From: Song Liu songliubraving@fb.com
mainline inclusion from mainline-5.2-rc7 commit 83f44ae0f8af category: bugfix bugzilla: 35738 CVE: NA
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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.156159511... Signed-off-by: Wei Li liwei391@huawei.com Reviewed-by: Jian Cheng cj.chengjian@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/x86/events/core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 40fb808e83965..640f85da2b342 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2356,13 +2356,13 @@ 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);