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arm/ftrace: Fix BE text poking

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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>
This commit is contained in:
Peter Zijlstra 2020-02-07 12:57:36 +01:00 committed by Ingo Molnar
parent 0a679e13ea
commit be993e44ba
1 changed files with 2 additions and 5 deletions
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7
arch/arm/kernel/ftrace.c
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@ -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))