[Bug math/13633] New: stripped libm drops ifunc identifiers

[Bug math/13633] New: stripped libm drops ifunc identifiers

[pcpa at mandriva dot com.br]

http://sourceware.org/bugzilla/show_bug.cgi?id=13633

             Bug #: 13633
           Summary: stripped libm drops ifunc identifiers
           Product: glibc
           Version: 2.15
            Status: NEW
          Severity: normal
          Priority: P2
         Component: math
        AssignedTo: aj@suse.de
        ReportedBy: pcpa@mandriva.com.br
    Classification: Unclassified


Both, eu-strip and binutils strip drop some identifiers from newer libm with
sse4.1 optimizations.

  Before strip:
000000000001a980 <floor>:
   1a980:       e8 1b a7 fe ff          callq  50a0 <__get_cpu_features@plt>
   1a985:       48 89 c2                mov    %rax,%rdx
   1a988:       48 8d 05 11 00 00 00    lea    0x11(%rip),%rax        # 1a9a0
<__floor_sse41>
   1a98f:       f7 42 10 00 00 08 00    testl  $0x80000,0x10(%rdx)
   1a996:       75 07                   jne    1a99f <floor+0x1f>
   1a998:       48 8d 05 b1 77 02 00    lea    0x277b1(%rip),%rax        #
42150 <__floor_c>
   1a99f:       c3                      retq   

000000000001a9a0 <__floor_sse41>:
   1a9a0:       66 0f 3a 0b c0 01       roundsd $0x1,%xmm0,%xmm0
   1a9a6:       c3                      retq   

  After strip:
000000000001a980 <floor>:
   1a980:       e8 1b a7 fe ff          callq  50a0 <__get_cpu_features@plt>
   1a985:       48 89 c2                mov    %rax,%rdx
   1a988:       48 8d 05 11 00 00 00    lea    0x11(%rip),%rax        # 1a9a0
<floor+0x20>
   1a98f:       f7 42 10 00 00 08 00    testl  $0x80000,0x10(%rdx)
   1a996:       75 07                   jne    1a99f <floor+0x1f>
   1a998:       48 8d 05 b1 77 02 00    lea    0x277b1(%rip),%rax        #
42150 <__signbitl+0x6950>
   1a99f:       c3                      retq   
   1a9a0:       66 0f 3a 0b c0 01       roundsd $0x1,%xmm0,%xmm0
   1a9a6:       c3                      retq   

  Most times this happens to work, but will break on special conditions if libm
is loaded as a
dependency of a dynamic module, for example, apache mod_php (using LD_PRELOAD
on these special
cases also "corrects" the problem).

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[Bug math/13633] stripped libm drops ifunc identifiers

[ppluzhnikov at google dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13633

Paul Pluzhnikov <ppluzhnikov at google dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ppluzhnikov at google dot
                   |                            |com

--- Comment #1 from Paul Pluzhnikov <ppluzhnikov at google dot com> 2012-01-30 21:54:46 UTC ---
(In reply to comment #0)

> Most times this happens to work, but will break on special conditions if libm
> is loaded as a dependency of a dynamic module

Sorry, I am not following.

Will break in what way?
Can you provide a minimal test case demonstrating breakage?

(I suspect this is just a dup of issue 13618, which actually has nothing
to do with strip.)

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[Bug math/13633] stripped libm drops ifunc identifiers

[pcpa at mandriva dot com.br]

http://sourceware.org/bugzilla/show_bug.cgi?id=13633

--- Comment #2 from Paulo César Pereira de Andrade <pcpa at mandriva dot com.br> 2012-01-31 00:32:52 UTC ---
(In reply to comment #1)
> (In reply to comment #0)
> 
> > Most times this happens to work, but will break on special conditions if libm
> > is loaded as a dependency of a dynamic module
> 
> Sorry, I am not following.
> 
> Will break in what way?
> Can you provide a minimal test case demonstrating breakage?
> 
> (I suspect this is just a dup of issue 13618, which actually has nothing
> to do with strip.)

  You are right. I opened the bug report due to a related
Mandriva bugzilla saying that a rebuilt glibc not stripping
libm would correct the problem.

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[Bug math/13633] stripped libm drops ifunc identifiers

[pcpa at mandriva dot com.br]

http://sourceware.org/bugzilla/show_bug.cgi?id=13633

--- Comment #3 from Paulo César Pereira de Andrade <pcpa at mandriva dot com.br> 2012-01-31 00:35:16 UTC ---
Created attachment 6185
  --> http://sourceware.org/bugzilla/attachment.cgi?id=6185
pr13633.c

Not as simple as the test case in #13618, this
should mimic what happens in httpd + mod_php.

Free free to close the report as a dupe.

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[Bug math/13633] stripped libm drops ifunc identifiers

[pcpa at mandriva dot com.br]

http://sourceware.org/bugzilla/show_bug.cgi?id=13633

Paulo César Pereira de Andrade <pcpa at mandriva dot com.br> changed:

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

--- Comment #4 from Paulo César Pereira de Andrade <pcpa at mandriva dot com.br> 2012-01-31 03:29:31 UTC ---
I did a backport of
http://sourceware.org/git/?p=glibc.git;a=commit;h=6ee65ed6ddbf04402fad0bec6aa9c73b9d982ae4
to the mandriva glibc package and confirm that
the "apache + mod_php" test case now works
correctly.

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[Bug math/13633] stripped libm drops ifunc identifiers

[ppluzhnikov at google dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13633

Paul Pluzhnikov <ppluzhnikov at google dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|FIXED                       |DUPLICATE

--- Comment #5 from Paul Pluzhnikov <ppluzhnikov at google dot com> 2012-01-31 03:49:05 UTC ---


*** This bug has been marked as a duplicate of bug 13618 ***

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[Bug math/13633] stripped libm drops ifunc identifiers

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=13633

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
              Flags|                            |security-

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