Second Case. Broken librsvg-2.16.1 code that references unaligned data, produced by gcc-4.1.2

gcc-4.2.1-bug.txt (text/plain), 3.19 KB, created by spiritus on 2007-03-03 02:21:14 UTC

 gdb python
GNU gdb 6.6
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This GDB was configured as "i686-pc-linux-gnu"...
(no debugging symbols found)
Using host libthread_db library "/lib/libthread_db.so.1".
(gdb) /usr/games/bin/glchess
Undefined command: "".  Try "help".
(gdb) r /usr/games/bin/glchess
Starting program: /usr/bin/python /usr/games/bin/glchess
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread -1211500880 (LWP 15070)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1211500880 (LWP 15070)]
0xb68ffa57 in ?? () from /usr/lib/librsvg-2.so.2
(gdb) i r
eax            0xbfc934e4       -1077332764
ecx            0x0      0
edx            0x82558e0        136665312
ebx            0xb690a700       -1232034048
esp            0xbfc933c0       0xbfc933c0
ebp            0xbfc933d8       0xbfc933d8
esi            0x0      0
edi            0xbfc934c0       -1077332800
eip            0xb68ffa57       0xb68ffa57 <_fini+1059303>
eflags         0x210246 [ PF ZF IF RF ID ]
cs             0x73     115
ss             0x7b     123
ds             0x7b     123
es             0x7b     123
fs             0x0      0
gs             0x33     51
(gdb) i r $eip
eip            0xb68ffa57       0xb68ffa57 <_fini+1059303>
(gdb) i r eip
eip            0xb68ffa57       0xb68ffa57 <_fini+1059303>
(gdb) x/20i $eip
0xb68ffa57 <_fini+1059303>:     movapd %xmm1,(%eax)
0xb68ffa5b <_fini+1059307>:     add    $0x1,%ecx
0xb68ffa5e <_fini+1059310>:     add    $0x10,%eax
0xb68ffa61 <_fini+1059313>:     add    $0x10,%edx
0xb68ffa64 <_fini+1059316>:     cmp    0xffffffe8(%ebp),%ecx
0xb68ffa67 <_fini+1059319>:     jb     0xb68ffa4e <_fini+1059294>
0xb68ffa69 <_fini+1059321>:     mov    0xfffffff4(%ebp),%eax
0xb68ffa6c <_fini+1059324>:     sub    %eax,0xffffffec(%ebp)
0xb68ffa6f <_fini+1059327>:     add    %eax,%esi
0xb68ffa71 <_fini+1059329>:     cmp    %eax,0xfffffff0(%ebp)
0xb68ffa74 <_fini+1059332>:     je     0xb68ffaa2 <_fini+1059378>
0xb68ffa76 <_fini+1059334>:     lea    0x0(,%esi,8),%eax
0xb68ffa7d <_fini+1059341>:     mov    0xc(%ebp),%ecx
0xb68ffa80 <_fini+1059344>:     lea    (%eax,%ecx,1),%edx
0xb68ffa83 <_fini+1059347>:     mov    0x8(%ebp),%edi
0xb68ffa86 <_fini+1059350>:     lea    0x24(%eax,%edi,1),%eax
0xb68ffa8a <_fini+1059354>:     xor    %ecx,%ecx
0xb68ffa8c <_fini+1059356>:     movsd  (%edx),%xmm0
0xb68ffa90 <_fini+1059360>:     movsd  %xmm0,(%eax)
0xb68ffa94 <_fini+1059364>:     add    $0x1,%ecx
(gdb) i r eax
eax            0xbfc934e4       -1077332764
(gdb) bt
#0  0xb68ffa57 in ?? () from /usr/lib/librsvg-2.so.2
#1  0x00000003 in ?? ()
#2  0x00000006 in ?? ()
#3  0x00000006 in ?? ()
#4  0x00000006 in ?? ()
#5  0x082332e8 in ?? ()
#6  0x0000016c in ?? ()
#7  0xbfc93528 in ?? ()
#8  0xb6904f4e in ?? () from /usr/lib/librsvg-2.so.2
#9  0xbfc934c0 in ?? ()
#10 0x082558e0 in ?? ()
#11 0xc0260000 in ?? ()
#12 0x00000000 in ?? ()
(gdb)