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Date: Mon, 11 Jan 2021 22:29:35 -0500
From: Rich Felker <dalias@libc.org>
To: Sagar Tiwari <fctorial@gmail.com>
Cc: musl@lists.openwall.com
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User-Agent: Mutt/1.5.21 (2010-09-15)
Subject: Re: [musl] printf segfaults on recent musl versions

On Tue, Jan 12, 2021 at 06:33:10AM +0530, Sagar Tiwari wrote:
> These changes fix the issue.
> 
> Another alternative is to manually call '__init_libc' with two args
> pointing to zeroed memory and
>  '__libc_start_init'. Don't know if it's safe?

It's not. __init_libc is not a public function. You can call
__libc_start_main (which is the ABI boundary) from your own entry
point file if you like though but I don't see any reason to prefer
that over just using [S]crt1.o.

Rich

> On 12/01/2021, Rich Felker <dalias@libc.org> wrote:
> > On Tue, Jan 12, 2021 at 12:46:40AM +0530, Sagar Tiwari wrote:
> >> I'm assembling a file with clang and linking it to custom compiled
> >> musl with ld. This is the project I'm using:
> >>
> >> https://drive.google.com/file/d/1RiKZTf_nJUak14fz7kSXbh7egJuDthDk/view?usp=sharing
> >
> > In the future, please send attachments not Google Drive links.
> >
> >> musl 1.1.8 is the last version that works with this project. I used
> >> clang 11.0.0 to compile both musl and this project.
> >
> > You can't call libc if you didn't enter the program through its entry
> > point (or an ABI-compatible one). If you name the mn function main,
> > link crt1.o (or the appropriate variant thereof), and drop the linker
> > script (which may be omitting other necessary items), it should work
> > as expected.