> On Feb 21, 2019, at 6:07 PM, Leon Romanovsky <leon@xxxxxxxxxx> wrote:
>
> From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
>
> The IB_MR_REREG_PD command rewrites mr->pd after successful rereg_user_mr(),
> such change causes to lost usecnt information and produce the following warning,
>
> [58060.273960] WARNING: CPU: 1 PID: 1771 at
> drivers/infiniband/core/verbs.c:336 ib_dealloc_pd+0x4e/0x60 [ib_core]
> [58060.283241] CPU: 1 PID: 1771 Comm: rereg_mr Tainted: G W OE 5.0.0-rc7-for-upstream-perf-2019-02-20_14-03-40-34 #1
> [58060.284467] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
> [58060.285691] RIP: 0010:ib_dealloc_pd+0x4e/0x60 [ib_core]
> [58060.286890] Code: 00 00 00 00 8b 43 18 85 c0 75 1f 48 8d 7b 28 e8 88
> d7 01 00 48 8b 43 08 48 89 df ff 90 f8 00 00 00 48 89 df 5b e9 b2 97 c4
> e0 <0f> 0b eb dd 0f 0b eb ca 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00
> [58060.289293] RSP: 0018:ffffc90003923dc0 EFLAGS: 00010286
> [58060.290490] RAX: 00000000ffffffff RBX: ffff88821f7f0400 RCX: ffff888236a40c00
> [58060.291668] RDX: ffff88821f7f0400 RSI: 0000000000000001 RDI: 0000000000000000
> [58060.292838] RBP: 0000000000000001 R08: ffff88835f665d80 R09: ffff8882209c90d8
> [58060.294007] R10: ffff88835ec003e0 R11: 0000000000000000 R12: ffff888221680ba0
> [58060.295132] R13: ffff888221680b00 R14: 00000000ffffffea R15: ffff88821f53c318
> [58060.296220] FS: 00007f70db11e740(0000) GS:ffff88835f640000(0000) knlGS:0000000000000000
> [58060.297321] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [58060.298435] CR2: 0000000001dfd030 CR3: 000000029d9d8000 CR4: 00000000000006e0
> [58060.299544] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [58060.300638] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [58060.301718] Call Trace:
> [58060.302813] uverbs_free_pd+0x2d/0x30 [ib_uverbs]
> [58060.303909] destroy_hw_idr_uobject+0x16/0x40 [ib_uverbs]
> [58060.305000] uverbs_destroy_uobject+0x28/0x170 [ib_uverbs]
> [58060.306099] __uverbs_cleanup_ufile+0x6b/0x90 [ib_uverbs]
> [58060.307144] uverbs_destroy_ufile_hw+0x8b/0x110 [ib_uverbs]
> [58060.308168] ib_uverbs_close+0x1f/0x80 [ib_uverbs]
> [58060.309191] __fput+0xb1/0x220
> [58060.310216] task_work_run+0x7f/0xa0
> [58060.311227] exit_to_usermode_loop+0x6b/0xb2
> [58060.312237] do_syscall_64+0xc5/0x100
> [58060.313249] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> [58060.314275] RIP: 0033:0x7f70dad00664
> [58060.315293] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f
> 80 00 00 00 00 8b 05 6a cd 20 00 48 63 ff 85 c0 75 13 b8 03 00 00 00 0f
> 05 <48> 3d 00 f0 ff ff 77 44 f3 c3 66 90 48 83 ec 18 48 89 7c 24 08 e8
> [58060.317403] RSP: 002b:00007fff1c3ac308 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
> [58060.318470] RAX: 0000000000000000 RBX: 00007f70db0ec010 RCX: 00007f70dad00664
> [58060.319471] RDX: 0000000000000021 RSI: 0000000000000002 RDI: 0000000000000003
> [58060.320438] RBP: 00007f70db11d338 R08: 0000000001dd52f0 R09: 00007f70db11e740
> [58060.321400] R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000001000
> [58060.322370] R13: 00007f70db0ec150 R14: 0000000000001000 R15: 00007f70db0ec010
> [58060.323332] ---[ end trace 76888cd25e6e2305 ]---
>
> Fixes: e278173fd19e ("RDMA/core: Cosmetic change - move member initialization to correct block")
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Reviewed-by: Majd Dibbiny <majd@xxxxxxxxxxxx>
> ---
> drivers/infiniband/core/uverbs_cmd.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
> index c57fd3a870ca..062a86c04123 100644
> --- a/drivers/infiniband/core/uverbs_cmd.c
> +++ b/drivers/infiniband/core/uverbs_cmd.c
> @@ -824,6 +824,7 @@ static int ib_uverbs_rereg_mr(struct uverbs_attr_bundle *attrs)
> }
> }
>
> + old_pd = mr->pd;
> ret = mr->device->ops.rereg_user_mr(mr, cmd.flags, cmd.start,
> cmd.length, cmd.hca_va,
> cmd.access_flags, pd,
> @@ -832,7 +833,6 @@ static int ib_uverbs_rereg_mr(struct uverbs_attr_bundle *attrs)
> goto put_uobj_pd;
>
> if (cmd.flags & IB_MR_REREG_PD) {
> - old_pd = mr->pd;
> atomic_inc(&pd->usecnt);
> mr->pd = pd;
> atomic_dec(&old_pd->usecnt);
> --
> 2.19.1
>
