Commit 698b8510 authored Jun 08, 2017 by Marcin Nowakowski Committed by Ralf Baechle Jun 08, 2017

MIPS: kprobes: flush_insn_slot should flush only if probe initialised



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: c1bf207d ("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>

parent 87051ec1

arch/mips/include/asm/kprobes.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@ typedef union mips_instruction kprobe_opcode_t;

		#define flush_insn_slot(p) \
		do { \
		if (p->addr) \
		flush_icache_range((unsigned long)p->addr, \
		(unsigned long)p->addr + \
		(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))); \