[PATCH v3] RISC-V: Fix IFUNC resolver cannot access gp pointer

[Palmer Dabbelt]

On Mon, 06 Jan 2025 18:32:54 PST (-0800), cyy@cyyself.name wrote:
> Ping again. It has already been 1 month after v3 patch was submitted.
>
> I think this patch is critical for RISC-V GCC Function multi-versioning
> to work correctly, as GCC 15, which has this feature, is going to be
> released.

IIUC the conclusion here was to avoid global symbol resolution in IFUNCs 
and instead use the pre-resolved function hwprobe VDSO function pointer 
passed in via a register.  There was a long discussion on this during 
the hwprobe/IFUNC support patches, and IIRC one during the FMV patches 
-- though I remember accepting those and now I'm not sure why, so maybe 
I'm just forgetting something here?

> On 12/10/24 15:57, Yangyu Chen wrote:
>> I also provide a POC to explain the bug existed in the past:
>>
>> https://github.com/cyyself/glibc/
>> commit/5525b4fcb7d62d6a9b4dbd44cbc5400f8b08698b
>>