From b664d57f39d01e775204d4f1a7e2f8bda77bc549 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 3 Oct 2017 16:18:02 +0900 Subject: [PATCH] kprobes/x86: Remove IRQ disabling from jprobe handlers Jprobes actually don't need to disable IRQs while calling handlers, because of how we specify the kernel interface in Documentation/kprobes.txt: ----- Probe handlers are run with preemption disabled. Depending on the architecture and optimization state, handlers may also run with interrupts disabled (e.g., kretprobe handlers and optimized kprobe handlers run without interrupt disabled on x86/x86-64). ----- So let's remove IRQ disabling from jprobes too. Signed-off-by: Masami Hiramatsu Cc: Alexei Starovoitov Cc: Alexei Starovoitov Cc: Ananth N Mavinakayanahalli Cc: Linus Torvalds Cc: Paul E . McKenney Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/150701508194.32266.14458959863314097305.stgit@devbox Signed-off-by: Ingo Molnar --- arch/x86/kernel/kprobes/core.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index f015371..0742491 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1080,8 +1080,6 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) * raw stack chunk with redzones: */ __memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, MIN_STACK_SIZE(addr)); - regs->flags &= ~X86_EFLAGS_IF; - trace_hardirqs_off(); regs->ip = (unsigned long)(jp->entry); /* -- 2.7.4