musl - Re: [RFC PATCH] Fix __libc_start_main prototype in [r]crt1.c to match the caller

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date: Wed, 21 Nov 2018 17:15:18 +0100
From: Ondřej Jirman <megous@...ous.com>
To: musl@...ts.openwall.com
Subject: Re: [RFC PATCH] Fix __libc_start_main prototype in [r]crt1.c
 to match the caller

On Wed, Nov 21, 2018 at 04:22:17PM +0100, Szabolcs Nagy wrote:
> * Szabolcs Nagy <nsz@...t70.net> [2018-11-21 16:09:04 +0100]:
> 
> > * megous@...ous.com <megous@...ous.com> [2018-11-21 15:51:50 +0100]:
> > > From: Ondrej Jirman <megous@...ous.com>
> > > 
> > > __libc_start_main function is not using the last three arguments.
> > > GCC in LTO mode complains about mismatch.
> > 
> > fix it in the other way then.
> > 
> > > -	__libc_start_main(main, argc, argv, _init, _fini, 0);
> > > +	__libc_start_main(main, argc, argv);
> > 
> > you just completely broke everything there didnt you?
> > 
> 
> sorry the _init, _fini there is only needed for glibc compat
> (i.e. executable linked with musl crt1.o, but using glibc
> to run it, which should not be a common use case)

I had a hunch that there was some reason outside of musl for these arguments,
therefore just the RFC. I guess, it's better to ignore the patch then.

I just saw a difference of prototypes, so I sent the patch.

> > how will the _init/_fini code of executables with
> > DT_INIT, DT_FINI dynamic tags run?
> > 
> > i think gcc still havent fixed weak object symbol alias
> > bugs with lto so e.g. you will get incorrect environ if
> > you lto link the libc.
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69271
> 
> these lto issues still apply.

I'm attempting a static build, for which this issue should not apply, AFAIK.

Though, I'm trying on mips, and it leads to GOT related error. So LTO of musl+my
code doesn't work anyway, because ld fails. I'll try with some other target just
to see if I can get something that works, without the limitations of mips arch.

regards,
  o.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.