From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) (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 A9EFE2F5497; Wed, 25 Jun 2025 23:16:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750893366; cv=none; b=pigYBlXMYxvlO6b9tlVfr8VAIlFEEby4BxGxoH5eQfLxLabVSRLbB24MyCZFEQSxvODtOBrVvb8uUldwFTU8AsLCj3Cjj5XPyc4+W7LalmHdpTIJO0mWgLdKzs28h7/oGhjYpZfIYYGsrKJzJIu4h2A172LE3Vd103ED8UhgJ1w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750893366; c=relaxed/simple; bh=W0V4txT2VqsqxUALEjtx7r8CsT4+EoEiM6gy9naSJcM=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=AuxyCa1DPGuTFJSeduKEdpDHs8fx+AcMnEWDloc87cj6Snh7G/bm0SElgwsZSC5+mKZuSPLEkoh8BylVKggaZuANENP1C7jpHw2XJP53Tn8or/MbjwkRYv+Gea9AVImXgNY6tZII8n9eMGHPx5XLAto+XI+rg+e9+Bx6QRdaFpg= 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=216.40.44.11 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 omf17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 89363104867; Wed, 25 Jun 2025 23:16:01 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: nevets@goodmis.org) by omf17.hostedemail.com (Postfix) with ESMTPA id 2D0AA17; Wed, 25 Jun 2025 23:15:57 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uUZLq-000000044gm-1Lqk; Wed, 25 Jun 2025 19:16:22 -0400 Message-ID: <20250625231622.172100822@goodmis.org> User-Agent: quilt/0.68 Date: Wed, 25 Jun 2025 19:15:44 -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 Subject: [PATCH v11 03/11] perf: Use current->flags & PF_KTHREAD instead of current->mm == NULL References: <20250625231541.584226205@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 X-Rspamd-Queue-Id: 2D0AA17 X-Stat-Signature: 8awn5n4x18skqdsj7a7fb8gdf9bock5t X-Rspamd-Server: rspamout06 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+v3d6/TViyaAoIBSiRhmJcrZ8wW5TPm9A= X-HE-Tag: 1750893357-171058 X-HE-Meta: U2FsdGVkX1+bN8xFD2uyi8X7VkIW4ToZOCWPRb9vQHFmdj7QGi/qz74rDTULSB0d9NelKCRG0HGYt5AvNRZX2ewVBuSvEY8BYJw87KRGEeLg8zyl48Kee2lq5ZAMUhT3XzsYSUxcaTWU89FVzI4A2DXveO3w0ulM7x3SdqIBmcRRGxxk6l4yWsQ9K24R7smgU6ktXQY338DwXRfwS+gzPbzdDrWtbLQ6wK94Xm5eXDSIcyjuyQRyPyKu4R20jQCkrP4ITHbPQy0hPt5Ffks2auaGi1duUjXnybmobGV8pWhJWZdWeXVPQv1i1Bu9FbV3rIhQWJ7DiH348SHEqq86BQdpABMs/tPs+wpyVm51iia/UmJq6i5fMmdpYo6fF7koY+BK9WRMk2Vp9amFH81AhqnucTxF+S9no9z0rGYV/AAxeqRdaqvBwfwnUPSH1c5fGwTNnktRgOPXLuwX2c5EUJLTziAr/W6LCWO0kz5UVEA= 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@noisy.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, if (user && !crosstask) { if (!user_mode(regs)) { - if (current->mm) - regs = task_pt_regs(current); - else + if (current->flags & PF_KTHREAD) regs = NULL; + else + regs = task_pt_regs(current); } if (regs) { diff --git a/kernel/events/core.c b/kernel/events/core.c index ca7e9e7d19bf..ae371007a2a6 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -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 != NULL) { + if (!(current->flags & PF_KTHREAD)) { struct page *p; pagefault_disable(); -- 2.47.2