This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: Encoding page size in the ELF header
- From: "Carlos O'Donell" <carlos at redhat dot com>
- To: Florian Weimer <fweimer at redhat dot com>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Fri, 25 Sep 2015 15:17:40 -0400
- Subject: Re: Encoding page size in the ELF header
- Authentication-results: sourceware.org; auth=none
- References: <56054662 dot 2010106 at redhat dot com>
On 09/25/2015 09:04 AM, Florian Weimer wrote:
> Not sure if this the right mailing list for this discussion.
>
> I think we should record the expected page size in the ELF header in
> some way. It affects the behavior of the static linker, the dynamic
> linker, and even some applications. (For example, an application might
> want to make a part of .data read-only after initialization, as a
> hardening measure.)
>
> What would be a good way to do that?
Can't the application just call getpagesize(), and then use that to
decide how to make .data read-only?
On RHEL we make sure the expected page size is plumbed through from the
static linker up to the application, which ensures that in ld on ppc64,
for example, you see 64K EXEC_PAGESIZE values, so getpagesize() DTRT.
What else is needed? Under what other configurations does this fail?
Cheers,
Carlos.