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 45B721F9A91; Sun, 26 Jan 2025 14:55:25 +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=1737903326; cv=none; b=CiBuk8rD3FxArxD+6JOcsEBA1jvYWKn1IuJ+TLCNULJmRRfZA7V9/Y5QR5A2zPRo0RKhKt91dkFvyFd+ZnGe7HrQ4+z0RgbKFT25sJD+sP6FmWwuxxILq4a0tt8jW33i1DJIpxanyB9TkbMLHLaOJ1OUZplOSRruS9aSrhuoM4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737903326; c=relaxed/simple; bh=ysuRH6x4E2uV1SDbyOSHJiVwPNoIDcApgVkK+7t+ojE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Cm5mUdrNM0oKJ0fgiwKFVTKUU6DkDBO4wy2hD57RdcfxCYVlw+XDDox/7YrHzv+1Kd6eypvm8tP1RPdiOUQbezoVvCm+yUGJxKn7djHJ1nzvQpuLpI4FDdgJpeXplySJbKBo6WoqhzNxsNTHc6EkmWvzxBipZqYjIquREfaZi/g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QhBHqz59; 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="QhBHqz59" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8B05C4CEE2; Sun, 26 Jan 2025 14:55:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737903325; bh=ysuRH6x4E2uV1SDbyOSHJiVwPNoIDcApgVkK+7t+ojE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QhBHqz597W2UiI/WW6qG8+82i3PzUPrbdfkkucG1LAmWJdBn4eWBins1AEanaJNB5 ndDoPxzKZsuyQmXQ9C91Icy5bJKUXqt1HySgB0HTFa/ClwLq8hs24zh/UvSwKzx3pO C+BMCOJaX0gPmSEJZQWkrORW93guQMuaNxpDkqiMArziOMuFkQ1B3sufHTe8UtZgrU V7D/F6ZZEr9VYXTl8t49c6biTuClqeD88JMwro/O+JxMZbOs8ZCoHTJb3HDUeI3cIE 7Of2eNrSaf3jqHin96W6lkF3HN/1lFUFH2HeQrQFXM+Y6DvFnwyyZ+TcV8szqj5MKg OKZWC+S4KTwcw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dmitry Baryshkov , Maxime Ripard , Sasha Levin , maarten.lankhorst@linux.intel.com, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.12 12/31] drm/connector: add mutex to protect ELD from concurrent access Date: Sun, 26 Jan 2025 09:54:28 -0500 Message-Id: <20250126145448.930220-12-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250126145448.930220-1-sashal@kernel.org> References: <20250126145448.930220-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.11 Content-Transfer-Encoding: 8bit From: Dmitry Baryshkov [ Upstream commit df7c8e3dde37a9d81c0613285b43600f3cc70f34 ] The connector->eld is accessed by the .get_eld() callback. This access can collide with the drm_edid_to_eld() updating the data at the same time. Add drm_connector.eld_mutex to protect the data from concurrenct access. Individual drivers are not updated (to reduce possible issues while applying the patch), maintainers are to find a best suitable way to lock that mutex while accessing the ELD data. Reviewed-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20241206-drm-connector-eld-mutex-v2-1-c9bce1ee8bea@linaro.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_connector.c | 1 + drivers/gpu/drm/drm_edid.c | 6 ++++++ include/drm/drm_connector.h | 5 ++++- 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c index fc35f47e2849e..bbdaaf7022b62 100644 --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -277,6 +277,7 @@ static int __drm_connector_init(struct drm_device *dev, INIT_LIST_HEAD(&connector->probed_modes); INIT_LIST_HEAD(&connector->modes); mutex_init(&connector->mutex); + mutex_init(&connector->eld_mutex); mutex_init(&connector->edid_override_mutex); mutex_init(&connector->hdmi.infoframes.lock); connector->edid_blob_ptr = NULL; diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 855beafb76ffb..13bc4c290b17d 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -5605,7 +5605,9 @@ EXPORT_SYMBOL(drm_edid_get_monitor_name); static void clear_eld(struct drm_connector *connector) { + mutex_lock(&connector->eld_mutex); memset(connector->eld, 0, sizeof(connector->eld)); + mutex_unlock(&connector->eld_mutex); connector->latency_present[0] = false; connector->latency_present[1] = false; @@ -5657,6 +5659,8 @@ static void drm_edid_to_eld(struct drm_connector *connector, if (!drm_edid) return; + mutex_lock(&connector->eld_mutex); + mnl = get_monitor_name(drm_edid, &eld[DRM_ELD_MONITOR_NAME_STRING]); drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s] ELD monitor %s\n", connector->base.id, connector->name, @@ -5717,6 +5721,8 @@ static void drm_edid_to_eld(struct drm_connector *connector, drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s] ELD size %d, SAD count %d\n", connector->base.id, connector->name, drm_eld_size(eld), total_sad_count); + + mutex_unlock(&connector->eld_mutex); } static int _drm_edid_to_sad(const struct drm_edid *drm_edid, diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index e3fa43291f449..1e2b25e204cb5 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -2001,8 +2001,11 @@ struct drm_connector { struct drm_encoder *encoder; #define MAX_ELD_BYTES 128 - /** @eld: EDID-like data, if present */ + /** @eld: EDID-like data, if present, protected by @eld_mutex */ uint8_t eld[MAX_ELD_BYTES]; + /** @eld_mutex: protection for concurrenct access to @eld */ + struct mutex eld_mutex; + /** @latency_present: AV delay info from ELD, if found */ bool latency_present[2]; /** -- 2.39.5