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| author | Jeff Dike <jdike@addtoit.com> | 2007-07-15 23:38:48 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-16 09:05:38 -0700 |
| commit | e18eecb8b35703a5eea73ee2b45324262029e62c (patch) | |
| tree | 8c276ae6633b8116ca366274091b00491fd50bbe /kernel/exit.c | |
| parent | 84812217e395f5272eac36856c0a2415d61fe139 (diff) | |
| download | lwn-e18eecb8b35703a5eea73ee2b45324262029e62c.tar.gz lwn-e18eecb8b35703a5eea73ee2b45324262029e62c.zip | |
Add generic exit-time stack-depth checking to CONFIG_DEBUG_STACK_USAGE
Add generic exit-time stack-depth checking to CONFIG_DEBUG_STACK_USAGE.
This also adds UML support.
Tested on UML and i386.
[akpm@linux-foundation.org: cleanups, speedups, tweaks]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index ca6a11b73023..64a5263c8c7b 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -858,6 +858,34 @@ static void exit_notify(struct task_struct *tsk) release_task(tsk); } +#ifdef CONFIG_DEBUG_STACK_USAGE +static void check_stack_usage(void) +{ + static DEFINE_SPINLOCK(low_water_lock); + static int lowest_to_date = THREAD_SIZE; + unsigned long *n = end_of_stack(current); + unsigned long free; + + while (*n == 0) + n++; + free = (unsigned long)n - (unsigned long)end_of_stack(current); + + if (free >= lowest_to_date) + return; + + spin_lock(&low_water_lock); + if (free < lowest_to_date) { + printk(KERN_WARNING "%s used greatest stack depth: %lu bytes " + "left\n", + current->comm, free); + lowest_to_date = free; + } + spin_unlock(&low_water_lock); +} +#else +static inline void check_stack_usage(void) {} +#endif + fastcall NORET_TYPE void do_exit(long code) { struct task_struct *tsk = current; @@ -949,6 +977,7 @@ fastcall NORET_TYPE void do_exit(long code) exit_sem(tsk); __exit_files(tsk); __exit_fs(tsk); + check_stack_usage(); exit_thread(); cpuset_exit(tsk); exit_keys(tsk); |