diff options
| author | Gerald Schaefer <gerald.schaefer@de.ibm.com> | 2012-10-08 16:30:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-09 16:22:30 +0900 |
| commit | 8e72033f2a489b6c98c4e3c7cc281b1afd6cb85c (patch) | |
| tree | 9ac78daf640471e00f3f0fbe22f6c24fb95b8817 /mm/huge_memory.c | |
| parent | 46dcde735c9d8953bbd8d105ca6779e5b5300c28 (diff) | |
| download | lwn-8e72033f2a489b6c98c4e3c7cc281b1afd6cb85c.tar.gz lwn-8e72033f2a489b6c98c4e3c7cc281b1afd6cb85c.zip | |
thp: make MADV_HUGEPAGE check for mm->def_flags
This adds a check to hugepage_madvise(), to refuse MADV_HUGEPAGE if
VM_NOHUGEPAGE is set in mm->def_flags. On s390, the VM_NOHUGEPAGE flag
will be set in mm->def_flags for kvm processes, to prevent any future thp
mappings. In order to also prevent MADV_HUGEPAGE on such an mm,
hugepage_madvise() should check mm->def_flags.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index bec6243b6965..010d32944d14 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1450,6 +1450,8 @@ out: int hugepage_madvise(struct vm_area_struct *vma, unsigned long *vm_flags, int advice) { + struct mm_struct *mm = vma->vm_mm; + switch (advice) { case MADV_HUGEPAGE: /* @@ -1457,6 +1459,8 @@ int hugepage_madvise(struct vm_area_struct *vma, */ if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP)) return -EINVAL; + if (mm->def_flags & VM_NOHUGEPAGE) + return -EINVAL; *vm_flags &= ~VM_NOHUGEPAGE; *vm_flags |= VM_HUGEPAGE; /* |