staging: Use static const char * const where possible

[net-next-2.6.git] / kernel / sys.c

diff --git a/kernel/sys.c b/kernel/sys.c
index 9da98dd472761de2b47e5745d149ad98bdfc030a..e9ad4448982860af9919df53c3368156a4bf2445 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1271,6 +1271,39 @@ SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
 
 #endif
 
+static inline bool rlim64_is_infinity(__u64 rlim64)
+{
+#if BITS_PER_LONG < 64
+       return rlim64 >= ULONG_MAX;
+#else
+       return rlim64 == RLIM64_INFINITY;
+#endif
+}
+
+static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
+{
+       if (rlim->rlim_cur == RLIM_INFINITY)
+               rlim64->rlim_cur = RLIM64_INFINITY;
+       else
+               rlim64->rlim_cur = rlim->rlim_cur;
+       if (rlim->rlim_max == RLIM_INFINITY)
+               rlim64->rlim_max = RLIM64_INFINITY;
+       else
+               rlim64->rlim_max = rlim->rlim_max;
+}
+
+static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
+{
+       if (rlim64_is_infinity(rlim64->rlim_cur))
+               rlim->rlim_cur = RLIM_INFINITY;
+       else
+               rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
+       if (rlim64_is_infinity(rlim64->rlim_max))
+               rlim->rlim_max = RLIM_INFINITY;
+       else
+               rlim->rlim_max = (unsigned long)rlim64->rlim_max;
+}
+
 /* make sure you are allowed to change @tsk limits before calling this */
 int do_prlimit(struct task_struct *tsk, unsigned int resource,
                struct rlimit *new_rlim, struct rlimit *old_rlim)
@@ -1336,6 +1369,67 @@ out:
        return retval;
 }
 
+/* rcu lock must be held */
+static int check_prlimit_permission(struct task_struct *task)
+{
+       const struct cred *cred = current_cred(), *tcred;
+
+       tcred = __task_cred(task);
+       if ((cred->uid != tcred->euid ||
+            cred->uid != tcred->suid ||
+            cred->uid != tcred->uid  ||
+            cred->gid != tcred->egid ||
+            cred->gid != tcred->sgid ||
+            cred->gid != tcred->gid) &&
+            !capable(CAP_SYS_RESOURCE)) {
+               return -EPERM;
+       }
+
+       return 0;
+}
+
+SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
+               const struct rlimit64 __user *, new_rlim,
+               struct rlimit64 __user *, old_rlim)
+{
+       struct rlimit64 old64, new64;
+       struct rlimit old, new;
+       struct task_struct *tsk;
+       int ret;
+
+       if (new_rlim) {
+               if (copy_from_user(&new64, new_rlim, sizeof(new64)))
+                       return -EFAULT;
+               rlim64_to_rlim(&new64, &new);
+       }
+
+       rcu_read_lock();
+       tsk = pid ? find_task_by_vpid(pid) : current;
+       if (!tsk) {
+               rcu_read_unlock();
+               return -ESRCH;
+       }
+       ret = check_prlimit_permission(tsk);
+       if (ret) {
+               rcu_read_unlock();
+               return ret;
+       }
+       get_task_struct(tsk);
+       rcu_read_unlock();
+
+       ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
+                       old_rlim ? &old : NULL);
+
+       if (!ret && old_rlim) {
+               rlim_to_rlim64(&old, &old64);
+               if (copy_to_user(old_rlim, &old64, sizeof(old64)))
+                       ret = -EFAULT;
+       }
+
+       put_task_struct(tsk);
+       return ret;
+}
+
 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
 {
        struct rlimit new_rlim;