From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755916AbaISKqU (ORCPT ); Fri, 19 Sep 2014 06:46:20 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:61613 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755313AbaISKqT (ORCPT ); Fri, 19 Sep 2014 06:46:19 -0400 Date: Fri, 19 Sep 2014 12:46:13 +0200 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Arnaldo Carvalho de Melo , Jiri Olsa , Thomas Gleixner , Andrew Morton Subject: [GIT PULL] perf fixes Message-ID: <20140919104613.GA11764@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, Please pull the latest perf-urgent-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus # HEAD: 3577af70a2ce4853d58e57d832e687d739281479 perf: Fix a race condition in perf_remove_from_context() Two kernel side fixes: a kprobes fix and a perf_remove_from_context() fix (which does not yet fix the migration bug which is WIP). Thanks, Ingo ------------------> Cong Wang (1): perf: Fix a race condition in perf_remove_from_context() Wang Nan (1): kprobes/x86: Free 'optinsn' cache when range check fails arch/x86/kernel/kprobes/opt.c | 4 +++- kernel/events/core.c | 10 ++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index f304773285ae..f1314d0bcf0a 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -338,8 +338,10 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op) * a relative jump. */ rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE; - if (abs(rel) > 0x7fffffff) + if (abs(rel) > 0x7fffffff) { + __arch_remove_optimized_kprobe(op, 0); return -ERANGE; + } buf = (u8 *)op->optinsn.insn; diff --git a/kernel/events/core.c b/kernel/events/core.c index f9c1ed002dbc..d640a8b4dcbc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1524,6 +1524,11 @@ static void perf_remove_from_context(struct perf_event *event, bool detach_group */ if (ctx->is_active) { raw_spin_unlock_irq(&ctx->lock); + /* + * Reload the task pointer, it might have been changed by + * a concurrent perf_event_context_sched_out(). + */ + task = ctx->task; goto retry; } @@ -1967,6 +1972,11 @@ perf_install_in_context(struct perf_event_context *ctx, */ if (ctx->is_active) { raw_spin_unlock_irq(&ctx->lock); + /* + * Reload the task pointer, it might have been changed by + * a concurrent perf_event_context_sched_out(). + */ + task = ctx->task; goto retry; }