Override elf_nacl.xr linker script so that libc_pic.os links correctly
[glibc/nacl-glibc.git] / nptl / pthread_getattr_np.c
blob9c25caff89ad0401cf2d412fb018ccba930bf525
1 /* Copyright (C) 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <assert.h>
21 #include <errno.h>
22 #include <inttypes.h>
23 #include <stdio.h>
24 #include <stdio_ext.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/resource.h>
28 #include "pthreadP.h"
29 #include <lowlevellock.h>
30 #include <ldsodefs.h>
33 int
34 pthread_getattr_np (thread_id, attr)
35 pthread_t thread_id;
36 pthread_attr_t *attr;
38 struct pthread *thread = (struct pthread *) thread_id;
39 struct pthread_attr *iattr = (struct pthread_attr *) attr;
40 int ret = 0;
42 lll_lock (thread->lock, LLL_PRIVATE);
44 /* The thread library is responsible for keeping the values in the
45 thread desriptor up-to-date in case the user changes them. */
46 memcpy (&iattr->schedparam, &thread->schedparam,
47 sizeof (struct sched_param));
48 iattr->schedpolicy = thread->schedpolicy;
50 /* Clear the flags work. */
51 iattr->flags = thread->flags;
53 /* The thread might be detached by now. */
54 if (IS_DETACHED (thread))
55 iattr->flags |= ATTR_FLAG_DETACHSTATE;
57 /* This is the guardsize after adjusting it. */
58 iattr->guardsize = thread->reported_guardsize;
60 /* The sizes are subject to alignment. */
61 if (__builtin_expect (thread->stackblock != NULL, 1))
63 iattr->stacksize = thread->stackblock_size;
64 iattr->stackaddr = (char *) thread->stackblock + iattr->stacksize;
66 else
68 /* No stack information available. This must be for the initial
69 thread. Get the info in some magical way. */
70 assert (abs (thread->pid) == thread->tid);
72 /* Stack size limit. */
73 struct rlimit rl;
75 /* The safest way to get the top of the stack is to read
76 /proc/self/maps and locate the line into which
77 __libc_stack_end falls. */
78 FILE *fp = fopen ("/proc/self/maps", "rc");
79 if (fp == NULL)
80 ret = errno;
81 /* We need the limit of the stack in any case. */
82 else
84 if (getrlimit (RLIMIT_STACK, &rl) != 0)
85 ret = errno;
86 else
88 /* We need no locking. */
89 __fsetlocking (fp, FSETLOCKING_BYCALLER);
91 /* Until we found an entry (which should always be the case)
92 mark the result as a failure. */
93 ret = ENOENT;
95 char *line = NULL;
96 size_t linelen = 0;
97 uintptr_t last_to = 0;
99 while (! feof_unlocked (fp))
101 if (__getdelim (&line, &linelen, '\n', fp) <= 0)
102 break;
104 uintptr_t from;
105 uintptr_t to;
106 if (sscanf (line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) != 2)
107 continue;
108 if (from <= (uintptr_t) __libc_stack_end
109 && (uintptr_t) __libc_stack_end < to)
111 /* Found the entry. Now we have the info we need. */
112 iattr->stacksize = rl.rlim_cur;
113 iattr->stackaddr = (void *) to;
115 /* The limit might be too high. */
116 if ((size_t) iattr->stacksize
117 > (size_t) iattr->stackaddr - last_to)
118 iattr->stacksize = (size_t) iattr->stackaddr - last_to;
120 /* We succeed and no need to look further. */
121 ret = 0;
122 break;
124 last_to = to;
127 free (line);
130 fclose (fp);
134 iattr->flags |= ATTR_FLAG_STACKADDR;
136 if (ret == 0)
138 size_t size = 16;
139 cpu_set_t *cpuset = NULL;
143 size <<= 1;
145 void *newp = realloc (cpuset, size);
146 if (newp == NULL)
148 ret = ENOMEM;
149 break;
151 cpuset = (cpu_set_t *) newp;
153 ret = __pthread_getaffinity_np (thread_id, size, cpuset);
155 /* Pick some ridiculous upper limit. Is 8 million CPUs enough? */
156 while (ret == EINVAL && size < 1024 * 1024);
158 if (ret == 0)
160 iattr->cpuset = cpuset;
161 iattr->cpusetsize = size;
163 else
165 free (cpuset);
166 if (ret == ENOSYS)
168 /* There is no such functionality. */
169 ret = 0;
170 iattr->cpuset = NULL;
171 iattr->cpusetsize = 0;
176 lll_unlock (thread->lock, LLL_PRIVATE);
178 return ret;