On Sat, Jan 2, 2016 at 11:01 AM, Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx> wrote: > On Sat, Jan 02, 2016 at 10:01:26AM -0500, Jeffrey Walton wrote: >> 0x000000010048d87b <+174>: xor %eax,%eax >> => 0x000000010048d87d <+176>: mov (%r11,%rax,1),%dl >> >> (gdb) info registers >> rax 0x9b7a 0x9b7a > > Why is AX not 0 here? That seems wrong. > It looks like a small issue with GCC 5.2 and -Os. The function that's being called has the signature (http://www.cryptopp.com/docs/ref/misc_8cpp_source.html#l00060): xorbuf(byte* out, const byte* in, const byte* mask, size_t len); When I examine frame 0 at the crash site, it looks like 'in' and 'len' are the same value (but 'len' is only 120 bytes in the frame above). I did not spot it sooner because GDB seems to ignore 'set output-radix 16'. Jeff
