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From: Kito Cheng <kito.cheng@sifive.com>
To: Florian Weimer <fweimer@redhat.com>
Cc: Yangyu Chen <cyy@cyyself.name>,
	Palmer Dabbelt <palmer@rivosinc.com>,
	libc-alpha@sourceware.org,  vincent.chen@sifive.com,
	schwab@suse.de
Subject: Re: [PATCH v2] RISC-V: Fix IFUNC resolver cannot access gp pointer
Date: Wed, 30 Oct 2024 18:26:56 +0800	[thread overview]
Message-ID: <CALLt3Tj06ytycyu2Xwf=02MUwrPLbK3-3i+XvA+djNtC2=9eQQ@mail.gmail.com> (raw)
In-Reply-To: <874j4ugd2o.fsf@oldenburg.str.redhat.com>

HI Florian:

On Wed, Oct 30, 2024 at 5:22 PM Florian Weimer <fweimer@redhat.com> wrote:
>
> * Kito Cheng:
>
> > Do you remember if there are any other issues that need to be resolved
> > other than the GP issue?
>
> In certain cases, IFUNC resolvers can be invoked when the object that
> provides has not been relocated yet.  That's impossible to address
> from within the IFUNC resolver.  (For the GP issue, the IFUNC resolver
> could just assume that GP isn't defined, I think.)

Hmmmm, I am a little surprised that since we are kinda learning the
function multi-version (FMV) from AArch64[1] and x86[2], they both
will reference global variables during the FMV IFUNC resolver, or is
it just bad design from your point of view?

Thanks :)

[1] https://github.com/gcc-mirror/gcc/blob/master/libgcc/config/aarch64/cpuinfo.c#L47
[2] https://github.com/gcc-mirror/gcc/blob/master/libgcc/config/i386/cpuinfo.c#L50C14-L50C29

>
> Thanks,
> Florian
>

  reply	other threads:[~2024-10-30 10:27 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-15 17:01 Yangyu Chen
2024-10-30  2:58 ` Yangyu Chen
2024-10-30  3:10   ` Palmer Dabbelt
2024-10-30  6:50     ` Yangyu Chen
2024-10-30  7:36       ` Kito Cheng
2024-10-30  9:22         ` Florian Weimer
2024-10-30 10:26           ` Kito Cheng [this message]
2024-10-30 10:42             ` Florian Weimer
2024-10-30 10:48               ` Kito Cheng
2024-10-30 11:09                 ` Florian Weimer
2024-10-30 18:28                   ` Yangyu Chen
2024-10-31 10:07                     ` Kito Cheng
2024-10-31 10:32                     ` Florian Weimer
2024-10-31 10:35                       ` Yangyu Chen
2024-10-31 10:51                         ` Florian Weimer
2024-11-13 10:29     ` Yangyu Chen

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