On Wed, Jan 30, 2019 at 2:20 PM Luke Nelson <luke.r.n...@gmail.com> wrote:
>
> pmpcfg_csr_{read,write} do not correctly handle accesses to PMP
> configurations 8 through 15 (CSR pmpcfg2) on RV64.
>
> The current code computes the pmpcfg index using:
>
> (reg_index * sizeof(target_ulong))
>
> This is incorrect on RV64. For example, when reg_index is 2 (i.e.,
> pmpcfg2), the computed configuration index will be 16-23, which
> should be 8-15.
>
> A correct way is to use (reg_index * 4) instead, which works for
> both RV32 and RV64.
>
> Cc: Xi Wang <xi.w...@gmail.com>
> Signed-off-by: Luke Nelson <luke.r.n...@gmail.com>
Good catch!
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Alistair
> ---
> target/riscv/pmp.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
> index 15a5366616..a1bee56c86 100644
> --- a/target/riscv/pmp.c
> +++ b/target/riscv/pmp.c
> @@ -311,9 +311,8 @@ void pmpcfg_csr_write(CPURISCVState *env, uint32_t
> reg_index,
> }
>
> for (i = 0; i < sizeof(target_ulong); i++) {
> - cfg_val = (val >> 8 * i) & 0xff;
> - pmp_write_cfg(env, (reg_index * sizeof(target_ulong)) + i,
> - cfg_val);
> + cfg_val = (val >> (i * 8)) & 0xff;
> + pmp_write_cfg(env, (reg_index * 4) + i, cfg_val);
> }
> }
>
> @@ -328,7 +327,7 @@ target_ulong pmpcfg_csr_read(CPURISCVState *env, uint32_t
> reg_index)
> target_ulong val = 0;
>
> for (i = 0; i < sizeof(target_ulong); i++) {
> - val = pmp_read_cfg(env, (reg_index * sizeof(target_ulong)) + i);
> + val = pmp_read_cfg(env, (reg_index * 4) + i);
> cfg_val |= (val << (i * 8));
> }
>
> --
> 2.19.1
>
>
