Re: [PATCH] rust/pl011: Fix range checks for device ID accesses

["Alex Bennée" <alex.bennee@linaro.org>]

Junjie Mao <junjie.mao@hotmail.com> writes:

> The peripheral and PrimeCell identification registers of pl011 are located at
> offset 0xFE0 - 0xFFC. To check if a read falls to such registers, the C
> implementation checks if the offset-shifted-by-2 (not the offset itself) is in
> the range 0x3F8 - 0x3FF.
>
> Use the same check in the Rust implementation.
>
> This fixes the timeout of the following avocado tests:
>
>   * tests/avocado/boot_linux_console.py:BootLinuxConsole.test_arm_virt
>   * tests/avocado/replay_kernel.py:ReplayKernelNormal.test_arm_virt
>   * tests/avocado/replay_kernel.py:ReplayKernelNormal.test_arm_vexpressa9
>
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Junjie Mao <junjie.mao@hotmail.com>

This certainly fixes the avocado failures.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  rust/hw/char/pl011/src/device.rs | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs
> index 2a85960b81..476cacc844 100644
> --- a/rust/hw/char/pl011/src/device.rs
> +++ b/rust/hw/char/pl011/src/device.rs
> @@ -182,7 +182,7 @@ pub fn read(&mut self, offset: hwaddr, _size: c_uint) -> std::ops::ControlFlow<u
>          use RegisterOffset::*;
>  
>          std::ops::ControlFlow::Break(match RegisterOffset::try_from(offset) {
> -            Err(v) if (0x3f8..0x400).contains(&v) => {
> +            Err(v) if (0x3f8..0x400).contains(&(v >> 2)) => {
>                  u64::from(self.device_id[(offset - 0xfe0) >> 2])
>              }
>              Err(_) => {

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro