From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 8C379212D64 for ; Mon, 3 Feb 2025 22:39:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738622369; cv=none; b=CEikfKGCz7jZP+FxU/6hhMEERDHkFVsFEAtUSJxvNQm1KDdDwp4iJdtgLcyh8HG0yKvasxobz/jx0Qcv8k/mXJUglnVrlaBWXBHSv0g8CHU0PgAvnjFwynC/6/IIbCVk2Vz8MTWkPx4CDMUV7X982g0fXnkRVkDs5KgWaWPAX58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738622369; c=relaxed/simple; bh=97oOx4z9pCZ0Iq/ojWzrHOGygbt98r31tFw6EuDjFTc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=S0uFBu8g1CmUzSpGXk0Ds8V/WY94Zwbt4wyxq+NJJifL65q8ZaSHUTNiYDnK9O30BmrRhNXp4UtOhUa4e1aGOeM16cF8zFcoEsHbB+3x6FNDdC3ie9A9wqrodv3jjhst8S4jbhn7OMWvWMwAd9vT+k54bYSQtKWP1ioIcBWiRUM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=IJdHS+GW; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="IJdHS+GW" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2ef9da03117so13930815a91.1 for ; Mon, 03 Feb 2025 14:39:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738622367; x=1739227167; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=rc7c9JPXikCd8Iu9pgV4LRP9xA48AK8hD/MXmnBG3Aw=; b=IJdHS+GWWcSwoLy6nifQJR+Bg8qGAnMgB3UwY9OuB/wtWW3FaJJNVdff/QX46U8qd8 ECcit3nRLN9jzvbLWP5iFFbaDnDbeMLaa/WqYnPNAFt8sVNnizlgQdPKqmoY3KTMfKzp Tq0A17IFtkwW1s2fiHm+WwxmvPUjtI1iiLvop274WlSW6vlbJU7Lu7JloBeGAV0ThqCB WSsNlJBuilICxzxU9BBcr7I1dr8WQjofel8fSZpihMahlJR4JhlM/0eEi+n1x6JgKR1M eeEUREcmmfzMTN2YOlUN/sloOIZVJjyYMJqjC2gua59R0wD9DEC34al/MZV/pAvahoCW aQNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738622367; x=1739227167; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=rc7c9JPXikCd8Iu9pgV4LRP9xA48AK8hD/MXmnBG3Aw=; b=bt6U+XIok4PN2KO567yk1Y2sIHZsZR4R35R0RT/M7vmLpo5wj9244hKy3pb/PZIwTR s8tNy7vTocr5/0NdfEuCFWGsA02M05VVM/wQ/ZXlUeJgL1CJOFFmWchqHoKYi9NzAFDP 42W7teMBmtxMgkIiB0h5h5P670K0RSp959S+Sr7teZr3eSntZ1dUfFshnnX3Q5jNTj7j uVHniSrTtF/UoUs3tkzeKwj9tdF2UzoPWyPncmcuUY6dtuyALQ6MlfhfO/F7/HDhkQL8 7krlize/YuUS2zppOUI3JpyXHjd1D3BpyYJ/EuXvpe4Ap7ud7y9+MB/EjVZCAOvC3fWC cihg== X-Forwarded-Encrypted: i=1; AJvYcCUFPXNmXPOR7imH/i4TGCK+iSeVnWEVaK/CK/SvUL9d1JU6oqwb4OydCsRchs4mCbHMFqlUFdQnmPG/7Iszcw==@lists.linux.dev X-Gm-Message-State: AOJu0Yz6CmLioppcEryAS+fs1og+25ObQD8dG69KM3zdvXoEhQs4UN/3 mTif8j4ci+972mfeHLqXLmr3039bT44dehfgwjh8qkV+Maa3yA2swQvds4tQrsErg0haMXGkDDV KQKkyEUlZwkhS3fVIczx9Ww== X-Google-Smtp-Source: AGHT+IEVoq/odtPJGxLrrYEYPRP3ZsRO1cKfDMWv4+6BAejNJPoBnN+rujdSVvcz7HzR2bynurMrReZ/ogt/1YT+mg== X-Received: from pjbsx4.prod.google.com ([2002:a17:90b:2cc4:b0:2ea:aa56:49c]) (user=almasrymina job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:53c7:b0:2ee:7870:8835 with SMTP id 98e67ed59e1d1-2f83ac83791mr40443324a91.33.1738622367078; Mon, 03 Feb 2025 14:39:27 -0800 (PST) Date: Mon, 3 Feb 2025 22:39:16 +0000 In-Reply-To: <20250203223916.1064540-1-almasrymina@google.com> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250203223916.1064540-1-almasrymina@google.com> X-Mailer: