Re: Bug#812928: udev: cdrom_id terminated by signal BUS
On Wed, Jan 27, 2016 at 5:23 PM, Ben Hutchings <ben@decadent.org.uk> wrote:
> Control: tag -1 moreinfo
>
> On Wed, 2016-01-27 at 23:54 +0100, Marco d'Itri wrote:
>> Control: reassign -1 src:linux
>> Control: found -1 4.3.0-1
>> Control: retitle -1 getauxval(AT_RANDOM) broken on sparc64
>>
>> On Jan 27, Anatoly Pugachev <matorola@gmail.com> wrote:
>>
>> > Program terminated with signal SIGUSR1, User defined signal 1.
>> > #0 0x000001000001b9b8 in initialize_srand () at src/basic/random-
>> > util.c:107
>> > 107 x ^= *(unsigned*) auxv;
>> > (gdb) bt
>> Looks like getauxval(AT_RANDOM) returns garbage on sparc64:
>>
>> x = 0;
>> auxv = (void*) getauxval(AT_RANDOM);
>> if (auxv)
>> x ^= *(unsigned*) auxv;
>
> There is no documented alignment guarantee for the AT_RANDOM bytes so I
> think this caller is wrong to treat it as an array of unsigned int.
Also, you can verify that from a debugger without changing the code,
by printing the value of the pointer `auxv` and check if either of the
lower two bits are set.
> What happens if you change it to:
>
> if (auxv)
> memcpy(&x, auxv, sizeof(x));
>
> ?
>
> Ben.
>
> --
> Ben Hutchings
> 73.46% of all statistics are made up.
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