Re: [PATCH] target/riscv: Add User CSRs read-only check

[Bin Meng]

On Mon, Aug 9, 2021 at 5:45 PM LIU Zhiwei <zhiwei_liu@c-sky.com> wrote:
>
>
> On 2021/8/9 下午5:35, Bin Meng wrote:
> > On Mon, Aug 9, 2021 at 3:09 PM LIU Zhiwei <zhiwei_liu@c-sky.com> wrote:
> > nits: please write something in the commit message
> OK
> >
> >> Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
> >> ---
> >>   target/riscv/csr.c | 6 +++++-
> >>   1 file changed, 5 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> >> index 9a4ed18ac5..ea62d9e653 100644
> >> --- a/target/riscv/csr.c
> >> +++ b/target/riscv/csr.c
> >> @@ -1422,11 +1422,11 @@ RISCVException riscv_csrrw(CPURISCVState *env, int 
> >> csrno,
> >>       RISCVException ret;
> >>       target_ulong old_value;
> >>       RISCVCPU *cpu = env_archcpu(env);
> >> +    int read_only = get_field(csrno, 0xC00) == 3;
> >>
> >>       /* check privileges and return -1 if check fails */
> >>   #if !defined(CONFIG_USER_ONLY)
> >>       int effective_priv = env->priv;
> >> -    int read_only = get_field(csrno, 0xC00) == 3;
> >>
> >>       if (riscv_has_ext(env, RVH) &&
> >>           env->priv == PRV_S &&
> >> @@ -1443,6 +1443,10 @@ RISCVException riscv_csrrw(CPURISCVState *env, int 
> >> csrno,
> >>           (!env->debugger && (effective_priv < get_field(csrno, 0x300)))) {
> >>           return RISCV_EXCP_ILLEGAL_INST;
> >>       }
> >> +#else
> >> +    if (write_mask && read_only) {
> > This can be merged by the !CONFIG_USER_ONLY case.
>
> Do you mean
>
> #if !defined(CONFIG_USER_ONLY)
>       if (!env->debugger && (effective_priv < get_field(csrno, 0x300))) {
>           return -RISCV_EXCP_ILLEGAL_INST;
> }
> #else

Should be #endif

>       if (write_mask && read_only) {
>           return -RISCV_EXCP_ILLEGAL_INST;
> }
>
> #endif

and drop this #endif

Regards,
Bin