Re: [PATCH v9 4/7] extable: Add function to search only kernel exception table

2019-08-14 Thread Santosh Sivaraj
Balbir Singh  writes:

> On 12/8/19 7:22 pm, Santosh Sivaraj wrote:
>> Certain architecture specific operating modes (e.g., in powerpc machine
>> check handler that is unable to access vmalloc memory), the
>> search_exception_tables cannot be called because it also searches the
>> module exception tables if entry is not found in the kernel exception
>> table.
>> 
>> Cc: Thomas Gleixner 
>> Cc: Ingo Molnar 
>> Cc: Nicholas Piggin 
>> Signed-off-by: Santosh Sivaraj 
>> Reviewed-by: Nicholas Piggin 
>> ---
>>  include/linux/extable.h |  2 ++
>>  kernel/extable.c| 11 +--
>>  2 files changed, 11 insertions(+), 2 deletions(-)
>> 
>> diff --git a/include/linux/extable.h b/include/linux/extable.h
>> index 41c5b3a25f67..81ecfaa83ad3 100644
>> --- a/include/linux/extable.h
>> +++ b/include/linux/extable.h
>> @@ -19,6 +19,8 @@ void trim_init_extable(struct module *m);
>>  
>>  /* Given an address, look for it in the exception tables */
>>  const struct exception_table_entry *search_exception_tables(unsigned long 
>> add);
>> +const struct exception_table_entry *
>> +search_kernel_exception_table(unsigned long addr);
>> 
>
> Can we find a better name search_kernel still sounds like all of the kernel.
> Can we rename it to search_kernel_linear_map_extable?

I thought search_kernel_exception_table and search_module_extables were
non-ambiguous enough :-) But If you think name will be confusing, I can
change that as suggested.

Thanks,
Santosh

>
>  
>>  #ifdef CONFIG_MODULES
>>  /* For extable.c to search modules' exception tables. */
>> diff --git a/kernel/extable.c b/kernel/extable.c
>> index e23cce6e6092..f6c9406eec7d 100644
>> --- a/kernel/extable.c
>> +++ b/kernel/extable.c
>> @@ -40,13 +40,20 @@ void __init sort_main_extable(void)
>>  }
>>  }
>>  
>> +/* Given an address, look for it in the kernel exception table */
>> +const
>> +struct exception_table_entry *search_kernel_exception_table(unsigned long 
>> addr)
>> +{
>> +return search_extable(__start___ex_table,
>> +  __stop___ex_table - __start___ex_table, addr);
>> +}
>> +
>>  /* Given an address, look for it in the exception tables. */
>>  const struct exception_table_entry *search_exception_tables(unsigned long 
>> addr)
>>  {
>>  const struct exception_table_entry *e;
>>  
>> -e = search_extable(__start___ex_table,
>> -   __stop___ex_table - __start___ex_table, addr);
>> +e = search_kernel_exception_table(addr);
>>  if (!e)
>>  e = search_module_extables(addr);
>>  return e;
>> 

-- 
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Re: [PATCH v9 4/7] extable: Add function to search only kernel exception table

2019-08-14 Thread Balbir Singh



On 12/8/19 7:22 pm, Santosh Sivaraj wrote:
> Certain architecture specific operating modes (e.g., in powerpc machine
> check handler that is unable to access vmalloc memory), the
> search_exception_tables cannot be called because it also searches the
> module exception tables if entry is not found in the kernel exception
> table.
> 
> Cc: Thomas Gleixner 
> Cc: Ingo Molnar 
> Cc: Nicholas Piggin 
> Signed-off-by: Santosh Sivaraj 
> Reviewed-by: Nicholas Piggin 
> ---
>  include/linux/extable.h |  2 ++
>  kernel/extable.c| 11 +--
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/extable.h b/include/linux/extable.h
> index 41c5b3a25f67..81ecfaa83ad3 100644
> --- a/include/linux/extable.h
> +++ b/include/linux/extable.h
> @@ -19,6 +19,8 @@ void trim_init_extable(struct module *m);
>  
>  /* Given an address, look for it in the exception tables */
>  const struct exception_table_entry *search_exception_tables(unsigned long 
> add);
> +const struct exception_table_entry *
> +search_kernel_exception_table(unsigned long addr);
> 

Can we find a better name search_kernel still sounds like all of the kernel.
Can we rename it to search_kernel_linear_map_extable?

 
>  #ifdef CONFIG_MODULES
>  /* For extable.c to search modules' exception tables. */
> diff --git a/kernel/extable.c b/kernel/extable.c
> index e23cce6e6092..f6c9406eec7d 100644
> --- a/kernel/extable.c
> +++ b/kernel/extable.c
> @@ -40,13 +40,20 @@ void __init sort_main_extable(void)
>   }
>  }
>  
> +/* Given an address, look for it in the kernel exception table */
> +const
> +struct exception_table_entry *search_kernel_exception_table(unsigned long 
> addr)
> +{
> + return search_extable(__start___ex_table,
> +   __stop___ex_table - __start___ex_table, addr);
> +}
> +
>  /* Given an address, look for it in the exception tables. */
>  const struct exception_table_entry *search_exception_tables(unsigned long 
> addr)
>  {
>   const struct exception_table_entry *e;
>  
> - e = search_extable(__start___ex_table,
> -__stop___ex_table - __start___ex_table, addr);
> + e = search_kernel_exception_table(addr);
>   if (!e)
>   e = search_module_extables(addr);
>   return e;
>