From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org, binutils@sourceware.org
Cc: libc-dev@lists.llvm.org, Rich Felker <dalias@libc.org>,
libc-alpha@sourceware.org,
Adhemerval Zanella <adhemerval.zanella@linaro.org>,
musl@lists.openwall.com
Subject: New powerpc vdso calling convention
Date: Sat, 25 Apr 2020 15:22:27 +1000 [thread overview]
Message-ID: <1587790194.w180xsw5be.astroid@bobo.none> (raw)
As noted in the 'scv' thread, powerpc's vdso calling convention does not
match the C ELF ABI calling convention (or the proposed scv convention).
I think we could implement a new ABI by basically duplicating function
entry points with different names.
The ELF v2 ABI convention would suit it well, because the caller already
requires the function address for ctr, so having it in r12 will
eliminate the need for address calculation, which suits the vdso data
page access.
Is there a need for ELF v1 specific calls as well, or could those just be
deprecated and remain on existing functions or required to use the ELF
v2 calls using asm wrappers?
Is there a good reason for the system call fallback to go in the vdso
function rather than have the caller handle it?
Thanks,
Nick
next reply other threads:[~2020-04-25 5:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-25 5:22 Nicholas Piggin [this message]
2020-04-25 5:40 ` [musl] New powerpc vdso calling convention Rich Felker
2020-04-25 7:47 ` Christophe Leroy
2020-04-25 10:56 ` Nicholas Piggin
2020-04-25 12:20 ` Christophe Leroy
2020-04-25 22:58 ` Nicholas Piggin
2020-04-25 23:11 ` Rich Felker
2020-04-26 3:41 ` Nicholas Piggin
2020-04-27 13:09 ` Adhemerval Zanella
2020-04-29 2:39 ` Nicholas Piggin
2020-04-29 12:15 ` Adhemerval Zanella
2020-05-05 21:56 ` Segher Boessenkool
2020-04-25 16:22 ` [musl] " Rich Felker
2020-04-25 23:07 ` Nicholas Piggin
2020-04-30 2:51 ` Michael Ellerman
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=1587790194.w180xsw5be.astroid@bobo.none \
--to=npiggin@gmail.com \
--cc=adhemerval.zanella@linaro.org \
--cc=binutils@sourceware.org \
--cc=dalias@libc.org \
--cc=libc-alpha@sourceware.org \
--cc=libc-dev@lists.llvm.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=musl@lists.openwall.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.