Messages in this thread Patch in this message | | | Date | Tue, 22 Apr 2008 12:18:37 -0500 | From | Eric Sandeen <> | Subject | [PATCH] Fix max-stack calculators to skip canary |
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With the canary on the end of the stack, anything which looks for 0 to mean unused when calculating max stack excursions must skip over this non-zero magic number.
Signed-off-by: Eric Sandeen <sandeen@redhat.com> ---
Index: linux-2.6.25/kernel/exit.c =================================================================== --- linux-2.6.25.orig/kernel/exit.c 2008-04-20 22:34:16.000000000 -0500 +++ linux-2.6.25/kernel/exit.c 2008-04-22 11:38:05.769412824 -0500 @@ -826,6 +826,8 @@ static void check_stack_usage(void) unsigned long *n = end_of_stack(current); unsigned long free; + n++; /* skip over canary at end */ + while (*n == 0) n++; free = (unsigned long)n - (unsigned long)end_of_stack(current); Index: linux-2.6.25/kernel/sched.c =================================================================== --- linux-2.6.25.orig/kernel/sched.c 2008-04-20 22:34:19.000000000 -0500 +++ linux-2.6.25/kernel/sched.c 2008-04-22 11:48:06.975407495 -0500 @@ -5190,6 +5190,8 @@ void sched_show_task(struct task_struct #ifdef CONFIG_DEBUG_STACK_USAGE { unsigned long *n = end_of_stack(p); + + n++; /* skip over canary at end */ while (!*n) n++; free = (unsigned long)n - (unsigned long)end_of_stack(p);
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