On Wed, 21 Nov 2018 14:34:44 PST (-0800), Alistair Francis wrote:
> Ensure that the calculate initrd offset points to a valid address for
> the architecture.
>
> Signed-off-by: Alistair Francis <alistair.fran...@wdc.com>
> Suggested-by: Alexander Graf <ag...@suse.de>
> Reported-by: Alexander Graf <ag...@suse.de>
> ---
> hw/riscv/virt.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 2b38f89070..4467195fac 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -85,7 +85,12 @@ static hwaddr load_initrd(const char *filename, uint64_t
> mem_size,
> * halfway into RAM, and for boards with 256MB of RAM or more we put
> * the initrd at 128MB.
> */
> - *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
> + /* As hwaddr is a 64-bit number we need to cast it for 32-bit */
> +#if defined(TARGET_RISCV32)
> + *start = (uint32_t) (kernel_entry + MIN(mem_size / 2, 128ULL * MiB));
> +#elif defined(TARGET_RISCV64)
> + *start = (uint64_t) (kernel_entry + MIN(mem_size / 2, 128 * MiB));
> +#endif
>
> size = load_ramdisk(filename, *start, mem_size - *start);
> if (size == -1) {
> --
> 2.19.1
Maybe I'm missing something, but wouldn't something like
uint64_t start_unclobbered = kernel_entry + MIN(mem_size / 2, 128ULL * MiB);
assert(start_unclobbered == (hwaddr)start_unclobbered);
*start = (hwaddr)start_unclobbered;
work better? That should actually check this all lines up, as opposed to just
silently truncating a bad address.
