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From: "H.J. Lu" <hjl.tools@gmail.com>
To: Florian Weimer <fweimer@redhat.com>
Cc: GNU C Library <libc-alpha@sourceware.org>
Subject: Re: [PATCH 1/2] x86-64/setcontext: Pop the pointer into %rdx after syscall
Date: Sun, 29 Apr 2018 22:07:00 -0000	[thread overview]
Message-ID: <CAMe9rOpHrEsHPKp=nJzb3ewV9Ge+OD-YXw05PQgyK8-BwuS0ww@mail.gmail.com> (raw)
In-Reply-To: <8b0e9b44-d231-ef32-05a7-5fad5c7352b1@redhat.com>

On Sun, Apr 29, 2018 at 2:03 PM, Florian Weimer <fweimer@redhat.com> wrote:
> On 04/26/2018 02:17 PM, H.J. Lu wrote:
>>
>> +       /* Pop the pointer into RDX which is preserved by the syscall.  */
>> +       popq    %rdx
>
>
> Sorry, the comment is a bit unclear.  Why do you need to restore %rdx if it
> is preserved by the system call?  Maybe it becomes clearer with a future
> change?
>

Here is the patch to use it:

https://github.com/hjl-tools/glibc/commit/182ce0987aada98b2d606276d4aa4fbd2527031b


-- 
H.J.

  reply	other threads:[~2018-04-29 22:07 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-26 12:17 H.J. Lu
2018-04-29 21:03 ` Florian Weimer
2018-04-29 22:07   ` H.J. Lu [this message]
2018-05-02  5:03   ` Carlos O'Donell

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