From: Jiri Olsa <jolsa@kernel.org>
To: Masami Hiramatsu <mhiramat@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Song Liu <song@kernel.org>, Peter Zijlstra <peterz@infradead.org>,
bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
x86@kernel.org, Yonghong Song <yhs@fb.com>,
Song Liu <songliubraving@fb.com>,
Andrii Nakryiko <andrii@kernel.org>
Subject: [PATCH 1/3] Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()"
Date: Mon, 27 Oct 2025 14:13:52 +0100 [thread overview]
Message-ID: <20251027131354.1984006-2-jolsa@kernel.org> (raw)
In-Reply-To: <20251027131354.1984006-1-jolsa@kernel.org>
This reverts commit 83f44ae0f8afcc9da659799db8693f74847e66b3.
When perf_callchain_kernel calls unwind_start with first_frame, AFAICS
we do not skip regs->ip, but it's added as part of the unwind process.
Hence reverting the extra perf_callchain_store for non-hw regs leg.
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
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 745caa6c15a3..fa6c47b50989 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2789,13 +2789,13 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
return;
}
- if (perf_callchain_store(entry, regs->ip))
- return;
-
- if (perf_hw_regs(regs))
+ if (perf_hw_regs(regs)) {
+ if (perf_callchain_store(entry, regs->ip))
+ return;
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);
--
2.51.0
next prev parent reply other threads:[~2025-10-27 13:14 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-27 13:13 [PATCH 0/3] x86/fgraph,bpf: Fix ORC stack unwind from return probe Jiri Olsa
2025-10-27 13:13 ` Jiri Olsa [this message]
2025-10-27 13:52 ` [PATCH 1/3] Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()" bot+bpf-ci
2025-10-27 20:19 ` Josh Poimboeuf
2025-10-27 22:38 ` Jiri Olsa
2025-10-29 3:39 ` Josh Poimboeuf
2025-10-29 7:17 ` Jiri Olsa
2025-10-30 21:48 ` Jiri Olsa
2025-10-31 1:37 ` Josh Poimboeuf
2025-10-27 22:25 ` Jiri Olsa
2025-10-27 13:13 ` [PATCH 2/3] x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probe Jiri Olsa
2025-10-28 7:02 ` Masami Hiramatsu
2025-10-27 13:13 ` [PATCH 3/3] selftests/bpf: Add stacktrace ips test for kprobe_multi/kretprobe_multi Jiri Olsa
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