From: Peter Zijlstra peterz@infradead.org
[ Upstream commit be993e44badc448add6a18d6f12b20615692c4c3 ]
The __patch_text() function already applies __opcode_to_mem_*(), so when __opcode_to_mem_*() is not the identity (BE*), it is applied twice, wrecking the instruction.
Fixes: 42e51f187f86 ("arm/ftrace: Use __patch_text()") Reported-by: Dmitry Osipenko digetx@gmail.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Tested-by: Dmitry Osipenko digetx@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/kernel/ftrace.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index bda949fd84e8b..93caf757f1d5d 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -81,13 +81,10 @@ static int ftrace_modify_code(unsigned long pc, unsigned long old, { unsigned long replaced;
- if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) { + if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) old = __opcode_to_mem_thumb32(old); - new = __opcode_to_mem_thumb32(new); - } else { + else old = __opcode_to_mem_arm(old); - new = __opcode_to_mem_arm(new); - }
if (validate) { if (probe_kernel_read(&replaced, (void *)pc, MCOUNT_INSN_SIZE))