diff options
Diffstat (limited to 'nptl')
| -rw-r--r-- | nptl/ChangeLog | 4 | ||||
| -rw-r--r-- | nptl/tst-pthread-getattr.c | 52 |
2 files changed, 16 insertions, 40 deletions
diff --git a/nptl/ChangeLog b/nptl/ChangeLog index 0a1c10fb8a..71f8e954d5 100644 --- a/nptl/ChangeLog +++ b/nptl/ChangeLog @@ -1,3 +1,7 @@ +2012-07-25 Siddhesh Poyarekar <siddhesh@redhat.com> + + * tst-pthread-getattr.c: Revert last change. + 2012-07-20 Siddhesh Poyarekar <siddhesh@redhat.com> * tst-pthread-getattr.c (MAX_STACK_SIZE): New max cap for stack diff --git a/nptl/tst-pthread-getattr.c b/nptl/tst-pthread-getattr.c index 692bce4629..6f2cfc6514 100644 --- a/nptl/tst-pthread-getattr.c +++ b/nptl/tst-pthread-getattr.c @@ -23,38 +23,16 @@ #include <sys/resource.h> #include <pthread.h> #include <alloca.h> -#include <assert.h> - -/* There is an obscure bug in the kernel due to which RLIMIT_STACK is sometimes - returned as unlimited when it is not, which may cause this test to fail. - There is also the other case where RLIMIT_STACK is intentionally set as - unlimited or very high, which may result in a vma that is too large and again - results in a test case failure. To avoid these problems, we cap the stack - size to one less than 8M. See the following mailing list threads for more - information about this problem: - <http://sourceware.org/ml/libc-alpha/2012-06/msg00599.html> - <http://sourceware.org/ml/libc-alpha/2012-06/msg00713.html>. */ -#define MAX_STACK_SIZE (8192 * 1024 - 1) - -#define _MIN(l,o) ((l) < (o) ? (l) : (o)) /* Move the stack pointer so that stackaddr is accessible and then check if it really is accessible. This will segfault if it fails. */ -static void * +static void allocate_and_test (void *stackaddr) { void *mem = &mem; - /* FIXME: mem >= stackaddr for _STACK_GROWSUP. */ + /* FIXME: The difference will be negative for _STACK_GROWSUP. */ mem = alloca ((size_t) (mem - stackaddr)); - assert (mem <= stackaddr); - - /* We don't access mem here because the compiler may move the stack pointer - beyond what we expect, thus making our alloca send the stack pointer - beyond stackaddr. Using only stackaddr without the assert may make the - compiler think that this instruction is independent of the above alloca - and hence reshuffle to do this dereference before the alloca. */ - *(int *)stackaddr = 42; - return stackaddr; + *(int *)(mem) = 0; } static int @@ -99,20 +77,17 @@ check_stack_top (void) return 1; } - printf ("current rlimit_stack is %zu\n", stack_limit.rlim_cur); - if (get_self_pthread_attr ("check_stack_top", &stackaddr, &stacksize)) return 1; - /* Reduce the rlimit to a page less that what is currently being returned - (subject to a maximum of MAX_STACK_SIZE) so that we ensure that - pthread_getattr_np uses rlimit. The figure is intentionally unaligned so - to verify that pthread_getattr_np returns an aligned stacksize that - correctly fits into the rlimit. We don't bother about the case where the - stack is limited by the vma below it and not by the rlimit because the - stacksize returned in that case is computed from the end of that vma and is - hence safe. */ - stack_limit.rlim_cur = _MIN(stacksize - 4095, MAX_STACK_SIZE); + /* Reduce the rlimit to a page less that what is currently being returned so + that we ensure that pthread_getattr_np uses rlimit. The figure is + intentionally unaligned so to verify that pthread_getattr_np returns an + aligned stacksize that correctly fits into the rlimit. We don't bother + about the case where the stack is limited by the vma below it and not by + the rlimit because the stacksize returned in that case is computed from + the end of that vma and is hence safe. */ + stack_limit.rlim_cur = stacksize - 4095; printf ("Adjusting RLIMIT_STACK to %zu\n", stack_limit.rlim_cur); if ((ret = setrlimit (RLIMIT_STACK, &stack_limit))) { @@ -125,10 +100,7 @@ check_stack_top (void) printf ("Adjusted rlimit: stacksize=%zu, stackaddr=%p\n", stacksize, stackaddr); - - /* So that the compiler does not optimize out this call. */ - stackaddr = allocate_and_test (stackaddr); - assert (*(int *)stackaddr == 42); + allocate_and_test (stackaddr); puts ("Stack top tests done"); |