Re: [Qemu-devel] [PATCH] scsi-disk: assert positive value to avoid compiler warning

[John Snow]

On 5/1/19 1:01 PM, Bruce Rogers wrote:
> While investigating link-time-optimization, the compiler complained as
> follows:
> In function ‘scsi_disk_new_request_dump’,
>     inlined from ‘scsi_new_request.part.24’ at hw/scsi/scsi-disk.c:2549:9,
>     inlined from ‘scsi_new_request’ at hw/scsi/scsi-disk.c:2533:21:
> hw/scsi/scsi-disk.c:2523:19: error: argument 1 value ‘18446744073709551612’ 
> exceeds maximum object size 9223372036854775807 
> [-Werror=alloc-size-larger-than=]
> hw/scsi/scsi-disk.c: In function ‘scsi_new_request’:
> /usr/include/glib-2.0/glib/gmem.h:78:10: note: in a call to allocation 
> function ‘g_malloc’ declared here
>  gpointer g_malloc         (gsize  n_bytes) G_GNUC_MALLOC 
> G_GNUC_ALLOC_SIZE(1);
> 
> Asserting that len is positive avoids this diagnostic. This assert is
> reasonable since the error case of scsi_cdb_length() has already been
> handled by a previous call to that function.
> 
> Signed-off-by: Bruce Rogers <address@hidden>
> ---
>  hw/scsi/scsi-disk.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> index e7e865ab3b..ac180fdddf 100644
> --- a/hw/scsi/scsi-disk.c
> +++ b/hw/scsi/scsi-disk.c
> @@ -2520,6 +2520,7 @@ static void scsi_disk_new_request_dump(uint32_t lun, 
> uint32_t tag, uint8_t *buf)
>      int len = scsi_cdb_length(buf);
>      char *line_buffer, *p;
>  
> +    assert(len > 0);
>      line_buffer = g_malloc(len * 5 + 1);
>  
>      for (i = 0, p = line_buffer; i < len; i++) {
> 

Reviewed-by: John Snow <address@hidden>