From nobody Fri Dec 19 12:31:42 2025 Received: from cstnet.cn (smtp21.cstnet.cn [159.226.251.21]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C017813AA3B; Wed, 3 Jul 2024 08:42:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.21 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719996162; cv=none; b=R2RcKR6QchxBFsYHCsg3j/GXNNzh+QB/VV6AvU7S3hsajHcIrQAxxzrf5XYGv0XXToaKJNTAtrsgAEtgt+znA3GtpUYPwcD2cTBKtvp66CBg9M0HZkQ6XN8198ZxvVGYDryVrknX9qjn7j4x90LMicei373BjItBVpYP+Ou4b+o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719996162; c=relaxed/simple; bh=t44mCL05z2gkQcpfbrS9S8Rane1BDpPul7oNt2V6sXw=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=BhmedPKQqi+9/yinVjtt+IXLAEtzuhGmiK5bRVK7xkKg9zfwYeT0ytneY02v4txcHwfw75uo9C4gxxytVb1SaHQArwUbnKIdHimukfo0boidXq848zwI9Wa+IRf8bK1Z7jdneFId+nlQKQvooLGiL8p4m+q1RW5Zm6N+cO8L70Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from localhost.localdomain (unknown [36.112.3.229]) by APP-01 (Coremail) with SMTP id qwCowAB3f8vvDoVmnndYAQ--.933S2; Wed, 03 Jul 2024 16:42:34 +0800 (CST) From: Haoxiang Li To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, mikelley@microsoft.com, parri.andrea@gmail.com Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, Haoxiang Li Subject: [PATCH v2] drivers: hv: vmbus: Add missing check for dma_set_mask in vmbus_device_register() Date: Wed, 3 Jul 2024 16:42:21 +0800 Message-Id: <20240703084221.12057-1-make24@iscas.ac.cn> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qwCowAB3f8vvDoVmnndYAQ--.933S2 X-Coremail-Antispam: 1UD129KBjvJXoWxuFyrJrW7Jr48GFWxWr4rKrg_yoW5Gr4Dpa yUWas0krW8WF4xZwsYva1UZFy5Kr4Syw1FvryrAwnF9Fn7Jr90q3y0yFy7A3Wjq3yxCF1U XFy5tw4ruFWUAr7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkG14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWUuVWrJwAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4j 6r4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAac4AC62xK8xCEY4vEwIxC4wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC 0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr 1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IE rcIFxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14 v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkG c2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4U MIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUQZ23UUU UU= X-CM-SenderInfo: ppdnvj2u6l2u1dvotugofq/ Content-Type: text/plain; charset="utf-8" child_device_obj->device cannot perform DMA properly if dma_set_mask() returns non-zero. Add check for dma_set_mask() and return the error if it fails. To do the right cleanup, call dma_set_mask() after device_register() so that we can use existent error path of vmbus_device_register(). Fixes: 3a5469582c24 ("Drivers: hv: vmbus: Fix initialization of device obje= ct in vmbus_device_register()") Signed-off-by: Haoxiang Li --- Changes in v2: Thanks for your comments. They help a lot. It is not sufficient to do the cleanup just with kfree(). The memory allocated by dev_set_name() should also be freed, which is done by put_device() (finally in kobject_cleanup() [1]). I think performing a complete cleanup within vmbus_device_register() would be verbose and detrimental to code maintenance. I suggest calling dma_set_mask() after device_register(), so that proper error handling can be achieved using the existent error path of vmbus_device_register(), i.e., err_dev_unregister [2]. Moreover, I found a similar usage in dmapool_checks() [3], which calls dma_set_mask_and_coherent() after device_register(). I believe the modification is workable. Reference link: [1]https://github.com/torvalds/linux/blob/master/lib/kobject.c#L695 [2]https://github.com/torvalds/linux/blob/master/drivers/hv/vmbus_drv.c#L19= 33 [3]https://github.com/torvalds/linux/blob/master/mm/dmapool_test.c#L105 --- drivers/hv/vmbus_drv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 12a707ab73f8..f3999d8afd77 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1897,7 +1897,6 @@ int vmbus_device_register(struct hv_device *child_dev= ice_obj) =20 child_device_obj->device.dma_parms =3D &child_device_obj->dma_parms; child_device_obj->device.dma_mask =3D &child_device_obj->dma_mask; - dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64)); =20 /* * Register with the LDM. This will kick off the driver/device @@ -1910,6 +1909,12 @@ int vmbus_device_register(struct hv_device *child_de= vice_obj) return ret; } =20 + ret =3D dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64)); + if (ret) { + pr_err("64-bit DMA enable failed!\n"); + goto err_dev_unregister; + } + child_device_obj->channels_kset =3D kset_create_and_add("channels", NULL, kobj); if (!child_device_obj->channels_kset) { --=20 2.25.1