From: Joseph Myers <joseph@codesourcery.com>
To: Florian Weimer <fweimer@redhat.com>
Cc: <libc-alpha@sourceware.org>
Subject: Re: Making a syscall before ld.so self-relocation on MIPS
Date: Wed, 17 May 2023 19:01:26 +0000 [thread overview]
Message-ID: <e2de7e84-9a3a-bc9c-2a19-7d1554870f0@codesourcery.com> (raw)
In-Reply-To: <87wn17jogh.fsf@oldenburg3.str.redhat.com>
On Wed, 17 May 2023, Florian Weimer via Libc-alpha wrote:
> I'm reviewing HIDDEN_VAR_NEEDS_DYNAMIC_RELOC if they support inline
> system calls (without function calls), so that I can make a system call
> (mmap actually) before initial self-relocation of the dynamic loader.
>
> So far, it looks good in theory, except on MIPS. First there is MIPS16:
>
> /* There's no MIPS16 syscall instruction, so we go through out-of-line
> standard MIPS wrappers. These do use inline snippets below though,
> through INTERNAL_SYSCALL_MIPS16. Spilling the syscall number to
> memory gives the best code in that case, avoiding the need to save
> and restore a static register. */
>
> Is MIPS16 the default in GCC? We don't build for explicitly in
> scripts/build-many-glibcs.py.
No, it's not the default; you need to use the -mips16 option.
--
Joseph S. Myers
joseph@codesourcery.com
next prev parent reply other threads:[~2023-05-17 19:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-17 9:29 Florian Weimer
2023-05-17 19:01 ` Joseph Myers [this message]
2023-05-17 19:30 ` Florian Weimer
2023-05-17 19:41 ` Joseph Myers
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