mt76: usb: make rx page_frag_cache access atomic (481bb043) · Commits · 戴 / test

Add rx_page_lock spinlock in order to make rx page fragment access atomic. This patch fixes the following crash that occasionally occurs during module loading/unloading BUG: unable to handle kernel paging request at ffff9f8322e19000 PGD 27ba01067 P4D 27ba01067 PUD 27ddba063 PMD 263b35063 PTE 8000000262e19061 Oops: 0003 [#1] SMP PTI CPU: 2 PID: 1766 Comm: systemd-udevd Not tainted 4.19.0-rc5+ #6 Hardware name: ASUSTeK COMPUTER INC. ESC2000 G2/Z9PE-D8 WS, BIOS 0405 03/19/2012 RIP: 0010:__memcpy+0x12/0x20 RSP: 0018:ffffba13849b3ad8 EFLAGS: 00010246 RAX: ffff9f8322e17004 RBX: 00000000000038f0 RCX: 000000000000031f RDX: 0000000000000000 RSI: ffffba13844cf058 RDI: ffff9f8322e18ffc RBP: 0000000000010c6c R08: 0000000000000000 R09: 0000607ec0000000 R10: 0000000000000003 R11: 0000000000003e2e R12: ffff9f8324cd9540 R13: 0000000000000000 R14: ffffba13849b3b30 R15: ffff9f8322e17000 FS: 00007fadec85b880(0000) GS:ffff9f833fa80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff9f8322e19000 CR3: 0000000263428001 CR4: 00000000000606e0 Call Trace: mt76x02u_mcu_fw_send_data+0x16c/0x270 [mt76x02_usb] mt76x0u_probe+0x35a/0x598 [mt76x0u] usb_probe_interface+0x113/0x310 really_probe+0x1c8/0x400 driver_probe_device+0x5c/0x130 __driver_attach+0xec/0x110 bus_for_each_dev+0x50/0x90 bus_add_driver+0x1c0/0x280 driver_register+0x5b/0xe0 usb_register_driver+0x7c/0x140 do_one_initcall+0x44/0x19b do_init_module+0x5a/0x210 load_module+0x175c/0x1bc0 __do_sys_finit_module+0x97/0xc0 do_syscall_64+0x3f/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fadeb6f1809 RSP: 002b:00007ffe548f9f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 00007fadebdf0d89 RCX: 00007fadeb6f1809 RDX: 0000000000000000 RSI: 00007fadebdf0d89 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000246 R12: 0000560b9ef58ab0 R13: 0000560b9ef29800 R14: 0000560b9ef59040 R15: 0000000000020000 Fixes: ("mt76: use a per rx queue page fragment cache") Reported-by:

Stanislaw Gruszka <sgruszka@redhat.com> Tested-by:

Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by:

Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by:

Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt76.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -122,6 +122,7 @@ struct mt76_queue {
		dma_addr_t desc_dma;
		struct sk_buff *rx_head;
		struct page_frag_cache rx_page;
		spinlock_t rx_page_lock;
		};

		struct mt76_mcu_ops {

drivers/net/wireless/mediatek/mt76/mt76x0/usb.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -249,11 +249,11 @@ static int mt76x0u_probe(struct usb_interface *usb_intf,
		if (!(mt76_rr(dev, MT_EFUSE_CTRL) & MT_EFUSE_CTRL_SEL))
		dev_warn(dev->mt76.dev, "Warning: eFUSE not present\n");

		ret = mt76u_mcu_init_rx(&dev->mt76);
		ret = mt76u_alloc_queues(&dev->mt76);
		if (ret < 0)
		goto err;

		ret = mt76u_alloc_queues(&dev->mt76);
		ret = mt76u_mcu_init_rx(&dev->mt76);
		if (ret < 0)
		goto err;

drivers/net/wireless/mediatek/mt76/mt76x2u_init.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -264,14 +264,14 @@ int mt76x2u_register_device(struct mt76x2_dev *dev)
		if (err < 0)
		return err;

		err = mt76u_mcu_init_rx(&dev->mt76);
		if (err < 0)
		return err;

		err = mt76u_alloc_queues(&dev->mt76);
		if (err < 0)
		goto fail;

		err = mt76u_mcu_init_rx(&dev->mt76);
		if (err < 0)
		return err;

		err = mt76x2u_init_hardware(dev);
		if (err < 0)
		goto fail;

drivers/net/wireless/mediatek/mt76/usb.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -280,6 +280,7 @@ mt76u_fill_rx_sg(struct mt76_dev dev, struct mt76u_buf buf,
		struct urb *urb = buf->urb;
		int i;

		spin_lock_bh(&q->rx_page_lock);
		for (i = 0; i < nsgs; i++) {
		struct page *page;
		void *data;
		@@ -293,6 +294,7 @@ mt76u_fill_rx_sg(struct mt76_dev dev, struct mt76u_buf buf,
		offset = data - page_address(page);
		sg_set_page(&urb->sg[i], page, sglen, offset);
		}
		spin_unlock_bh(&q->rx_page_lock);

		if (i < nsgs) {
		int j;
		@@ -521,6 +523,7 @@ static int mt76u_alloc_rx(struct mt76_dev *dev)
		struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
		int i, err, nsgs;

		spin_lock_init(&q->rx_page_lock);
		spin_lock_init(&q->lock);
		q->entry = devm_kzalloc(dev->dev,
		MT_NUM_RX_ENTRIES * sizeof(*q->entry),
		@@ -558,12 +561,15 @@ static void mt76u_free_rx(struct mt76_dev *dev)
		for (i = 0; i < q->ndesc; i++)
		mt76u_buf_free(&q->entry[i].ubuf);

		spin_lock_bh(&q->rx_page_lock);
		if (!q->rx_page.va)
		return;
		goto out;

		page = virt_to_page(q->rx_page.va);
		__page_frag_cache_drain(page, q->rx_page.pagecnt_bias);
		memset(&q->rx_page, 0, sizeof(q->rx_page));
		out:
		spin_unlock_bh(&q->rx_page_lock);
		}

		static void mt76u_stop_rx(struct mt76_dev *dev)

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