On Sun, 10 May 2015, Dan Carpenter wrote:
> I don't really have a strong opinion either way... It's unlikely that
> we will introduce a bug here and if we did, I think it would be caught
> immediately in testing.
>
> It's pretty common to treat the first member of a struct as special.
> What annoys me is when people do
>
> struct foo {
> int one, two, three;
> whatever;
> };
>
> memcpy(&foo.one, src, sizoef(struct foo));
>
> Argh!? These triger buffer overflows warnings in Smatch and I don't
> see the point since &foo.one is less readable than &foo! Oh well, I
> think these were common enough, I had to treat it as idiomatic and add a
> special case for them.
>
just ran a naive scanner for that pattern but only could find this one instance
./net/sctp/sm_make_chunk.c:3103 ugly memset
3102 if (af->is_any(&addr))
3103 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
my scanner ist:
@uses_first@
identifier f;
idexpression s;
identifier e;
position p;
@@
f(...){
<+...
* memcpy@p(&s.e,...,sizeof(s));
...+>
}
@script:python@
p << uses_first.p;
@@
print "%s:%s ugly memset" % (p[0].file,p[0].line)
so is my scanner broken/incomplete or has this pattern lost its popularity ?
thx!
hofrat
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