From nobody Fri Oct 10 13:43:04 2025 Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) (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 5196915383A; Sat, 14 Jun 2025 02:46:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.14 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749869174; cv=none; b=RCdU/b41C5/RGOms12i8HtxfyHboX86zA+DqlR7uLYdauxJBhQCBv5PHpTcXqWXX4KRMUwTo970p7kaRmPxhqPjVEhjPqDN7geGNAgw8mh5upijm9jv1TjRj3PoFCz2pxm7OIJ2ibhgvaEQL0GGhgSZi1TcfY0EyTRzi3aPc+GU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749869174; c=relaxed/simple; bh=P431Xsnqui3cxWjbZJTxi5mE9YPKPRSkaYRnObmYMjc=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=GEWM2orh+k0QBwGk6SWsWgb8K3aJsP7K1LOAPf8ul/Sq4+B7xoWeXiQVCkZb+piu4tPiyKWw9/JDhFggEfef3HnMCRLm0exX8QHhrEhiLINKfCh/eBu5k5cShGGO+rn1eyNL71+6Iz0ORWY9163MV1fNNKNesrJo9CWUDv0gmN0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 54709C1B24; Sat, 14 Jun 2025 02:45:40 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: nevets@goodmis.org) by omf01.hostedemail.com (Postfix) with ESMTPA id 41E4D60009; Sat, 14 Jun 2025 02:45:37 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uQGvM-00000002SnR-14KT; Fri, 13 Jun 2025 22:47:16 -0400 Message-ID: <20250614024716.103249316@goodmis.org> User-Agent: quilt/0.68 Date: Fri, 13 Jun 2025 22:46:08 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, x86@kernel.org Cc: Masami Hiramatsu , Mathieu Desnoyers , Josh Poimboeuf , Peter Zijlstra , Ingo Molnar , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Andrii Nakryiko , Indu Bhagat , "Jose E. Marchesi" , Beau Belgrave , Jens Remus , Linus Torvalds , Andrew Morton Subject: [PATCH v10 03/11] perf: Use current->flags & PF_KTHREAD instead of current->mm == NULL References: <20250614024605.597728558@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Stat-Signature: gh9us45h4e8psc1qttkwxihrnuzj1mpc X-Rspamd-Server: rspamout04 X-Rspamd-Queue-Id: 41E4D60009 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+D2cbZAeherMC4l1RmnvmKaS9U/cP+v2c= X-HE-Tag: 1749869137-398534 X-HE-Meta: U2FsdGVkX19NR++Z9YvGmoBnfjuP/vP1QemDs+0hRMqCwe9D7IHDkS7uQu8ouLklv69enG7UECykxwrC427JmHa8RXuMZIMVqQY+8bRV55cSxzSfVS4hNQafqyEucQfYvm+Hj/U5fU11guwl+S1K40wMrPIgSptasqOq6HxjZiw/XPnUJ1z8s8IIOhWqO8dSVMs9RCQMTvDl7K74gAVbNz5Qk+Ao7stAR5UbQcCD/NtL+kMmU5WcPv9kaILDfl6O7kl6qbYBu2DeHS/U193/KPeQn6c6q6wodUHFrw6ObPc1iiXAnqqVkqn/BRbA8fDkpFnBOhYIG6adIRUvx7ncLdGXIyDDHxRobo1C2i56FiIJgA0bkPIG9t8ncALqEJMHWb6yDHiYZmDcRir3YBDUqnsgKxgsVKfa/Tf9kM+Qli5NkWzZ5OhTl3kgYVZCAENYGmJ4QB7GwpBtzIjFDhqjrpE4LaMdugpymA6xdRvKPqc= Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Steven Rostedt To determine if a task is a kernel thread or not, it is more reliable to use (current->flags & PF_KTHREAD) than to rely on current->mm being NULL. That is because some kernel tasks (io_uring helpers) may have a mm field. Link: https://lore.kernel.org/linux-trace-kernel/20250424163607.GE18306@noi= sy.programming.kicks-ass.net/ Signed-off-by: Steven Rostedt (Google) --- kernel/events/callchain.c | 6 +++--- kernel/events/core.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index cd0e3fc7ed05..42d21761cb4d 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -246,10 +246,10 @@ get_perf_callchain(struct pt_regs *regs, bool kernel,= bool user, =20 if (user && !crosstask) { if (!user_mode(regs)) { - if (current->mm) - regs =3D task_pt_regs(current); - else + if (current->flags & PF_KTHREAD) regs =3D NULL; + else + regs =3D task_pt_regs(current); } =20 if (regs) { diff --git a/kernel/events/core.c b/kernel/events/core.c index d8688668d21a..375115492c02 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8032,7 +8032,7 @@ static u64 perf_virt_to_phys(u64 virt) * Try IRQ-safe get_user_page_fast_only first. * If failed, leave phys_addr as 0. */ - if (current->mm !=3D NULL) { + if (!(current->flags & PF_KTHREAD)) { struct page *p; =20 pagefault_disable(); --=20 2.47.2