An egcs optimizer bug caused incorrect tcp checksum recalculation in libalias
for the rewritten PORT command packet and the server subsequently discard the
packet.
The following piece of C code (from TcpChecksum() in alias_util.c)
u_short *ptr;
int sum, oddbyte;
oddbyte = 0;
*((u_char *) &oddbyte) = *(u_char *) ptr;
sum += oddbyte;
is compiled into (%esi = ptr, %ecx = sum)
0x28067038 <TcpChecksum+80>: movb (%esi),%al
0x2806703a <TcpChecksum+82>: addl %eax,%ecx
egcs should have zeroed %eax before the movb.
libalias compiled without -O works correctly.
-lq
To Unsubscribe: send mail to majord...@freebsd.org
with "unsubscribe freebsd-current" in the body of the message
