From e18eecb8b35703a5eea73ee2b45324262029e62c Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Sun, 15 Jul 2007 23:38:48 -0700 Subject: 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 Cc: Oleg Nesterov Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index ca6a11b7302..64a5263c8c7 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); -- cgit v1.2.3