7bb572fddd
If CONFIG_ARM_SMMU_V3 is enabled, arm64's dma_ops will replace arm64_swiotlb_dma_ops with iommu_dma_ops. When releasing contiguous dma memory, the new ops will call the vunmap function which cannot be run in interrupt context. Currently, spin_lock_bh is called before vunmap is executed. This disables BH and causes the interrupt context to be detected to generate a kernel panic like below: [ 2831.573400] kernel BUG at mm/vmalloc.c:1621! [ 2831.577659] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ... [ 2831.699907] Process rmmod (pid: 1893, stack limit = 0x0000000055103ee2) [ 2831.706507] Call trace: [ 2831.708941] vunmap+0x48/0x50 [ 2831.711897] dma_common_free_remap+0x78/0x88 [ 2831.716155] __iommu_free_attrs+0xa8/0x1c0 [ 2831.720255] hclge_free_cmd_desc+0xc8/0x118 [hclge] [ 2831.725128] hclge_destroy_cmd_queue+0x34/0x68 [hclge] [ 2831.730261] hclge_uninit_ae_dev+0x90/0x100 [hclge] [ 2831.735127] hnae3_unregister_ae_dev+0xb0/0x868 [hnae3] [ 2831.740345] hns3_remove+0x3c/0x90 [hns3] [ 2831.744344] pci_device_remove+0x48/0x108 [ 2831.748342] device_release_driver_internal+0x164/0x200 [ 2831.753553] driver_detach+0x4c/0x88 [ 2831.757116] bus_remove_driver+0x60/0xc0 [ 2831.761026] driver_unregister+0x34/0x60 [ 2831.764935] pci_unregister_driver+0x30/0xb0 [ 2831.769197] hns3_exit_module+0x10/0x978 [hns3] [ 2831.773715] SyS_delete_module+0x1f8/0x248 [ 2831.777799] el0_svc_naked+0x30/0x34 This patch fixes it by using spin_lock instead of spin_lock_bh. Fixes: 68c0a5c70614 ("net: hns3: Add HNS3 IMP(Integrated Mgmt Proc) Cmd Interface Support") Signed-off-by: Xi Wang <wangxi11@huawei.com> Signed-off-by: Peng Li <lipeng321@huawei.com> Signed-off-by: Salil Mehta <salil.mehta@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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 Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
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.