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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 12:53:37 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 12:53:37 -0800 |
commit | ac73e3dc8acd0a3be292755db30388c3580f5674 (patch) | |
tree | 5abef6cb82b205b5dbbb69dca950b8a5aae716de /mm/mmap.c | |
parent | 148842c98a24e508aecb929718818fbf4c2a6ff3 (diff) | |
parent | dfefd226b0bf7c435a58d75a0ce2f9273b9825f6 (diff) | |
download | linux-next-ac73e3dc8acd0a3be292755db30388c3580f5674.tar.gz |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
- a few random little subsystems
- almost all of the MM patches which are staged ahead of linux-next
material. I'll trickle to post-linux-next work in as the dependents
get merged up.
Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
mm: cleanup kstrto*() usage
mm: fix fall-through warnings for Clang
mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
mm:backing-dev: use sysfs_emit in macro defining functions
mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
mm: use sysfs_emit for struct kobject * uses
mm: fix kernel-doc markups
zram: break the strict dependency from lzo
zram: add stat to gather incompressible pages since zram set up
zram: support page writeback
mm/process_vm_access: remove redundant initialization of iov_r
mm/zsmalloc.c: rework the list_add code in insert_zspage()
mm/zswap: move to use crypto_acomp API for hardware acceleration
mm/zswap: fix passing zero to 'PTR_ERR' warning
mm/zswap: make struct kernel_param_ops definitions const
userfaultfd/selftests: hint the test runner on required privilege
userfaultfd/selftests: fix retval check for userfaultfd_open()
userfaultfd/selftests: always dump something in modes
userfaultfd: selftests: make __{s,u}64 format specifiers portable
...
Diffstat (limited to 'mm/mmap.c')
-rw-r--r-- | mm/mmap.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 5c8b4485860d..10598e5d4757 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2731,8 +2731,8 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *new; int err; - if (vma->vm_ops && vma->vm_ops->split) { - err = vma->vm_ops->split(vma, addr); + if (vma->vm_ops && vma->vm_ops->may_split) { + err = vma->vm_ops->may_split(vma, addr); if (err) return err; } @@ -3405,10 +3405,14 @@ static const char *special_mapping_name(struct vm_area_struct *vma) return ((struct vm_special_mapping *)vma->vm_private_data)->name; } -static int special_mapping_mremap(struct vm_area_struct *new_vma) +static int special_mapping_mremap(struct vm_area_struct *new_vma, + unsigned long flags) { struct vm_special_mapping *sm = new_vma->vm_private_data; + if (flags & MREMAP_DONTUNMAP) + return -EINVAL; + if (WARN_ON_ONCE(current->mm != new_vma->vm_mm)) return -EFAULT; @@ -3418,6 +3422,17 @@ static int special_mapping_mremap(struct vm_area_struct *new_vma) return 0; } +static int special_mapping_split(struct vm_area_struct *vma, unsigned long addr) +{ + /* + * Forbid splitting special mappings - kernel has expectations over + * the number of pages in mapping. Together with VM_DONTEXPAND + * the size of vma should stay the same over the special mapping's + * lifetime. + */ + return -EINVAL; +} + static const struct vm_operations_struct special_mapping_vmops = { .close = special_mapping_close, .fault = special_mapping_fault, @@ -3425,6 +3440,7 @@ static const struct vm_operations_struct special_mapping_vmops = { .name = special_mapping_name, /* vDSO code relies that VVAR can't be accessed remotely */ .access = NULL, + .may_split = special_mapping_split, }; static const struct vm_operations_struct legacy_special_mapping_vmops = { |