userns: Use cred->user_ns instead of cred->user->user_ns

Optimize performance and prepare for the removal of the user_ns reference
from user_struct.  Remove the slow long walk through cred->user->user_ns and
instead go straight to cred->user_ns.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman
2011-11-16 23:15:31 -08:00
parent 7e6bd8fadd
commit c4a4d60379
12 changed files with 24 additions and 24 deletions

View File

@@ -81,7 +81,7 @@ int cap_capable(const struct cred *cred, struct user_namespace *targ_ns,
return 0;
/* Do we have the necessary capabilities? */
if (targ_ns == cred->user->user_ns)
if (targ_ns == cred->user_ns)
return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;
/* Have we tried all of the parent namespaces? */
@@ -136,10 +136,10 @@ int cap_ptrace_access_check(struct task_struct *child, unsigned int mode)
rcu_read_lock();
cred = current_cred();
child_cred = __task_cred(child);
if (cred->user->user_ns == child_cred->user->user_ns &&
if (cred->user_ns == child_cred->user_ns &&
cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
goto out;
if (ns_capable(child_cred->user->user_ns, CAP_SYS_PTRACE))
if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE))
goto out;
ret = -EPERM;
out:
@@ -168,10 +168,10 @@ int cap_ptrace_traceme(struct task_struct *parent)
rcu_read_lock();
cred = __task_cred(parent);
child_cred = current_cred();
if (cred->user->user_ns == child_cred->user->user_ns &&
if (cred->user_ns == child_cred->user_ns &&
cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
goto out;
if (has_ns_capability(parent, child_cred->user->user_ns, CAP_SYS_PTRACE))
if (has_ns_capability(parent, child_cred->user_ns, CAP_SYS_PTRACE))
goto out;
ret = -EPERM;
out:
@@ -214,7 +214,7 @@ static inline int cap_inh_is_capped(void)
/* they are so limited unless the current task has the CAP_SETPCAP
* capability
*/
if (cap_capable(current_cred(), current_cred()->user->user_ns,
if (cap_capable(current_cred(), current_cred()->user_ns,
CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0)
return 0;
return 1;
@@ -866,7 +866,7 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
|| ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/
|| (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
|| (cap_capable(current_cred(),
current_cred()->user->user_ns, CAP_SETPCAP,
current_cred()->user_ns, CAP_SETPCAP,
SECURITY_CAP_AUDIT) != 0) /*[4]*/
/*
* [1] no changing of bits that are locked