This is a note to let you know that I've just added the patch titled

    x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs

to the 3.18-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     
x86-asm-traps-disable-tracing-and-kprobes-in-fixup_bad_iret-and-sync_regs.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <[email protected]>
Date: Mon, 24 Nov 2014 17:39:06 -0800
Subject: x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and 
sync_regs

From: Andy Lutomirski <[email protected]>

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 <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: 
http://lkml.kernel.org/r/50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.l...@amacapital.net
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 arch/x86/kernel/traps.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- 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(st
        BUG_ON(!user_mode_vm(&new_stack->regs));
        return new_stack;
 }
+NOKPROBE_SYMBOL(fixup_bad_iret);
 #endif
 
 /*


Patches currently in stable-queue which might be from [email protected] are

queue-3.18/x86_64-switch_to-load-tls-descriptors-before-switching-ds-and-es.patch
queue-3.18/x86-asm-traps-disable-tracing-and-kprobes-in-fixup_bad_iret-and-sync_regs.patch
queue-3.18/x86-tls-disallow-unusual-tls-segments.patch
queue-3.18/x86-tls-validate-tls-entries-to-protect-espfix.patch
queue-3.18/x86-kvm-clear-paravirt_enabled-on-kvm-guests-for-espfix32-s-benefit.patch
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