6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christoph Hellwig <hch@xxxxxx> [ Upstream commit 1b265da7ea1e1ae997fa119c2846bb389eb39c6b ] Patch series "remove follow_pfn". This series open codes follow_pfn in the only remaining caller, although the code there remains questionable. It then also moves follow_phys into the only user and simplifies it a bit. This patch (of 3): Switch from follow_pfn to follow_pte so that we can get rid of follow_pfn. Note that this doesn't fix any of the pre-existing raciness and lack of permission checking in the code. Link: https://lkml.kernel.org/r/20240324234542.2038726-1-hch@xxxxxx Link: https://lkml.kernel.org/r/20240324234542.2038726-2-hch@xxxxxx Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Fei Li <fei1.li@xxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Stable-dep-of: 3d6586008f7b ("drivers/virt/acrn: fix PFNMAP PTE checks in acrn_vm_ram_map()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/virt/acrn/mm.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/virt/acrn/mm.c b/drivers/virt/acrn/mm.c index fa5d9ca6be570..69c3f619f8819 100644 --- a/drivers/virt/acrn/mm.c +++ b/drivers/virt/acrn/mm.c @@ -171,18 +171,24 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap) mmap_read_lock(current->mm); vma = vma_lookup(current->mm, memmap->vma_base); if (vma && ((vma->vm_flags & VM_PFNMAP) != 0)) { + spinlock_t *ptl; + pte_t *ptep; + if ((memmap->vma_base + memmap->len) > vma->vm_end) { mmap_read_unlock(current->mm); return -EINVAL; } - ret = follow_pfn(vma, memmap->vma_base, &pfn); - mmap_read_unlock(current->mm); + ret = follow_pte(vma->vm_mm, memmap->vma_base, &ptep, &ptl); if (ret < 0) { + mmap_read_unlock(current->mm); dev_dbg(acrn_dev.this_device, "Failed to lookup PFN at VMA:%pK.\n", (void *)memmap->vma_base); return ret; } + pfn = pte_pfn(ptep_get(ptep)); + pte_unmap_unlock(ptep, ptl); + mmap_read_unlock(current->mm); return acrn_mm_region_add(vm, memmap->user_vm_pa, PFN_PHYS(pfn), memmap->len, -- 2.43.0
