
62 | strsignal (SIGTRAP)); | |
63 | else | |
64 | snprintf (buf, sizeof (buf), "%s (stopped)", | |
65 | strsignal (WSTOPSIG (status))); | |
66 | } | |
67 | else if (WIFSIGNALED (status)) | |
68 | snprintf (buf, sizeof (buf), "%s (terminated)", | |
69 | strsignal (WTERMSIG (status))); | |
70 | else | |
71 | snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status)); | |
72 | ||
73 | return buf; | |
74 | } | |
75 | ||
96d7229d LM |
76 | /* Wrapper function for waitpid which handles EINTR, and emulates |
77 | __WALL for systems where that is not available. */ | |
78 | ||
79 | int | |
80 | my_waitpid (int pid, int *status, int flags) | |
81 | { | |
82 | int ret, out_errno; | |
83 | ||
84 | linux_debug ("my_waitpid (%d, 0x%x)\n", pid, flags); | |
85 | ||
86 | if (flags & __WALL) | |
87 | { | |
88 | sigset_t block_mask, org_mask, wake_mask; | |
89 | int wnohang; | |
90 | ||
91 | wnohang = (flags & WNOHANG) != 0; | |
92 | flags &= ~(__WALL | __WCLONE); | |
96d7229d | 93 | |
2fa0369e PA |
94 | if (!wnohang) |
95 | { | |
96 | flags |= WNOHANG; | |
97 | ||
98 | /* Block all signals while here. This avoids knowing about | |
99 | LinuxThread's signals. */ | |
100 | sigfillset (&block_mask); | |
101 | sigprocmask (SIG_BLOCK, &block_mask, &org_mask); | |
96d7229d | 102 | |
2fa0369e PA |
103 | /* ... except during the sigsuspend below. */ |
104 | sigemptyset (&wake_mask); | |
105 | } | |
96d7229d LM |
106 | |
107 | while (1) | |
108 | { | |
109 | /* Since all signals are blocked, there's no need to check | |
110 | for EINTR here. */ | |
111 | ret = waitpid (pid, status, flags); | |
112 | out_errno = errno; | |
113 | ||
114 | if (ret == -1 && out_errno != ECHILD) | |
115 | break; | |
116 | else if (ret > 0) | |
117 | break; | |
118 | ||
119 | if (flags & __WCLONE) | |
120 | { | |
121 | /* We've tried both flavors now. If WNOHANG is set, | |
122 | there's nothing else to do, just bail out. */ | |
123 | if (wnohang) | |
124 | break; | |
125 | ||
126 | linux_debug ("blocking\n"); | |
127 | ||
128 | /* Block waiting for signals. */ | |
129 | sigsuspend (&wake_mask); | |
130 | } | |
131 | flags ^= __WCLONE; | |
132 | } | |
133 | ||
2fa0369e PA |
134 | if (!wnohang) |
135 | sigprocmask (SIG_SETMASK, &org_mask, NULL); | |
96d7229d LM |
136 | } |
137 | else | |
138 | { | |
139 | do | |
140 | ret = waitpid (pid, status, flags); | |
141 | while (ret == -1 && errno == EINTR); | |
142 | out_errno = errno; | |
143 | } | |
144 | ||
145 | linux_debug ("my_waitpid (%d, 0x%x): status(%x), %d\n", | |
146 | pid, flags, status ? *status : -1, ret); | |
147 | ||
148 | errno = out_errno; | |
149 | return ret; | |
150 | } |