Bug 216864

Summary: ldd -u gives false positives on x86_64
Product: [Fedora] Fedora Reporter: Arjan van de Ven <arjan>
Component: glibcAssignee: Jakub Jelinek <jakub>
Status: CLOSED NOTABUG QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 6CC: drepper
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2006-11-22 20:47:11 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Arjan van de Ven 2006-11-22 13:47:08 UTC 
Description of problem:

[root@benny tmp]# cat test.c
#include <stdio.h>

void main()
{
        printf("hello world\n");
}
[root@benny tmp]# make test
cc     test.c   -o test
[root@benny tmp]# ldd -u test
Unused direct dependencies:
        /lib64/libc.so.6


(minimal testcase; this happens with a real big program as well)

ldd -u somehow doesn't think any of the direct dependencies are used even though
they really are...
Comment 1 Jakub Jelinek 2006-11-22 20:31:41 UTC 
Use ldd -u -r if you want to take into account also PLT relocations.
I agree ldd -u alone doesn't make much sense, but if I remember well that's
to much Solaris ldd behavior.
Comment 2 Ulrich Drepper 2006-11-22 20:47:11 UTC 
Indeed, this functionality is modelled after the Solaris version.  There are
situations conceivable where -u without -r might be useful.  It won't be
changed, learn to live with it.