[rpmsg,1/1] rpmsg: virtio_rpmsg_bus: fix unexpected huge vmap mappings
diff mbox series

Message ID 1544512623-15090-1-git-send-email-fugang.duan@nxp.com
State New
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Series
  • [rpmsg,1/1] rpmsg: virtio_rpmsg_bus: fix unexpected huge vmap mappings
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Commit Message

Andy Duan Dec. 11, 2018, 7:21 a.m. UTC
From: Fugang Duan <fugang.duan@nxp.com>

If RPMSG dma memory allocate from per-device mem pool by calling .dma_alloc_coherent(),
the size is bigger than 2M bytes and alignment with 2M (PMD_SIZE), then kernel dump by
calling .vmalloc_to_page().

Since per-device dma pool do vmap mappings by __ioremap(), __ioremap() might use
the hugepage mapping, which in turn will cause the vmalloc_page failed to return
the correct page due to the PTE not setup.

For exp, when reserve 8M bytes per-device dma mem pool, __ioremap() will use hugepage
mapping:
 __ioremap
	ioremap_page_range
		ioremap_pud_range
			ioremap_pmd_range
				pmd_set_huge(pmd, phys_addr + addr, prot)

Commit:029c54b09599 ("mm/vmalloc.c: huge-vmap: fail gracefully on unexpected huge
vmap mapping") ensure that vmalloc_to_page() does not go off into the weeds trying
to dereference huge PUDs or PMDs as table entries:
rpmsg_sg_init ->
	vmalloc_to_page->
		WARN_ON_ONCE(pmd_bad(*pmd));

In generally, .dma_alloc_coherent() allocate memory from CMA pool/DMA pool/atomic_pool,
or swiotlb slabs pool, the virt address mapping to physical address should be lineal,
so for the rpmsg scatterlist initialization can use physical address to find the page
by calling .phys_to_page(), which can avoid to use .vmalloc_to_page().

Kernel dump:
[    0.881722] WARNING: CPU: 0 PID: 1 at mm/vmalloc.c:301 vmalloc_to_page+0xbc/0xc8
[    0.889094] Modules linked in:
[    0.892139] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.78-05581-gc61a572 #206
[    0.899604] Hardware name: Freescale i.MX8QM MEK (DT)
[    0.904643] task: ffff8008f6c98000 task.stack: ffff000008068000
[    0.910549] PC is at vmalloc_to_page+0xbc/0xc8
[    0.914987] LR is at rpmsg_sg_init+0x70/0xcc
[    0.919238] pc : [<ffff0000081c80d4>] lr : [<ffff000008ac471c>] pstate: 40000045
[    0.926619] sp : ffff00000806b8b0
[    0.929923] x29: ffff00000806b8b0 x28: ffff00000961cdf0
[    0.935220] x27: ffff00000961cdf0 x26: 0000000000000000
[    0.940519] x25: 0000000000040000 x24: ffff00000961ce40
[    0.945819] x23: ffff00000f000000 x22: ffff00000961ce30
[    0.951118] x21: 0000000000000000 x20: ffff00000806b950
[    0.956417] x19: 0000000000000000 x18: 000000000000000e
[    0.961717] x17: 0000000000000001 x16: 0000000000000019
[    0.967016] x15: 0000000000000033 x14: 616d64202c303030
[    0.972316] x13: 3030306630303030 x12: 3066666666206176
[    0.977615] x11: 203a737265666675 x10: 62203334394c203a
[    0.982914] x9 : 000000000000009f x8 : ffff00000806b970
[    0.988214] x7 : 0000000000000000 x6 : ffff000009690712
[    0.993513] x5 : 0000000000000000 x4 : 0000000080000000
[    0.998812] x3 : 00e8000090800f0d x2 : ffff8008ffffd3c0
[    1.004112] x1 : 0000000000000000 x0 : ffff00000f000000
[    1.009416] Call trace:
[    1.011849] Exception stack(0xffff00000806b770 to 0xffff00000806b8b0)
[    1.018279] b760:                                   ffff00000f000000 0000000000000000
[    1.026094] b780: ffff8008ffffd3c0 00e8000090800f0d 0000000080000000 0000000000000000
[    1.033915] b7a0: ffff000009690712 0000000000000000 ffff00000806b970 000000000000009f
[    1.041731] b7c0: 62203334394c203a 203a737265666675 3066666666206176 3030306630303030
[    1.049550] b7e0: 616d64202c303030 0000000000000033 0000000000000019 0000000000000001
[    1.057368] b800: 000000000000000e 0000000000000000 ffff00000806b950 0000000000000000
[    1.065188] b820: ffff00000961ce30 ffff00000f000000 ffff00000961ce40 0000000000040000
[    1.073008] b840: 0000000000000000 ffff00000961cdf0 ffff00000961cdf0 ffff00000806b8b0
[    1.080825] b860: ffff000008ac471c ffff00000806b8b0 ffff0000081c80d4 0000000040000045
[    1.088646] b880: ffff0000092c8528 ffff00000806b890 ffffffffffffffff ffff000008ac4710
[    1.096461] b8a0: ffff00000806b8b0 ffff0000081c80d4
[    1.101327] [<ffff0000081c80d4>] vmalloc_to_page+0xbc/0xc8
[    1.106800] [<ffff000008ac4968>] rpmsg_probe+0x1f0/0x49c
[    1.112107] [<ffff00000859a9a0>] virtio_dev_probe+0x198/0x210
[    1.117839] [<ffff0000086a1c70>] driver_probe_device+0x220/0x2d4
[    1.123829] [<ffff0000086a1e90>] __device_attach_driver+0x98/0xc8
[    1.129913] [<ffff00000869fe7c>] bus_for_each_drv+0x54/0x94
[    1.135470] [<ffff0000086a1944>] __device_attach+0xc4/0x12c
[    1.141029] [<ffff0000086a1ed0>] device_initial_probe+0x10/0x18
[    1.146937] [<ffff0000086a0e48>] bus_probe_device+0x90/0x98
[    1.152501] [<ffff00000869ef88>] device_add+0x3f4/0x570
[    1.157709] [<ffff00000869f120>] device_register+0x1c/0x28
[    1.163182] [<ffff00000859a4f8>] register_virtio_device+0xb8/0x114
[    1.169353] [<ffff000008ac5e94>] imx_rpmsg_probe+0x3a0/0x5d0
[    1.175003] [<ffff0000086a3768>] platform_drv_probe+0x50/0xbc
[    1.180730] [<ffff0000086a1c70>] driver_probe_device+0x220/0x2d4
[    1.186725] [<ffff0000086a1dc8>] __driver_attach+0xa4/0xa8
[    1.192199] [<ffff00000869fdc4>] bus_for_each_dev+0x58/0x98
[    1.197759] [<ffff0000086a1598>] driver_attach+0x20/0x28
[    1.203058] [<ffff0000086a1114>] bus_add_driver+0x1c0/0x224
[    1.208619] [<ffff0000086a26ec>] driver_register+0x68/0x108
[    1.214178] [<ffff0000086a36ac>] __platform_driver_register+0x4c/0x54
[    1.220614] [<ffff0000093d14fc>] imx_rpmsg_init+0x1c/0x50
[    1.225999] [<ffff000008084144>] do_one_initcall+0x38/0x124
[    1.231560] [<ffff000009370d28>] kernel_init_freeable+0x18c/0x228
[    1.237640] [<ffff000008d51b60>] kernel_init+0x10/0x100
[    1.242849] [<ffff000008085348>] ret_from_fork+0x10/0x18
[    1.248154] ---[ end trace bcc95d4e07033434 ]---

