This is the mail archive of the libc-hacker@sources.redhat.com mailing list for the glibc project.

Note that libc-hacker is a closed list. You may look at the archives of this list, but subscription and posting are not open.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: new syscall stub support for ia64 libc

From: Jakub Jelinek <jakub at redhat dot com>
To: davidm at hpl dot hp dot com
Cc: Ulrich Drepper <drepper at redhat dot com>, libc-hacker at sources dot redhat dot com
Date: Mon, 8 Dec 2003 17:08:44 +0100
Subject: Re: new syscall stub support for ia64 libc
References: <16308.31118.610889.519920@napali.hpl.hp.com> <3FB53113.7050309@redhat.com> <16309.13147.182193.889647@napali.hpl.hp.com> <3FB53B28.5010102@redhat.com> <16309.62461.395811.966659@napali.hpl.hp.com> <3FB90F86.3060908@redhat.com> <16313.53298.919379.719647@napali.hpl.hp.com> <3FB9D475.7020005@redhat.com> <16324.23316.792750.173666@napali.hpl.hp.com> <16333.36844.428517.980589@napali.hpl.hp.com>
Reply-to: Jakub Jelinek <jakub at redhat dot com>

On Tue, Dec 02, 2003 at 11:25:32PM -0800, David Mosberger wrote:
> Executive Summary:
> 
>  Please apply this patch.  It's Good.
> 
> Long version:
> 
> The patch below adds new syscall support for ia64 Linux.  Compared to
> the earlier versions, it has a new autoconf test which ensures that
> USE_DL_SYSINFO only gets defined if the compiler uses an unwinder that
> is based on libunwind.  As explained earlier, the built-in unwinder
> for GCC is hopeless and so there is no point trying to support it.

The current IA-64 AT_SYSINFO_EHDR virtual DSO seems to be unfortunately
binary incompatible with older GCCs, which is IMHO a bad thing.
When kernel provides AT_SYSINFO_EHDR but userland doesn't grok it yet,
things should work the old way.
I think simply swapping the 2 PT_LOAD segments in virtual DSO would help,
ie. put PF_E segment before PF_R.
AT_SYSINFO_EHDR would point to the Elf64_Ehdr (followed by Elf64_Phdrs)
in the PF_R, ie. 0xa000000000020000.

I've briefly looked at .unwabi and will fix it in unwind-ia64.c as well
as other issues which I'll come over.

	Jakub

Follow-Ups:
- Re: new syscall stub support for ia64 libc
  - From: David Mosberger
- Re: new syscall stub support for ia64 libc
  - From: David Mosberger

References:
- Re: new syscall stub support for ia64 libc
  - From: David Mosberger

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]