From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- Documentation/gpu/amdgpu/driver-misc.rst | 156 +++++++++++++++++++++++++++++++ 1 file changed, 156 insertions(+) create mode 100644 Documentation/gpu/amdgpu/driver-misc.rst (limited to 'Documentation/gpu/amdgpu/driver-misc.rst') diff --git a/Documentation/gpu/amdgpu/driver-misc.rst b/Documentation/gpu/amdgpu/driver-misc.rst new file mode 100644 index 000000000..e1a964c3a --- /dev/null +++ b/Documentation/gpu/amdgpu/driver-misc.rst @@ -0,0 +1,156 @@ +================================ + Misc AMDGPU driver information +================================ + +GPU Product Information +======================= + +Information about the GPU can be obtained on certain cards +via sysfs + +product_name +------------ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: product_name + +product_number +-------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: product_number + +serial_number +------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: serial_number + +fru_id +------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: fru_id + +manufacturer +------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c + :doc: manufacturer + +unique_id +--------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: unique_id + +board_info +---------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: board_info + +GPU Memory Usage Information +============================ + +Various memory accounting can be accessed via sysfs + +mem_info_vram_total +------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c + :doc: mem_info_vram_total + +mem_info_vram_used +------------------ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c + :doc: mem_info_vram_used + +mem_info_vis_vram_total +----------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c + :doc: mem_info_vis_vram_total + +mem_info_vis_vram_used +---------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c + :doc: mem_info_vis_vram_used + +mem_info_gtt_total +------------------ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c + :doc: mem_info_gtt_total + +mem_info_gtt_used +----------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c + :doc: mem_info_gtt_used + +PCIe Accounting Information +=========================== + +pcie_bw +------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: pcie_bw + +pcie_replay_count +----------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: pcie_replay_count + +GPU SmartShift Information +========================== + +GPU SmartShift information via sysfs + +smartshift_apu_power +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: smartshift_apu_power + +smartshift_dgpu_power +--------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: smartshift_dgpu_power + +smartshift_bias +--------------- + +.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c + :doc: smartshift_bias + +UMA Carveout +============ + +Some versions of Atom ROM expose available options for the VRAM carveout sizes, +and allow changes to the carveout size via the ATCS function code 0xA on supported +BIOS implementations. + +For those platforms, users can use the following files under uma/ to set the +carveout size, in a way similar to what Windows users can do in the "Tuning" +tab in AMD Adrenalin. + +Note that for BIOS implementations that don't support this, these files will not +be created at all. + +uma/carveout_options +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: uma/carveout_options + +uma/carveout +-------------------- + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c + :doc: uma/carveout -- cgit v1.3.1