From 353a7186f1ec39881d6b20d4b150f283393e4ce6 Mon Sep 17 00:00:00 2001 From: Marcin Nowakowski Date: Thu, 8 Jun 2017 15:20:32 +0200 Subject: [PATCH] MIPS: kprobes: flush_insn_slot should flush only if probe initialised [ 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 Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16296/ Signed-off-by: Ralf Baechle Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/asm/kprobes.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/mips/include/asm/kprobes.h b/arch/mips/include/asm/kprobes.h index daba1f9a4f79..174aedce3167 100644 --- a/arch/mips/include/asm/kprobes.h +++ b/arch/mips/include/asm/kprobes.h @@ -40,7 +40,8 @@ typedef union mips_instruction kprobe_opcode_t; #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) -- 2.11.0