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authorSong Liu <songliubraving@fb.com>2019-06-26 19:33:52 -0500
committerThomas Gleixner <tglx@linutronix.de>2019-06-28 00:11:20 +0200
commit83f44ae0f8afcc9da659799db8693f74847e66b3 (patch)
tree97dbd7bf501484ccf72a747381e1b32c1c31e172
parentc1f7fec1eb6a2c86d01bc22afce772c743451d88 (diff)
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.c10
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);