Re: [PATCH] xen/arm: optee: Fix arm_smccc_smc's a0 for OPTEE_SMC_DISABLE_SHM_CACHE

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Mon, 27 Sep 2021, Oleksandr Tyshchenko wrote:
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> 
> Fix a possible copy-paste error in arm_smccc_smc's first argument (a0)
> for OPTEE_SMC_DISABLE_SHM_CACHE case.
> 
> This error causes Linux > v5.14-rc5 (b5c10dd04b7418793517e3286cde5c04759a86de
> optee: Clear stale cache entries during initialization) to stuck
> repeatedly issuing OPTEE_SMC_DISABLE_SHM_CACHE call and waiting for
> the result to be OPTEE_SMC_RETURN_ENOTAVAIL which will never happen.
> 
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>

I added Fixes: and Backport: tags to the commit


> ---
> I wonder whether this patch wants backporting to the old versions
> since OPTEE support went in.
> ---
>  xen/arch/arm/tee/optee.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/xen/arch/arm/tee/optee.c b/xen/arch/arm/tee/optee.c
> index 3453615..6df0d44 100644
> --- a/xen/arch/arm/tee/optee.c
> +++ b/xen/arch/arm/tee/optee.c
> @@ -1692,7 +1692,7 @@ static bool optee_handle_call(struct cpu_user_regs 
> *regs)
>          return true;
>  
>      case OPTEE_SMC_DISABLE_SHM_CACHE:
> -        arm_smccc_smc(OPTEE_SMC_ENABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0,
> +        arm_smccc_smc(OPTEE_SMC_DISABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0,
>                        OPTEE_CLIENT_ID(current->domain), &resp);
>          set_user_reg(regs, 0, resp.a0);
>          if ( resp.a0 == OPTEE_SMC_RETURN_OK ) {
> -- 
> 2.7.4
>