From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20150515080530.340331869@1wt.eu> Date: Fri, 15 May 2015 10:05:31 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andy Lutomirski , Linus Torvalds , Steven Rostedt , Ingo Molnar , Ben Hutchings , Willy Tarreau Subject: [ 01/48] x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 In-Reply-To: <9c2783dfae10ef2d1e9b08bcc1e562c5@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski commit 7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 upstream. 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: Linus Torvalds Cc: Steven Rostedt Link: http://lkml.kernel.org/r/50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.luto@amacapital.net Signed-off-by: Ingo Molnar [bwh: Backported to 3.2: - Use __kprobes instead of NOKPROBE_SYMBOL() - Don't use __visible] Signed-off-by: Ben Hutchings (cherry picked from commit 8ea4c465ecb59846abed3d000d64b21b8e31aeb0) Signed-off-by: Willy Tarreau --- arch/x86/kernel/traps.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 8a39a6c..b999043 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -493,7 +493,7 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) * for scheduling or signal handling. The actual stack switch is done in * entry.S */ -asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) +asmlinkage notrace __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) { struct pt_regs *regs = eregs; /* Did already sync */ @@ -518,7 +518,7 @@ struct bad_iret_stack { struct pt_regs regs; }; -asmlinkage +asmlinkage notrace __kprobes struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) { /* -- 1.7.12.2.21.g234cd45.dirty