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

Naveen N. Rao naveen.n.rao at linux.vnet.ibm.com
Sat Sep 16 19:43:45 AEST 2017


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.

- Naveen



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