From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
x86@kernel.org, Jiri Olsa <jolsa@kernel.org>,
Namhyung Kim <namhyung@kernel.org>
Subject: [PATCH v7 16/17] perf: Simplify get_perf_callchain() user logic
Date: Fri, 02 May 2025 12:48:02 -0400 [thread overview]
Message-ID: <20250502165010.082067388@goodmis.org> (raw)
In-Reply-To: 20250502164746.178864972@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:[~2025-05-02 16:50 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-02 16:47 [PATCH v7 00/17] unwind_user: perf: x86: Deferred unwinding infrastructure Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 01/17] unwind_user: Add user space unwinding API Steven Rostedt
2025-05-04 9:30 ` Ingo Molnar
2025-05-04 16:43 ` Steven Rostedt
2025-05-04 17:53 ` Josh Poimboeuf
2025-05-02 16:47 ` [PATCH v7 02/17] unwind_user: Add frame pointer support Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 03/17] unwind_user/x86: Enable frame pointer unwinding on x86 Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 04/17] perf/x86: Rename and move get_segment_base() and make it global Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 05/17] unwind_user: Add compat mode frame pointer support Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 06/17] unwind_user/x86: Enable compat mode frame pointer unwinding on x86 Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 07/17] unwind_user/deferred: Add unwind_deferred_trace() Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 08/17] unwind_user/deferred: Add unwind cache Steven Rostedt
2025-05-04 9:37 ` Ingo Molnar
2025-05-04 16:21 ` Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 09/17] unwind_user/deferred: Add deferred unwinding interface Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 10/17] unwind_user/deferred: Make unwind deferral requests NMI-safe Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 11/17] unwind deferred: Use bitmask to determine which callbacks to call Steven Rostedt
2025-05-09 1:36 ` Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 12/17] unwind deferred: Use SRCU unwind_deferred_task_work() Steven Rostedt
2025-05-02 16:47 ` [PATCH v7 13/17] perf: Remove get_perf_callchain() init_nr argument Steven Rostedt
2025-05-02 16:48 ` [PATCH v7 14/17] perf: Have get_perf_callchain() return NULL if crosstask and user are set Steven Rostedt
2025-05-02 16:48 ` [PATCH v7 15/17] perf: Use current->flags & PF_KTHREAD instead of current->mm == NULL Steven Rostedt
2025-05-02 16:48 ` Steven Rostedt [this message]
2025-05-02 16:48 ` [PATCH v7 17/17] perf: Skip user unwind if the task is a kernel thread Steven Rostedt
2025-05-04 9:41 ` [PATCH v7 00/17] unwind_user: perf: x86: Deferred unwinding infrastructure Ingo Molnar
2025-05-04 16:32 ` Steven Rostedt
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