On Sun, 27 Sep 2020 at 15:00, Alistair Francis <alistair.fran...@wdc.com> wrote:
>
> Reported-by: Eduardo Habkost <ehabk...@redhat.com>
> Signed-off-by: Alistair Francis <alistair.fran...@wdc.com>
> Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> Message-Id:
> <4cf1beb7dafb9143c261d266557d3173bf160524.1598376594.git.alistair.fran...@wdc.com>
> ---
> @@ -269,13 +258,18 @@ static RegisterInfoArray
> *register_init_block(DeviceState *owner,
> int index = rae[i].addr / data_size;
> RegisterInfo *r = &ri[index];
>
> - *r = (RegisterInfo) {
> - .data = data + data_size * index,
> - .data_size = data_size,
> - .access = &rae[i],
> - .opaque = owner,
> - };
> - register_init(r);
> + if (data + data_size * index == 0 || !&rae[i]) {
> + continue;
Coverity thinks (CID 1432800) that this is dead code, because
"data + data_size * index" can never be NULL[*]. What was this
intending to test for ? (maybe data == NULL? Missing dereference
operator ?)
[*] The C spec is quite strict about what valid pointer arithmetic
is; in particular adding to a NULL pointer is undefined behaviour,
and pointer arithmetic that overflows and wraps around is
undefined behaviour, so there's no way to get a 0 result from
"ptr + offset" without the expression being UB.
thanks
-- PMM
