From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 53F2BD2444A for ; Thu, 4 Dec 2025 17:45:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B4D2A10E9A4; Thu, 4 Dec 2025 17:45:50 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="ZhcPeO/L"; dkim-atps=neutral Received: from mail-pf1-f176.google.com (mail-pf1-f176.google.com [209.85.210.176]) by gabe.freedesktop.org (Postfix) with ESMTPS id DB05810E9A3 for ; Thu, 4 Dec 2025 17:45:49 +0000 (UTC) Received: by mail-pf1-f176.google.com with SMTP id d2e1a72fcca58-7e1651ae0d5so966406b3a.1 for ; Thu, 04 Dec 2025 09:45:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1764870349; x=1765475149; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:from:to:cc:subject:date:message-id:reply-to; bh=0UJJ9ylZNUJ5QoY8mWfjT/WmltuI6aBtQizOSUZ/irg=; b=ZhcPeO/LQuZZUj3EUqI3qMpelW3Pukpw4uR1ew53v/m82ZEKGCUSWLNtfLxMSn3nt8 ZnoeGOkvD5QHuKIiToGoC0UCEXEdoJNsG9LkKb80Ovk+98nVR/RyatbJbHH2x86/A7kT 1j+8nH+NaaUhZRRgLY+k3q+b7iiWXjJj9simXWQUAtoVmQaGGvVtfmSZuXn5dHU6yBPj sxTl12kjOLfW/lnNPIg0P+gsePElwVPI8YEqAcFMkzF347jzZg2rOwXaZuy4RktFqtdq Jm1vLrD5se80pTTwJ6JQu2wFIc1jjwTpmch8LjrYHqajydYcxyI8PLxYQc7xGKprTJAN VsHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764870349; x=1765475149; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=0UJJ9ylZNUJ5QoY8mWfjT/WmltuI6aBtQizOSUZ/irg=; b=YAdPEmX0G2MGp1YbCMv9vIgiOIggzPIlVXgI3ZmUqtTcLkRvhEmpR2zU5T/ZSASuiK y4tBe3+NltN82XSI+7Tmb9yUTHjA8qZQTre830ExL8NYXPfG4uhd7F4IuP94rbzQ1VOI 5JALq6584InLLW4jB/LL4x+AdqKCWQk8Vy6F9Mwqbzx3tkKB8rAVHZPK4Fe52f4Ca6OM EziGMDYyz8O7lr7GyeRP3HfZJ4wplCVoWcjlLlYS4uPd3qKWSnmXB9wABNBYv24EcL4l aWRjEMpNn5ob7Xvu0d+LWg4in3tLQwyoJIubr/e5sY3jbS/0KatZfVefcuOSPmyd2qgG /yIQ== X-Forwarded-Encrypted: i=1; AJvYcCXKBBKSQzj00dTIhwR6di2aX+sxlntduAmibHGdgRz6lBFiUCgSven60BjRBz/SbXtwQQo8pHJSVbg=@lists.freedesktop.org X-Gm-Message-State: AOJu0Yw0eh+zvMLZN/DQSXSZWYaBBnQ2RgUC4iuMZvgoz/SEI2vsCKtM tqgOcIv95SBcUnxJr1qsuQkUmaY3Enr301qj8N929MbIZC3oa/1rnF3l X-Gm-Gg: ASbGnctn/7xtA+1d+JAv+K+xAv2QS1vKHyYFkgLB6BR0XjnPVvszgsGyTlk+pJ9rZZu mKskiLfegLhIrO7oRP53Ny1Xuf9aEArtAWb0rnL4GQbCo3s5eH118cvUf+7JiWBMawLmh+dB0pd fjEtB0e4VKq6aGdAKI4g4FcFZYmG8MU12wqWd97LVPoOD1zFoJJAr2laHMWKA+SpHM5aaV9Yqeh z+W5RtBNuh2L0PDW2KkeNRJtEphmuu+V54Bn7W6CwVdhgWm7CsOf4o3mYu3chFarzk8HPLRk4je sGgUXOEpz8TV/uthzOL5879GBw2hpKnHnrGR/pYpXX+9HP+al45FIlRz2FIQd4+OKWRNL6T36KQ GMDVCChMnZl6fnQhFFFAuzOcfFJHUzSzLBa2RHRFYWvKPcfwYCsnckIFcrALmCAEx7nO7hF+Tkw pL8JSKweWI8oIwyQtoBlxjP3QmdDV9qTWaBIUyY4bIWowVKOOcGCjfBA== X-Google-Smtp-Source: AGHT+IH4YFefcYl0av0SSMa1tyYZe0aI66vFA78al0YxNHaZIxPY/iDWSneR7gR+YVY2zh0tO5lD7w== X-Received: by 2002:a05:6a20:6a05:b0:350:66b2:9729 with SMTP id adf61e73a8af0-364038a863bmr4087291637.60.1764870349297; Thu, 04 Dec 2025 09:45:49 -0800 (PST) Received: from localhost (73.154.16.34.bc.googleusercontent.com. [34.16.154.73]) by smtp.gmail.com with UTF8SMTPSA id 41be03b00d2f7-bf6a1306a8bsm2381263a12.18.2025.12.04.09.45.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Dec 2025 09:45:49 -0800 (PST) From: Chia-I Wu To: Boris Brezillon , Steven Price , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Grant Likely , Heiko Stuebner , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, tvrtko.ursulin@igalia.com Subject: [PATCH v2] drm/panthor: fix for dma-fence safe access rules Date: Thu, 4 Dec 2025 09:45:45 -0800 Message-ID: <20251204174545.399059-1-olvaffe@gmail.com> X-Mailer: git-send-email 2.52.0.223.gf5cc29aaa4-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Commit 506aa8b02a8d6 ("dma-fence: Add safe access helpers and document the rules") details the dma-fence safe access rules. The most common culprit is that drm_sched_fence_get_timeline_name may race with group_free_queue. Signed-off-by: Chia-I Wu Reviewed-by: Boris Brezillon Reviewed-by: Liviu Dudau Reviewed-by: Steven Price --- v2: collect R-bs and drop misleading Fixes: tag --- drivers/gpu/drm/panthor/panthor_sched.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c index 33b9ef537e359..a8b1347e4da71 100644 --- a/drivers/gpu/drm/panthor/panthor_sched.c +++ b/drivers/gpu/drm/panthor/panthor_sched.c @@ -23,6 +23,7 @@ #include #include #include +#include #include "panthor_devfreq.h" #include "panthor_device.h" @@ -923,6 +924,9 @@ static void group_release_work(struct work_struct *work) release_work); u32 i; + /* dma-fences may still be accessing group->queues under rcu lock. */ + synchronize_rcu(); + for (i = 0; i < group->queue_count; i++) group_free_queue(group, group->queues[i]); -- 2.52.0.223.gf5cc29aaa4-goog