Hi Marc,
On Fri, May 26, 2023 at 03:33:33PM +0100, Marc Zyngier wrote:
> Using is_kernel_in_hyp_mode() in hypervisor code is a pretty bad
> mistake. This helper only checks for CurrentEL being EL2, which
> is always true.
>
> Make the link fail if using the helper in hypervisor context
> by referencing a non-existent function. Whilst we're at it,
> flag the helper as __always_inline, which it really should be.
>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/virt.h | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
> index 4eb601e7de50..91029709d133 100644
> --- a/arch/arm64/include/asm/virt.h
> +++ b/arch/arm64/include/asm/virt.h
> @@ -110,8 +110,13 @@ static inline bool is_hyp_mode_mismatched(void)
> return __boot_cpu_mode[0] != __boot_cpu_mode[1];
> }
>
> -static inline bool is_kernel_in_hyp_mode(void)
> +extern void gotcha_is_kernel_in_hyp_mode(void);
> +
> +static __always_inline bool is_kernel_in_hyp_mode(void)
> {
> +#if defined(__KVM_NVHE_HYPERVISOR__) || defined(__KVM_VHE_HYPERVISOR__)
> + gotcha_is_kernel_in_hyp_mode();
> +#endif
> return read_sysreg(CurrentEL) == CurrentEL_EL2;
> }
Would BUILD_BUG() work in this context, or have I missed something?
--
Thanks,
Oliver
