From owner-freebsd-hackers  Tue Mar 23 22:23:40 1999
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From: Nate Williams <nate@mt.sri.com>
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To: Steve Price <sprice@hiwaay.net>
Cc: freebsd-hackers@FreeBSD.ORG, jdp@FreeBSD.ORG
Subject: Re: dladdr(3) question
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> I know I'm probably doing something stupid here, but I
> seem to be having a problem getting dladdr(3) to work.

I just researched this (since I'm as interested in Steve as to why this
doesn't work. :) It appears to me that dladdr is *NOT* supported in ELF
in the current code.  However, it is supported in a.out (in 3.* only).

The functionality is missing in /usr/src/libexec/rtld-elf, although I
suspect it's an oversight and not intentional.

I'm not *real* familiar with the loader code, but given it's already
implemented for a.out I suspect it should be easy to add to the elf
loader.

John would know more (hope he's feeling better).



Nate
--------------------
> Here's the code ...
> 
> #include <dlfcn.h>
> #include <stdio.h>
> #include <stdlib.h>
> int foo() {
> 	return 0;
> }
> int main() {
> 	Dl_info dlinfo;
> 	if (dladdr(foo, &dlinfo) == 0) {
> 		printf("dladdr failed: %s\n", dlerror());
> 		exit(1);
> 	}
> 	printf("dli_fname = %s\n", dlinfo.dli_fname);
> 	return 0;
> }
> 
> ... and a couple of sample runs.
> 
> bsd[~]$ ./a.out
> dladdr failed: Service unavailable
> bsd[~]$ uname -rs
> FreeBSD 4.0-CURRENT
> 
> pepito[~]$ ./a.out
> dli_fname = a.out
> pepito[~]$ uname -rs
> SunOS 5.7
> 
> Anyone have any ideas where I'm missing the boat?
> 
> -steve
> 
> 
> 
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