[PATCH] jump_label: fix jump_label update

[PATCH] jump_label: fix jump_label update

[Xiao Guangrong]

The key of module is out of __stop___jump_table, it causes the events
of modules does not work

This bug is introduced by commit: 7cbc5b8d4a775a43875a09e29c49a2a8195b5b2d

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
 kernel/jump_label.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index fa27e75..dcad2fb 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -375,11 +375,15 @@ int jump_label_text_reserved(void *start, void *end)
 
 static void jump_label_update(struct jump_label_key *key, int enable)
 {
-	struct jump_entry *entry = key->entries;
+	struct jump_entry *entry = key->entries, *stop = __stop___jump_table;
+	struct module *mod = __module_address((jump_label_t)key);
+
+	if (mod)
+		stop = mod->jump_entries + mod->num_jump_entries;
 
 	/* if there are no users, entry can be NULL */
 	if (entry)
-		__jump_label_update(key, entry, __stop___jump_table, enable);
+		__jump_label_update(key, entry, stop, enable);
 
 #ifdef CONFIG_MODULES
 	__jump_label_mod_update(key, enable);
-- 
1.7.5.4

Re: [PATCH] jump_label: fix jump_label update

[Jiri Olsa]

On Sat, Jun 18, 2011 at 04:02:29AM +0800, Xiao Guangrong wrote:
> The key of module is out of __stop___jump_table, it causes the events
> of modules does not work

right, I missed the case when the key is defined in the module itself


> 
> This bug is introduced by commit: 7cbc5b8d4a775a43875a09e29c49a2a8195b5b2d
> 
> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> ---
>  kernel/jump_label.c |    8 ++++++--
>  1 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/jump_label.c b/kernel/jump_label.c
> index fa27e75..dcad2fb 100644
> --- a/kernel/jump_label.c
> +++ b/kernel/jump_label.c
> @@ -375,11 +375,15 @@ int jump_label_text_reserved(void *start, void *end)
>  
>  static void jump_label_update(struct jump_label_key *key, int enable)
>  {
> -	struct jump_entry *entry = key->entries;
> +	struct jump_entry *entry = key->entries, *stop = __stop___jump_table;
> +	struct module *mod = __module_address((jump_label_t)key);
> +
> +	if (mod)
> +		stop = mod->jump_entries + mod->num_jump_entries;
this breaks !CONFIG_MODULES compilation

thanks,
jirka

>  
>  	/* if there are no users, entry can be NULL */
>  	if (entry)
> -		__jump_label_update(key, entry, __stop___jump_table, enable);
> +		__jump_label_update(key, entry, stop, enable);
>  
>  #ifdef CONFIG_MODULES
>  	__jump_label_mod_update(key, enable);
> -- 
> 1.7.5.4

Re: [PATCH] jump_label: fix jump_label update

[Xiao Guangrong]

On 06/20/2011 08:53 PM, Jiri Olsa wrote:

>>  static void jump_label_update(struct jump_label_key *key, int enable)
>>  {
>> -	struct jump_entry *entry = key->entries;
>> +	struct jump_entry *entry = key->entries, *stop = __stop___jump_table;
>> +	struct module *mod = __module_address((jump_label_t)key);
>> +
>> +	if (mod)
>> +		stop = mod->jump_entries + mod->num_jump_entries;
> this breaks !CONFIG_MODULES compilation
> 

I will fix it, thanks Jiri!

Re: [PATCH] jump_label: fix jump_label update

[Steven Rostedt]

On Sat, Jun 18, 2011 at 04:02:29AM +0800, Xiao Guangrong wrote:
> The key of module is out of __stop___jump_table, it causes the events
> of modules does not work
> 
> This bug is introduced by commit: 7cbc5b8d4a775a43875a09e29c49a2a8195b5b2d

What exactly breaks? I just tried events in modules, and they still work
for me.

> 
> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> ---
>  kernel/jump_label.c |    8 ++++++--
>  1 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/jump_label.c b/kernel/jump_label.c
> index fa27e75..dcad2fb 100644
> --- a/kernel/jump_label.c
> +++ b/kernel/jump_label.c
> @@ -375,11 +375,15 @@ int jump_label_text_reserved(void *start, void *end)
>  
>  static void jump_label_update(struct jump_label_key *key, int enable)
>  {
> -	struct jump_entry *entry = key->entries;
> +	struct jump_entry *entry = key->entries, *stop = __stop___jump_table;
> +	struct module *mod = __module_address((jump_label_t)key);
> +
> +	if (mod)
> +		stop = mod->jump_entries + mod->num_jump_entries;
>  
>  	/* if there are no users, entry can be NULL */
>  	if (entry)
> -		__jump_label_update(key, entry, __stop___jump_table, enable);
> +		__jump_label_update(key, entry, stop, enable);
>  
>  #ifdef CONFIG_MODULES
>  	__jump_label_mod_update(key, enable);

Doesn't the __jump_label_mod_update() do the job?

-- Steve

Re: [PATCH] jump_label: fix jump_label update

[Steven Rostedt]

On Mon, Jun 20, 2011 at 08:39:35PM -0400, Steven Rostedt wrote:
> On Sat, Jun 18, 2011 at 04:02:29AM +0800, Xiao Guangrong wrote:
> > The key of module is out of __stop___jump_table, it causes the events
> > of modules does not work
> > 
> > This bug is introduced by commit: 7cbc5b8d4a775a43875a09e29c49a2a8195b5b2d
> 
> What exactly breaks? I just tried events in modules, and they still work
> for me.

OK, it does break for me. I tested with CONFIG_JUMP_LABEL not set :-p

Please Cc me on further patches.

Thanks,

-- Steve