From 29ae7d96d166fa08c7232daf8a314ef5ba1efd20 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 10 Apr 2024 17:55:26 +0200 Subject: [PATCH] mm: pass VMA instead of MM to follow_pte() ... and centralize the VM_IO/VM_PFNMAP sanity check in there. We'll now also perform these sanity checks for direct follow_pte() invocations. For generic_access_phys(), we might now check multiple times: nothing to worry about, really. Link: https://lkml.kernel.org/r/20240410155527.474777-3-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Sean Christopherson [KVM] Cc: Alex Williamson Cc: Christoph Hellwig Cc: Fei Li Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Ingo Molnar Cc: Paolo Bonzini Cc: Yonghua Huang Signed-off-by: Andrew Morton --- arch/s390/pci/pci_mmio.c | 4 ++-- arch/x86/mm/pat/memtype.c | 5 +---- drivers/vfio/vfio_iommu_type1.c | 4 ++-- drivers/virt/acrn/mm.c | 3 +-- include/linux/mm.h | 2 +- mm/memory.c | 15 ++++++++------- virt/kvm/kvm_main.c | 4 ++-- 7 files changed, 17 insertions(+), 20 deletions(-) diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c index a90499c087f0..5398729bfe1b 100644 --- a/arch/s390/pci/pci_mmio.c +++ b/arch/s390/pci/pci_mmio.c @@ -169,7 +169,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr, if (!(vma->vm_flags & VM_WRITE)) goto out_unlock_mmap; - ret = follow_pte(vma->vm_mm, mmio_addr, &ptep, &ptl); + ret = follow_pte(vma, mmio_addr, &ptep, &ptl); if (ret) goto out_unlock_mmap; @@ -308,7 +308,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr, if (!(vma->vm_flags & VM_WRITE)) goto out_unlock_mmap; - ret = follow_pte(vma->vm_mm, mmio_addr, &ptep, &ptl); + ret = follow_pte(vma, mmio_addr, &ptep, &ptl); if (ret) goto out_unlock_mmap; diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c index d01c3b0bd6eb..bdc2a240c2aa 100644 --- a/arch/x86/mm/pat/memtype.c +++ b/arch/x86/mm/pat/memtype.c @@ -954,10 +954,7 @@ static int follow_phys(struct vm_area_struct *vma, unsigned long *prot, pte_t *ptep, pte; spinlock_t *ptl; - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) - return -EINVAL; - - if (follow_pte(vma->vm_mm, vma->vm_start, &ptep, &ptl)) + if (follow_pte(vma, vma->vm_start, &ptep, &ptl)) return -EINVAL; pte = ptep_get(ptep); diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index b5c15fe8f9fc..3a0218171cfa 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -518,7 +518,7 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, spinlock_t *ptl; int ret; - ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl); + ret = follow_pte(vma, vaddr, &ptep, &ptl); if (ret) { bool unlocked = false; @@ -532,7 +532,7 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, if (ret) return ret; - ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl); + ret = follow_pte(vma, vaddr, &ptep, &ptl); if (ret) return ret; } diff --git a/drivers/virt/acrn/mm.c b/drivers/virt/acrn/mm.c index 2d98e1e185c4..db8ff1d0ac23 100644 --- a/drivers/virt/acrn/mm.c +++ b/drivers/virt/acrn/mm.c @@ -187,8 +187,7 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap) } for (i = 0; i < nr_pages; i++) { - ret = follow_pte(vma->vm_mm, - memmap->vma_base + i * PAGE_SIZE, + ret = follow_pte(vma, memmap->vma_base + i * PAGE_SIZE, &ptep, &ptl); if (ret) break; diff --git a/include/linux/mm.h b/include/linux/mm.h index 0b933f9f4864..c25ce6992951 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2420,7 +2420,7 @@ void free_pgd_range(struct mmu_gather *tlb, unsigned long addr, unsigned long end, unsigned long floor, unsigned long ceiling); int copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma); -int follow_pte(struct mm_struct *mm, unsigned long address, +int follow_pte(struct vm_area_struct *vma, unsigned long address, pte_t **ptepp, spinlock_t **ptlp); int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, void *buf, int len, int write); diff --git a/mm/memory.c b/mm/memory.c index 59c05dc8b18a..1d45d25c1bba 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5926,7 +5926,7 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) /** * follow_pte - look up PTE at a user virtual address - * @mm: the mm_struct of the target address space + * @vma: the memory mapping * @address: user virtual address * @ptepp: location to store found PTE * @ptlp: location to store the lock for the PTE @@ -5945,15 +5945,19 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) * * Return: zero on success, -ve otherwise. */ -int follow_pte(struct mm_struct *mm, unsigned long address, +int follow_pte(struct vm_area_struct *vma, unsigned long address, pte_t **ptepp, spinlock_t **ptlp) { + struct mm_struct *mm = vma->vm_mm; pgd_t *pgd; p4d_t *p4d; pud_t *pud; pmd_t *pmd; pte_t *ptep; + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) + goto out; + pgd = pgd_offset(mm, address); if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) goto out; @@ -6007,11 +6011,8 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, int offset = offset_in_page(addr); int ret = -EINVAL; - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) - return -EINVAL; - retry: - if (follow_pte(vma->vm_mm, addr, &ptep, &ptl)) + if (follow_pte(vma, addr, &ptep, &ptl)) return -EINVAL; pte = ptep_get(ptep); pte_unmap_unlock(ptep, ptl); @@ -6026,7 +6027,7 @@ retry: if (!maddr) return -ENOMEM; - if (follow_pte(vma->vm_mm, addr, &ptep, &ptl)) + if (follow_pte(vma, addr, &ptep, &ptl)) goto out_unmap; if (!pte_same(pte, ptep_get(ptep))) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index fb49c2a60200..f57dbacb8689 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2902,7 +2902,7 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, spinlock_t *ptl; int r; - r = follow_pte(vma->vm_mm, addr, &ptep, &ptl); + r = follow_pte(vma, addr, &ptep, &ptl); if (r) { /* * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does @@ -2917,7 +2917,7 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, if (r) return r; - r = follow_pte(vma->vm_mm, addr, &ptep, &ptl); + r = follow_pte(vma, addr, &ptep, &ptl); if (r) return r; }