Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider: - [Medium] drm/imagination: wrong page count check and loop bound in pvr_vm_get_pt_phys_addrs() - [Low] drm/imagination: mismatched kernel-doc member names in struct pvr_fw_device --
commit 1c0b6ad7b66c2f99b867a56a6bc1405d6e8aad70 Author: Alessio Belle <[email protected]> drm/imagination: Limit access to the MIPS firmware interface This commit splits struct pvr_fw_mips_data into separate structures for the main MIPS firmware logic and the MIPS VM logic, removes pvr_fw_mips.h, and adds pvr_vm_get_pt_phys_addrs() to retrieve the physical addresses of the MIPS firmware page table. > diff --git a/drivers/gpu/drm/imagination/pvr_fw.h > b/drivers/gpu/drm/imagination/pvr_fw.h > index 4b25291135b69..0d4507f55c84b 100644 > --- a/drivers/gpu/drm/imagination/pvr_fw.h > +++ b/drivers/gpu/drm/imagination/pvr_fw.h > @@ -310,10 +310,15 @@ struct pvr_fw_device { > /** @funcs: Function table for the FW processor used by this device. */ > const struct pvr_fw_defs *defs; > > - /** @processor_data: Pointer to data specific to FW processor. */ > + /** @processor_data: Data specific to FW processor. */ > union { > - /** @mips_data: Pointer to MIPS-specific data. */ > - struct pvr_fw_mips_data *mips_data; > + /** @mips_data: MIPS-specific data. */ > + struct { > + /** @mips_fw_data: Pointer to MIPS-FW-specific data. */ > + struct pvr_fw_mips_data *fw_data; > + /** @mips_vm_data: Pointer to MIPS-VM-specific data. */ > + struct pvr_vm_mips_data *vm_data; > + } mips_data; [Severity: Low] This isn't a bug, but in struct pvr_fw_device in drivers/gpu/drm/imagination/pvr_fw.h, should the kernel-doc tags @mips_fw_data and @mips_vm_data be @fw_data and @vm_data to match the struct member names? > diff --git a/drivers/gpu/drm/imagination/pvr_vm_mips.c > b/drivers/gpu/drm/imagination/pvr_vm_mips.c > index 5847a1c92bea8..264ea0fccf9c1 100644 > --- a/drivers/gpu/drm/imagination/pvr_vm_mips.c > +++ b/drivers/gpu/drm/imagination/pvr_vm_mips.c > @@ -16,6 +17,31 @@ > #include <linux/types.h> > #include <linux/vmalloc.h> > > +#define PVR_MIPS_PT_PAGE_COUNT \ > + DIV_ROUND_UP(ROGUE_MIPSFW_MAX_NUM_PAGETABLE_PAGES * > ROGUE_MIPSFW_PAGE_SIZE_4K, PAGE_SIZE) > + > +/** > + * struct pvr_vm_mips_data - MIPS-VM-specific data > + */ > +struct pvr_vm_mips_data { > + /** > + * @pt_pages: Pages containing MIPS pagetable. > + */ > + struct page *pt_pages[PVR_MIPS_PT_PAGE_COUNT]; > + > + /** @pt: Pointer to CPU mapping of MIPS pagetable. */ > + u32 *pt; > + > + /** @pt_dma_addr: DMA mappings of MIPS pagetable. */ > + dma_addr_t pt_dma_addr[PVR_MIPS_PT_PAGE_COUNT]; [ ... ] > @@ -230,8 +256,38 @@ pvr_vm_mips_unmap(struct pvr_device *pvr_dev, struct > pvr_fw_object *fw_obj) > ROGUE_MIPSFW_LOG2_PAGE_SIZE_4K; > > for (u32 pfn = start_pfn; pfn < end_pfn; pfn++) > - WRITE_ONCE(mips_data->pt[pfn], 0); > + WRITE_ONCE(vm_data->pt[pfn], 0); > > pvr_mmu_flush_request_all(pvr_dev); > WARN_ON(pvr_mmu_flush_exec(pvr_dev, true)); > } > + > +/** > + * pvr_vm_get_pt_phys_addrs() - Acquire the physical addresses of the MIPS > FW page table pages > + * @pvr_dev: Target PowerVR device. > + * @phys_addrs: Output array for physical addresses of MIPS FW page table > pages. > + * @max_num_addrs: Maximum number of addresses that can be written to > @phys_addrs. > + * > + * Returns: > + * * 0 on success, or > + * * -%EINVAL if @phys_addrs cannot accommodate all MIPS FW page table > pages. > + */ > +int > +pvr_vm_get_pt_phys_addrs(struct pvr_device *pvr_dev, u64 *phys_addrs, int > max_num_addrs) > +{ > + struct pvr_fw_device *fw_dev = &pvr_dev->fw_dev; > + struct pvr_vm_mips_data *vm_data = > fw_dev->processor_data.mips_data.vm_data; > + > + if (ARRAY_SIZE(vm_data->pt_pages) > max_num_addrs) > + return -EINVAL; > + > + for (u32 page_nr = 0; page_nr < max_num_addrs; page_nr++) { > + /* Firmware expects 4k pages, but host page size might be > different. */ > + u32 src_page_nr = (page_nr * ROGUE_MIPSFW_PAGE_SIZE_4K) >> > PAGE_SHIFT; > + u32 page_offset = (page_nr * ROGUE_MIPSFW_PAGE_SIZE_4K) & > ~PAGE_MASK; > + > + phys_addrs[page_nr] = vm_data->pt_dma_addr[src_page_nr] + > page_offset; > + } > + > + return 0; > +} [Severity: Medium] In pvr_vm_get_pt_phys_addrs() in drivers/gpu/drm/imagination/pvr_vm_mips.c (and its declaration in drivers/gpu/drm/imagination/pvr_vm_mips.h), should the size check and loop bound use ROGUE_MIPSFW_MAX_NUM_PAGETABLE_PAGES instead of ARRAY_SIZE(vm_data->pt_pages) and max_num_addrs, and should max_num_addrs be an unsigned type such as u32? vm_data->pt_pages and vm_data->pt_dma_addr are sized to PVR_MIPS_PT_PAGE_COUNT, which is the number of host PAGE_SIZE pages (for example, 1 on 16K or 64K page hosts), whereas phys_addrs is populated with 4K MIPS firmware page table addresses (ROGUE_MIPSFW_MAX_NUM_PAGETABLE_PAGES = 4). Checking ARRAY_SIZE(vm_data->pt_pages) > max_num_addrs validates against the host page count rather than ROGUE_MIPSFW_MAX_NUM_PAGETABLE_PAGES, so on 16K or 64K page hosts a buffer with fewer than 4 entries would pass the check. Additionally, iterating page_nr up to max_num_addrs rather than ROGUE_MIPSFW_MAX_NUM_PAGETABLE_PAGES means that if a caller passes max_num_addrs > ROGUE_MIPSFW_MAX_NUM_PAGETABLE_PAGES, src_page_nr will index past the end of vm_data->pt_dma_addr[]. Because max_num_addrs is a signed int compared against unsigned ARRAY_SIZE() and u32 page_nr, this also triggers -Wsign-compare warnings and allows negative values to bypass the check. -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=1
