On 1 September 2012 11:43, Stefan Weil <s...@weilnetz.de> wrote:
> Report from smatch:
> lm4549.c:234 lm4549_write_samples(14) error:
> buffer overflow 's->buffer' 1024 <= 1024
>
> There must be enough space to add two entries starting with index
> s->buffer_level, therefore the old check was wrong.
>
> Signed-off-by: Stefan Weil <s...@weilnetz.de>
> ---
> hw/lm4549.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/lm4549.c b/hw/lm4549.c
> index 80b3ec4..e0137d5 100644
> --- a/hw/lm4549.c
> +++ b/hw/lm4549.c
> @@ -224,7 +224,7 @@ uint32_t lm4549_write_samples(lm4549_state *s, uint32_t
> left, uint32_t right)
> This model supports 16-bit playback.
> */
>
> - if (s->buffer_level >= LM4549_BUFFER_SIZE) {
> + if (s->buffer_level > LM4549_BUFFER_SIZE - 2) {
> DPRINTF("write_sample Buffer full\n");
> return 0;
> }
> --
> 1.7.10
I don't object to making the change to placate the analyser,
but I don't think this is actually a buffer overrun. We always
add and remove samples from the buffer two at a time, so it's
not possible to get here with s->buffer_level == BUFFER_SIZE-1
(which is the only case where the old and new conditions
give different answers).
-- PMM
