lkl: pci: Fix freeing DMA allocation with CPU address#637
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lkl_dma_alloc() returns a kernel virtual address derived from the allocated page. The DMA ops free callback receives that same CPU address, but lkl_dma_free() passed it directly to __free_pages(), which expects a struct page pointer. Convert the CPU address with virt_to_page() before freeing it. Add an LKL PCI KUnit test that exercises dma_alloc_attrs() and dma_free_attrs() through stub PCI host ops, and wire it into the LKL test configuration via PCI_KUNIT. Signed-off-by: Cheng Lingfei <chenglingfei@foxmail.com>
We also enable kunit test in CI, and remove kunit.filter_glob= in CONFIG_BUILTIN_CMDLINE to avoid the kasan and pci test be filtered out. Signed-off-by: Cheng Lingfei <chenglingfei@foxmail.com>
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thanks @clingfei ! |
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Yes, I am using CONFIG_MMU=y. I wanted to see how LKL supports DMA. Then I realized that this might be a confusion between __free_pages and free_pages. |
thehajime
reviewed
May 26, 2026
As we have already removed the filter, the KASAN_CMD_LINE and other macros are always empty. Thus we remove them. Signed-off-by: Cheng Lingfei <chenglingfei@foxmail.com>
tavip
approved these changes
May 27, 2026
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thanks ! |
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lkl_dma_alloc() returns a kernel virtual address derived from the allocated page. The DMA ops free callback receives that same CPU address, but lkl_dma_free() passed it directly to __free_pages(), which expects a struct page pointer.
Convert the CPU address with virt_to_page() before freeing it.
Add an LKL PCI KUnit test that exercises dma_alloc_attrs() and dma_free_attrs() through stub PCI host ops, and wire it into the LKL test configuration via PCI_KUNIT.