git-send-email 2.48.1.362.g079036d154-goog Message-ID: <20250203223916.1064540-7-almasrymina@google.com> Subject: [PATCH net-next v3 6/6] net: devmem: make dmabuf unbinding scheduled work From: Mina Almasry To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux.dev, linux-kselftest@vger.kernel.org Cc: Mina Almasry , Donald Hunter , Jakub Kicinski , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Jonathan Corbet , Andrew Lunn , Neal Cardwell , David Ahern , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , "=?UTF-8?q?Eugenio=20P=C3=A9rez?=" , Stefan Hajnoczi , Stefano Garzarella , Shuah Khan , sdf@fomichev.me, asml.silence@gmail.com, dw@davidwei.uk, Jamal Hadi Salim , Victor Nogueira , Pedro Tammela , Samiullah Khawaja Content-Type: text/plain; charset="UTF-8" The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, resulting in a BUG like seen by Stan: [ 1.548495] BUG: sleeping function called from invalid context at drivers/dma-buf/dma-buf.c:1255 [ 1.548741] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 149, name: ncdevmem [ 1.548926] preempt_count: 201, expected: 0 [ 1.549026] RCU nest depth: 0, expected: 0 [ 1.549197] [ 1.549237] ============================= [ 1.549331] [ BUG: Invalid wait context ] [ 1.549425] 6.13.0-rc3-00770-gbc9ef9606dc9-dirty #15 Tainted: G W [ 1.549609] ----------------------------- [ 1.549704] ncdevmem/149 is trying to lock: [ 1.549801] ffff8880066701c0 (reservation_ww_class_mutex){+.+.}-{4:4}, at: dma_buf_unmap_attachment_unlocked+0x4b/0x90 [ 1.550051] other info that might help us debug this: [ 1.550167] context-{5:5} [ 1.550229] 3 locks held by ncdevmem/149: [ 1.550322] #0: ffff888005730208 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x40/0xf0 [ 1.550530] #1: ffff88800b148f98 (sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_close+0x19/0x80 [ 1.550731] #2: ffff88800b148f18 (slock-AF_INET6){+.-.}-{3:3}, at: __tcp_close+0x185/0x4b0 [ 1.550921] stack backtrace: [ 1.550990] CPU: 0 UID: 0 PID: 149 Comm: ncdevmem Tainted: G W 6.13.0-rc3-00770-gbc9ef9606dc9-dirty #15 [ 1.551233] Tainted: [W]=WARN [ 1.551304] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 1.551518] Call Trace: [ 1.551584] [ 1.551636] dump_stack_lvl+0x86/0xc0 [ 1.551723] __lock_acquire+0xb0f/0xc30 [ 1.551814] ? dma_buf_unmap_attachment_unlocked+0x4b/0x90 [ 1.551941] lock_acquire+0xf1/0x2a0 [ 1.552026] ? dma_buf_unmap_attachment_unlocked+0x4b/0x90 [ 1.552152] ? dma_buf_unmap_attachment_unlocked+0x4b/0x90 [ 1.552281] ? dma_buf_unmap_attachment_unlocked+0x4b/0x90 [ 1.552408] __ww_mutex_lock+0x121/0x1060 [ 1.552503] ? dma_buf_unmap_attachment_unlocked+0x4b/0x90 [ 1.552648] ww_mutex_lock+0x3d/0xa0 [ 1.552733] dma_buf_unmap_attachment_unlocked+0x4b/0x90 [ 1.552857] __net_devmem_dmabuf_binding_free+0x56/0xb0 [ 