[PATCH v8 1/6] Uprobes: Simplify uprobe_register() body

Ravi Bangoria
2018-08-09T04:19:32Z

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

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
---
kernel/events/uprobes.c | 69 ++++++++++++++++++++++++++-----------------------
1 file changed, 36 insertions(+), 33 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index ccc579a7d32e..471eac896635 100644
--- 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;
--
2.14.4