Re: [PATCH 13/23] hw/usb/hcd-xhci: Avoid dynamic stack allocation

[Richard Henderson]

On 5/5/21 2:10 PM, Philippe Mathieu-Daudé wrote:
> Use autofree heap allocation instead of variable-length
> array on the stack.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>   hw/usb/hcd-xhci.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
> index 7acfb8137bc..59a267e3c8b 100644
> --- a/hw/usb/hcd-xhci.c
> +++ b/hw/usb/hcd-xhci.c
> @@ -2387,7 +2387,7 @@ static void xhci_detach_slot(XHCIState *xhci, USBPort 
> *uport)
>   static TRBCCode xhci_get_port_bandwidth(XHCIState *xhci, uint64_t pctx)
>   {
>       dma_addr_t ctx;
> -    uint8_t bw_ctx[xhci->numports+1];
> +    g_autofree uint8_t *bw_ctx = g_malloc(xhci->numports + 1);


There is a later use of sizeof(bw_ctx), which is now broken.

Also, I think you might as well remove this buffer entirely and use the address 
space memset routine you recently added.


r~