s390/Kconfig: make use of 'depends on cc-option'

[linux-2.6-microblaze.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 5a0fd51..1f6c45f 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -125,6 +125,15 @@ int nr_threads;                    /* The idle threads do not count.. */
 
 static int max_threads;                /* tunable limit on nr_threads */
 
+#define NAMED_ARRAY_INDEX(x)   [x] = __stringify(x)
+
+static const char * const resident_page_types[] = {
+       NAMED_ARRAY_INDEX(MM_FILEPAGES),
+       NAMED_ARRAY_INDEX(MM_ANONPAGES),
+       NAMED_ARRAY_INDEX(MM_SWAPENTS),
+       NAMED_ARRAY_INDEX(MM_SHMEMPAGES),
+};
+
 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
 
 __cacheline_aligned DEFINE_RWLOCK(tasklist_lock);  /* outer */
@@ -645,12 +654,15 @@ static void check_mm(struct mm_struct *mm)
 {
        int i;
 
+       BUILD_BUG_ON_MSG(ARRAY_SIZE(resident_page_types) != NR_MM_COUNTERS,
+                        "Please make sure 'struct resident_page_types[]' is updated as well");
+
        for (i = 0; i < NR_MM_COUNTERS; i++) {
                long x = atomic_long_read(&mm->rss_stat.count[i]);
 
                if (unlikely(x))
-                       printk(KERN_ALERT "BUG: Bad rss-counter state "
-                                         "mm:%p idx:%d val:%ld\n", mm, i, x);
+                       pr_alert("BUG: Bad rss-counter state mm:%p type:%s val:%ld\n",
+                                mm, resident_page_types[i], x);
        }
 
        if (mm_pgtables_bytes(mm))
@@ -903,10 +915,12 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
                tsk->cpus_ptr = &tsk->cpus_mask;
 
        /*
-        * One for us, one for whoever does the "release_task()" (usually
-        * parent)
+        * One for the user space visible state that goes away when reaped.
+        * One for the scheduler.
         */
-       refcount_set(&tsk->usage, 2);
+       refcount_set(&tsk->rcu_users, 2);
+       /* One for the rcu users */
+       refcount_set(&tsk->usage, 1);
 #ifdef CONFIG_BLK_DEV_IO_TRACE
        tsk->btrace_seq = 0;
 #endif
@@ -2511,39 +2525,19 @@ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
 #ifdef __ARCH_WANT_SYS_CLONE3
 noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
                                              struct clone_args __user *uargs,
-                                             size_t size)
+                                             size_t usize)
 {
+       int err;
        struct clone_args args;
 
-       if (unlikely(size > PAGE_SIZE))
+       if (unlikely(usize > PAGE_SIZE))
                return -E2BIG;
-
-       if (unlikely(size < sizeof(struct clone_args)))
+       if (unlikely(usize < CLONE_ARGS_SIZE_VER0))
                return -EINVAL;
 
-       if (unlikely(!access_ok(uargs, size)))
-               return -EFAULT;
-
-       if (size > sizeof(struct clone_args)) {
-               unsigned char __user *addr;
-               unsigned char __user *end;
-               unsigned char val;
-
-               addr = (void __user *)uargs + sizeof(struct clone_args);
-               end = (void __user *)uargs + size;
-
-               for (; addr < end; addr++) {
-                       if (get_user(val, addr))
-                               return -EFAULT;
-                       if (val)
-                               return -E2BIG;
-               }
-
-               size = sizeof(struct clone_args);
-       }
-
-       if (copy_from_user(&args, uargs, size))
-               return -EFAULT;
+       err = copy_struct_from_user(&args, sizeof(args), uargs, usize);
+       if (err)
+               return err;
 
        /*
         * Verify that higher 32bits of exit_signal are unset and that
@@ -2590,6 +2584,17 @@ static bool clone3_args_valid(const struct kernel_clone_args *kargs)
        return true;
 }
 
+/**
+ * clone3 - create a new process with specific properties
+ * @uargs: argument structure
+ * @size:  size of @uargs
+ *
+ * clone3() is the extensible successor to clone()/clone2().
+ * It takes a struct as argument that is versioned by its size.
+ *
+ * Return: On success, a positive PID for the child process.
+ *         On error, a negative errno number.
+ */
 SYSCALL_DEFINE2(clone3, struct clone_args __user *, uargs, size_t, size)
 {
        int err;