Martin Schwidefsky f285144f81 sched/x86: Do not clear PREEMPT_NEED_RESCHED on preempt count reset ... The per-cpu preempt count of x86 contains two values, the actual preempt count and the inverted PREEMPT_NEED_RESCHED bit. If a corrupted preempt count is detected the preempt_count_set() function is used to reset the preempt count. In case the inverted PREEMPT_NEED_RESCHED bit is zero at the time of the reset, the preemption indication is lost. Use raw_cpu_cmpxchg_4() to reset only the count part and leave the PREEMPT_NEED_RESCHED bit as it is. This improves the kernel's behavior when it runs into preempt count leaks and tries to fix them up. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1478523660-733-1-git-send-email-schwidefsky@de.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>		2016-11-16 10:29:04 +01:00
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asm	sched/x86: Do not clear PREEMPT_NEED_RESCHED on preempt count reset	2016-11-16 10:29:04 +01:00
uapi/asm	Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-10-03 17:29:01 -07:00