diff options
Diffstat (limited to 'mm/mremap.c')
| -rw-r--r-- | mm/mremap.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index b522cd0259a0..e465ffe279bb 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -9,6 +9,7 @@ */ #include <linux/mm.h> +#include <linux/mm_inline.h> #include <linux/hugetlb.h> #include <linux/shm.h> #include <linux/ksm.h> @@ -23,6 +24,7 @@ #include <linux/mmu_notifier.h> #include <linux/uaccess.h> #include <linux/userfaultfd_k.h> +#include <linux/mempolicy.h> #include <asm/cacheflush.h> #include <asm/tlb.h> @@ -716,7 +718,7 @@ static unsigned long move_vma(struct vm_area_struct *vma, if (excess) { vma->vm_flags |= VM_ACCOUNT; if (split) - vma->vm_next->vm_flags |= VM_ACCOUNT; + find_vma(mm, vma->vm_end)->vm_flags |= VM_ACCOUNT; } return new_addr; @@ -866,9 +868,10 @@ out: static int vma_expandable(struct vm_area_struct *vma, unsigned long delta) { unsigned long end = vma->vm_end + delta; + if (end < vma->vm_end) /* overflow */ return 0; - if (vma->vm_next && vma->vm_next->vm_start < end) /* intersection */ + if (find_vma_intersection(vma->vm_mm, vma->vm_end, end)) return 0; if (get_unmapped_area(NULL, vma->vm_start, end - vma->vm_start, 0, MAP_FIXED) & ~PAGE_MASK) @@ -975,20 +978,23 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, /* * Always allow a shrinking remap: that just unmaps * the unnecessary pages.. - * __do_munmap does all the needed commit accounting, and + * do_mas_munmap does all the needed commit accounting, and * downgrades mmap_lock to read if so directed. */ if (old_len >= new_len) { int retval; + MA_STATE(mas, &mm->mm_mt, addr + new_len, addr + new_len); - retval = __do_munmap(mm, addr+new_len, old_len - new_len, - &uf_unmap, true); - if (retval < 0 && old_len != new_len) { - ret = retval; - goto out; + retval = do_mas_munmap(&mas, mm, addr + new_len, + old_len - new_len, &uf_unmap, true); /* Returning 1 indicates mmap_lock is downgraded to read. */ - } else if (retval == 1) + if (retval == 1) { downgraded = true; + } else if (retval < 0 && old_len != new_len) { + ret = retval; + goto out; + } + ret = addr; goto out; } @@ -1008,6 +1014,9 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, /* can we just expand the current mapping? */ if (vma_expandable(vma, new_len - old_len)) { long pages = (new_len - old_len) >> PAGE_SHIFT; + unsigned long extension_start = addr + old_len; + unsigned long extension_end = addr + new_len; + pgoff_t extension_pgoff = vma->vm_pgoff + (old_len >> PAGE_SHIFT); if (vma->vm_flags & VM_ACCOUNT) { if (security_vm_enough_memory_mm(mm, pages)) { @@ -1016,8 +1025,18 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, } } - if (vma_adjust(vma, vma->vm_start, addr + new_len, - vma->vm_pgoff, NULL)) { + /* + * Function vma_merge() is called on the extension we are adding to + * the already existing vma, vma_merge() will merge this extension with + * the already existing vma (expand operation itself) and possibly also + * with the next vma if it becomes adjacent to the expanded vma and + * otherwise compatible. + */ + vma = vma_merge(mm, vma, extension_start, extension_end, + vma->vm_flags, vma->anon_vma, vma->vm_file, + extension_pgoff, vma_policy(vma), + vma->vm_userfaultfd_ctx, anon_vma_name(vma)); + if (!vma) { vm_unacct_memory(pages); ret = -ENOMEM; goto out; |