From: Matheus Castanho <msc@linux.ibm.com>
To: Andreas Schwab <schwab@linux-m68k.org>
Cc: Matheus Castanho via Libc-alpha <libc-alpha@sourceware.org>,
tuliom@linux.ibm.com, npiggin@gmail.com
Subject: Re: [PATCH] powerpc: Add missing registers to clobbers list for syscalls [BZ #27623]
Date: Mon, 29 Mar 2021 10:27:08 -0300 [thread overview]
Message-ID: <87v99aks43.fsf@linux.ibm.com> (raw)
In-Reply-To: <87k0pzmeqh.fsf@igel.home>
Andreas Schwab <schwab@linux-m68k.org> writes:
> On Mär 22 2021, Matheus Castanho via Libc-alpha wrote:
>
>> Some registers that can be clobbered by the kernel during a syscall are not
>> listed on the clobbers list in sysdeps/unix/sysv/linux/powerpc/sysdep.h.
>>
>> For syscalls using sc:
>> - XER is zeroed by the kernel on exit
>>
>> For syscalls using scv:
>> - XER is zeroed by the kernel on exit
>> - Different from the sc case, most CR fields can be clobbered (according to
>> the ELF ABI and the Linux kernel's syscall ABI for powerpc
>> (linux/Documentation/powerpc/syscall64-abi.rst)
>>
>> These are likely not causing issues today, but they should be added to the
>> clobbers list just in case things change on the kernel side in the future.
>
> What about INTERNAL_VSYSCALL_CALL_TYPE? Doesn't that clobber XER[CA]
> and CR1/5/6/7 like ordinary function calls?
>
> Andreas.
Yes, looks like they should be added to the clobbers list there too. I'll send
a v2 shortly.
--
Matheus Castanho
prev parent reply other threads:[~2021-03-29 13:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 14:20 Matheus Castanho
2021-03-22 14:42 ` Andreas Schwab
2021-03-29 13:27 ` Matheus Castanho [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87v99aks43.fsf@linux.ibm.com \
--to=msc@linux.ibm.com \
--cc=libc-alpha@sourceware.org \
--cc=npiggin@gmail.com \
--cc=schwab@linux-m68k.org \
--cc=tuliom@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).