From: "Steven Rostedt (Google)" <rostedt@goodmis.org> stable inclusion from stable-v5.10.137 commit 43e059d01628137ea9b9082483c4917856b336ae category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit ac6c1b2ca77e722a1e5d651f12f437f2f237e658 upstream. When a ftrace_bug happens (where ftrace fails to modify a location) it is helpful to have what was at that location as well as what was expected to be there. But with the conversion to text_poke() the variable that assigns the expected for debugging was dropped. Unfortunately, I noticed this when I needed it. Add it back. Link: https://lkml.kernel.org/r/20220726101851.069d2e70@gandalf.local.home Cc: "x86@kernel.org" <x86@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: 768ae4406a5c ("x86/ftrace: Use text_poke()") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- arch/x86/kernel/ftrace.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index e760f6b5f0b4..d096b5a1dbeb 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -93,6 +93,7 @@ static int ftrace_verify_code(unsigned long ip, const char *old_code) /* Make sure it is what we expect it to be */ if (memcmp(cur_code, old_code, MCOUNT_INSN_SIZE) != 0) { + ftrace_expected = old_code; WARN_ON(1); return -EINVAL; } -- 2.20.1