Commit bb18c5de authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Peter Zijlstra
Browse files

uprobes: change uprobe_register() to use uprobe_unregister() instead of __uprobe_unregister() 



If register_for_each_vma() fails uprobe_register() can safely drop
uprobe->register_rwsem and use uprobe_unregister(). There is no worry
about the races with another register/unregister, consumer_add() was
already called so this case doesn't differ from _unregister() right
after the successful _register().

Yes this means the extra up_write() + down_write(), but this is the
slow and unlikely case anyway.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatar"Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240801132739.GA8809@redhat.com
parent 3c83a9ad

kernel/events/uprobes.c

+7 −5
Original line number Diff line number Diff line
@@ -1174,16 +1174,18 @@ struct uprobe *uprobe_register(struct inode *inode, 
	if (likely(uprobe_is_active(uprobe))) {

		consumer_add(uprobe, uc);

		ret = register_for_each_vma(uprobe, uc);

		if (ret)

			__uprobe_unregister(uprobe, uc);

	}

	up_write(&uprobe->register_rwsem);

	put_uprobe(uprobe);



	if (ret) {

		if (unlikely(ret == -EAGAIN))

			goto retry;

		uprobe_unregister(uprobe, uc);

		return ERR_PTR(ret);

	}



	return ret ? ERR_PTR(ret) : uprobe;

	return uprobe;

}

EXPORT_SYMBOL_GPL(uprobe_register);