Bug 7635 - dlsym can't find objects in the case of dlopen(NULL, flag)
Summary: dlsym can't find objects in the case of dlopen(NULL, flag)
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: glibc
Version: 6.1
Hardware: i386
OS: Linux
Target Milestone: ---
Assignee: Cristian Gafton
QA Contact:
Depends On:
TreeView+ depends on / blocked
Reported: 1999-12-06 19:02 UTC by braddr
Modified: 2008-05-01 15:37 UTC (History)
0 users

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2000-01-05 03:16:47 UTC

Attachments (Terms of Use)

Description braddr 1999-12-06 19:02:44 UTC
Unlike solaris, this program demonstrates that glibc has issues resolving
symbols to data elements.  I've tried it with glibc 2.0.7 and 2.1.2, both
with and without x being initialized:

#include <stdio.h>
#include <stdlib.h>

#include <dlfcn.h>

int x=1;

int main()
    void *handle = dlopen(NULL, RTLD_NOW);
    int *symbol = (int*)dlsym(handle, "x");
    char *errmsg = dlerror();

    printf("%d\n", x);

    if (symbol)
        printf("%d\n", *symbol);
        printf("error: %s\n", errmsg);
    return 0;

Comment 1 braddr 1999-12-06 22:47:59 UTC
Actually, it seems unable to locate any local symbols.. main, or if I add
another function it can't look up that one either.  It seems that
dlopen(NULL,blah) is what's broken possibly.

Comment 2 braddr 1999-12-13 19:27:59 UTC
change the sort desc to match the actual bug report

Comment 3 Cristian Gafton 2000-01-05 03:02:59 UTC
Yepp, this is a bug.

Comment 4 Cristian Gafton 2000-01-05 03:16:59 UTC
Oops, not really a bug. You need to pass -rdynamic at the link time to have this
fucntionality (you need to be able to access your own proram space like a shared

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