[PATCH] ftrace/x86: Add back ftrace_expected for ftrace bug reports
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2022-12-09 15:53:10
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Subsystem:
function hooks (ftrace), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Steven Rostedt, Masami Hiramatsu, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: "Steven Rostedt (Google)" <rostedt@goodmis.org> After someone reported a bug report with a failed modification due to the expected value not matching what was found, it came to my attention that the ftrace_expected is no longer set when that happens. This makes for debugging the issue a bit more difficult. Set ftrace_expected to the expected code before calling ftrace_bug, so that it shows what was expected and why it failed. Link: https://lore.kernel.org/all/CA+wXwBQ-VhK+hpBtYtyZP-NiX4g8fqRRWithFOHQW-0coQ3vLg@mail.gmail.com/ (local) Cc: stable@vger.kernel.org Fixes: 768ae4406a5c ("x86/ftrace: Use text_poke()") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> --- arch/x86/kernel/ftrace.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index bd165004776d..e07234ec7e23 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c@@ -217,7 +217,9 @@ void ftrace_replace_code(int enable) ret = ftrace_verify_code(rec->ip, old); if (ret) { + ftrace_expected = old; ftrace_bug(ret, rec); + ftrace_expected = NULL; return; } }
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2.35.1