diff options
author | Linus Torvalds | 2011-06-08 15:11:56 -0700 |
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committer | Linus Torvalds | 2011-06-08 15:11:56 -0700 |
commit | 95f4efb2d78661065aaf0be57f5bf00e4d2aea1d (patch) | |
tree | e344402e6428194515a0550ef30cf7cb8eeb0fdf /drivers/mtd | |
parent | 4c1f683a4a343808536a5617ede85dfc34430472 (diff) |
selinux: simplify and clean up inode_has_perm()
This is a rather hot function that is called with a potentially NULL
"struct common_audit_data" pointer argument. And in that case it has to
provide and initialize its own dummy common_audit_data structure.
However, all the _common_ cases already pass it a real audit-data
structure, so that uncommon NULL case not only creates a silly run-time
test, more importantly it causes that function to have a big stack frame
for the dummy variable that isn't even used in the common case!
So get rid of that stupid run-time behavior, and make the (few)
functions that currently call with a NULL pointer just call a new helper
function instead (naturally called inode_has_perm_noapd(), since it has
no adp argument).
This makes the run-time test be a static code generation issue instead,
and allows for a much denser stack since none of the common callers need
the dummy structure. And a denser stack not only means less stack space
usage, it means better cache behavior. So we have a win-win-win from
this simplification: less code executed, smaller stack footprint, and
better cache behavior.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/mtd')
0 files changed, 0 insertions, 0 deletions