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author | Aaron Tomlin <atomlin@redhat.com> | 2014-09-12 14:16:19 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2014-09-19 12:35:24 +0200 |
commit | 0d9e26329b0c9263d4d9e0422d80a0e73268c52f (patch) | |
tree | ab0e520be3ecb71faa143c55a30cb9e8f48135e1 /kernel/sched | |
parent | a70857e46dd13e87ae06bf0e64cb6a2d4f436265 (diff) | |
download | lwn-0d9e26329b0c9263d4d9e0422d80a0e73268c52f.tar.gz lwn-0d9e26329b0c9263d4d9e0422d80a0e73268c52f.zip |
sched: Add default-disabled option to BUG() when stack end location is overwritten
Currently in the event of a stack overrun a call to schedule()
does not check for this type of corruption. This corruption is
often silent and can go unnoticed. However once the corrupted
region is examined at a later stage, the outcome is undefined
and often results in a sporadic page fault which cannot be
handled.
This patch checks for a stack overrun and takes appropriate
action since the damage is already done, there is no point
in continuing.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: aneesh.kumar@linux.vnet.ibm.com
Cc: dzickus@redhat.com
Cc: bmr@redhat.com
Cc: jcastillo@redhat.com
Cc: oleg@redhat.com
Cc: riel@redhat.com
Cc: prarit@redhat.com
Cc: jgh@redhat.com
Cc: minchan@kernel.org
Cc: mpe@ellerman.id.au
Cc: tglx@linutronix.de
Cc: rostedt@goodmis.org
Cc: hannes@cmpxchg.org
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lubomir Rintel <lkundrak@v3.sk>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1410527779-8133-4-git-send-email-atomlin@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r-- | kernel/sched/core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4b1ddebed54a..61ee2b327a27 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2693,6 +2693,9 @@ static noinline void __schedule_bug(struct task_struct *prev) */ static inline void schedule_debug(struct task_struct *prev) { +#ifdef CONFIG_SCHED_STACK_END_CHECK + BUG_ON(unlikely(task_stack_end_corrupted(prev))); +#endif /* * Test if we are atomic. Since do_exit() needs to call into * schedule() atomically, we ignore that path. Otherwise whine |