From nobody Wed Oct 8 07:29:13 2025 Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) (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 BA1E927FD62; Tue, 1 Jul 2025 18:04:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.12 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751393065; cv=none; b=oyRMFbeMPYEBkCOgXwj0BTpgRqWMvSuvgMRx5jQSPHSYISOrrwrGLUwy1LS/2i9atmmY1DKDDSeZuITLnOaWcIMVS/sLUBJN6drtID72a+sN5i+gw2NUYZVCw01i9fJkwL/UmUXu5yP3cVKGuXA+4SG4eS+29/6Ua/bJOFo62as= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751393065; c=relaxed/simple; bh=nuAkCPXrkAMipqh+INMZEGvjPsxbevVY5SLiOS8YuA4=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=ekpJaBfvjil/Tjd29GNGQFYfdxE93jPkfcgafQEKPYFbzB1M2A1Yxn0SoXbR0Kv/qZpUV87ijYZPq+wL8QYaFI28tdswMvIvg2RInacpiLhCaZ8T38mJGm7KaeRNZtCLUAK/TAVqVVy8KnzTW9IDWafgDuLJKF5FkDRDouTUDz4= 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=216.40.44.12 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 omf15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id ED024160607; Tue, 1 Jul 2025 18:04:20 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: nevets@goodmis.org) by omf15.hostedemail.com (Postfix) with ESMTPA id BB7B11B; Tue, 1 Jul 2025 18:04:17 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uWfLk-00000007g0k-0lrR; Tue, 01 Jul 2025 14:04:56 -0400 Message-ID: <20250701180456.042282570@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 01 Jul 2025 14:04:13 -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 , Jens Axboe , Florian Weimer Subject: [PATCH v12 03/11] perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL References: <20250701180410.755491417@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: bk8f7yxnpt8j774if75zxffur31cscx1 X-Rspamd-Server: rspamout04 X-Rspamd-Queue-Id: BB7B11B X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX18HFOMwrhxelB/a3hYoLuUib7pdmcv9yIw= X-HE-Tag: 1751393057-642338 X-HE-Meta: U2FsdGVkX19L6iz7EjeKouppemnzNLApJKCiaF1TtaSkp4600dE/VCZpcSH56EAvH+MvxP7vFhs+ObbqYOJps3NVyxveCDm+i20q/DDENaqARxUVU2f1/LcVTC4BYYwDqTwTkB+rVFSnp7ODtXCAk0FxvAIU3tD4oH98yeYgArRmZafSp/XvhWB2uWRAL091PQsBX1YwUpyjC7tuaq35Bq6ZMITKO3MJldv3+4NtT1NSwUDMVRPrud2wW8wJtdRv/EWQ7QjzyjWoF6w+SC5Q3NyHP3ArzYSqMMrZKCddaK1MnKNLpgZS2/4u5bJExlW3D4/PAYgc7rrOD6Wv0jSdn2jtEy8645E/M86/Qc3Yym8dmPrE5cG+sq+63kIOTfBnQ5KAyZlqcqFomlmTpGQLE/f/Wn1fAZicbOMM6ycGYXPONJJEb45s2wr3NubzIUn7l4iYnfvww+cqrr8vN6WPZA4vKa4AWkQhfCGYkutwuyM= 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|PF_USER_WORKERi)) 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/ Link: https://lore.kernel.org/all/20250624130744.602c5b5f@batman.local.home/ Signed-off-by: Steven Rostedt (Google) --- Changes since v11: https://lore.kernel.org/20250625231622.172100822@goodmis= .org - Also check against PF_USER_WORKER as io workers do not have PF_KTHREAD set. kernel/events/callchain.c | 6 +++--- kernel/events/core.c | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index cd0e3fc7ed05..5982d18f169b 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 | PF_USER_WORKER)) 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 f2f7cff826e0..2c524fe4bd19 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7414,7 +7414,7 @@ static void perf_sample_regs_user(struct perf_regs *r= egs_user, if (user_mode(regs)) { regs_user->abi =3D perf_reg_abi(current); regs_user->regs =3D regs; - } else if (!(current->flags & PF_KTHREAD)) { + } else if (!(current->flags & (PF_KTHREAD | PF_USER_WORKER))) { perf_get_regs_user(regs_user, regs); } else { regs_user->abi =3D PERF_SAMPLE_REGS_ABI_NONE; @@ -8054,7 +8054,7 @@ 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