From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751938AbaKYGas (ORCPT ); Tue, 25 Nov 2014 01:30:48 -0500 Received: from terminus.zytor.com ([198.137.202.10]:33971 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751823AbaKYGar (ORCPT ); Tue, 25 Nov 2014 01:30:47 -0500 Date: Mon, 24 Nov 2014 22:30:30 -0800 From: tip-bot for Andy Lutomirski Message-ID: Cc: hpa@zytor.com, luto@amacapital.net, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, rostedt@goodmis.org, tglx@linutronix.de, mingo@kernel.org Reply-To: mingo@kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org, rostedt@goodmis.org, linux-kernel@vger.kernel.org, luto@amacapital.net, hpa@zytor.com In-Reply-To: <50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.luto@amacapital.net> References: <50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.luto@amacapital.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs Git-Commit-ID: 7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 Gitweb: http://git.kernel.org/tip/7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 Author: Andy Lutomirski AuthorDate: Mon, 24 Nov 2014 17:39:06 -0800 Committer: Ingo Molnar CommitDate: Tue, 25 Nov 2014 07:26:55 +0100 x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs These functions can be executed on the int3 stack, so kprobes are dangerous. Tracing is probably a bad idea, too. Fixes: b645af2d5905 ("x86_64, traps: Rework bad_iret") Signed-off-by: Andy Lutomirski Cc: # Backport as far back as it would apply Cc: Linus Torvalds Cc: Steven Rostedt Link: http://lkml.kernel.org/r/50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- arch/x86/kernel/traps.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index de801f2..07ab8e9 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -387,7 +387,7 @@ NOKPROBE_SYMBOL(do_int3); * for scheduling or signal handling. The actual stack switch is done in * entry.S */ -asmlinkage __visible struct pt_regs *sync_regs(struct pt_regs *eregs) +asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs) { struct pt_regs *regs = eregs; /* Did already sync */ @@ -413,7 +413,7 @@ struct bad_iret_stack { struct pt_regs regs; }; -asmlinkage __visible +asmlinkage __visible notrace struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) { /* @@ -436,6 +436,7 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) BUG_ON(!user_mode_vm(&new_stack->regs)); return new_stack; } +NOKPROBE_SYMBOL(fixup_bad_iret); #endif /*