[PATCH 3/3] RISC-V: KVM: Use correct restricted types

[Atish Patra]

On Wed, Jan 31, 2024 at 4:05 AM Andrew Jones <ajones at ventanamicro.com> wrote:
>
> __le32 and __le64 types should be used with le32_to_cpu() and
> le64_to_cpu() and __user is needed for pointers referencing
> guest memory, as sparse helpfully points out.
>
> Fixes: e9f12b5fff8a ("RISC-V: KVM: Implement SBI STA extension")
> Reported-by: kernel test robot <lkp at intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202401020142.lwFEDK5v-lkp@intel.com/
> Signed-off-by: Andrew Jones <ajones at ventanamicro.com>
> ---
>  arch/riscv/kvm/vcpu_sbi_sta.c | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/arch/riscv/kvm/vcpu_sbi_sta.c b/arch/riscv/kvm/vcpu_sbi_sta.c
> index 01f09fe8c3b0..d8cf9ca28c61 100644
> --- a/arch/riscv/kvm/vcpu_sbi_sta.c
> +++ b/arch/riscv/kvm/vcpu_sbi_sta.c
> @@ -26,8 +26,12 @@ void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu)
>  {
>         gpa_t shmem = vcpu->arch.sta.shmem;
>         u64 last_steal = vcpu->arch.sta.last_steal;
> -       u32 *sequence_ptr, sequence;
> -       u64 *steal_ptr, steal;
> +       __le32 __user *sequence_ptr;
> +       __le64 __user *steal_ptr;
> +       __le32 sequence_le;
> +       __le64 steal_le;
> +       u32 sequence;
> +       u64 steal;
>         unsigned long hva;
>         gfn_t gfn;
>
> @@ -47,22 +51,22 @@ void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu)
>                 return;
>         }
>
> -       sequence_ptr = (u32 *)(hva + offset_in_page(shmem) +
> +       sequence_ptr = (__le32 __user *)(hva + offset_in_page(shmem) +
>                                offsetof(struct sbi_sta_struct, sequence));
> -       steal_ptr = (u64 *)(hva + offset_in_page(shmem) +
> +       steal_ptr = (__le64 __user *)(hva + offset_in_page(shmem) +
>                             offsetof(struct sbi_sta_struct, steal));
>
> -       if (WARN_ON(get_user(sequence, sequence_ptr)))
> +       if (WARN_ON(get_user(sequence_le, sequence_ptr)))
>                 return;
>
> -       sequence = le32_to_cpu(sequence);
> +       sequence = le32_to_cpu(sequence_le);
>         sequence += 1;
>
>         if (WARN_ON(put_user(cpu_to_le32(sequence), sequence_ptr)))
>                 return;
>
> -       if (!WARN_ON(get_user(steal, steal_ptr))) {
> -               steal = le64_to_cpu(steal);
> +       if (!WARN_ON(get_user(steal_le, steal_ptr))) {
> +               steal = le64_to_cpu(steal_le);
>                 vcpu->arch.sta.last_steal = READ_ONCE(current->sched_info.run_delay);
>                 steal += vcpu->arch.sta.last_steal - last_steal;
>                 WARN_ON(put_user(cpu_to_le64(steal), steal_ptr));
> --
> 2.43.0
>

Reviewed-by: Atish Patra <atishp at rivosinc.com>

-- 
Regards,
Atish