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%3Ba=su...

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@vger.kernel.org know about it.

From foo@baz Tue Apr 10 10:31:53 CEST 2018

From: Marcin Nowakowski marcin.nowakowski@imgtec.com 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@imgtec.com

[ 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@imgtec.com Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16296/ Signed-off-by: Ralf Baechle ralf@linux-mips.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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@imgtec.com 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