| Message ID | 20210521174745.2219620-1-Liam.Howlett@Oracle.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | mm: Add vma_lookup() | expand |
Hello, I missed David Hildenbrand on the CC list and in the v2 change log. I added David Hildenbrand <david@redhat.com> to the Acked-By for the series as well. Sorry for the oversight. Thank you, Liam * Liam Howlett <liam.howlett@oracle.com> [210521 13:47]: > 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(). > > v2: > - Changed find_vma_intersection() comments and whitespace to be > compliant. Thanks Davidlohr Bueso > - Moved vma_lookup() call in vma_to_resize() to be separate from the > declaration as requested by Davidlohr Bueso > - Added Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> for 08/22 > "arch/m68k/kernel/sys_m68k: Use vma_lookup() in sys_cacheflush()" > - Added Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> > - Added Acked-by: Davidlohr Bueso <dbueso@suse.de> > > This patch set was originally part of the maple tree patch set. > 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(), update find_vma_intersection() comments > 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 +-- > .../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 | 36 ++++++++++++++++--- > 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 | 5 +-- > net/ipv4/tcp.c | 4 +-- > virt/kvm/kvm_main.c | 2 +- > 22 files changed, 69 insertions(+), 45 deletions(-) > > -- > 2.30.2
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(). v2: - Changed find_vma_intersection() comments and whitespace to be compliant. Thanks Davidlohr Bueso - Moved vma_lookup() call in vma_to_resize() to be separate from the declaration as requested by Davidlohr Bueso - Added Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> for 08/22 "arch/m68k/kernel/sys_m68k: Use vma_lookup() in sys_cacheflush()" - Added Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> - Added Acked-by: Davidlohr Bueso <dbueso@suse.de> This patch set was originally part of the maple tree patch set. 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(), update find_vma_intersection() comments 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 +-- .../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 | 36 ++++++++++++++++--- 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 | 5 +-- net/ipv4/tcp.c | 4 +-- virt/kvm/kvm_main.c | 2 +- 22 files changed, 69 insertions(+), 45 deletions(-)