From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
bpf@vger.kernel.org, x86@kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
Namhyung Kim <namhyung@kernel.org>
Subject: [PATCH v8 17/18] perf: Simplify get_perf_callchain() user logic
Date: Fri, 09 May 2025 12:45:41 -0400 [thread overview]
Message-ID: <20250509165156.474492361@goodmis.org> (raw)
In-Reply-To: 20250509164524.448387100@goodmis.org
From: Josh Poimboeuf <jpoimboe@kernel.org>
Simplify the get_perf_callchain() user logic a bit. task_pt_regs()
should never be NULL.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/events/callchain.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index cda145dc11bd..2798c0c9f782 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -247,21 +247,19 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, bool user,
if (user) {
if (!user_mode(regs)) {
if (current->flags & PF_KTHREAD)
- regs = NULL;
- else
- regs = task_pt_regs(current);
+ goto exit_put;
+ regs = task_pt_regs(current);
}
- if (regs) {
- if (add_mark)
- perf_callchain_store_context(&ctx, PERF_CONTEXT_USER);
+ if (add_mark)
+ perf_callchain_store_context(&ctx, PERF_CONTEXT_USER);
- start_entry_idx = entry->nr;
- perf_callchain_user(&ctx, regs);
- fixup_uretprobe_trampoline_entries(entry, start_entry_idx);
- }
+ start_entry_idx = entry->nr;
+ perf_callchain_user(&ctx, regs);
+ fixup_uretprobe_trampoline_entries(entry, start_entry_idx);
}
+exit_put:
put_callchain_entry(rctx);
return entry;
--
2.47.2
next prev parent reply other threads:[~2025-05-09 16:51 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-09 16:45 [PATCH v8 00/18] unwind_user: perf: x86: Deferred unwinding infrastructure Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 01/18] unwind_user: Add user space unwinding API Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 02/18] unwind_user: Add frame pointer support Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 03/18] unwind_user/x86: Enable frame pointer unwinding on x86 Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 04/18] perf/x86: Rename and move get_segment_base() and make it global Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 05/18] unwind_user: Add compat mode frame pointer support Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 06/18] unwind_user/x86: Enable compat mode frame pointer unwinding on x86 Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 07/18] unwind_user/deferred: Add unwind_deferred_trace() Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 08/18] unwind_user/deferred: Add unwind cache Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 09/18] unwind_user/deferred: Add deferred unwinding interface Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 10/18] unwind_user/deferred: Make unwind deferral requests NMI-safe Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 11/18] unwind deferred: Use bitmask to determine which callbacks to call Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 12/18] unwind deferred: Use SRCU unwind_deferred_task_work() Steven Rostedt
2025-05-09 21:49 ` Andrii Nakryiko
2025-05-10 13:41 ` Steven Rostedt
2025-05-12 16:17 ` Andrii Nakryiko
2025-05-09 16:45 ` [PATCH v8 13/18] unwind: Clear unwind_mask on exit back to user space Steven Rostedt
2025-05-09 16:45 ` [PATCH v8 14/18] perf: Remove get_perf_callchain() init_nr argument Steven Rostedt
2025-05-09 17:11 ` Alexei Starovoitov
2025-05-09 16:45 ` [PATCH v8 15/18] perf: Have get_perf_callchain() return NULL if crosstask and user are set Steven Rostedt
2025-05-09 21:53 ` Andrii Nakryiko
2025-05-10 13:46 ` Steven Rostedt
2025-05-10 17:59 ` Josh Poimboeuf
2025-05-12 22:27 ` Andrii Nakryiko
2025-05-09 16:45 ` [PATCH v8 16/18] perf: Use current->flags & PF_KTHREAD instead of current->mm == NULL Steven Rostedt
2025-05-09 16:45 ` Steven Rostedt [this message]
2025-05-09 16:45 ` [PATCH v8 18/18] perf: Skip user unwind if the task is a kernel thread Steven Rostedt
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