2011-06-17 20:02:07

by Xiao Guangrong

Subject: [PATCH] jump_label: fix jump_label update

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 <[email protected]>
---
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

2011-06-20 12:53:59

by Jiri Olsa

Subject: Re: [PATCH] jump_label: fix jump_label update

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 <[email protected]>
> ---
> 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

2011-06-20 18:56:13

by Xiao Guangrong

Subject: Re: [PATCH] jump_label: fix jump_label update

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!

2011-06-21 00:39:37

by Steven Rostedt

Subject: Re: [PATCH] jump_label: fix jump_label update

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 <[email protected]>
> ---
> 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

2011-06-21 01:30:14

by Steven Rostedt

Subject: Re: [PATCH] jump_label: fix jump_label update

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