[PATCH 3/5] powerpc64: Add .opd based function descriptor dereference

Michael Ellerman mpe at ellerman.id.au
Tue Sep 19 20:22:37 AEST 2017

"Naveen N. Rao" <naveen.n.rao at linux.vnet.ibm.com> writes:

> On 2017/09/16 12:53PM, Sergey Senozhatsky wrote:
>> We are moving towards separate kernel and module function descriptor
>> dereference callbacks. This patch enables it for powerpc64.
>> For pointers that belong to the kernel
>> -  Added __start_opd and __end_opd pointers, to track the kernel
>>    .opd section address range;
>> -  Added dereference_kernel_function_descriptor(). Now we
>>    will dereference only function pointers that are within
>>    [__start_opd, __end_opd];
>> For pointers that belong to a module
>> -  Added dereference_module_function_descriptor() to handle module
>>    function descriptor dereference. Now we will dereference only
>>    pointers that are within [module->opd.start, module->opd.end].
> Would it be simpler to just use kernel_text_address() and dereference 
> everything else? See commit 83e840c770f2c5 ("powerpc64/elfv1: Only 
> dereference function descriptor for non-text symbols") for a related 
> patch.

Yeah that would be a lot simpler and probably work perfectly well.


More information about the Linuxppc-dev mailing list