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| author | Song Liu <songliubraving@fb.com> | 2019-06-26 19:33:52 -0500 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-06-28 00:11:20 +0200 |
| commit | 83f44ae0f8afcc9da659799db8693f74847e66b3 (patch) | |
| tree | 97dbd7bf501484ccf72a747381e1b32c1c31e172 | |
| parent | c1f7fec1eb6a2c86d01bc22afce772c743451d88 (diff) | |
| download | lwn-83f44ae0f8afcc9da659799db8693f74847e66b3.tar.gz lwn-83f44ae0f8afcc9da659799db8693f74847e66b3.zip | |
perf/x86: Always store regs->ip in perf_callchain_kernel()
The stacktrace_map_raw_tp BPF selftest is failing because the RIP saved by
perf_arch_fetch_caller_regs() isn't getting saved by perf_callchain_kernel().
This was broken by the following commit:
d15d356887e7 ("perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER")
With that change, when starting with non-HW regs, the unwinder starts
with the current stack frame and unwinds until it passes up the frame
which called perf_arch_fetch_caller_regs(). So regs->ip needs to be
saved deliberately.
Fixes: d15d356887e7 ("perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER")
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kairui Song <kasong@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/3975a298fa52b506fea32666d8ff6a13467eee6d.1561595111.git.jpoimboe@redhat.com
| -rw-r--r-- | arch/x86/events/core.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index f315425d8468..4fb3ca1e699d 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2402,13 +2402,13 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re return; } - if (perf_hw_regs(regs)) { - if (perf_callchain_store(entry, regs->ip)) - return; + if (perf_callchain_store(entry, regs->ip)) + return; + + if (perf_hw_regs(regs)) unwind_start(&state, current, regs, NULL); - } else { + else unwind_start(&state, current, NULL, (void *)regs->sp); - } for (; !unwind_done(&state); unwind_next_frame(&state)) { addr = unwind_get_return_address(&state); |