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Diffstat (limited to 'nptl/pthread_getattr_np.c')
-rw-r--r--nptl/pthread_getattr_np.c78
1 files changed, 74 insertions, 4 deletions
diff --git a/nptl/pthread_getattr_np.c b/nptl/pthread_getattr_np.c
index 4e580437cf..dfacd887c9 100644
--- a/nptl/pthread_getattr_np.c
+++ b/nptl/pthread_getattr_np.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
@@ -17,7 +17,14 @@
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
#include <string.h>
+#include <sys/resource.h>
#include "pthreadP.h"
#include <lowlevellock.h>
@@ -29,6 +36,7 @@ pthread_getattr_np (thread_id, attr)
{
struct pthread *thread = (struct pthread *) thread_id;
struct pthread_attr *iattr = (struct pthread_attr *) attr;
+ int ret = 0;
/* We have to handle cancellation in the following code since we are
locking another threads desriptor. */
@@ -53,13 +61,75 @@ pthread_getattr_np (thread_id, attr)
iattr->guardsize = thread->guardsize;
/* The sizes are subject to alignment. */
- iattr->stacksize = thread->stackblock_size;
- iattr->stackaddr = (char *) thread->stackblock + iattr->stacksize;
+ if (__builtin_expect (thread->stackblock != NULL, 1))
+ {
+ iattr->stacksize = thread->stackblock_size;
+ iattr->stackaddr = (char *) thread->stackblock + iattr->stacksize;
+ }
+ else
+ {
+ /* No stack information available. This must be for the initial
+ thread. Get the info in some magical way. */
+ assert (thread->pid == thread->tid);
+
+ /* Defined in ld.so. */
+ extern void *__libc_stack_end;
+
+ /* Stack size limit. */
+ struct rlimit rl;
+
+ /* The safest way to get the top of the stack is to read
+ /proc/self/maps and locate the line into which
+ __libc_stack_end falls. */
+ FILE *fp = fopen ("/proc/self/maps", "rc");
+ if (fp == NULL)
+ ret = errno;
+ /* We need the limit of the stack in any case. */
+ else if (getrlimit (RLIMIT_STACK, &rl) != 0)
+ ret = errno;
+ else
+ {
+ /* We need no locking. */
+ __fsetlocking (fp, FSETLOCKING_BYCALLER);
+
+ /* Until we found an entry (which should always be the case)
+ mark the result as a failure. */
+ ret = ENOENT;
+
+ char *line = NULL;
+ size_t linelen = 0;
+
+ while (! feof_unlocked (fp))
+ {
+ if (__getdelim (&line, &linelen, '\n', fp) <= 0)
+ break;
+
+ uintptr_t from;
+ uintptr_t to;
+ if (sscanf (line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) == 2
+ && from <= (uintptr_t) __libc_stack_end
+ && (uintptr_t) __libc_stack_end < to)
+ {
+ /* Found the entry. Now we have the info we need. */
+ iattr->stacksize = rl.rlim_cur;
+ iattr->stackaddr = (void *) to;
+
+ /* We succeed and no need to look further. */
+ ret = 0;
+ break;
+ }
+ }
+
+ fclose (fp);
+ free (line);
+ }
+ }
+
iattr->flags |= ATTR_FLAG_STACKADDR;
lll_unlock (thread->lock);
pthread_cleanup_pop (0);
- return 0;
+ return ret;
}