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 8EEC02951A0; Wed, 30 Apr 2025 20:01:05 +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=1746043265; cv=none; b=G3olADn9HJ13Dfsxh6kkU9KDgXc+ftZ0cPwE9uU9/sUDIIVZ6RAKsUVIXN9ppL8O7ER6wxPjAULh98+E+zjMssTZCI1lkQvNhM2GSTYhDP4hDD7xjo4sIngIuuQ95ec8Nwx/Yy4llhOZHFUz+H33+UOVvM9+Qy6HOsU4Y8tQqCU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746043265; c=relaxed/simple; bh=UruFrykajNjxMX/0A6fTNZ1MktM/smIbdfB+M9Tloe0=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=fNhsuU7H6yXr81NUgaE1aGq0hqx5YjBl4KIuwgD61KMS/BE1z1EcDoKbkSMSr71Zxcpb/EY867Sgf9meDqsZcc7VMd7AIzpmhFJsuICwIRcuczH+7J4bWTTveCqS4MkyyDsXg0w+UIGXBgl9FL9KbseC8lfwN6/poH9lSnDYhu4= 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 29566C4CEEC; Wed, 30 Apr 2025 20:01:05 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uADcD-00000001dSb-23nB; Wed, 30 Apr 2025 16:01:09 -0400 Message-ID: <20250430200109.343166050@goodmis.org> User-Agent: quilt/0.68 Date: Wed, 30 Apr 2025 15:57:57 -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 v7 11/18] perf: Use current->flags & PF_KTHREAD instead of current->mm == NULL References: <20250430195746.827125963@goodmis.org> Precedence: bulk X-Mailing-List: linux-toolchains@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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@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 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, if (user) { 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 67581babe9ba..430dd158b1ee 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7989,7 +7989,7 @@ 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