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 56C1827CB04; Wed, 20 Aug 2025 18:04:26 +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=1755713066; cv=none; b=OyTeucoUVZk1iUO5GPDJPY9IIF/PyNOX3SSr7Ai7sgmitBPMyZaF1jUwU4mAMNUve7/v/t4YoM3JO55QAkqo+1yU3ED4r4PgmfHYIlQg+4UGTngCBe63AYSkw3OKNIo7yRxriZkJD4CQsTZh9nYisqwmruOl7JiWLMfCSNjuCZc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755713066; c=relaxed/simple; bh=mHbF4+q1ErlU4eyF5kJRPdSwNKPbHxuYmpdQVQQMw8g=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=b1WA55ZHI+JL5lJmCKZnzdBz83nPnzZ76Hd6vZamM6xSeGFT60PKgrI2IgfS4jEepYoy1e+qoILfkMWGRmTGYFzEDTvJF6AoZlMxIC7Aob13R3Kt+ke7Oo41xi9dl+xC3hU8f7jxk9pMOmUq+ZMfIbCt37NHsDiMJXJEGXoLDp8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YTppM/T/; 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="YTppM/T/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0938C19425; Wed, 20 Aug 2025 18:04:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755713065; bh=mHbF4+q1ErlU4eyF5kJRPdSwNKPbHxuYmpdQVQQMw8g=; h=Date:From:To:Cc:Subject:References:From; b=YTppM/T/13nHLTQ91ofyhORHDnPvQsRC8jRl3ekOalM8sFzVZd5wOusRW00j5xv+Y 4Kr24xaVO0iNUhHviybMcLQKLsMPv+iKwC66i0emoKLeIa1+HktUXPggtyrnCfVlSn SjdAr+Zdb2nOhjhjpWf0/ksx0ptNStS1MzocRICVUvh3e6A7pt/fHRu5wFdohZsKXj YyDPSqi9Uu9eyuZCvdlmum9O3s3UJ4iXFDCt+h5GnQGIZhX+wz3SJbsA/gS6X3D1+i CL6RB289sYGP4cNVoucfaA1SIMxEZzD7pcLRFG5dMM/i5EjsD6JALTBN43xVn0FloD rrwL6+NMoAhuw== Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uonAi-00000000ruE-36PA; Wed, 20 Aug 2025 14:04:28 -0400 Message-ID: <20250820180428.592367294@kernel.org> User-Agent: quilt/0.68 Date: Wed, 20 Aug 2025 14:03:41 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Thomas Gleixner Subject: [RESEND][PATCH 3/5] perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL References: <20250820180338.701352023@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@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) --- 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 bade8e0fced7..f880cec0c980 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7446,7 +7446,7 @@ 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; @@ -8086,7 +8086,7 @@ 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 | PF_USER_WORKER))) { struct page *p; pagefault_disable(); -- 2.50.1