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| author | Dan Williams <dan.j.williams@intel.com> | 2017-11-15 16:56:11 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2017-11-15 16:56:11 -0800 |
| commit | 4247f24c23589bcc3bc3490515ef8c9497e9ae55 (patch) | |
| tree | 89726a0e171c443a3e8def2992b56dbd8a21df21 /mm/mmap.c | |
| parent | 79ab67ede21f536851a99ea68ee6fc1f5435e055 (diff) | |
| parent | 9f586fff6574f6ecbf323f92d44ffaf0d96225fe (diff) | |
Merge branch 'for-4.15/dax' into libnvdimm-for-nextlibnvdimm-for-4.15
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 680506faceae..924839fac0e6 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr, if (file) { struct inode *inode = file_inode(file); + unsigned long flags_mask; + + flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags; switch (flags & MAP_TYPE) { case MAP_SHARED: + /* + * Force use of MAP_SHARED_VALIDATE with non-legacy + * flags. E.g. MAP_SYNC is dangerous to use with + * MAP_SHARED as you don't know which consistency model + * you will get. We silently ignore unsupported flags + * with MAP_SHARED to preserve backward compatibility. + */ + flags &= LEGACY_MAP_MASK; + /* fall through */ + case MAP_SHARED_VALIDATE: + if (flags & ~flags_mask) + return -EOPNOTSUPP; if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE)) return -EACCES; |