Commit d13206fb authored by Marcin Nowakowski's avatar Marcin Nowakowski Committed by Ben Hutchings

MIPS: kprobes: flush_insn_slot should flush only if probe initialised

commit 698b8510 upstream.

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: default avatarMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16296/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent f44699a8
...@@ -40,7 +40,8 @@ typedef union mips_instruction kprobe_opcode_t; ...@@ -40,7 +40,8 @@ typedef union mips_instruction kprobe_opcode_t;
#define flush_insn_slot(p) \ #define flush_insn_slot(p) \
do { \ do { \
flush_icache_range((unsigned long)p->addr, \ if (p->addr) \
flush_icache_range((unsigned long)p->addr, \
(unsigned long)p->addr + \ (unsigned long)p->addr + \
(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))); \ (MAX_INSN_SIZE * sizeof(kprobe_opcode_t))); \
} while (0) } while (0)
......
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