Per the report, this is a regression and reverting 68dbe80f5b51
("crypto: ccp - Release dma channels before dmaengine unrgister"),
which appeared in v6.1, avoids the problem.
The bugzilla is assigned to PCI, and I know PCI does have similar
sysfs duplicate filename issues, but I don't know whether this
instance is related to 68dbe80f5b51 or to the PCI core.
On Thu, Jan 05, 2023 at 03:12:26PM +0000, bugzilla-daemon@xxxxxxxxxx wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=216888
> Summary: "sysfs: cannot create duplicate filename
> /dma/dma0chan0" with 68dbe80f ("crypto: ccp - Release
> dma channels before dmaengine unrgister")
>
> An issue was found in the CCP driver (drivers/crypto/ccp/) that
> the patch 68dbe80f ("crypto: ccp - Release dma channels before
> dmaengine unrgister") causes the following errors/warnings with
> just unloading and loading the CCP driver. I'm not sure if this
> can be reproduced without the CCP hardware:
>
> # uname -r
> 6.2.0-0.rc2.18.eln124.x86_64
>
> # lspci | grep 'Encryption controller'
> 02:00.1 Encryption controller: Advanced Micro Devices, Inc. [AMD]
> Zeppelin Cryptographic Coprocessor NTBCCP ### PCIID: 1022:1468
> Subsystem: 1022:1468
> 03:00.2 Encryption controller: Advanced Micro Devices, Inc. [AMD]
> Family 17h (Models 00h-0fh) Platform Security Processor ### PCIID:
> 1022:1456 Subsystem: 1022:1456
>
> # rmmod kvm_amd ccp ; modprobe ccp
> [ 140.965403] sysfs: cannot create duplicate filename
> '/devices/pci0000:00/0000:00:07.1/0000:03:00.2/dma/dma0chan0'
> [ 140.975736] CPU: 0 PID: 388 Comm: kworker/0:2 Kdump: loaded Not
> tainted 6.2.0-0.rc2.18.eln124.x86_64 #1
> [ 140.985185] Hardware name: HPE ProLiant DL325 Gen10/ProLiant DL325
> Gen10, BIOS A41 07/17/2020
> [ 140.993761] Workqueue: events work_for_cpu_fn
> [ 140.998151] Call Trace:
> [ 141.000613] <TASK>
> [ 141.002726] dump_stack_lvl+0x33/0x46
> [ 141.006415] sysfs_warn_dup.cold+0x17/0x23
> [ 141.010542] sysfs_create_dir_ns+0xba/0xd0
> [ 141.014670] kobject_add_internal+0xba/0x260
> [ 141.018970] kobject_add+0x81/0xb0
> [ 141.022395] device_add+0xdc/0x7e0
> [ 141.025822] ? complete_all+0x20/0x90
> [ 141.029510] __dma_async_device_channel_register+0xc9/0x130
> [ 141.035119] dma_async_device_register+0x19e/0x3b0
> [ 141.039943] ccp_dmaengine_register+0x334/0x3f0 [ccp]
> [ 141.045042] ccp5_init+0x662/0x6a0 [ccp]
> [ 141.049000] ? devm_kmalloc+0x40/0xd0
> [ 141.052688] ccp_dev_init+0xbb/0xf0 [ccp]
> [ 141.056732] ? __pci_set_master+0x56/0xd0
> [ 141.060768] sp_init+0x70/0x90 [ccp]
> [ 141.064377] sp_pci_probe+0x186/0x1b0 [ccp]
> [ 141.068596] local_pci_probe+0x41/0x80
> [ 141.072374] work_for_cpu_fn+0x16/0x20
> [ 141.076145] process_one_work+0x1c8/0x380
> [ 141.080181] worker_thread+0x1ab/0x380
> [ 141.083953] ? __pfx_worker_thread+0x10/0x10
> [ 141.088250] kthread+0xda/0x100
> [ 141.091413] ? __pfx_kthread+0x10/0x10
> [ 141.095185] ret_from_fork+0x2c/0x50
> [ 141.098788] </TASK>
> [ 141.100996] kobject_add_internal failed for dma0chan0 with -EEXIST,
> don't try to register things with the same name in the same directory.
> [ 141.113703] ccp 0000:03:00.2: ccp initialization failed
> [ 141.118983] ccp 0000:03:00.2: SEV: memory encryption not enabled by BIOS
> [ 141.125728] ccp 0000:03:00.2: psp enabled
> [ 141.130020] ccp 0000:02:00.1: could not enable MSI-X (-22), trying MSI
> [ 141.136939] sysfs: cannot create duplicate filename '/class/dma/dma0chan0'
> [ 141.143863] CPU: 0 PID: 388 Comm: kworker/0:2 Kdump: loaded Not
> tainted 6.2.0-0.rc2.18.eln124.x86_64 #1
> [ 141.153313] Hardware name: HPE ProLiant DL325 Gen10/ProLiant DL325
> Gen10, BIOS A41 07/17/2020
> [ 141.161889] Workqueue: events work_for_cpu_fn
> [ 141.166274] Call Trace:
> [ 141.168733] <TASK>
> [ 141.170845] dump_stack_lvl+0x33/0x46
> [ 141.174531] sysfs_warn_dup.cold+0x17/0x23
> [ 141.178652] sysfs_do_create_link_sd+0xcf/0xe0
> [ 141.183124] device_add+0x28a/0x7e0
> [ 141.186634] ? complete_all+0x20/0x90
> [ 141.190318] __dma_async_device_channel_register+0xc9/0x130
> [ 141.195925] dma_async_device_register+0x19e/0x3b0
> [ 141.200745] ccp_dmaengine_register+0x334/0x3f0 [ccp]
> [ 141.205838] ccp5_init+0x662/0x6a0 [ccp]
> [ 141.209795] ? devm_kmalloc+0x40/0xd0
> [ 141.213479] ccp_dev_init+0xbb/0xf0 [ccp]
> [ 141.217524] ? __pci_set_master+0x56/0xd0
> [ 141.221559] sp_init+0x70/0x90 [ccp]
> [ 141.225166] sp_pci_probe+0x186/0x1b0 [ccp]
> [ 141.229385] local_pci_probe+0x41/0x80
> [ 141.233159] work_for_cpu_fn+0x16/0x20
> [ 141.236933] process_one_work+0x1c8/0x380
> [ 141.240966] worker_thread+0x1ab/0x380
> [ 141.244737] ? __pfx_worker_thread+0x10/0x10
> [ 141.249032] kthread+0xda/0x100
> [ 141.252192] ? __pfx_kthread+0x10/0x10
> [ 141.255964] ret_from_fork+0x2c/0x50
> [ 141.259563] </TASK>
> [ 141.261902] ccp 0000:02:00.1: ccp initialization failed
>
> This is reproducible with the latest upstream v6.2-rc2 code,
> "6.2.0-0.rc2.18.eln124.x86_64" is just the v6.2-rc2 code built
> with Fedora/ELN kernel configs. I'm talking about the commit
> 68dbe80f because just reverting it makes the above errors/warnings
> disappear.
