SELinux: move common_audit_data to a noinline slow path function

selinux_inode_has_perm is a hot path.  Instead of declaring the
common_audit_data on the stack move it to a noinline function only used in
the rare case we need to send an audit message.

Signed-off-by: Eric Paris <eparis@redhat.com>

1 files changed, 21 insertions, 11 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8417a6afaf30..b3bd8e1d268a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2658,11 +2658,29 @@ static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *na
         return dentry_has_perm(cred, dentry, FILE__READ);
 }
 
-static int selinux_inode_permission(struct inode *inode, int mask)
+static noinline int audit_inode_permission(struct inode *inode,
+                                           u32 perms, u32 audited, u32 denied,
+                                           unsigned flags)
 {
-        const struct cred *cred = current_cred();
         struct common_audit_data ad;
         struct selinux_audit_data sad = {0,};
+        struct inode_security_struct *isec = inode->i_security;
+        int rc;
+
+        COMMON_AUDIT_DATA_INIT(&ad, INODE);
+        ad.selinux_audit_data = &sad;
+        ad.u.inode = inode;
+
+        rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
+                            audited, denied, &ad, flags);
+        if (rc)
+                return rc;
+        return 0;
+}
+
+static int selinux_inode_permission(struct inode *inode, int mask)
+{
+        const struct cred *cred = current_cred();
         u32 perms;
         bool from_access;
         unsigned flags = mask & MAY_NOT_BLOCK;
@@ -2696,15 +2714,7 @@ static int selinux_inode_permission(struct inode *inode, int mask)
         if (likely(!audited))
                 return rc;
 
-        COMMON_AUDIT_DATA_INIT(&ad, INODE);
-        ad.selinux_audit_data = &sad;
-        ad.u.inode = inode;
-
-        if (from_access)
-                ad.selinux_audit_data->auditdeny |= FILE__AUDIT_ACCESS;
-
-        rc2 = slow_avc_audit(sid, isec->sid, isec->sclass, perms,
-                             audited, denied, &ad, flags);
+        rc2 = audit_inode_permission(inode, perms, audited, denied, flags);
         if (rc2)
                 return rc2;
         return rc;