Re: Bug#1037264: cksum crashes intermittently with "Illegal instruction" on some Xen DomU

[Axel Beckert]

Hi Kristoffer,

Kristoffer Brånemyr wrote:
> But I think it's a bit suspicious that it only crashes sometimes.If
> there was some instruction which causes this, should it not happen
> everytime?

Good point.

> Can you reproduce the problem running cksum in gdb?

Yes:

# dd if=/dev/urandom count=1 2> /dev/null | gdb -ex run -ex bt -batch cksum
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGILL, Illegal instruction.
0x000055555556ccf5 in cksum_pclmul (fp=0x7ffff7faca80 <_IO_2_1_stdin_>, 
crc_out=0x7fffffffe8d0, length_out=0x7fffffffe8c8) at src/cksum_pclmul.c:59
59      src/cksum_pclmul.c: No such file or directory.
#0  0x000055555556ccf5 in cksum_pclmul (fp=0x7ffff7faca80 <_IO_2_1_stdin_>, 
crc_out=0x7fffffffe8d0, length_out=0x7fffffffe8c8) at src/cksum_pclmul.c:59
#1  0x000055555555abb0 in crc_sum_stream (stream=0x7ffff7faca80 
<_IO_2_1_stdin_>, resstream=0x7fffffffe9f0, length=0x7fffffffe9e8) at 
src/cksum.c:269
#2  0x0000555555557eaa in digest_file (filename=filename@entry=0x55555556d14f 
"-", bin_result=bin_result@entry=0x7fffffffe9f0 '/' <repeats 16 times>, "\377", 
missing=missing@entry=0x7fffffffe9e0, length=length@entry=0x7fffffffe9e8, 
binary=<optimized out>) at src/digest.c:945
#3  0x00005555555571c7 in main (argc=1, argv=<optimized out>) at 
src/digest.c:1504

Does this help?

                Regards, Axel
-- 
 ,''`.  |  Axel Beckert <abe@debian.org>, https://people.debian.org/~abe/
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