[Bug libc/3924] New: LD_AUDIT implementation causing process segfaulting

[Bug libc/3924] New: LD_AUDIT implementation causing process segfaulting

[olsajiri at gmail dot com]

There's a bug in the sysdeps/i386/dl-trampoline.S _dl_runtime_profile function
making process segfaulting. Under some conditions the 'edi' and 'esi' registers
are restored to wrong values. IMHO this could be fixed like this:

Index: sysdeps/i386/dl-trampoline.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/i386/dl-trampoline.S,v
retrieving revision 1.2
diff -r1.2 dl-trampoline.S
116d115
<       andl $0xfffffff0, %edi  # Align stack

edi and esi registers are pushed on stack before it is alligned. In case it is
really aligned those register wont be restored properly. I tried the fix and it
is working for me. I dont know the reason for alligning the stack here, so
hopefully I'm not missing something... :)

I'm running the 2.4 version, but seems it is an issue in current sources as well.

regards
Jiri Olsa

-- 
           Summary: LD_AUDIT implementation causing process segfaulting
           Product: glibc
           Version: 2.4
            Status: NEW
          Severity: enhancement
          Priority: P2
         Component: libc
        AssignedTo: drepper at redhat dot com
        ReportedBy: olsajiri at gmail dot com
                CC: glibc-bugs at sources dot redhat dot com


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[olsajiri at gmail dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|enhancement                 |normal
 GCC target triplet|                            |x86


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2007-02-17 07:18 -------
Provide example code.  As I wrote on the list already, I don't see anything
wrong.  The alignment is needed and is correctly expressed for the unwinder.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[olsajiri at gmail dot com]

------- Additional Comments From olsajiri at gmail dot com  2007-04-17 22:05 -------
Created an attachment (id=1726)
 --> (http://sourceware.org/bugzilla/attachment.cgi?id=1726&action=view)
example code

create an shared library 'libaudit.so' from the source and run:

LD_AUDIT=<PATH>/libaudit.so /bin/ls

this segfaults for me most of the time

-- 


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[olsajiri at gmail dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[olsajiri at gmail dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[olsajiri at gmail dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P1


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2007-08-24 02:58 -------
Fixed in cvs.  Your patch is not correct.

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


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[olsajiri at gmail dot com]

------- Additional Comments From olsajiri at gmail dot com  2007-08-27 20:20 -------
The example code is still not working with the fixed libc code.

Regarding the framesizep output agrument of la_i86_gnu_pltenter function:

If there's a framesizep set to any value but zero, the ls binary will segfault.
If there's a framesizep set to zero value, the ls binary will run without errors.

Does the example code work ok for you?

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


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[Bug libc/3924] LD_AUDIT implementation causing process segfaulting

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2007-10-07 05:32 -------
There was another little bug in the code which I fixed.  But an equally bad bug
is that you test module is requesting too large stack frames.  Unless I reduced
the size to something more reasonable the copy operation will sometimes/often
segfault.  Current cvs has all the changes.

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


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