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 9CB5320459A; Tue, 8 Jul 2025 02:00:50 +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=1751940050; cv=none; b=PdkRP8Y3uTYKrz0S7nYTL8RqO9LdfbzCQolk9fXC8hxWGbEnY813TYg4I5DqLQssZw9D3F3LKlRJE3EaKxrTnXLUSukTDPQQuSq6byE7Ymwz5w0RrcDA/oyjk72pE2hD5th8UClUrm4ZoplvwZPtJGwb3kysXWhzOe5CXGo/R9Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751940050; c=relaxed/simple; bh=/LTAfcjza1uzXV2X9tyx4ljH3sU7KdDveD6pJLOcz4A=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=HD5jo3o5VLPa3TqomVn0Fq8aHLO+ZySkCOYKeqscE2pfpwdL/L1jdSqiuWhV4/Mz8LG5T6tYMtKx+v6HIEWTA9jXRGRX21CkTTZ3jvLRoMljDAEgZY6HG0M+UeB1Bmi4B+f5IDiOT5FREuINTtUOVeXIzTVUTVOuXr/HZoXmDAM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aSy4BAUM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aSy4BAUM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 474F3C116C6; Tue, 8 Jul 2025 02:00:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751940050; bh=/LTAfcjza1uzXV2X9tyx4ljH3sU7KdDveD6pJLOcz4A=; h=Date:From:To:Cc:Subject:References:From; b=aSy4BAUMiwQlbOp+VaYaAAFHGxpqrBKS4n3MbAnmj8eOgHX7T7RVCVn0PbQ1DDQrL jjC0La1OJmS/3n8xsUIwErT0To7LD0ZEI7FhBklVoAenDqwNJtcKQC8XlyHMO192SA gu07I2wRKzvl6KBthnnmts5YmA0obN/QKzypUszpvqWoDiU9hCY47ubNFxMxQ3g7E+ ivwTW5DpVbyvkl/QmDRlclrrzYEnUe43qhCThLujYnlAvZnWtNN/vdz4i/0DfE5aYz AvBJOzE4sBwEzeJKRNXL0glc/lzPgtTtpjTq3vR6tfCH/esckX4FPxy7JS+uEHAuaC 1hkxCF8IRehGQ== Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uYxda-00000000D59-2M7c; Mon, 07 Jul 2025 22:00:50 -0400 Message-ID: <20250708020050.410920799@kernel.org> User-Agent: quilt/0.68 Date: Mon, 07 Jul 2025 22:00:06 -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 , Sam James Subject: [PATCH v13 03/11] perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL References: <20250708020003.565862284@kernel.org> Precedence: bulk X-Mailing-List: bpf@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|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@noisy.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, if (user && !crosstask) { if (!user_mode(regs)) { - if (current->mm) - regs = task_pt_regs(current); - else + if (current->flags & (PF_KTHREAD | PF_USER_WORKER)) regs = NULL; + else + regs = task_pt_regs(current); } if (regs) { diff --git a/kernel/events/core.c b/kernel/events/core.c index b2a53cabcb17..cf35dc707ad5 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7414,7 +7414,7 @@ static void perf_sample_regs_user(struct perf_regs *regs_user, if (user_mode(regs)) { regs_user->abi = perf_reg_abi(current); regs_user->regs = 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 = 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 != NULL) { + if (!(current->flags & PF_KTHREAD)) { struct page *p; pagefault_disable(); -- 2.47.2