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Commit 38e967ae authored by Ravi Bangoria's avatar Ravi Bangoria Committed by Steven Rostedt (VMware)
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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: default avatarSong Liu <songliubraving@fb.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent f8a79d5c

kernel/events/uprobes.c

+36 −33
Original line number Diff line number Diff line
@@ -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;