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kprobes/x86: Use preempt_enable() in optimized_callback()

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The following commit:

  a19b2e3d78 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”)

removed local_irq_save/restore() from optimized_callback(), the handler
might be interrupted by the rescheduling interrupt and might be
rescheduled - so we must not use the preempt_enable_no_resched() macro.

Use preempt_enable() instead, to not lose preemption events.

[ mingo: Improved the changelog. ]

Reported-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dwmw@amazon.co.uk
Fixes: a19b2e3d78 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”)
Link: http://lkml.kernel.org/r/154002887331.7627.10194920925792947001.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Masami Hiramatsu 2018-10-20 18:47:53 +09:00 committed by Ingo Molnar
parent c2712b8581
commit 2e62024c26
1 changed files with 1 additions and 1 deletions
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2
arch/x86/kernel/kprobes/opt.c
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@ -179,7 +179,7 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs)
opt_pre_handler(&op->kp, regs);
__this_cpu_write(current_kprobe, NULL);
}
preempt_enable_no_resched();
preempt_enable();
}
NOKPROBE_SYMBOL(optimized_callback);