1 /* Copyright (C) 2002-2014 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, see
17 <http://www.gnu.org/licenses/>. */
23 #include <stdio_ext.h>
26 #include <sys/resource.h>
28 #include <lowlevellock.h>
33 pthread_getattr_np (thread_id, attr)
37 struct pthread *thread = (struct pthread *) thread_id;
38 struct pthread_attr *iattr = (struct pthread_attr *) attr;
41 lll_lock (thread->lock, LLL_PRIVATE);
43 /* The thread library is responsible for keeping the values in the
44 thread desriptor up-to-date in case the user changes them. */
45 memcpy (&iattr->schedparam, &thread->schedparam,
46 sizeof (struct sched_param));
47 iattr->schedpolicy = thread->schedpolicy;
49 /* Clear the flags work. */
50 iattr->flags = thread->flags;
52 /* The thread might be detached by now. */
53 if (IS_DETACHED (thread))
54 iattr->flags |= ATTR_FLAG_DETACHSTATE;
56 /* This is the guardsize after adjusting it. */
57 iattr->guardsize = thread->reported_guardsize;
59 /* The sizes are subject to alignment. */
60 if (__glibc_likely (thread->stackblock != NULL))
62 iattr->stacksize = thread->stackblock_size;
63 iattr->stackaddr = (char *) thread->stackblock + iattr->stacksize;
67 /* No stack information available. This must be for the initial
68 thread. Get the info in some magical way. */
69 assert (abs (thread->pid) == thread->tid);
71 /* Stack size limit. */
74 /* The safest way to get the top of the stack is to read
75 /proc/self/maps and locate the line into which
76 __libc_stack_end falls. */
77 FILE *fp = fopen ("/proc/self/maps", "rce");
80 /* We need the limit of the stack in any case. */
83 if (getrlimit (RLIMIT_STACK, &rl) != 0)
87 /* We consider the main process stack to have ended with
88 the page containing __libc_stack_end. There is stuff below
89 it in the stack too, like the program arguments, environment
90 variables and auxv info, but we ignore those pages when
91 returning size so that the output is consistent when the
92 stack is marked executable due to a loaded DSO requiring
94 void *stack_end = (void *) ((uintptr_t) __libc_stack_end
95 & -(uintptr_t) GLRO(dl_pagesize));
97 stack_end += GLRO(dl_pagesize);
99 /* We need no locking. */
100 __fsetlocking (fp, FSETLOCKING_BYCALLER);
102 /* Until we found an entry (which should always be the case)
103 mark the result as a failure. */
108 uintptr_t last_to = 0;
110 while (! feof_unlocked (fp))
112 if (__getdelim (&line, &linelen, '\n', fp) <= 0)
117 if (sscanf (line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) != 2)
119 if (from <= (uintptr_t) __libc_stack_end
120 && (uintptr_t) __libc_stack_end < to)
122 /* Found the entry. Now we have the info we need. */
123 iattr->stackaddr = stack_end;
125 rl.rlim_cur - (size_t) (to - (uintptr_t) stack_end);
127 /* Cut it down to align it to page size since otherwise we
128 risk going beyond rlimit when the kernel rounds up the
129 stack extension request. */
130 iattr->stacksize = (iattr->stacksize
131 & -(intptr_t) GLRO(dl_pagesize));
133 /* The limit might be too high. */
134 if ((size_t) iattr->stacksize
135 > (size_t) iattr->stackaddr - last_to)
136 iattr->stacksize = (size_t) iattr->stackaddr - last_to;
138 /* We succeed and no need to look further. */
152 iattr->flags |= ATTR_FLAG_STACKADDR;
157 cpu_set_t *cpuset = NULL;
163 void *newp = realloc (cpuset, size);
169 cpuset = (cpu_set_t *) newp;
171 ret = __pthread_getaffinity_np (thread_id, size, cpuset);
173 /* Pick some ridiculous upper limit. Is 8 million CPUs enough? */
174 while (ret == EINVAL && size < 1024 * 1024);
178 iattr->cpuset = cpuset;
179 iattr->cpusetsize = size;
186 /* There is no such functionality. */
188 iattr->cpuset = NULL;
189 iattr->cpusetsize = 0;
194 lll_unlock (thread->lock, LLL_PRIVATE);