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From: Josh Poimboeuf <jpoimboe@kernel.org>
To: x86@kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ingo Molnar <mingo@kernel.org>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	linux-kernel@vger.kernel.org,
	Indu Bhagat <indu.bhagat@oracle.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	linux-perf-users@vger.kernel.org, Mark Brown <broonie@kernel.org>,
	linux-toolchains@vger.kernel.org, Jordan Rome <jordalgo@meta.com>,
	Sam James <sam@gentoo.org>
Subject: [PATCH v2 08/11] perf: Simplify get_perf_callchain() user logic
Date: Sat, 14 Sep 2024 01:02:10 +0200	[thread overview]
Message-ID: <d3453cfd4b6bcc0283865cf2dd2b03caaba8001a.1726268190.git.jpoimboe@kernel.org> (raw)
In-Reply-To: <cover.1726268190.git.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>
---
 kernel/events/callchain.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 655fb25a725b..2278402b7ac9 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -241,22 +241,20 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, bool user,
 
 	if (user) {
 		if (!user_mode(regs)) {
-			if  (current->mm)
-				regs = task_pt_regs(current);
-			else
-				regs = NULL;
+			if (!current->mm)
+				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;
-- 
2.46.0


  parent reply	other threads:[~2024-09-13 23:03 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-13 23:02 [PATCH v2 00/11] unwind, perf: sframe user space unwinding, deferred perf callchains Josh Poimboeuf
2024-09-13 23:02 ` [PATCH v2 01/11] unwind: Introduce generic user space unwinding interface Josh Poimboeuf
2024-09-13 23:02 ` [PATCH v2 02/11] unwind/x86: Add HAVE_USER_UNWIND Josh Poimboeuf
2024-09-16 11:46   ` Peter Zijlstra
2024-10-20  8:09     ` Josh Poimboeuf
2024-09-13 23:02 ` [PATCH v2 03/11] unwind: Introduce SFrame user space unwinding Josh Poimboeuf
2024-09-14 11:23   ` Steven Rostedt
2024-10-01 18:20     ` Indu Bhagat
2024-10-01 18:36       ` Steven Rostedt
2024-10-02  8:18         ` Florian Weimer
2024-10-02 14:05           ` Steven Rostedt
2024-10-23 13:59   ` Jens Remus
2024-10-27 17:49     ` Josh Poimboeuf
2024-09-13 23:02 ` [PATCH v2 04/11] unwind/x86/64: Add HAVE_USER_UNWIND_SFRAME Josh Poimboeuf
2024-09-13 23:02 ` [PATCH v2 05/11] perf/x86: Use user_unwind interface Josh Poimboeuf
2024-09-16  6:48   ` kernel test robot
2024-09-17 22:01     ` Namhyung Kim
2024-09-13 23:02 ` [PATCH v2 06/11] perf: Remove get_perf_callchain() 'init_nr' argument Josh Poimboeuf
2024-09-13 23:02 ` [PATCH v2 07/11] perf: Remove get_perf_callchain() 'crosstask' argument Josh Poimboeuf
2024-09-13 23:02 ` Josh Poimboeuf [this message]
2024-09-13 23:02 ` [PATCH v2 09/11] perf: Introduce deferred user callchains Josh Poimboeuf
2024-09-17 22:07   ` Namhyung Kim
2024-09-13 23:02 ` [PATCH v2 10/11] perf/x86: Add HAVE_PERF_CALLCHAIN_DEFERRED Josh Poimboeuf
2024-09-13 23:02 ` [PATCH v2 11/11] perf/x86: Enable SFrame unwinding for deferred user callchains Josh Poimboeuf
2024-09-14 12:12 ` [PATCH v2 00/11] unwind, perf: sframe user space unwinding, deferred perf callchains Steven Rostedt
2024-09-15 11:11   ` Josh Poimboeuf
2024-09-15 11:38     ` Steven Rostedt
2024-09-16 14:08     ` Peter Zijlstra
2024-09-16 15:39       ` Josh Poimboeuf
2024-09-16 18:15         ` Peter Zijlstra
2024-09-16  0:15           ` Mathieu Desnoyers
2024-09-16  0:33             ` Mathieu Desnoyers
2024-09-17  0:37               ` Mathieu Desnoyers
2024-09-16 22:46           ` Steven Rostedt
2024-09-17 21:58             ` Namhyung Kim
2024-09-18  5:14               ` Mathieu Desnoyers
2024-10-03  2:31         ` Steven Rostedt
2024-10-03  2:37           ` Josh Poimboeuf
2024-10-03 14:56             ` Steven Rostedt
2024-09-16 16:03       ` Steven Rostedt
2024-09-14 19:37 ` Namhyung Kim
2024-10-23 13:22 ` Jens Remus
2024-10-24  2:22   ` Steven Rostedt
2024-10-27 17:24   ` Josh Poimboeuf

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