[Bug libc/4131] New: BUG : dladdr() doesn't return the correct results

[Bug libc/4131] New: BUG : dladdr() doesn't return the correct results

[suzuki at in dot ibm dot com]

We encountered a problem with dl-addr which would return incorrect results for
an address lookup.

The problem occurs when a library (say libA) is mapped (by glibc) in the space
between two loaded segments of an already mapped library ( we have seen this
library is most of the time ld-linux.so). In this case we have,

LD.SO.l_map_start < LIBA.l_map_start < LIBA.l_map_end < LD.SO.l_map_end


So while looking up an address in LIBA, we get the result as LD.SO which
confuses the caller.

This is due to the following bug in the dl-addr logic:

1) We find a link_map whose [l_map_start,l_map_end) encloses the address.

2) We consult only the *LAST* loaded segment of the lib to check if the address
lies beyond the segment's end address.

So, if the ld.so is consulted before libA, we end up in returning ld.so as the
result.

The proper fix here would be to make sure that the address *falls in* _any_ of
the segments of the library.

-- 
           Summary: BUG : dladdr() doesn't return the correct results
           Product: glibc
           Version: 2.4
            Status: NEW
          Severity: critical
          Priority: P2
         Component: libc
        AssignedTo: drepper at redhat dot com
        ReportedBy: suzuki at in dot ibm dot com
                CC: glibc-bugs at sources dot redhat dot com
 GCC build triplet: All
  GCC host triplet: All
GCC target triplet: All


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[Bug libc/4131] BUG : dladdr() doesn't return the correct results

[suzuki at in dot ibm dot com]

------- Additional Comments From suzuki at in dot ibm dot com  2007-03-05 20:29 -------
Created an attachment (id=1598)
 --> (http://sourceware.org/bugzilla/attachment.cgi?id=1598&action=view)
Patch to fix dl-addr

The patch fixes the bug in dl-addr.  

The patch makes sure that the address being looked up lies in one of the loaded
segments of the library.

Thanks

Suzuki

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|drepper at redhat dot com   |suzuki at in dot ibm dot com
             Status|NEW                         |ASSIGNED


http://sourceware.org/bugzilla/show_bug.cgi?id=4131

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[Bug libc/4131] BUG : dladdr() doesn't return the correct results

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2007-05-06 22:02 -------
I rewrote the patch to be more efficient and clearer.  Also, you are not
following the coding standard, don't update the copyright year, etc.

Plus: do not ever change priority of severity.  You cannot judge this.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal
             Status|ASSIGNED                    |RESOLVED
           Priority|P2                          |P1
         Resolution|                            |FIXED


http://sourceware.org/bugzilla/show_bug.cgi?id=4131

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[Bug libc/4131] BUG : dladdr() doesn't return the correct results

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2007-07-12 15:15 -------
Subject: Bug 4131

CVSROOT:	/cvs/glibc
Module name:	libc
Branch: 	glibc-2_5-branch
Changes by:	jakub@sourceware.org	2007-07-12 15:15:16

Modified files:
	.              : ChangeLog 
	elf            : dl-addr.c 

Log message:
	2007-05-06  Ulrich Drepper  <drepper@redhat.com>
	
	[BZ #4131]
	* elf/dl-addr.c (_dl_addr): Compare address with actual segment
	boundaries to work around systems with overlapping binary loading.
	Based on a patch by Suzuki <suzuki@in.ibm.com>.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/libc/ChangeLog.diff?cvsroot=glibc&only_with_tag=glibc-2_5-branch&r1=1.10362.2.80&r2=1.10362.2.81
http://sourceware.org/cgi-bin/cvsweb.cgi/libc/elf/dl-addr.c.diff?cvsroot=glibc&only_with_tag=glibc-2_5-branch&r1=1.31&r2=1.31.2.1



-- 


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[Bug libc/4131] BUG : dladdr() doesn't return the correct results

[bugs at elyoung dot com]

------- Additional Comments From bugs at elyoung dot com  2007-10-09 05:05 -------
Hi,
I'm not sure the procedure here, so excuse me if reopening was incorrect.

This bug still seems to affect the 2.6 branch. (and the trunk as well?)
Can we get the same patch into the 2.6 branch to fix this there, or do we need a
separate bug to track it?

Thanks,
--Mike

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bugs at elyoung dot com
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |


http://sourceware.org/bugzilla/show_bug.cgi?id=4131

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[Bug libc/4131] BUG : dladdr() doesn't return the correct results

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2007-10-15 01:36 -------
Don't open bugs for branches.  They might or might get a fix.  In general nobody
should expect any branch to be updated.  Just use the latest code.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|                            |FIXED


http://sourceware.org/bugzilla/show_bug.cgi?id=4131

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