[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20181121161400.GC23599@brightrain.aerifal.cx>
Date: Wed, 21 Nov 2018 11:14:00 -0500
From: Rich Felker <dalias@...c.org>
To: musl@...ts.openwall.com
Subject: Re: Question regarding dynamic loader
On Wed, Nov 21, 2018 at 09:25:50AM -0500, Rich Felker wrote:
> On Wed, Nov 21, 2018 at 02:55:19PM +0100, Gernot Reisinger wrote:
> > I wonder if calling constructor functions from crt code is an intended musl
> > libc behavior. My personal - non expert - gut feeling considers glibc
> > behavior "more correct". Is there a chance that musl will change this
> > behavior?
>
> The musl behavior here is intentional. For FDPIC targets, it's
> impossible to run *any* application code, in the main application or
> shared libraries, before the main application's crt1 has executed,
> because there are (essentially -- the equivalent of) self-relocations
> performed at that stage that the dynamic linker can't see. If any
> ctors were invoked directly by the dynamic linker before passing
> control the the main application's entry point, they would run without
> these relocations in the main application having been performed,
> possibly resulting in runaway-wrong execution.
For reference, this was initially done in commit
c87a52103399135d2f57a91a8bcc749d8cb2ca83. Of course these code paths
have changed significantly since then, but it gives some historical
context.
Rich
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
