Le 10/05/2021 à 18:58, Liam Howlett a écrit :
Many places in the kernel use find_vma() to get a vma and then check the start address of the vma to ensure the next vma was not returned. Other places use the find_vma_intersection() call with add, addr + 1 as the range; looking for just the vma at a specific address. The third use of find_vma() is by developers who do not know that the function starts searching at the provided address upwards for the next vma. This results in a bug that is often overlooked for a long time. Adding the new vma_lookup() function will allow for cleaner code by removing the find_vma() calls which check limits, making find_vma_intersection() calls of a single address to be shorter, and potentially reduce the incorrect uses of find_vma(). This patch set was originally part of the maple tree patch set.
FWIW, for the whole series: Reviewed-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx>
Changes since being broken out on its own: - Changed initial implementation of vma_lookup() to use find_vma() as requested by Michel Lespinasse. - Updated commit comments to be more descriptive These patches are based on next-20210506 Liam R. Howlett (22): mm: Add vma_lookup() drm/i915/selftests: Use vma_lookup() in __igt_mmap() arch/arc/kernel/troubleshoot: use vma_lookup() instead of find_vma() arch/arm64/kvm: Use vma_lookup() instead of find_vma_intersection() arch/powerpc/kvm/book3s_hv_uvmem: Use vma_lookup() instead of find_vma_intersection() arch/powerpc/kvm/book3s: Use vma_lookup() in kvmppc_hv_setup_htab_rma() arch/mips/kernel/traps: Use vma_lookup() instead of find_vma() arch/m68k/kernel/sys_m68k: Use vma_lookup() in sys_cacheflush() x86/sgx: Use vma_lookup() in sgx_encl_find() virt/kvm: Use vma_lookup() instead of find_vma_intersection() vfio: Use vma_lookup() instead of find_vma_intersection() net/ipv5/tcp: Use vma_lookup() in tcp_zerocopy_receive() drm/amdgpu: Use vma_lookup() in amdgpu_ttm_tt_get_user_pages() media: videobuf2: Use vma_lookup() in get_vaddr_frames() misc/sgi-gru/grufault: Use vma_lookup() in gru_find_vma() kernel/events/uprobes: Use vma_lookup() in find_active_uprobe() lib/test_hmm: Use vma_lookup() in dmirror_migrate() mm/ksm: Use vma_lookup() in find_mergeable_vma() mm/migrate: Use vma_lookup() in do_pages_stat_array() mm/mremap: Use vma_lookup() in vma_to_resize() mm/memory.c: Use vma_lookup() in __access_remote_vm() mm/mempolicy: Use vma_lookup() in __access_remote_vm() arch/arc/kernel/troubleshoot.c | 8 ++++---- arch/arm64/kvm/mmu.c | 2 +- arch/m68k/kernel/sys_m68k.c | 4 ++-- arch/mips/kernel/traps.c | 4 +--- arch/powerpc/kvm/book3s_hv.c | 4 ++-- arch/powerpc/kvm/book3s_hv_uvmem.c | 2 +- arch/x86/kernel/cpu/sgx/encl.h | 4 ++-- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 ++-- .../gpu/drm/i915/gem/selftests/i915_gem_mman.c | 2 +- drivers/media/common/videobuf2/frame_vector.c | 2 +- drivers/misc/sgi-gru/grufault.c | 4 ++-- drivers/vfio/vfio_iommu_type1.c | 2 +- include/linux/mm.h | 18 ++++++++++++++++++ kernel/events/uprobes.c | 4 ++-- lib/test_hmm.c | 5 ++--- mm/ksm.c | 6 ++---- mm/memory.c | 4 ++-- mm/mempolicy.c | 2 +- mm/migrate.c | 4 ++-- mm/mremap.c | 4 ++-- net/ipv4/tcp.c | 4 ++-- virt/kvm/kvm_main.c | 2 +- 22 files changed, 54 insertions(+), 41 deletions(-)