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
---
 drivers/rpmsg/virtio_rpmsg_bus.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

Patch
diff mbox series

diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index 664f957..dfe3ebe 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -196,16 +196,16 @@  static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
  * location (in vmalloc or in kernel).
  */
 static void
-rpmsg_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len)
+rpmsg_sg_init(struct virtproc_info *vrp, struct scatterlist *sg,
+	      void *cpu_addr, unsigned int len)
 {
-	if (is_vmalloc_addr(cpu_addr)) {
-		sg_init_table(sg, 1);
-		sg_set_page(sg, vmalloc_to_page(cpu_addr), len,
-			    offset_in_page(cpu_addr));
-	} else {
-		WARN_ON(!virt_addr_valid(cpu_addr));
-		sg_init_one(sg, cpu_addr, len);
-	}
+	unsigned int offset;
+	dma_addr_t dev_add = vrp->bufs_dma + (cpu_addr - vrp->rbufs);
+	struct page *page = phys_to_page(dma_to_phys(vrp->bufs_dev, dev_add));
+
+	offset = offset_in_page(cpu_addr);
+	sg_init_table(sg, 1);
+	sg_set_page(sg, page, len, offset);
 }
 
 /**
@@ -626,7 +626,7 @@  static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev,
 			 msg, sizeof(*msg) + msg->len, true);
 #endif
 
-	rpmsg_sg_init(&sg, msg, sizeof(*msg) + len);
+	rpmsg_sg_init(vrp, &sg, msg, sizeof(*msg) + len);
 
 	mutex_lock(&vrp->tx_lock);
 
@@ -750,7 +750,7 @@  static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
 		dev_warn(dev, "msg received with no recipient\n");
 
 	/* publish the real size of the buffer */
-	rpmsg_sg_init(&sg, msg, vrp->buf_size);
+	rpmsg_sg_init(vrp, &sg, msg, vrp->buf_size);
 
 	/* add the buffer back to the remote processor's virtqueue */
 	err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL);
@@ -934,7 +934,7 @@  static int rpmsg_probe(struct virtio_device *vdev)
 		struct scatterlist sg;
 		void *cpu_addr = vrp->rbufs + i * vrp->buf_size;
 
-		rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size);
+		rpmsg_sg_init(vrp, &sg, cpu_addr, vrp->buf_size);
 
 		err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr,
 					  GFP_KERNEL);