From nobody Sat Oct 11 11:43:59 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 1C70714A4DF; Wed, 11 Jun 2025 01:36:14 +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=1749605776; cv=none; b=bKCTzrOF6enTnKqj6s/krzHOkBHxBPt485NNC0s6/RXHYfxGhPksLSgo84sjeg2LzCHFx1U6xqFseu5Hs0DjQorQxXRIvIUbztEj7s+NgdN0r86pv2trjOBuDwKHI5OlG9BH4IG+g45bAgYXB7Qs8HWYt9giE+5xWkUPrG6RgHk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749605776; c=relaxed/simple; bh=Afq9c+LZDEcxKxQklFJWpidk1WuTg4q1GZpkp8qg2dI=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=BlcyO0FqRuFMCJXkXY3h7IMeH3Tu7diL7IhgR36PZcYU/AUU8N7NjDfPGDnxnUp/cDKhi+ZmMqkifwCbmHqPmNwYXQRCtBEBfbrp4icSXUiX3GhFU0q04Z4Io394vbHxIAXZOd+eTOCRETN5V9dT/jWRiyFerCUhSB1zTteMeNI= 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 omf19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id EBA691D14F0; Wed, 11 Jun 2025 01:36:09 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: nevets@goodmis.org) by omf19.hostedemail.com (Postfix) with ESMTPA id D101D2002B; Wed, 11 Jun 2025 01:36:06 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uPAPL-00000000wNT-06tj; Tue, 10 Jun 2025 21:37:39 -0400 Message-ID: <20250611013738.873755285@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 10 Jun 2025 21:34:24 -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 v9 03/11] perf: Use current->flags & PF_KTHREAD instead of current->mm == NULL References: <20250611013421.040264741@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: D101D2002B X-Rspamd-Server: rspamout08 X-Stat-Signature: eoxmtm6kuw1k7hbwt6rqcoc8hq6bdzwn X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+lbtAa6HT/mr8WjfWpq2zFTUdqmeUO2FI= X-HE-Tag: 1749605766-583811 X-HE-Meta: U2FsdGVkX1//GvV0vjtYlpGMLc+68D6SRqkZ29zEjoAKJSTaQ06JC29Q8WD7ObNDZg/FKvnkEaMoKsHu17DgKb3SpKd1xHayUirE2uWCf1oxejSH62NF///9D21H/wEJbT3LkYqNV9E0t5L8aLUiw/5k8uOGGh6UwhrWrN2wQbNSRRRDR9iblw0z7Y0DvWsYQ1ilvGzhJ9QxhlAQ5yaMoZyisY12nu6BlTNc5tXWTJ2u7ur2ApSDE4ds2BObp7IxFEjXxg3gb8f1Uct2k3rEYi4VxstojU0W3ilFMnuErE39oynzkghJ698jIJU8gwwvWY8tgnlkk12BGXxNCeaaxdtSAPyTx2Fu1AdO1eCCcMSEQ2tJEpw+CsWVpaRoL42vAuM4l1Jzina3lOgPPSH8iWPM0kAjrs5zzD41XCdl3SxbLC7V9uuVKlUpMu3ZBARzJdP8VYPooCpcW93AUpN3FCkXfqgFP/VK2tsT6pSM2ZI= 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 abf258913ab6..cda145dc11bd 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) { 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