On Sun, Aug 25, 2013 at 09:18:42PM +0200, Florian Weimer wrote:
> On 08/25/2013 12:47 PM, Kurt Roeckx wrote:
> 
> >-      *dst = ((GElf_auxv_t *) data_scn->d.d_buf)[ndx];
> >+      memcpy(dst, &((GElf_auxv_t *) data_scn->d.d_buf)[ndx], sizeof(*dst));
> 
> That's not correct, the cast is already undefined if the pointer
> lacks sufficient alignment.  GCC might even translate the latter
> into the former.

You're of course right that that case is undefined behavior.

> memcpy(dst, data_scn->d.d_buf + ndx * sizeof(GElf_auxv_t),
> sizeof(GElf_axuv_t));

d_buf is a void *, and I don't think that has defined behavior either.  It
should probably be:
memcpy(dst, (char *)data_scn->d.d_buf + ndx * sizeof(GElf_auxv_t), 
sizeof(GElf_axuv_t));


Kurt

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