This is a note to let you know that I've just added the patch titled
kprobes/x86: Blacklist indirect thunk functions for kprobes
to the 4.4-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:
kprobes-x86-blacklist-indirect-thunk-functions-for-kprobes.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c1804a236894ecc942da7dc6c5abe209e56cba93 Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Date: Fri, 19 Jan 2018 01:14:51 +0900
Subject: kprobes/x86: Blacklist indirect thunk functions for kprobes
From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
commit c1804a236894ecc942da7dc6c5abe209e56cba93 upstream.
Mark __x86_indirect_thunk_* functions as blacklist for kprobes
because those functions can be called from anywhere in the kernel
including blacklist functions of kprobes.
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/151629209111.10241.5444852823378068683.stgit@devbox
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/lib/retpoline.S | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -25,7 +25,8 @@ ENDPROC(__x86_indirect_thunk_\reg)
* than one per register with the correct names. So we do it
* the simple and nasty way...
*/
-#define EXPORT_THUNK(reg) EXPORT_SYMBOL(__x86_indirect_thunk_ ## reg)
+#define __EXPORT_THUNK(sym) _ASM_NOKPROBE(sym); EXPORT_SYMBOL(sym)
+#define EXPORT_THUNK(reg) __EXPORT_THUNK(__x86_indirect_thunk_ ## reg)
#define GENERATE_THUNK(reg) THUNK reg ; EXPORT_THUNK(reg)
GENERATE_THUNK(_ASM_AX)
Patches currently in stable-queue which might be from mhiramat@xxxxxxxxxx are
queue-4.4/kprobes-x86-disable-optimizing-on-the-function-jumps-to-indirect-thunk.patch
queue-4.4/kprobes-x86-blacklist-indirect-thunk-functions-for-kprobes.patch
queue-4.4/retpoline-introduce-start-end-markers-of-indirect-thunk.patch