From: Jiri Olsa <jolsa@kernel.org>
To: Masami Hiramatsu <mhiramat@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Josh Poimboeuf <jpoimboe@kernel.org>
Cc: 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>,
Mahe Tardy <mahe.tardy@gmail.com>
Subject: [PATCH bpf-next 1/4] x86/fgraph: Fix return_to_handler regs.rsp value
Date: Mon, 12 Jan 2026 22:49:37 +0100 [thread overview]
Message-ID: <20260112214940.1222115-2-jolsa@kernel.org> (raw)
In-Reply-To: <20260112214940.1222115-1-jolsa@kernel.org>
The previous change (Fixes commit) messed up the rsp register value,
which is wrong because it's already adjusted with FRAME_SIZE, we need
the original value (after UNWIND_HINT_FUNC hint).
Fixes: 20a0bc10272f ("x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probe")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
arch/x86/kernel/ftrace_64.S | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index a132608265f6..613be81b6e88 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -368,13 +368,15 @@ SYM_CODE_START(return_to_handler)
subq $8, %rsp
UNWIND_HINT_FUNC
+ movq %rsp, %rdi
+
/* Save ftrace_regs for function exit context */
subq $(FRAME_SIZE), %rsp
movq %rax, RAX(%rsp)
movq %rdx, RDX(%rsp)
movq %rbp, RBP(%rsp)
- movq %rsp, RSP(%rsp)
+ movq %rdi, RSP(%rsp)
movq %rsp, %rdi
call ftrace_return_to_handler
--
2.52.0
next prev parent reply other threads:[~2026-01-12 21:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-12 21:49 [PATCH bpf-next 0/4] x86/fgraph,bpf: Fix ORC stack unwind from kprobe_multi Jiri Olsa
2026-01-12 21:49 ` Jiri Olsa [this message]
2026-01-12 21:49 ` [PATCH bpf-next 2/4] x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path Jiri Olsa
2026-01-12 22:07 ` Steven Rostedt
2026-01-13 11:43 ` Jiri Olsa
2026-01-15 18:52 ` Andrii Nakryiko
2026-01-16 16:25 ` Jiri Olsa
2026-01-16 22:24 ` Andrii Nakryiko
2026-01-20 14:50 ` Steven Rostedt
2026-01-20 16:17 ` Jiri Olsa
2026-01-12 21:49 ` [PATCH bpf-next 3/4] selftests/bpf: Fix kprobe multi stacktrace_ips test Jiri Olsa
2026-01-12 21:49 ` [PATCH bpf-next 4/4] selftests/bpf: Allow to benchmark trigger with stacktrace Jiri Olsa
2026-01-15 18:48 ` Andrii Nakryiko
2026-01-15 18:50 ` Andrii Nakryiko
2026-01-16 16:30 ` Jiri Olsa
2026-01-16 16:26 ` Jiri Olsa
2026-01-22 8:35 ` Jiri Olsa
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