There is a bug in the CKRM CPU scheduler. This has been reported to the

[linux-2.6.git] / mm / mlock.c

diff --git a/mm/mlock.c b/mm/mlock.c
index 2124d30..aa3f047 100644 (file)
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -200,3 +200,36 @@ asmlinkage long sys_munlockall(void)
        up_write(&current->mm->mmap_sem);
        return ret;
 }
+
+/*
+ * Objects with different lifetime than processes (SHM_LOCK and SHM_HUGETLB
+ * shm segments) get accounted against the user_struct instead.
+ */
+static spinlock_t shmlock_user_lock = SPIN_LOCK_UNLOCKED;
+
+int user_shm_lock(size_t size, struct user_struct *user)
+{
+       unsigned long lock_limit, locked;
+       int allowed = 0;
+
+       spin_lock(&shmlock_user_lock);
+       locked = size >> PAGE_SHIFT;
+       lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
+       lock_limit >>= PAGE_SHIFT;
+       if (locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK))
+               goto out;
+       get_uid(user);
+       user->locked_shm += locked;
+       allowed = 1;
+out:
+       spin_unlock(&shmlock_user_lock);
+       return allowed;
+}
+
+void user_shm_unlock(size_t size, struct user_struct *user)
+{
+       spin_lock(&shmlock_user_lock);
+       user->locked_shm -= (size >> PAGE_SHIFT);
+       spin_unlock(&shmlock_user_lock);
+       free_uid(user);
+}