From: Li Zefan Date: Wed, 17 Jun 2009 23:26:33 +0000 (-0700) Subject: devcgroup: skip superfluous checks when found the DEV_ALL elem X-Git-Tag: v2.6.31-rc1~237 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=cd5008196f7e583f4c558531a2bca59f6c674c5b devcgroup: skip superfluous checks when found the DEV_ALL elem While walking through the whitelist, if the DEV_ALL item is found, no more check is needed. Signed-off-by: Li Zefan Acked-by: Serge Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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; }