On 01/07/2013 11:40 AM, Jason Baron wrote:
> On Mon, Jan 07, 2013 at 08:58:09AM -0500, Sasha Levin wrote:
>> jump_label_text_reserved() doesn't modify the memory it works on, it just
>> checks whether there are any jump labels there.
>>
>> Constify the parameters of it to prevent warnings when working with it.
>>
>
> I don't see any 'const' data passed to jump_label_text_reserved()? Where is
> the
> warning coming from? New users?
Out of tree code.
Though once we constify jump_label_text_reserved() and some other similar helper
functions, we can constify more existing code in kprobes/jumplabels/etc as well.
Take check_kprobe_address_safe() for example, the 'struct kprobe *p' it accepts
should probably be const as well.
> Also, does this mean 'ftrace_text_reserved()' and
> 'alternatives_text_reserved()'
> need to be updated as well?
Jamie has raised this point in private as well. It would make sense to fix
them as well, I haven't done that here only because we haven't stumbled on this
issue with those functions.
I'd be happy to send a patch that fixes it for all of them.
Thanks,
Sasha
> Thanks,
>
> -Jason
>
>
>> Reviewed-by: Jamie Iles <jamie.i...@oracle.com>
>> Signed-off-by: Sasha Levin <sasha.le...@oracle.com>
>> ---
>> include/linux/jump_label.h | 4 ++--
>> kernel/jump_label.c | 10 ++++++----
>> 2 files changed, 8 insertions(+), 6 deletions(-)
>>
>> diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
>> index 0976fc4..d917a2a 100644
>> --- a/include/linux/jump_label.h
>> +++ b/include/linux/jump_label.h
>> @@ -116,7 +116,7 @@ extern void arch_jump_label_transform(struct jump_entry
>> *entry,
>> enum jump_label_type type);
>> extern void arch_jump_label_transform_static(struct jump_entry *entry,
>> enum jump_label_type type);
>> -extern int jump_label_text_reserved(void *start, void *end);
>> +extern int jump_label_text_reserved(const void *start, const void *end);
>> extern void static_key_slow_inc(struct static_key *key);
>> extern void static_key_slow_dec(struct static_key *key);
>> extern void static_key_slow_dec_deferred(struct static_key_deferred *key);
>> @@ -174,7 +174,7 @@ static inline void static_key_slow_dec_deferred(struct
>> static_key_deferred *key)
>> static_key_slow_dec(&key->key);
>> }
>>
>> -static inline int jump_label_text_reserved(void *start, void *end)
>> +static inline int jump_label_text_reserved(const void *start, const void
>> *end)
>> {
>> return 0;
>> }
>> diff --git a/kernel/jump_label.c b/kernel/jump_label.c
>> index 60f48fa..6dc71c6 100644
>> --- a/kernel/jump_label.c
>> +++ b/kernel/jump_label.c
>> @@ -120,7 +120,8 @@ void jump_label_rate_limit(struct static_key_deferred
>> *key,
>> }
>> EXPORT_SYMBOL_GPL(jump_label_rate_limit);
>>
>> -static int addr_conflict(struct jump_entry *entry, void *start, void *end)
>> +static int addr_conflict(struct jump_entry *entry,
>> + const void *start, const void *end)
>> {
>> if (entry->code <= (unsigned long)end &&
>> entry->code + JUMP_LABEL_NOP_SIZE > (unsigned long)start)
>> @@ -130,7 +131,8 @@ static int addr_conflict(struct jump_entry *entry, void
>> *start, void *end)
>> }
>>
>> static int __jump_label_text_reserved(struct jump_entry *iter_start,
>> - struct jump_entry *iter_stop, void *start, void *end)
>> + struct jump_entry *iter_stop,
>> + const void *start, const void *end)
>> {
>> struct jump_entry *iter;
>>
>> @@ -222,7 +224,7 @@ struct static_key_mod {
>> struct module *mod;
>> };
>>
>> -static int __jump_label_mod_text_reserved(void *start, void *end)
>> +static int __jump_label_mod_text_reserved(const void *start, const void
>> *end)
>> {
>> struct module *mod;
>>
>> @@ -419,7 +421,7 @@ early_initcall(jump_label_init_module);
>> *
>> * returns 1 if there is an overlap, 0 otherwise
>> */
>> -int jump_label_text_reserved(void *start, void *end)
>> +int jump_label_text_reserved(const void *start, const void *end)
>> {
>> int ret = __jump_label_text_reserved(__start___jump_table,
>> __stop___jump_table, start, end);
>> --
>> 1.8.0.2
>>
--
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