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When the driver is uninstalled and the VF is disabled concurrently, a
kernel crash occurs. The reason is that the two actions call function
pci_disable_sriov(). The num_VFs is checked to determine whether to
release the corresponding resources. During the second calling, num_VFs
is not 0 and the resource release function is called. However, the
corresponding resource has been released during the first invoking.
Therefore, the problem occurs:
[15277.839633][T50670] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
...
[15278.131557][T50670] Call trace:
[15278.134686][T50670] klist_put+0x28/0x12c
[15278.138682][T50670] klist_del+0x14/0x20
[15278.142592][T50670] device_del+0xbc/0x3c0
[15278.146676][T50670] pci_remove_bus_device+0x84/0x120
[15278.151714][T50670] pci_stop_and_remove_bus_device+0x6c/0x80
[15278.157447][T50670] pci_iov_remove_virtfn+0xb4/0x12c
[15278.162485][T50670] sriov_disable+0x50/0x11c
[15278.166829][T50670] pci_disable_sriov+0x24/0x30
[15278.171433][T50670] hnae3_unregister_ae_algo_prepare+0x60/0x90 [hnae3]
[15278.178039][T50670] hclge_exit+0x28/0xd0 [hclge]
[15278.182730][T50670] __se_sys_delete_module.isra.0+0x164/0x230
[15278.188550][T50670] __arm64_sys_delete_module+0x1c/0x30
[15278.193848][T50670] invoke_syscall+0x50/0x11c
[15278.198278][T50670] el0_svc_common.constprop.0+0x158/0x164
[15278.203837][T50670] do_el0_svc+0x34/0xcc
[15278.207834][T50670] el0_svc+0x20/0x30
For details, see the following figure.
rmmod hclge disable VFs
----------------------------------------------------
hclge_exit() sriov_numvfs_store()
... device_lock()
pci_disable_sriov() hns3_pci_sriov_configure()
pci_disable_sriov()
sriov_disable()
sriov_disable() if !num_VFs :
if !num_VFs : return;
return; sriov_del_vfs()
sriov_del_vfs() ...
... klist_put()
klist_put() ...
... num_VFs = 0;
num_VFs = 0; device_unlock();
In this patch, when driver is removing, we get the device_lock()
to protect num_VFs, just like sriov_numvfs_store().
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.