diff options
author | Ingo Molnar <mingo@kernel.org> | 2017-10-20 13:06:52 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2017-10-20 13:06:52 +0200 |
commit | 967535223f9a8d95c187a8728480b569164cd4f4 (patch) | |
tree | b68a403701555a747b25c903d8136d86a1a1c133 /mm/mremap.c | |
parent | 5b65c4677a57a1d4414212f9995aa0e46a21ff80 (diff) | |
parent | ce56a86e2ade45d052b3228cdfebe913a1ae7381 (diff) |
Merge branch 'x86/urgent' into x86/mm, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/mremap.c')
-rw-r--r-- | mm/mremap.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index 3f23715d3c69..cfec004c4ff9 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -223,7 +223,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma, new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr); if (!new_pmd) break; - if (pmd_trans_huge(*old_pmd)) { + if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd)) { if (extent == HPAGE_PMD_SIZE) { bool moved; /* See comment in move_ptes() */ @@ -384,6 +384,19 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr, if (!vma || vma->vm_start > addr) return ERR_PTR(-EFAULT); + /* + * !old_len is a special case where an attempt is made to 'duplicate' + * a mapping. This makes no sense for private mappings as it will + * instead create a fresh/new mapping unrelated to the original. This + * is contrary to the basic idea of mremap which creates new mappings + * based on the original. There are no known use cases for this + * behavior. As a result, fail such attempts. + */ + if (!old_len && !(vma->vm_flags & (VM_SHARED | VM_MAYSHARE))) { + pr_warn_once("%s (%d): attempted to duplicate a private mapping with mremap. This is not supported.\n", current->comm, current->pid); + return ERR_PTR(-EINVAL); + } + if (is_vm_hugetlb_page(vma)) return ERR_PTR(-EINVAL); |