Bug 1748194

Summary:	glibc: Permit moving versioned symbols between different sonames
Product:	Red Hat Enterprise Linux 8	Reporter:	Florian Weimer <fweimer>
Component:	glibc	Assignee:	glibc team <glibc-bugzilla>
Status:	CLOSED DUPLICATE	QA Contact:	qe-baseos-tools-bugs
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	8.2	CC:	amahdal, ashankar, codonell, dj, fweimer, mnewsome, mosvald, pfrankli
Target Milestone:	pre-dev-freeze	Keywords:	Patch
Target Release:	8.2
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	If docs needed, set a value
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Last Closed:	2019-11-15 18:29:15 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1473680
Bug Blocks:	1738779, 1748197

Description Florian Weimer 2019-09-03 07:06:01 UTC

The glibc dynamic linker currently prevents moving a symbol from one soname to another if the symbol is versioned.  This is an artifact of the way symbol-specific versioning is implemented in glibc.  There is no fundamental technical reason to disallow this, and glibc 2.30 upstream lifts this restriction.

Upstream commit:

commit f0b2132b35248c1f4a80f62a2c38cddcc802aa8c
Author: Florian Weimer <fweimer>
Date:   Fri Jun 28 10:12:50 2019 +0200

    ld.so: Support moving versioned symbols between sonames [BZ #24741]
    
    This change should be fully backwards-compatible because the old
    code aborted the load if a soname mismatch was encountered
    (instead of searching further for a matching symbol).  This means
    that no different symbols are found.
    
    The soname check was explicitly disabled for the skip_map != NULL
    case.  However, this only happens with dl(v)sym and RTLD_NEXT,
    and those lookups do not come with a verneed entry that could be used
    for the check.
    
    The error check was already explicitly disabled for the skip_map !=
    NULL case, that is, when dl(v)sym was called with RTLD_NEXT.  But
    _dl_vsym always sets filename in the struct r_found_version argument
    to NULL, so the check was not active anyway.  This means that
    symbol lookup results for the skip_map != NULL case do not change,
    either.

Comment 2 Carlos O'Donell 2019-11-15 18:29:15 UTC


*** This bug has been marked as a duplicate of bug 1764231 ***