Hi,
It looks like a compiler bug to me...
Some users have complained that when the following code is
compiled without the -fno-strict-aliasing, the order of the write and
memcpy is inverted (which mean a bogus len is mem-copied into the
stream).
Code (from linux/include/net/iw_handler.h) :
--------------------------------------------
static inline char *
iwe_stream_add_event(char * stream, /* Stream of events */
char * ends, /* End of stream */
struct iw_event *iwe, /* Payload */
int event_len) /* Real size of payload */
{
/* Check if it's possible */
if((stream + event_len) < ends) {
iwe->len = event_len;
memcpy(stream, (char *) iwe, event_len);
stream += event_len;
}
return stream;
}
--------------------------------------------
IMHO, the compiler should have enough context to know that the
reordering is dangerous. Any suggestion to make this simple code more
bullet proof is welcomed.
Have fun...
Jean
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This archive was generated by hypermail 2b29 : Fri Feb 28 2003 - 22:00:33 EST