Commit-ID: 2e62024c265aa69315ed02835623740030435380 Gitweb: https://git.kernel.org/tip/2e62024c265aa69315ed02835623740030435380 Author: Masami Hiramatsu <mhiramat@xxxxxxxxxx> AuthorDate: Sat, 20 Oct 2018 18:47:53 +0900 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Mon, 22 Oct 2018 03:31:01 +0200 kprobes/x86: Use preempt_enable() in optimized_callback() The following commit: a19b2e3d7839 ("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@xxxxxxxxxx> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: dwmw@xxxxxxxxxxxx Fixes: a19b2e3d7839 ("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@xxxxxxxxxx> --- arch/x86/kernel/kprobes/opt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index eaf02f2e7300..40b16b270656 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -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);
