On Thursday 19 November 2009 04:09:48 am Kevin Wolf wrote: > >> ... > >> In hw/e1000.c at line 89, vlan is declared to be 4 bytes. At line 382 is > >> an attempt to do a memmove over it with a size of 12. > > > > Obviously this was intentional. Would replacing > > memmove(tp->vlan, tp->data, 12); > > by > > memmove(tp->data - 4, tp->data, 12); > > be better and satisfy the analysis tool?
No. Its likely point out a negative index. > > Or even better (hopefully the compiler will combine both statements) > > memmove(tp->vlan, tp->data, 4); > > memmove(tp->data, tp->data + 4, 8); This would make it happier. But if a comment was made that its intentionally overrunning the vlan array, it would cause less concern. > But I think splitting it into two memmoves is better anyway. There is no > warning in the declaration of the struct that these fields need to be > consecutive, so someone might have the idea of reordering the fields or > inserting a new one in between and things break... Right. Someone might use a cache analysis tool in the future and see that it runs faster with reordered fields... -Steve
