diff options
Diffstat (limited to 'nptl')
| -rw-r--r-- | nptl/ChangeLog | 5 | ||||
| -rw-r--r-- | nptl/pthread_getattr_np.c | 78 |
2 files changed, 79 insertions, 4 deletions
diff --git a/nptl/ChangeLog b/nptl/ChangeLog index 17648b8008..2491cd990e 100644 --- a/nptl/ChangeLog +++ b/nptl/ChangeLog @@ -1,3 +1,8 @@ +2003-09-16 Ulrich Drepper <drepper@redhat.com> + + * pthread_getattr_np.c (pthread_getattr_np): Correctly fill in the + stack-related values for the initial thread. + 2003-09-15 Jakub Jelinek <jakub@redhat.com> * Makefile (CFLAGS-pthread_once.c): Add $(uses-callbacks). 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; } |