On Wed, May 22, 2019 at 06:45:41PM +0800, John Garry wrote:
commit 0b777eee88d712256ba8232a9429edb17c4f9ceb upstream
In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after devres release"), we changed the ordering of tearing down the device DMA ops and releasing all the device's resources; this was because the DMA ops should be maintained until we release the device's managed DMA memories.
However, we have seen another crash on an arm64 system when a device driver probe fails:
hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2 scsi host1: hisi_sas_v3_hw BUG: Bad page state in process swapper/0 pfn:313f5 page:ffff7e0000c4fd40 count:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe00000001000(reserved) raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set bad because of flags: 0x1000(reserved) Modules linked in: CPU: 49 PID: 1 Comm: swapper/0 Not tainted 5.1.0-rc1-43081-g22d97fd-dirty #1433 Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI RC0 - V1.12.01 01/29/2019 Call trace: dump_backtrace+0x0/0x118 show_stack+0x14/0x1c dump_stack+0xa4/0xc8 bad_page+0xe4/0x13c free_pages_check_bad+0x4c/0xc0 __free_pages_ok+0x30c/0x340 __free_pages+0x30/0x44 __dma_direct_free_pages+0x30/0x38 dma_direct_free+0x24/0x38 dma_free_attrs+0x9c/0xd8 dmam_release+0x20/0x28 release_nodes+0x17c/0x220 devres_release_all+0x34/0x54 really_probe+0xc4/0x2c8 driver_probe_device+0x58/0xfc device_driver_attach+0x68/0x70 __driver_attach+0x94/0xdc bus_for_each_dev+0x5c/0xb4 driver_attach+0x20/0x28 bus_add_driver+0x14c/0x200 driver_register+0x6c/0x124 __pci_register_driver+0x48/0x50 sas_v3_pci_driver_init+0x20/0x28 do_one_initcall+0x40/0x25c kernel_init_freeable+0x2b8/0x3c0 kernel_init+0x10/0x100 ret_from_fork+0x10/0x18 Disabling lock debugging due to kernel taint BUG: Bad page state in process swapper/0 pfn:313f6 page:ffff7e0000c4fd80 count:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 89.322983] flags: 0xfffe00000001000(reserved) raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
The crash occurs for the same reason.
In this case, on the really_probe() failure path, we are still clearing the DMA ops prior to releasing the device's managed memories.
This patch fixes this issue by reordering the DMA ops teardown and the call to devres_release_all() on the failure path.
Reported-by: Xiang Chen chenxiang66@hisilicon.com Tested-by: Xiang Chen chenxiang66@hisilicon.com Signed-off-by: John Garry john.garry@huawei.com Cc: stable stable@vger.kernel.org # 4.12.x - 4.19.x Reviewed-by: Robin Murphy robin.murphy@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [jpg: backport to 4.19.x and earlier] Signed-off-by: John Garry john.garry@huawei.com
Now queued up everywhere, thanks for the backport.
greg k-h