Commit f3973d8b authored by Guchun Chen's avatar Guchun Chen Committed by Xiongfeng Wang
Browse files

drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume 

mainline inclusion
from mainline-v5.15-rc5
commit 248b0616
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4NB
CVE: CVE-2021-47421

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=248b061689a40f4fed05252ee2c89f87cf26d7d8



--------------------------------

In current code, when a PCI error state pci_channel_io_normal is detectd,
it will report PCI_ERS_RESULT_CAN_RECOVER status to PCI driver, and PCI
driver will continue the execution of PCI resume callback report_resume by
pci_walk_bridge, and the callback will go into amdgpu_pci_resume
finally, where write lock is releasd unconditionally without acquiring
such lock first. In this case, a deadlock will happen when other threads
start to acquire the read lock.

To fix this, add a member in amdgpu_device strucutre to cache
pci_channel_state, and only continue the execution in amdgpu_pci_resume
when it's pci_channel_io_frozen.

Fixes: c9a6b82f ("drm/amdgpu: Implement DPC recovery")
Suggested-by: default avatarAndrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: default avatarGuchun Chen <guchun.chen@amd.com>
Reviewed-by: default avatarAndrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>

Conflicts:
drivers/gpu/drm/amd/amdgpu/amdgpu.h
[wangxiongfeng: fix context conflicts in struct amdgpu_device]
Signed-off-by: default avatarXiongfeng Wang <wangxiongfeng2@huawei.com>
parent ebe8b9e4

drivers/gpu/drm/amd/amdgpu/amdgpu.h

+1 −0
Original line number Diff line number Diff line
@@ -997,6 +997,7 @@ struct amdgpu_device { 


	bool                            in_pci_err_recovery;

	struct pci_saved_state          *pci_state;

	pci_channel_state_t		pci_channel_state;

};



static inline struct amdgpu_device *drm_to_adev(struct drm_device *ddev)

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

+6 −0
Original line number Diff line number Diff line
@@ -4932,6 +4932,8 @@ pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev, pci_channel_sta 
		return PCI_ERS_RESULT_DISCONNECT;

	}



	adev->pci_channel_state = state;



	switch (state) {

	case pci_channel_io_normal:

		return PCI_ERS_RESULT_CAN_RECOVER;
@@ -5067,6 +5069,10 @@ void amdgpu_pci_resume(struct pci_dev *pdev) 


	DRM_INFO("PCI error: resume callback!!\n");



	/* Only continue execution for the case of pci_channel_io_frozen */

	if (adev->pci_channel_state != pci_channel_io_frozen)

		return;



	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {

		struct amdgpu_ring *ring = adev->rings[i];