move exec_permission() up to the rest of permission-related functions

... and convert the comment before it into linuxdoc form.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-06-19 13:14:21 -04:00
parent 3bfa784a65
commit f4d6ff89d8
1 changed files with 38 additions and 34 deletions

View File

@ -303,6 +303,44 @@ int inode_permission(struct inode *inode, int mask)
return security_inode_permission(inode, mask);
}
/**
* exec_permission - check for right to do lookups in a given directory
* @inode: inode to check permission on
* @flags: IPERM_FLAG_ flags.
*
* Short-cut version of inode_permission(), for calling on directories
* during pathname resolution. Combines parts of inode_permission()
* and generic_permission(), and tests ONLY for MAY_EXEC permission.
*
* If appropriate, check DAC only. If not appropriate, or
* short-cut DAC fails, then call ->permission() to do more
* complete permission check.
*/
static inline int exec_permission(struct inode *inode, unsigned int flags)
{
int ret;
struct user_namespace *ns = inode_userns(inode);
if (inode->i_op->permission) {
ret = inode->i_op->permission(inode, MAY_EXEC, flags);
if (likely(!ret))
goto ok;
} else {
ret = acl_permission_check(inode, MAY_EXEC, flags,
inode->i_op->check_acl);
if (likely(!ret))
goto ok;
if (ret != -EACCES)
return ret;
if (ns_capable(ns, CAP_DAC_OVERRIDE) ||
ns_capable(ns, CAP_DAC_READ_SEARCH))
goto ok;
}
return ret;
ok:
return security_inode_exec_permission(inode, flags);
}
/*
* get_write_access() gets write permission for a file.
* put_write_access() releases this write permission.
@ -551,40 +589,6 @@ static int complete_walk(struct nameidata *nd)
return status;
}
/*
* Short-cut version of permission(), for calling on directories
* during pathname resolution. Combines parts of permission()
* and generic_permission(), and tests ONLY for MAY_EXEC permission.
*
* If appropriate, check DAC only. If not appropriate, or
* short-cut DAC fails, then call ->permission() to do more
* complete permission check.
*/
static inline int exec_permission(struct inode *inode, unsigned int flags)
{
int ret;
struct user_namespace *ns = inode_userns(inode);
if (inode->i_op->permission) {
ret = inode->i_op->permission(inode, MAY_EXEC, flags);
if (likely(!ret))
goto ok;
} else {
ret = acl_permission_check(inode, MAY_EXEC, flags,
inode->i_op->check_acl);
if (likely(!ret))
goto ok;
if (ret != -EACCES)
return ret;
if (ns_capable(ns, CAP_DAC_OVERRIDE) ||
ns_capable(ns, CAP_DAC_READ_SEARCH))
goto ok;
}
return ret;
ok:
return security_inode_exec_permission(inode, flags);
}
static __always_inline void set_root(struct nameidata *nd)
{
if (!nd->root.mnt)