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From: Max Filippov <jcmvbkbc@gmail.com>
To: Rich Felker <dalias@libc.org>
Cc: musl@lists.openwall.com
Subject: Re: [musl] Initial xtensa/fdpic port review
Date: Thu, 29 Feb 2024 04:03:02 -0800	[thread overview]
Message-ID: <CAMo8Bf+bA-a0vgi1uxBbiHfFMUgkn8ceJy+jjHaCwogSsJgiMw@mail.gmail.com> (raw)
In-Reply-To: <CAMo8BfKS=jcOkcZFEFkgwJJ2oJ4jMODn-Mg-38MmH2FOzzR1kg@mail.gmail.com>

On Wed, Feb 28, 2024 at 1:28 PM Max Filippov <jcmvbkbc@gmail.com> wrote:
> On Wed, Feb 28, 2024 at 10:30 AM Rich Felker <dalias@libc.org> wrote:
> > Is there a reason local, relative jumps/calls can't be done by
> > computing the address of a nearby label and using the offset relative
> > to that? That's how they (at least some types; I forget the details)
> > work on sh/fdpic.
>
> IIUC that would require the actual PC knowledge and there's no direct
> access to the PC on xtensa.

I thought about it for a bit and although the current PC can easily
be fetched I don't see how it can work for multiple text segments
without a GOT entry. OTOH a link-time conversion of a call without
GOT to a call with GOT in case the target and the call site are in
the different text segments seems feasible.

-- 
Thanks.
-- Max

  reply	other threads:[~2024-02-29 12:03 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-27 23:24 Rich Felker
2024-02-28  0:13 ` Rich Felker
2024-02-28 17:20   ` Max Filippov
2024-02-28 18:30     ` Rich Felker
2024-02-28 18:37       ` Rich Felker
2024-02-28 19:34         ` Max Filippov
2024-02-28 19:41           ` Max Filippov
2024-02-28 20:14             ` Rich Felker
2024-02-28 20:26               ` Rich Felker
2024-02-28 20:37                 ` Rich Felker
2024-02-28 21:28       ` Max Filippov
2024-02-29 12:03         ` Max Filippov [this message]
2024-02-29 15:35           ` Rich Felker
2024-02-29 16:25       ` Max Filippov
2024-02-29 18:16         ` Rich Felker
2024-03-19 15:25       ` Max Filippov
2024-03-19 16:08       ` Max Filippov

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