From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751194AbdJCHSj (ORCPT ); Tue, 3 Oct 2017 03:18:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:52924 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750879AbdJCHSi (ORCPT ); Tue, 3 Oct 2017 03:18:38 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF3CB21869 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=mhiramat@kernel.org From: Masami Hiramatsu To: Ingo Molnar , mingo@redhat.com Cc: x86@kernel.org, Steven Rostedt , Masami Hiramatsu , linux-kernel@vger.kernel.org, Peter Zijlstra , Ananth N Mavinakayanahalli , Thomas Gleixner , "H . Peter Anvin" , "Paul E . McKenney" , Alexei Starovoitov , Alexei Starovoitov Subject: [BUGFIX PATCH] kprobes/x86: Remove IRQ disabling from jprobe handlers Date: Tue, 3 Oct 2017 16:18:02 +0900 Message-Id: <150701508194.32266.14458959863314097305.stgit@devbox> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20170930231251.emiuyrapdgzpcylp@inn> References: <20170930231251.emiuyrapdgzpcylp@inn> In-Reply-To: <20170930231251.emiuyrapdgzpcylp@inn> References: <20170930231251.emiuyrapdgzpcylp@inn> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jprobe actually doesn't need to disable IRQs while calling handlers, because Documentation/kprobes.txt says: ----- 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 --- 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 b48e0efd668e..bd36f3c33cd0 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1099,8 +1099,6 @@ 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); /*