Re: WARNING in dma_map_page_attrs

[Christoph Hellwig]

I don't think the merge commit makes sense here.  But what we see here
is that dma_map_page is called on the rxe device, without that device
having a DMA mask.  For now this needs a workaround in rxe, but for
5.11 I'll send a patch to remove dma-virt and just handle this case
inside of the rdma core.

On Wed, Oct 21, 2020 at 12:03:19PM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    c4d6fe73 Merge tag 'xarray-5.9' of git://git.infradead.org..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=14862ff0500000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=7d790573d3e379c4
> dashboard link: https://syzkaller.appspot.com/bug?extid=34dc2fea3478e659af01
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+34dc2fea3478e659af01@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> infiniband syz1: set active
> infiniband syz1: added vcan0
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 9851 at kernel/dma/mapping.c:149 dma_map_page_attrs+0x493/0x700 kernel/dma/mapping.c:149
> Modules linked in:
> CPU: 1 PID: 9851 Comm: syz-executor.1 Not tainted 5.9.0-syzkaller #0
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
> RIP: 0010:dma_map_page_attrs+0x493/0x700 kernel/dma/mapping.c:149
> Code: 80 3c 10 00 0f 85 ed 01 00 00 48 8b 1d 36 c3 fa 0c e9 2d fc ff ff 48 89 c3 e9 d1 fd ff ff e8 04 12 12 00 0f 0b e8 fd 11 12 00 <0f> 0b 49 c7 c4 ff ff ff ff e9 d5 fd ff ff e8 ea 11 12 00 48 8d 7b
> RSP: 0018:ffffc90001546c68 EFLAGS: 00010246
> RAX: 0000000000040000 RBX: ffffffff894d0040 RCX: ffffc9000dbe4000
> RDX: 0000000000040000 RSI: ffffffff815d3b03 RDI: ffff88806a988b00
> RBP: ffff8880236cc400 R08: 0000000000000002 R09: 0000000000000000
> R10: 0000000000000002 R11: 0000000000000000 R12: ffffea00008db300
> R13: ffff88806a9886e8 R14: 00000000000004b8 R15: 0000000000000002
> FS:  00007f678fae2700(0000) GS:ffff88802ce00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f299a39b190 CR3: 0000000069f31000 CR4: 0000000000350ee0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  dma_map_single_attrs include/linux/dma-mapping.h:279 [inline]
>  ib_dma_map_single include/rdma/ib_verbs.h:3967 [inline]
>  ib_mad_post_receive_mads+0x23f/0xd60 drivers/infiniband/core/mad.c:2715
>  ib_mad_port_start drivers/infiniband/core/mad.c:2862 [inline]
>  ib_mad_port_open drivers/infiniband/core/mad.c:3016 [inline]
>  ib_mad_init_device+0x72b/0x1400 drivers/infiniband/core/mad.c:3092
>  add_client_context+0x405/0x5e0 drivers/infiniband/core/device.c:680
>  enable_device_and_get+0x1d5/0x3c0 drivers/infiniband/core/device.c:1301
>  ib_register_device drivers/infiniband/core/device.c:1376 [inline]
>  ib_register_device+0x7a7/0xa40 drivers/infiniband/core/device.c:1335
>  rxe_register_device+0x46d/0x570 drivers/infiniband/sw/rxe/rxe_verbs.c:1182
>  rxe_add+0x12fe/0x16d0 drivers/infiniband/sw/rxe/rxe.c:247
>  rxe_net_add+0x8c/0xe0 drivers/infiniband/sw/rxe/rxe_net.c:507
>  rxe_newlink drivers/infiniband/sw/rxe/rxe.c:269 [inline]
>  rxe_newlink+0xb7/0xe0 drivers/infiniband/sw/rxe/rxe.c:250
>  nldev_newlink+0x30e/0x540 drivers/infiniband/core/nldev.c:1555
>  rdma_nl_rcv_msg+0x367/0x690 drivers/infiniband/core/netlink.c:195
>  rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
>  rdma_nl_rcv+0x2f2/0x440 drivers/infiniband/core/netlink.c:259
>  netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
>  netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
>  netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
>  sock_sendmsg_nosec net/socket.c:651 [inline]
>  sock_sendmsg+0xcf/0x120 net/socket.c:671
>  ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353
>  ___sys_sendmsg+0xf3/0x170 net/socket.c:2407
>  __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440
>  do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> RIP: 0033:0x45d9f9
> Code: bd b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 8b b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007f678fae1c88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 000000000071f480 RCX: 000000000045d9f9
> RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000003
> RBP: 00000000004aab13 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf00
> R13: 00007ffc6f9b8bbf R14: 00007f678fac2000 R15: 0000000000000003
> 
> 
> ---
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> 
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