Messages in this thread Patch in this message | | | Date | Tue, 11 Feb 2020 12:01:43 -0000 | From | "tip-bot2 for Peter Zijlstra" <> | Subject | [tip: perf/urgent] arm/ftrace: Fix BE text poking |
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The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: be993e44badc448add6a18d6f12b20615692c4c3 Gitweb: https://git.kernel.org/tip/be993e44badc448add6a18d6f12b20615692c4c3 Author: Peter Zijlstra <peterz@infradead.org> AuthorDate: Fri, 07 Feb 2020 12:57:36 +01:00 Committer: Ingo Molnar <mingo@kernel.org> CommitterDate: Tue, 11 Feb 2020 12:56:26 +01:00
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 <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> --- 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 2a5ff69..10499d4 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))
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