diff options
| -rw-r--r-- | include/linux/mm.h | 3 | ||||
| -rw-r--r-- | ipc/shm.c | 11 | ||||
| -rw-r--r-- | mm/mmap.c | 38 |
3 files changed, 27 insertions, 25 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 956025940053..5b5f26d6588a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2922,6 +2922,9 @@ extern int do_munmap(struct mm_struct *, unsigned long, size_t, extern int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior); #ifdef CONFIG_MMU +extern int do_vma_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, + unsigned long start, unsigned long end, + struct list_head *uf, bool downgrade); extern int __mm_populate(unsigned long addr, unsigned long len, int ignore_errors); static inline void mm_populate(unsigned long addr, unsigned long len) diff --git a/ipc/shm.c b/ipc/shm.c index 1c6a6b319a49..60e45e7045d4 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1786,8 +1786,8 @@ long ksys_shmdt(char __user *shmaddr) */ file = vma->vm_file; size = i_size_read(file_inode(vma->vm_file)); - do_vmi_munmap(&vmi, mm, vma->vm_start, - vma->vm_end - vma->vm_start, NULL, false); + do_vma_munmap(&vmi, vma, vma->vm_start, vma->vm_end, + NULL, false); /* * We discovered the size of the shm segment, so * break out of here and fall through to the next @@ -1810,9 +1810,10 @@ long ksys_shmdt(char __user *shmaddr) /* finding a matching vma now does not alter retval */ if ((vma->vm_ops == &shm_vm_ops) && ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) && - (vma->vm_file == file)) - do_vmi_munmap(&vmi, mm, vma->vm_start, - vma->vm_end - vma->vm_start, NULL, false); + (vma->vm_file == file)) { + do_vma_munmap(&vmi, vma, vma->vm_start, vma->vm_end, + NULL, false); + } vma = vma_next(&vmi); } diff --git a/mm/mmap.c b/mm/mmap.c index 894017841d5d..408e9cc47333 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -180,9 +180,6 @@ static int check_brk_limits(unsigned long addr, unsigned long len) return mlock_future_check(current->mm, current->mm->def_flags, len); } -static int do_brk_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, - unsigned long newbrk, unsigned long oldbrk, - struct list_head *uf); static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *brkvma, unsigned long addr, unsigned long request, unsigned long flags); SYSCALL_DEFINE1(brk, unsigned long, brk) @@ -236,7 +233,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) /* * Always allow shrinking brk. - * do_brk_munmap() may downgrade mmap_lock to read. + * do_vma_munmap() may downgrade mmap_lock to read. */ if (brk <= mm->brk) { int ret; @@ -248,11 +245,11 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) goto out; /* mapping intersects with an existing non-brk vma. */ /* * mm->brk must be protected by write mmap_lock. - * do_brk_munmap() may downgrade the lock, so update it - * before calling do_brk_munmap(). + * do_vma_munmap() may downgrade the lock, so update it + * before calling do_vma_munmap(). */ mm->brk = brk; - ret = do_brk_munmap(&vmi, brkvma, newbrk, oldbrk, &uf); + ret = do_vma_munmap(&vmi, brkvma, newbrk, oldbrk, &uf, true); if (ret == 1) { downgraded = true; goto success; @@ -2951,26 +2948,27 @@ out: } /* - * brk_munmap() - Unmap a full or partial vma. - * @vmi: The vma iterator - * @vma: The vma to be modified - * @newbrk: the start of the address to unmap - * @oldbrk: The end of the address to unmap + * do_vma_munmap() - Unmap a full or partial vma. + * @vmi: The vma iterator pointing at the vma + * @vma: The first vma to be munmapped + * @start: the start of the address to unmap + * @end: The end of the address to unmap * @uf: The userfaultfd list_head + * @downgrade: Attempt to downgrade or not * - * Returns: 1 on success. - * unmaps a partial VMA mapping. Does not handle alignment, downgrades lock if - * possible. + * Returns: 0 on success and not downgraded, 1 on success and downgraded. + * unmaps a VMA mapping when the vma iterator is already in position. + * Does not handle alignment. */ -static int do_brk_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, - unsigned long newbrk, unsigned long oldbrk, - struct list_head *uf) +int do_vma_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, + unsigned long start, unsigned long end, + struct list_head *uf, bool downgrade) { struct mm_struct *mm = vma->vm_mm; int ret; - arch_unmap(mm, newbrk, oldbrk); - ret = do_vmi_align_munmap(vmi, vma, mm, newbrk, oldbrk, uf, true); + arch_unmap(mm, start, end); + ret = do_vmi_align_munmap(vmi, vma, mm, start, end, uf, downgrade); validate_mm_mt(mm); return ret; } |