From: Song Liu <songliubraving@fb.com> mainline inclusion from mainline-5.2-rc7 commit 83f44ae0f8af category: bugfix bugzilla: 35738 CVE: NA ------------------------------------------------- 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); -- 2.25.1