Re: dl_iterate_phdr() behaves differently on musl and glibc

[Rich Felker <dalias@libc.org>]

On Mon, May 28, 2018 at 03:44:15PM +0200, Bob B. wrote:
> Hi list.
> 
> I noticed a difference in behavior of dl_iterate_phdr() when playing with musl and glibc.
> The program I tried was the example on the bottom of the page: https://linux.die.net/man/3/dl_iterate_phdr
> 
> What happens is that musl returns the program itself when run + shared objects.
> glibc only returns the shared objects.
> 
> Not sure which one is right. Or if both are acceptable.
> Any light to clear why the different behavior is appreciated.

I was unaware of that difference, but omitting the main program seems
like a serious limitation that makes the interface a lot less useful.
I'm not sure if there's any other way to get the information.

The manual page documents the function as enumerating the "shared
objects", which one could interpret only as libraries, but I usually
consider a dynamic program as a "shared object" itself.

Is there a reason musl's behavior is problematic here? Even without
the ambiguity I'd be hesitant to change it since programs may be
relying on it.

Rich