[PATCH] devcgroup: skip superfluous checks when found the DEV_ALLelem

From: Li Zefan
Date: Tue Apr 07 2009 - 01:46:57 EST


While walking through the whitelist, if the DEV_ALL item is found,
no more check is needed.

Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
---
security/device_cgroup.c | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 5fda7df..b8186ba 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -490,7 +490,7 @@ int devcgroup_inode_permission(struct inode *inode, int mask)

list_for_each_entry_rcu(wh, &dev_cgroup->whitelist, list) {
if (wh->type & DEV_ALL)
- goto acc_check;
+ goto found;
if ((wh->type & DEV_BLOCK) && !S_ISBLK(inode->i_mode))
continue;
if ((wh->type & DEV_CHAR) && !S_ISCHR(inode->i_mode))
@@ -499,11 +499,12 @@ int devcgroup_inode_permission(struct inode *inode, int mask)
continue;
if (wh->minor != ~0 && wh->minor != iminor(inode))
continue;
-acc_check:
+
if ((mask & MAY_WRITE) && !(wh->access & ACC_WRITE))
continue;
if ((mask & MAY_READ) && !(wh->access & ACC_READ))
continue;
+found:
rcu_read_unlock();
return 0;
}
@@ -527,7 +528,7 @@ int devcgroup_inode_mknod(int mode, dev_t dev)

list_for_each_entry_rcu(wh, &dev_cgroup->whitelist, list) {
if (wh->type & DEV_ALL)
- goto acc_check;
+ goto found;
if ((wh->type & DEV_BLOCK) && !S_ISBLK(mode))
continue;
if ((wh->type & DEV_CHAR) && !S_ISCHR(mode))
@@ -536,9 +537,10 @@ int devcgroup_inode_mknod(int mode, dev_t dev)
continue;
if (wh->minor != ~0 && wh->minor != MINOR(dev))
continue;
-acc_check:
+
if (!(wh->access & ACC_MKNOD))
continue;
+found:
rcu_read_unlock();
return 0;
}
--
1.5.4.rc3

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