This is a note to let you know that I've just added the patch titled
MIPS: kprobes: flush_insn_slot should flush only if probe initialised
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:
mips-kprobes-flush_insn_slot-should-flush-only-if-probe-initialised.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 foo@baz Tue Apr 10 10:31:53 CEST 2018
From: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
Date: Thu, 8 Jun 2017 15:20:32 +0200
Subject: MIPS: kprobes: flush_insn_slot should flush only if probe initialised
From: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
[ Upstream commit 698b851073ddf5a894910d63ca04605e0473414e ]
When ftrace is used with kprobes, it is possible for a kprobe to contain
an invalid location (ie. only initialised to 0 and not to a specific
location in the code). Trying to perform a cache flush on such location
leads to a crash r4k_flush_icache_range().
Fixes: c1bf207d6ee1 ("MIPS: kprobe: Add support.")
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/16296/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/mips/include/asm/kprobes.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/mips/include/asm/kprobes.h
+++ b/arch/mips/include/asm/kprobes.h
@@ -40,7 +40,8 @@ typedef union mips_instruction kprobe_op
#define flush_insn_slot(p) \
do { \
- flush_icache_range((unsigned long)p->addr, \
+ if (p->addr) \
+ flush_icache_range((unsigned long)p->addr, \
(unsigned long)p->addr + \
(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))); \
} while (0)
Patches currently in stable-queue which might be from marcin.nowakowski@xxxxxxxxxx are
queue-4.4/mips-mm-fixed-mappings-correct-initialisation.patch
queue-4.4/mips-mm-adjust-pkmap-location.patch
queue-4.4/mips-kprobes-flush_insn_slot-should-flush-only-if-probe-initialised.patch