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authorChristoph Hellwig <hch@lst.de>2015-01-14 10:42:32 +0100
committerJens Axboe <axboe@fb.com>2015-01-20 14:02:58 -0700
commitb4caecd48005fbed3949dde6c1cb233142fd69e9 (patch)
tree1fdd9b7c15568c79eb3c1ed84a39858ddbcbc88b /security
parent97b713ba3ebaa6c8d84c2c720f5468a7c6a6eb4e (diff)
fs: introduce f_op->mmap_capabilities for nommu mmap support
Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'security')
-rw-r--r--security/security.c13
1 files changed, 6 insertions, 7 deletions
diff --git a/security/security.c b/security/security.c
index 18b35c63fc0c..a0442b20f001 100644
--- a/security/security.c
+++ b/security/security.c
@@ -726,16 +726,15 @@ static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
return prot | PROT_EXEC;
/*
* ditto if it's not on noexec mount, except that on !MMU we need
- * BDI_CAP_EXEC_MMAP (== VM_MAYEXEC) in this case
+ * NOMMU_MAP_EXEC (== VM_MAYEXEC) in this case
*/
if (!(file->f_path.mnt->mnt_flags & MNT_NOEXEC)) {
#ifndef CONFIG_MMU
- unsigned long caps = 0;
- struct address_space *mapping = file->f_mapping;
- if (mapping && mapping->backing_dev_info)
- caps = mapping->backing_dev_info->capabilities;
- if (!(caps & BDI_CAP_EXEC_MAP))
- return prot;
+ if (file->f_op->mmap_capabilities) {
+ unsigned caps = file->f_op->mmap_capabilities(file);
+ if (!(caps & NOMMU_MAP_EXEC))
+ return prot;
+ }
#endif
return prot | PROT_EXEC;
}

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