Uprobes: Simplify uprobe_register() body

Simplify uprobe_register() function body and let __uprobe_register()
handle everything. Also move dependency functions around to avoid build
failures.

Link: http://lkml.kernel.org/r/20180809041856.1547-2-ravi.bangoria@linux.ibm.com
Reviewed-by: Song Liu <songliubraving@fb.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index ccc579a..471eac8 100644 (file)
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -840,13 +840,8 @@ register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new)
        return err;
 }
 
-static int __uprobe_register(struct uprobe *uprobe, struct uprobe_consumer *uc)
-{
-       consumer_add(uprobe, uc);
-       return register_for_each_vma(uprobe, uc);
-}
-
-static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *uc)
+static void
+__uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *uc)
 {
        int err;
 
@@ -860,24 +855,46 @@ static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *u
 }
 
 /*
- * uprobe_register - register a probe
+ * uprobe_unregister - unregister a already registered probe.
+ * @inode: the file in which the probe has to be removed.
+ * @offset: offset from the start of the file.
+ * @uc: identify which probe if multiple probes are colocated.
+ */
+void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
+{
+       struct uprobe *uprobe;
+
+       uprobe = find_uprobe(inode, offset);
+       if (WARN_ON(!uprobe))
+               return;
+
+       down_write(&uprobe->register_rwsem);
+       __uprobe_unregister(uprobe, uc);
+       up_write(&uprobe->register_rwsem);
+       put_uprobe(uprobe);
+}
+EXPORT_SYMBOL_GPL(uprobe_unregister);
+
+/*
+ * __uprobe_register - register a probe
  * @inode: the file in which the probe has to be placed.
  * @offset: offset from the start of the file.
  * @uc: information on howto handle the probe..
  *
- * Apart from the access refcount, uprobe_register() takes a creation
+ * Apart from the access refcount, __uprobe_register() takes a creation
  * refcount (thro alloc_uprobe) if and only if this @uprobe is getting
  * inserted into the rbtree (i.e first consumer for a @inode:@offset
  * tuple).  Creation refcount stops uprobe_unregister from freeing the
  * @uprobe even before the register operation is complete. Creation
  * refcount is released when the last @uc for the @uprobe
- * unregisters. Caller of uprobe_register() is required to keep @inode
+ * unregisters. Caller of __uprobe_register() is required to keep @inode
  * (and the containing mount) referenced.
  *
  * Return errno if it cannot successully install probes
  * else return 0 (success)
  */
-int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
+static int __uprobe_register(struct inode *inode, loff_t offset,
+                            struct uprobe_consumer *uc)
 {
        struct uprobe *uprobe;
        int ret;
@@ -904,7 +921,8 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
        down_write(&uprobe->register_rwsem);
        ret = -EAGAIN;
        if (likely(uprobe_is_active(uprobe))) {
-               ret = __uprobe_register(uprobe, uc);
+               consumer_add(uprobe, uc);
+               ret = register_for_each_vma(uprobe, uc);
                if (ret)
                        __uprobe_unregister(uprobe, uc);
        }
@@ -915,6 +933,12 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
                goto retry;
        return ret;
 }
+
+int uprobe_register(struct inode *inode, loff_t offset,
+                   struct uprobe_consumer *uc)
+{
+       return __uprobe_register(inode, offset, uc);
+}
 EXPORT_SYMBOL_GPL(uprobe_register);
 
 /*
@@ -946,27 +970,6 @@ int uprobe_apply(struct inode *inode, loff_t offset,
        return ret;
 }
 
-/*
- * uprobe_unregister - unregister a already registered probe.
- * @inode: the file in which the probe has to be removed.
- * @offset: offset from the start of the file.
- * @uc: identify which probe if multiple probes are colocated.
- */
-void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
-{
-       struct uprobe *uprobe;
-
-       uprobe = find_uprobe(inode, offset);
-       if (WARN_ON(!uprobe))
-               return;
-
-       down_write(&uprobe->register_rwsem);
-       __uprobe_unregister(uprobe, uc);
-       up_write(&uprobe->register_rwsem);
-       put_uprobe(uprobe);
-}
-EXPORT_SYMBOL_GPL(uprobe_unregister);
-
 static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm)
 {
        struct vm_area_struct *vma;