memory alignment problems with -current on amd64? [Found Cause]

[Mark Atkinson]

Joseph Koshy wrote:
>> example, my latest failure:
>> peigen.c: In function '_bfd_pei_only_swap_filehdr_out':
>> peigen.c:2089: internal compiler error: Bus error: 10
>> Please submit a full bug report,
>> with preprocessed source if appropriate.
> 
>> With an deliberately induced bus error, a program will dump core.
> 
> You may need to specify option "-dH" if you want gcc to dump core on
> error.  See: contrib/gcc/diagnostic.[ch].

Very useful tip.  after several tries I was able to get a core.   However, 
I'm not sure how useful it is.   The stack looks like it was blown out (gdb 
shows 1042 frames and complains after that, plus the addresses seem to be 
random garbage.)

I changed CFLAGS to -O0 -dH

cc -O0 -dH -DIN_GCC -DHAVE_CONFIG_H -DPREFIX=\"/usr/obj/usr/src/tmp/usr\" -
I/usr/obj/usr/src/tmp/usr/src/gnu/usr.bin/cc/cc_int/../cc_tools -
I/usr/src/gnu/usr.bin/cc/cc_int/../cc_tools -
I/usr/src/gnu/usr.bin/cc/cc_int/../../../../contrib/gcc -
I/usr/src/gnu/usr.bin/cc/cc_int/../../../../contrib/gcc/config -
I/usr/src/gnu/usr.bin/cc/cc_int/../../../../contrib/gcclibs/include -
I/usr/src/gnu/usr.bin/cc/cc_int/../../../../contrib/gcclibs/libcpp/include -
I/usr/src/gnu/usr.bin/cc/cc_int/../../../../contrib/gcclibs/libdecnumber  -
I/usr/obj/usr/src/tmp/legacy/usr/include -c 
/usr/src/gnu/usr.bin/cc/cc_int/../../../../contrib/gcc/flow.c                                                 
In file included from 
/usr/src/gnu/usr.bin/cc/cc_int/../../../../contrib/gcc/flow.c:133:                                                                                  
/usr/src/gnu/usr.bin/cc/cc_int/../../../../contrib/gcc/flags.h:174: internal 
compiler error: Bus error: 10                                                                
cc: Internal error: Abort trap: 6 (program cc1)                                                                                                                           
Please submit a full bug report.                                                                                                                                          
See <URL:http://gcc.gnu.org/bugs.html> for instructions.                                                                                                                  


(gdb) info registers
rax            0x0      0
rbx            0x7fffffffdb3c   140737488345916
rcx            0x852f5c 8728412                
rdx            0x0      0                      
rsi            0x6      6                      
rdi            0x5a2f   23087                  
rbp            0x7fffffffdbf0   0x7fffffffdbf0 
rsp            0x7fffffffdb28   0x7fffffffdb28 
r8             0xffffff000760f880       -1099387832192
r9             0x7fffffffdb18   140737488345880       
r10            0x1      1
r11            0x206    518
r12            0x7fffffffdc00   140737488346112
r13            0x92b765 9615205
r14            0x8019fe060      34386993248
r15            0x0      0
rip            0x852f3c 0x852f3c
eflags         0x246    582
cs             0x2b     43
ss             0x23     35
ds             0x0      0
es             0x0      0
fs             0x0      0
gs             0x0      0


-- 
Mark Atkinson
atkin901 at yahoo.com
(!wired)?(coffee++):(wired);