Gary Thomas wrote:
Jose Vasconcellos wrote:
Redboot gets an exception when trying to set any IP address with fconfig
when using gcc-4.3.2 on an ixp425 target (armeb). The issue seems to be
an alignment problem as val_ptr contains an odd address; it looks
like gcc
is optimizing and trying to do a copy on a word boundary. The removal of
the cast fixes the problem.
--- fconfig.c 2009-01-18 14:34:11.000000000 -0500
+++ fconfig.c.new 2009-01-18 14:35:22.000000000 -0500
@@ -388,7 +388,7 @@
break;
#ifdef CYGPKG_REDBOOT_NETWORKING
case CONFIG_IP:
- memcpy(&hold_ip_val.s_addr, &((in_addr_t *)val_ptr)->s_addr,
sizeof(in_addr_t));
+ memcpy(&hold_ip_val.s_addr, val_ptr, sizeof(in_addr_t));
if (!_gethostbyname(line, &new_ip_val)) {
return CONFIG_BAD;
}
Sounds like a *BUG* in the compiler. Have you reported it?
This does more than remove the cast :-) What if the s_addr field is not
at the start of the structure? I know it hasn't moved in 25+ years, but
I don't like tossing correctness [even if only pedantic] away.
Maybe there's another way to solve this. Does it happen on arm[el]?
This doesn't look like a compiler bug to me. I suspect that this problem
affects other arm variants but I only have access to an ixp425. The code
is incorrect as val_ptr is pointing to a place in a configuration buffer for
the raw data. Imposing (via a cast) the structure is not the right solution.
Note that a few lines down in the source, the copy in the other direction
does not have such a cast.
Jose
