From be993e44badc448add6a18d6f12b20615692c4c3 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 7 Feb 2020 12:57:36 +0100 Subject: [PATCH] arm/ftrace: Fix BE text poking 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 Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Dmitry Osipenko --- 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 2a5ff69c28e6..10499d44964a 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -78,13 +78,10 @@ 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))