1.552979] skb_release_data+0x120/0x1f0 [ 1.553074] __kfree_skb+0x29/0xa0 [ 1.553156] tcp_write_queue_purge+0x41/0x310 [ 1.553259] tcp_v4_destroy_sock+0x127/0x320 [ 1.553363] ? __tcp_close+0x169/0x4b0 [ 1.553452] inet_csk_destroy_sock+0x53/0x130 [ 1.553560] __tcp_close+0x421/0x4b0 [ 1.553646] tcp_close+0x24/0x80 [ 1.553724] inet_release+0x5d/0x90 [ 1.553806] sock_close+0x4a/0xf0 [ 1.553886] __fput+0x9c/0x2b0 [ 1.553960] task_work_run+0x89/0xc0 [ 1.554046] do_exit+0x27f/0x980 [ 1.554125] do_group_exit+0xa4/0xb0 [ 1.554211] __x64_sys_exit_group+0x17/0x20 [ 1.554309] x64_sys_call+0x21a0/0x21a0 [ 1.554400] do_syscall_64+0xec/0x1d0 [ 1.554487] ? exc_page_fault+0x8a/0xf0 [ 1.554585] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 1.554703] RIP: 0033:0x7f2f8a27abcd Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Suggested-by: Stanislav Fomichev Signed-off-by: Mina Almasry --- net/core/devmem.c | 4 +++- net/core/devmem.h | 10 ++++++---- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/net/core/devmem.c b/net/core/devmem.c index 5de887545f5e..23463de19f50 100644 --- a/net/core/devmem.c +++ b/net/core/devmem.c @@ -46,8 +46,10 @@ static dma_addr_t net_devmem_get_dma_addr(const struct net_iov *niov) ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT); } -void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) +void __net_devmem_dmabuf_binding_free(struct work_struct *wq) { + struct net_devmem_dmabuf_binding *binding = container_of(wq, typeof(*binding), unbind_w); + size_t size, avail; gen_pool_for_each_chunk(binding->chunk_pool, diff --git a/net/core/devmem.h b/net/core/devmem.h index 874e891e70e0..63d16dbaca2d 100644 --- a/net/core/devmem.h +++ b/net/core/devmem.h @@ -52,6 +52,8 @@ struct net_devmem_dmabuf_binding { * net_iovs in the TX path. */ struct net_iov **tx_vec; + + struct work_struct unbind_w; }; #if defined(CONFIG_NET_DEVMEM) @@ -74,7 +76,7 @@ struct dmabuf_genpool_chunk_owner { struct net_devmem_dmabuf_binding *binding; }; -void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding); +void __net_devmem_dmabuf_binding_free(struct work_struct *wq); struct net_devmem_dmabuf_binding * net_devmem_bind_dmabuf(struct net_device *dev, enum dma_data_direction direction, @@ -129,7 +131,8 @@ net_devmem_dmabuf_binding_put(struct net_devmem_dmabuf_binding *binding) if (!refcount_dec_and_test(&binding->ref)) return; - __net_devmem_dmabuf_binding_free(binding); + INIT_WORK(&binding->unbind_w, __net_devmem_dmabuf_binding_free); + schedule_work(&binding->unbind_w); } void net_devmem_get_net_iov(struct net_iov *niov); @@ -161,8 +164,7 @@ static inline void net_devmem_put_net_iov(struct net_iov *niov) { } -static inline void -__net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) +static inline void __net_devmem_dmabuf_binding_free(struct work_struct *wq) { } -- 2.48.1.362.g079036d154-goog