locking: Implement new raw_spinlock

[safe/jmp/linux-2.6] / kernel / kprobes.c

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 00d01b0..e5342a3 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -676,6 +676,40 @@ static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p)
        return (kprobe_opcode_t *)(((char *)addr) + p->offset);
 }
 
+/* Check passed kprobe is valid and return kprobe in kprobe_table. */
+static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p)
+{
+       struct kprobe *old_p, *list_p;
+
+       old_p = get_kprobe(p->addr);
+       if (unlikely(!old_p))
+               return NULL;
+
+       if (p != old_p) {
+               list_for_each_entry_rcu(list_p, &old_p->list, list)
+                       if (list_p == p)
+                       /* kprobe p is a valid probe */
+                               goto valid;
+               return NULL;
+       }
+valid:
+       return old_p;
+}
+
+/* Return error if the kprobe is being re-registered */
+static inline int check_kprobe_rereg(struct kprobe *p)
+{
+       int ret = 0;
+       struct kprobe *old_p;
+
+       mutex_lock(&kprobe_mutex);
+       old_p = __get_valid_kprobe(p);
+       if (old_p)
+               ret = -EINVAL;
+       mutex_unlock(&kprobe_mutex);
+       return ret;
+}
+
 int __kprobes register_kprobe(struct kprobe *p)
 {
        int ret = 0;
@@ -688,6 +722,10 @@ int __kprobes register_kprobe(struct kprobe *p)
                return -EINVAL;
        p->addr = addr;
 
+       ret = check_kprobe_rereg(p);
+       if (ret)
+               return ret;
+
        preempt_disable();
        if (!kernel_text_address((unsigned long) p->addr) ||
            in_kprobes_functions((unsigned long) p->addr)) {
@@ -757,26 +795,6 @@ out:
 }
 EXPORT_SYMBOL_GPL(register_kprobe);
 
-/* Check passed kprobe is valid and return kprobe in kprobe_table. */
-static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p)
-{
-       struct kprobe *old_p, *list_p;
-
-       old_p = get_kprobe(p->addr);
-       if (unlikely(!old_p))
-               return NULL;
-
-       if (p != old_p) {
-               list_for_each_entry_rcu(list_p, &old_p->list, list)
-                       if (list_p == p)
-                       /* kprobe p is a valid probe */
-                               goto valid;
-               return NULL;
-       }
-valid:
-       return old_p;
-}
-
 /*
  * Unregister a kprobe without a scheduler synchronization.
  */
@@ -1017,9 +1035,9 @@ int __kprobes register_kretprobe(struct kretprobe *rp)
        /* Pre-allocate memory for max kretprobe instances */
        if (rp->maxactive <= 0) {
 #ifdef CONFIG_PREEMPT
-               rp->maxactive = max(10, 2 * NR_CPUS);
+               rp->maxactive = max(10, 2 * num_possible_cpus());
 #else
-               rp->maxactive = NR_CPUS;
+               rp->maxactive = num_possible_cpus();
 #endif
        }
        spin_lock_init(&rp->lock);
@@ -1331,7 +1349,7 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v)
        return 0;
 }
 
-static struct seq_operations kprobes_seq_ops = {
+static const struct seq_operations kprobes_seq_ops = {
        .start = kprobe_seq_start,
        .next  = kprobe_seq_next,
        .stop  = kprobe_seq_stop,
@@ -1343,7 +1361,7 @@ static int __kprobes kprobes_open(struct inode *inode, struct file *filp)
        return seq_open(filp, &kprobes_seq_ops);
 }
 
-static struct file_operations debugfs_kprobes_operations = {
+static const struct file_operations debugfs_kprobes_operations = {
        .open           = kprobes_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
@@ -1525,7 +1543,7 @@ static ssize_t write_enabled_file_bool(struct file *file,
        return count;
 }
 
-static struct file_operations fops_kp = {
+static const struct file_operations fops_kp = {
        .read =         read_enabled_file_bool,
        .write =        write_enabled_file_bool,
 };