From: Santosh Sivaraj <santosh@fossix.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>,
Segher Boessenkool <segher@kernel.crashing.org>
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH] powerpc/vdso64: inline __get_datapage()
Date: Thu, 22 Aug 2019 21:48:56 +0530 [thread overview]
Message-ID: <87mug1i367.fsf@santosiv.in.ibm.com> (raw)
In-Reply-To: <6108a7ed-b4f9-f02f-ca63-1d663bda4990@c-s.fr>
Christophe Leroy <christophe.leroy@c-s.fr> writes:
> Le 21/08/2019 à 14:15, Segher Boessenkool a écrit :
>> On Wed, Aug 21, 2019 at 01:50:52PM +0200, Christophe Leroy wrote:
>>> Do you have any idea on how to avoid that bcl/mflr stuff ?
>>
>> Do a load from some fixed address? Maybe an absolute address, even?
>> lwz r3,-12344(0) or similar (that address is in kernel space...)
>>
>> There aren't many options, and certainly not many *good* options!
>>
>
> IIUC, the VDSO is seen by apps the same way as a dynamic lib. Couldn't
> the relocation be done only once when the app loads the VDSO as for a
> regular .so lib ?
How does address space randomization work for .so libs?
>
> It looks like it is what others do, at least x86 and arm64, unless I
> misunderstood their code.
>
> Christophe
prev parent reply other threads:[~2019-08-22 16:21 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-16 14:48 [PATCH] powerpc/vdso32: inline __get_datapage() Christophe Leroy
2019-08-21 4:37 ` Benjamin Herrenschmidt
2019-08-21 9:29 ` [PATCH] powerpc/vdso64: " Santosh Sivaraj
2019-08-21 9:46 ` Christophe Leroy
2019-08-21 11:20 ` Santosh Sivaraj
2019-08-21 15:58 ` Nathan Lynch
2019-08-21 11:44 ` Segher Boessenkool
2019-08-21 11:50 ` Christophe Leroy
2019-08-21 12:15 ` Segher Boessenkool
2019-08-21 16:23 ` Christophe Leroy
2019-08-22 16:18 ` Santosh Sivaraj [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=87mug1i367.fsf@santosiv.in.ibm.com \
--to=santosh@fossix.org \
--cc=christophe.leroy@c-s.fr \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=segher@kernel.crashing.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).