From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B7B4425B699; Fri, 25 Apr 2025 14:56:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745592975; cv=none; b=CUTAFKTZ+YYRzOzJfdlDTHk2J/EjrRtl0g1LyHNCi0UwvP2z+WYfrYoJ0h62UW9NQQT2F20hCE+WYwf3NTr5BeevrtetANR9d8GNve+U8ixo+Wa63K73/9dVxeqzc4ThIg5CczX/kU+k8sWEJtBk1QEr4MJklXyWs2lLWrGAGCY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745592975; c=relaxed/simple; bh=diBVNlfmiYdvupvvl/cOG5YtdHuq4nOozxDL0W1fHFk=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=UtFJTR7cKOJsh0EMAZZ6of4d/H50776gQXs/oxS34juIQMqRcDStneEHMatXa80vb1U/X+8QfppUJNTCFj4ghjjsMTPn7ITcyAho/BUR+0yhulpKxkX7Y4oSHKkoF/KzLNsoriv45hhXUfQFoLGPfXIvDfP3HBNT5sdDFdJSh1A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id A012BC4CEE4; Fri, 25 Apr 2025 14:56:15 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98) (envelope-from ) id 1u8KVJ-0000000HSlu-3Wjm; Fri, 25 Apr 2025 10:58:13 -0400 Message-ID: <20250425145813.690011020@goodmis.org> User-Agent: quilt/0.68 Date: Fri, 25 Apr 2025 10:54:34 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Josh Poimboeuf , x86@kernel.org, Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Indu Bhagat , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Mark Brown , linux-toolchains@vger.kernel.org, Jordan Rome , Sam James , Andrii Nakryiko , Jens Remus , Florian Weimer , Andy Lutomirski , Weinan Liu , Blake Jones , Beau Belgrave , "Jose E. Marchesi" , Alexander Aring Subject: [PATCH v6 12/18] perf: Simplify get_perf_callchain() user logic References: <20250425145422.132820147@goodmis.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Josh Poimboeuf Simplify the get_perf_callchain() user logic a bit. task_pt_regs() should never be NULL. Acked-by: Namhyung Kim Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) --- Changes since v5: https://lore.kernel.org/20250424162633.048002581@goodmis.org - Use (current->flags & PF_KTHREAD) instead of current->mm == NULL to determine if a task is a kernel thread or not (Peter Zijlstra) 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