Re: [PATCH rdma-rc v1] RDMA/mlx5: Don't set desc_size in user mr

From: Jason Gunthorpe <jgg@nvidia.com>
To: Leon Romanovsky <leon@kernel.org>
Cc: Doug Ledford <dledford@redhat.com>,
	Aharon Landau <aharonl@nvidia.com>,
	linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
	Maor Gottlieb <maorg@nvidia.com>
Subject: Re: [PATCH rdma-rc v1] RDMA/mlx5: Don't set desc_size in user mr
Date: Tue, 19 Oct 2021 20:28:22 -0300	[thread overview]
Message-ID: <20211019232822.GB4135767@nvidia.com> (raw)
In-Reply-To: <a4846a11c9de834663e521770da895007f9f0d30.1634642730.git.leonro@nvidia.com>

On Tue, Oct 19, 2021 at 02:30:10PM +0300, Leon Romanovsky wrote:
> From: Aharon Landau <aharonl@nvidia.com>
> 
> reg_create() is used for user MRs only and should not set desc_size at
> all. Attempt to set it causes to the following trace:
> 
> BUG: unable to handle page fault for address: 0000000800000000
> PGD 0 P4D 0
> Oops: 0000 [#1] SMP PTI
> CPU: 5 PID: 890 Comm: ib_write_bw Not tainted 5.15.0-rc4+ #47
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
> RIP: 0010:mlx5_ib_dereg_mr+0x14/0x3b0 [mlx5_ib]
> Code: 48 63 cd 4c 89 f7 48 89 0c 24 e8 37 30 03 e1 48 8b 0c 24 eb a0 90 0f 1f 44 00 00 41 56 41 55 41 54 55 53 48 89 fb 48 83 ec 30 <48> 8b 2f 65 48 8b 04 25 28 00 00 00 48 89 44 24 28 31 c0 8b 87 c8
> RSP: 0018:ffff88811afa3a60 EFLAGS: 00010286
> RAX: 000000000000001c RBX: 0000000800000000 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000800000000
> RBP: 0000000800000000 R08: 0000000000000000 R09: c0000000fffff7ff
> R10: ffff88811afa38f8 R11: ffff88811afa38f0 R12: ffffffffa02c7ac0
> R13: 0000000000000000 R14: ffff88811afa3cd8 R15: ffff88810772fa00
> FS:  00007f47b9080740(0000) GS:ffff88852cd40000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000800000000 CR3: 000000010761e003 CR4: 0000000000370ea0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  mlx5_ib_free_odp_mr+0x95/0xc0 [mlx5_ib]
>  mlx5_ib_dereg_mr+0x128/0x3b0 [mlx5_ib]
>  ib_dereg_mr_user+0x45/0xb0 [ib_core]
>  ? xas_load+0x8/0x80
>  destroy_hw_idr_uobject+0x1a/0x50 [ib_uverbs]
>  uverbs_destroy_uobject+0x2f/0x150 [ib_uverbs]
>  uobj_destroy+0x3c/0x70 [ib_uverbs]
>  ib_uverbs_cmd_verbs+0x467/0xb00 [ib_uverbs]
>  ? uverbs_finalize_object+0x60/0x60 [ib_uverbs]
>  ? ttwu_queue_wakelist+0xa9/0xe0
>  ? pty_write+0x85/0x90
>  ? file_tty_write.isra.33+0x214/0x330
>  ? process_echoes+0x60/0x60
>  ib_uverbs_ioctl+0xa7/0x110 [ib_uverbs]
>  __x64_sys_ioctl+0x10d/0x8e0
>  ? vfs_write+0x17f/0x260
>  do_syscall_64+0x3c/0x80
>  entry_SYSCALL_64_after_hwframe+0x44/0xae
> 
> Fixes: a639e66703ee ("RDMA/mlx5: Zero out ODP related items in the mlx5_ib_mr")
> Signed-off-by: Aharon Landau <aharonl@nvidia.com>
> Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> ---
> v1:
>  * Added Jason's hunk to initialize implicit_children.
> v0: https://lore.kernel.org/all/f60a002566ae19014659afe94d7fcb7a10cfb353.1634033956.git.leonro@nvidia.com
> ---
>  drivers/infiniband/hw/mlx5/mr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied to for-rc, thanks

Jason