Re: [Sks-devel] sks recon cores when it claims "reconciliation complete"

[Yaron Minsky]

Chris Kuethe said:
>
> I don't know much about debugging ocaml, I assume that "alloc_small" is
> some sort of ocaml intrinsic? I find a bunch of things that call it in the
> sks source, but no definition thereof...

You're certainly write about that.  It's just one of the caml memory
allocation functions.

> pyxis:ttypa# gdb sks sks.core
> GNU gdb 4.16.1
> Copyright 1996 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you
> are
> welcome to change it and/or distribute copies of it under certain
> conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for
> details.
> This GDB was configured as "i386-unknown-openbsd3.4"...
> Core was generated by `sks'.
> Program terminated with signal 11, Segmentation fault.
> Reading symbols from /usr/lib/libz.so.3.0...done.
> Reading symbols from /usr/local/lib/libdb.so.4.2...done.
> Reading symbols from /usr/lib/libm.so.1.0...done.
> Reading symbols from /usr/lib/libc.so.30.3...done.
> Reading symbols from /usr/libexec/ld.so...done.
> #0  0x1c0e3f6b in alloc_small ()
> (gdb) bt
> #0  0x1c0e3f6b in alloc_small ()
> #1  0x1c0ed7f0 in alloc_custom ()
> #2  0x1c0bec68 in sx_split ()
> #3  0x1c085aac in Numerix__fun_2305 ()
> #4  0x60cf7fe0 in ?? ()
> Cannot access memory at address 0x10cf7fe0.
>
> objdump -S says this was going on....
> 1c0e3f64 <alloc_small>:
> 1c0e3f64:       55                      push   %ebp
> 1c0e3f65:       89 e5                   mov    %esp,%ebp
> 1c0e3f67:       83 ec 0c                sub    $0xc,%esp
> 1c0e3f6a:       57                      push   %edi
> 1c0e3f6b:       56                      push   %esi
>                                                       *CORE*
> 1c0e3f6c:       53                      push   %ebx
> 1c0e3f6d:       8b 75 08                mov    0x8(%ebp),%esi
> 1c0e3f70:       8b 7d 0c                mov    0xc(%ebp),%edi
> 1c0e3f73:       8d 1c b5 04 00 00 00    lea    0x4(,%esi,4),%ebx
> 1c0e3f7a:       a1 bc ad 05 3c          mov    0x3c05adbc,%eax
> 1c0e3f7f:       29 d8                   sub    %ebx,%eax
> 1c0e3f81:       a3 bc ad 05 3c          mov    %eax,0x3c05adbc
> 1c0e3f86:       3b 05 c0 ad 05 3c       cmp    0x3c05adc0,%eax
> 1c0e3f8c:       73 12                   jae    1c0e3fa0 <alloc_small+0x3c>
> 1c0e3f8e:       01 d8                   add    %ebx,%eax
> 1c0e3f90:       a3 bc ad 05 3c          mov    %eax,0x3c05adbc
> 1c0e3f95:       e8 f2 f6 ff ff          call   1c0e368c <minor_collection>
> 1c0e3f9a:       29 1d bc ad 05 3c       sub    %ebx,0x3c05adbc
> 1c0e3fa0:       8b 15 bc ad 05 3c       mov    0x3c05adbc,%edx
> 1c0e3fa6:       c1 e6 0a                shl    $0xa,%esi
> 1c0e3fa9:       8d 84 3e 00 03 00 00    lea    0x300(%esi,%edi,1),%eax
> 1c0e3fb0:       89 02                   mov    %eax,(%edx)
> 1c0e3fb2:       a1 bc ad 05 3c          mov    0x3c05adbc,%eax
> 1c0e3fb7:       83 c0 04                add    $0x4,%eax
> 1c0e3fba:       5b                      pop    %ebx
> 1c0e3fbb:       5e                      pop    %esi
> 1c0e3fbc:       5f                      pop    %edi
> 1c0e3fbd:       c9                      leave
> 1c0e3fbe:       c3                      ret
> 1c0e3fbf:       90                      nop
>
> (gdb) info registers
> eax            0x7      7
> ecx            0x0      0
> edx            0x4      4
> ebx            0x5      5
> esp            0xcf7fe000       0xcf7fe000
> ebp            0xcf7fe010       0xcf7fe010
> esi            0x3c059460       1006998624
> edi            0x8      8
> eip            0x1c0e3f6b       0x1c0e3f6b
> eflags         0x10292  66194
> cs             0x2b     43
> ss             0x33     51
> ds             0x33     51
> es             0x33     51
> fs             0x33     51
> gs             0x33     51
>
>
> I'll try run the bytecode version with backtrace turned on and see if that
> gets me any further. or not...
>
> pyxis:ttypa# ocamlrun bin/sks.bc help
> Fatal error: unknown C primitive `unix_dup'
>
> I'll see if the cvs code helps any. nope... that cores too and nothing
> interesting in the logs. Not even at debug level 10.
>
> OS: OpenBSD 3.4-current i388
> DB: 4.2.52
> ML: Ocaml 3.07
> CC: "gcc version 2.95.3 20010125 (prerelease, propolice)"
>
> Ideas?
>
> CK
>
> --
> Chris Kuethe, GCIA CISSP: Secure Systems Specialist - U of A CNS
>       office: 157 General Services Bldg.    +1.780.492.8135
>               address@hidden
>
>      GDB has a 'break' feature; why doesn't it have 'fix' too?
>
>
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>


|--------/            Yaron M. Minsky              \--------|
|--------\ http://www.cs.cornell.edu/home/yminsky/ /--------|

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