Stanislaw Gruszka bea6832cc8 sched: fix divide by zero at {thread_group,task}_times ... On architectures where cputime_t is 64 bit type, is possible to trigger divide by zero on do_div(temp, (__force u32) total) line, if total is a non zero number but has lower 32 bit's zeroed. Removing casting is not a good solution since some do_div() implementations do cast to u32 internally. This problem can be triggered in practice on very long lived processes: PID: 2331 TASK: ffff880472814b00 CPU: 2 COMMAND: "oraagent.bin" #0 [ffff880472a51b70] machine_kexec at ffffffff8103214b #1 [ffff880472a51bd0] crash_kexec at ffffffff810b91c2 #2 [ffff880472a51ca0] oops_end at ffffffff814f0b00 #3 [ffff880472a51cd0] die at ffffffff8100f26b #4 [ffff880472a51d00] do_trap at ffffffff814f03f4 #5 [ffff880472a51d60] do_divide_error at ffffffff8100cfff #6 [ffff880472a51e00] divide_error at ffffffff8100be7b [exception RIP: thread_group_times+0x56] RIP: ffffffff81056a16 RSP: ffff880472a51eb8 RFLAGS: 00010046 RAX: bc3572c9fe12d194 RBX: ffff880874150800 RCX: 0000000110266fad RDX: 0000000000000000 RSI: ffff880472a51eb8 RDI: 001038ae7d9633dc RBP: ffff880472a51ef8 R8: 00000000b10a3a64 R9: ffff880874150800 R10: 00007fcba27ab680 R11: 0000000000000202 R12: ffff880472a51f08 R13: ffff880472a51f10 R14: 0000000000000000 R15: 0000000000000007 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff880472a51f00] do_sys_times at ffffffff8108845d #8 [ffff880472a51f40] sys_times at ffffffff81088524 #9 [ffff880472a51f80] system_call_fastpath at ffffffff8100b0f2 RIP: 0000003808caac3a RSP: 00007fcba27ab6d8 RFLAGS: 00000202 RAX: 0000000000000064 RBX: ffffffff8100b0f2 RCX: 0000000000000000 RDX: 00007fcba27ab6e0 RSI: 000000000076d58e RDI: 00007fcba27ab6e0 RBP: 00007fcba27ab700 R8: 0000000000000020 R9: 000000000000091b R10: 00007fcba27ab680 R11: 0000000000000202 R12: 00007fff9ca41940 R13: 0000000000000000 R14: 00007fcba27ac9c0 R15: 00007fff9ca41940 ORIG_RAX: 0000000000000064 CS: 0033 SS: 002b Cc: stable@vger.kernel.org Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120808092714.GA3580@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>		2012-08-13 18:41:54 +02:00
..
auto_group.c	sched: Clean up parameter passing of proc_sched_autogroup_set_nice()	2012-03-02 12:23:49 +01:00
auto_group.h
clock.c
core.c	sched: fix divide by zero at {thread_group,task}_times	2012-08-13 18:41:54 +02:00
cpupri.c	sched: Fix minor code style issues	2012-07-26 11:47:00 +02:00
cpupri.h
debug.c	sched/debug: Fix printing large integers on 32-bit platforms	2012-05-14 15:05:28 +02:00
fair.c	sched, cgroup: Reduce rq->lock hold times for large cgroup hierarchies	2012-08-13 18:41:54 +02:00
features.h	sched: Fix more load-balancing fallout	2012-04-26 12:54:52 +02:00
idle_task.c	sched/nohz: Rewrite and fix load-avg computation -- again	2012-07-05 20:58:13 +02:00
Makefile	init_task: Create generic init_task instance	2012-05-05 13:00:21 +02:00
rt.c	sched/rt: Fix lockdep annotation within find_lock_lowest_rq()	2012-06-06 16:52:26 +02:00
sched.h	sched, cgroup: Reduce rq->lock hold times for large cgroup hierarchies	2012-08-13 18:41:54 +02:00
stats.c	sched: Remove sched_switch	2012-01-27 13:28:53 +01:00
stats.h
stop_task.c