From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Joe Lawrence <joe.lawrence@redhat.com>, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc/vdso: remove deprecated VDS64_HAS_DESCRIPTORS references
Date: Wed, 18 Mar 2020 00:14:43 +1100 (AEDT) [thread overview]
Message-ID: <48hYYH662sz9sSM@ozlabs.org> (raw)
In-Reply-To: <20200224211848.26087-1-joe.lawrence@redhat.com>
On Mon, 2020-02-24 at 21:18:48 UTC, Joe Lawrence wrote:
> The original 2005 patch that introduced the powerpc vdso, pre-git
> ("ppc64: Implement a vDSO and use it for signal trampoline") notes that:
>
> ... symbols exposed by the vDSO aren't "normal" function symbols, apps
> can't be expected to link against them directly, the vDSO's are both
> seen as if they were linked at 0 and the symbols just contain offsets
> to the various functions. This is done on purpose to avoid a
> relocation step (ppc64 functions normally have descriptors with abs
> addresses in them). When glibc uses those functions, it's expected to
> use it's own trampolines that know how to reach them.
>
> Despite that explanation, there remains dead #ifdef
> VDS64_HAS_DESCRIPTORS code-blocks that provide alternate function
> definitions that setup function descriptors.
>
> Since VDS64_HAS_DESCRIPTORS has been unused for all these years, we
> might as well finally remove it from the codebase.
>
> Link: https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-February/204430.=
> html
> Link: https://lore.kernel.org/lkml/1108002773.7733.196.camel@gaston/
> Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/ffd3eaf178b0f616a071e510e289d937330b0b35
cheers
prev parent reply other threads:[~2020-03-17 13:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-17 16:08 vdso function descriptors (VDS64_HAS_DESCRIPTORS)? Joe Lawrence
2020-02-23 0:07 ` Segher Boessenkool
2020-02-24 10:17 ` Benjamin Herrenschmidt
2020-02-24 15:20 ` Joe Lawrence
2020-02-24 15:34 ` Benjamin Herrenschmidt
2020-02-24 21:18 ` [PATCH] powerpc/vdso: remove deprecated VDS64_HAS_DESCRIPTORS references Joe Lawrence
2020-02-24 23:37 ` Michael Ellerman
2020-03-17 13:14 ` Michael Ellerman [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=48hYYH662sz9sSM@ozlabs.org \
--to=patch-notifications@ellerman.id.au \
--cc=joe.lawrence@redhat.com \
--cc=linuxppc-dev@lists.ozlabs.org \
/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 NNTP newsgroup(s).