From nobody Thu Oct 2 18:16:43 2025 Received: from mail-wm1-f50.google.com (mail-wm1-f50.google.com [209.85.128.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C1B63289E06 for ; Fri, 12 Sep 2025 11:28:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.50 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757676541; cv=none; b=V6VGSpFBZg/XXbnHMuIzF04ot3IUVQ3NSHll8qR/iIcFMWVGuipjsmg5n1HjEnGbfeBkvGGeWFqy+GRU0/LyH4WtBtXpmCaLp55rhb9ShRUHbTTl/Xtx4vAnqIvIZtVa2ZyP3/LzPsrBC99qmCmII2Yfri+92ETwkztJC2Z5zYA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757676541; c=relaxed/simple; bh=GEi4Pu+BiQVVyU3qMyfkPd4FuBQrgtgvLqtdUY8/eKQ=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=nEDT1I2SqpPszlKJ9l+nr882qaZJZQwSgA42gPLj09BFthnO+Io/3ArGHj6Q2n52u74eSWi+cWNT00rZmY8WruAHkJXmdeXe0i8U82epBduX9zGoLH6Xb6UGRqgRB/eieCtWw16XWdOpXRm1ay0339ZfpnMTGmgtgKDvifSDKEY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=YkOnNN0t; arc=none smtp.client-ip=209.85.128.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YkOnNN0t" Received: by mail-wm1-f50.google.com with SMTP id 5b1f17b1804b1-45dd513f4ecso11845765e9.3 for ; Fri, 12 Sep 2025 04:28:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1757676538; x=1758281338; darn=vger.kernel.org; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=zwVKnR8rFntApp7ZzuwxI7ZqvcEkE867VJlDRhLtWrE=; b=YkOnNN0tKCd7dFUxBO6a6OGfcGbvZUvBtanLpBXdR2QKt7UCxNFIPudZ9eszCm7xhx 3IjxRynPnObsQs0MTKw/1AQhqJjasI61s95+FdIm9vdYHhw0Z8L8PHrWyUPXCSfyR4ss wR+0OT0xMHyZvtmG32aOE1Q14ILRm1Q+hFAcOnhD4bKw4x3o2Faegk2SW0mBHXMtyRny OOh0b+92gOCc+8055HK1pKQMF1dTrcPeHEDoP3AxCGKZNpN39zb9UUtbUzNQIAaeEPPJ 2LKMzURZjq4xBTjrmjGO/AMov3eNE2JikehFC2EiCYvaDYcYOITbevyheofk+ZzIe14c wETg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757676538; x=1758281338; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=zwVKnR8rFntApp7ZzuwxI7ZqvcEkE867VJlDRhLtWrE=; b=hBa1+44rQN23vh4e1evZdBVPEjaSnkK8JFWgxpzuTw4Latlj/VU3cbx/w7+43wqHMQ 66szXFSiZQaxs+dOKncklWPxH1e5gl4TaaEBoI2IhN6QsCnoopGpUEJTzFdByKMXyoN+ 7SUrOksCrHnuAlZc1Qx3JgH748bVxodIB2uL/2YP/QmYjTUQJvGmNoSAOlAFnSVXn4PG IaDLaOPnWew+7JDPK7mCgKllBsRvAhhfj9VUdnMFEMEEdisBuldApcF9khQQy5Tv0uog /EsCPa7WMA6zJEIdRrvysQWYwio4vZ1NHLbS4zlWJ74u6gJaHdfxuYYAViYOpFJ2i7Ha GY2g== X-Forwarded-Encrypted: i=1; AJvYcCWHpCBIFRsjA0HGK5xiskORC0INhqhE+7msjqFNFzwBHOAZQlo9vVcBAOxmkybNxvNVuMDniKCwrYknxaA=@vger.kernel.org X-Gm-Message-State: AOJu0YyW+gBJ6mUswbrniKwWNoYl3ELkNhwcCfyPA4EPcoqJ3MR05jJl OtlAuHGJSlBxyFJlt6vBlDN7zqH9su6qaeTDuNMEdpxxe8FPhJu4qZs= X-Gm-Gg: ASbGncvwUZOCDnee8HckpfMPxH9xXHjssDh0rv6k2oBWGg0mDaP58Xq+j7HKASsncJG H6SDepWR6P3iQ13smy6j4ZgY4luXUG90ULYYQAmoEHl1bpoBOezbXtI/kKCNQSaQH8VmnrMevXO pg8rTdJJMyX+O18kBMeiWo6rq+y0oRJScA+yxvWsb7FHyfTLilUgtpW1GYGG6hH1zR79B7nV+xI KjzGdwF08LEaLrtpKl/qUu7ySGy+pms72dbSlI45u+rC1bkMqDMRVpsaJm3qy0Tt6EmlmJL0Ovc P6PLiCXBTrkrnd8E3olwXs0td5dN6yj/D65FHDehHDnEU4e/v+IcvX6tPAb+AWwyqZvx8m8PzwO X59A3ZmHJtHh7mVNJlq34QnA= X-Google-Smtp-Source: AGHT+IFO8Zfr+KXGf/gZA9YAUU3Z1l/VSfoJhHCmcp+Qzls93TzCsPrunrvFxGOcxkZ8FeqrxBfgLw== X-Received: by 2002:a05:600c:4f8b:b0:458:a7fa:211d with SMTP id 5b1f17b1804b1-45f2121ac21mr22734455e9.29.1757676537834; Fri, 12 Sep 2025 04:28:57 -0700 (PDT) Received: from vova-pc ([85.94.110.241]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45e037c3ce5sm59042975e9.16.2025.09.12.04.28.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 Sep 2025 04:28:57 -0700 (PDT) Date: Fri, 12 Sep 2025 13:28:55 +0200 From: Vladimir Riabchun To: rostedt@goodmis.org Cc: mhiramat@kernel.org, mark.rutland@arm.com, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH v2] ftrace: Fix softlockup in ftrace_module_enable Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" A soft lockup was observed when loading amdgpu module. If a module has a lot of tracable functions, multiple calls to kallsyms_lookup can spend too much time in RCU critical section and with disabled preemption, causing kernel panic. This is the same issue that was fixed in commit d0b24b4e91fc ("ftrace: Prevent RCU stall on PREEMPT_VOLUNTARY kernels") and commit 42ea22e754ba ("ftrace: Add cond_resched() to ftrace_graph_set_hash()"). Fix it the same way by adding cond_resched() in ftrace_module_enable. Signed-off-by: Vladimir Riabchun --- Changes since v1: https://lore.kernel.org/all/aMLPm__QGrQCwz1t@vova-pc/ - Move cond_resched below within_module check - Add some details in commit description kernel/trace/ftrace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index a69067367c29..42bd2ba68a82 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7535,6 +7535,8 @@ void ftrace_module_enable(struct module *mod) if (!within_module(rec->ip, mod)) break; =20 + cond_resched(); + /* Weak functions should still be ignored */ if (!test_for_valid_rec(rec)) { /* Clear all other flags. Should not be enabled anyway */ --=20 2.43.0