Re: [PATCH v2 2/2] cxl-cdat:Fix the check on the return value of fread()

[Philippe Mathieu-Daudé]

On 12/4/23 09:16, Hao Zeng wrote:
> The bug in this code (CID 1507822) is that the
> check on the return value of fread() is wrong. fread()
> returns the number of items read or written, so
> checking for == 0 only catches "no data read at all",
> not "only read half the data".
>
> Signed-off-by: Zeng Hao <zenghao@kylinos.cn>
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   hw/cxl/cxl-cdat.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/cxl/cxl-cdat.c b/hw/cxl/cxl-cdat.c
> index ba7ed1aafd..130531a9cd 100644
> --- a/hw/cxl/cxl-cdat.c
> +++ b/hw/cxl/cxl-cdat.c
> @@ -126,7 +126,7 @@ static void ct3_load_cdat(CDATObject *cdat, Error **errp)
>       fseek(fp, 0, SEEK_SET);
>       cdat->buf = g_malloc0(file_size);

Pointless bzero in g_malloc0, however this code would be
simplified using g_file_get_contents().

>   
> -    if (fread(cdat->buf, file_size, 1, fp) == 0) {
> +    if (fread(cdat->buf, file_size, 1, fp) != file_size) {
>           error_setg(errp, "CDAT: File read failed");
>           fclose(fp);
>           return;