From d102f19a2085ac931cb998e6153b73248cca49f1 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Wed, 23 Dec 2020 11:25:53 -0800 Subject: [PATCH] target/riscv/pmp: Raise exception if no PMP entry is configured As per the privilege specification, any access from S/U mode should fail if no pmp region is configured. Signed-off-by: Atish Patra Reviewed-by: Alistair Francis Message-id: 20201223192553.332508-1-atish.patra@wdc.com Signed-off-by: Alistair Francis --- target/riscv/op_helper.c | 5 +++++ target/riscv/pmp.c | 4 ++-- target/riscv/pmp.h | 1 + 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c index d55def76cf..1eddcb94de 100644 --- a/target/riscv/op_helper.c +++ b/target/riscv/op_helper.c @@ -150,6 +150,11 @@ target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb) uint64_t mstatus = env->mstatus; target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP); + + if (!pmp_get_num_rules(env) && (prev_priv != PRV_M)) { + riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC()); + } + target_ulong prev_virt = get_field(env->mstatus, MSTATUS_MPV); mstatus = set_field(mstatus, MSTATUS_MIE, get_field(mstatus, MSTATUS_MPIE)); diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c index 2eda8e1e2f..80d0334e1b 100644 --- a/target/riscv/pmp.c +++ b/target/riscv/pmp.c @@ -74,7 +74,7 @@ static inline int pmp_is_locked(CPURISCVState *env, uint32_t pmp_index) /* * Count the number of active rules. */ -static inline uint32_t pmp_get_num_rules(CPURISCVState *env) +uint32_t pmp_get_num_rules(CPURISCVState *env) { return env->pmp_state.num_rules; } @@ -237,7 +237,7 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr, /* Short cut if no rules */ if (0 == pmp_get_num_rules(env)) { - return true; + return (env->priv == PRV_M) ? true : false; } if (size == 0) { diff --git a/target/riscv/pmp.h b/target/riscv/pmp.h index 6c6b4c9bef..c8d5ef4a69 100644 --- a/target/riscv/pmp.h +++ b/target/riscv/pmp.h @@ -64,5 +64,6 @@ bool pmp_is_range_in_tlb(CPURISCVState *env, hwaddr tlb_sa, target_ulong *tlb_size); void pmp_update_rule_addr(CPURISCVState *env, uint32_t pmp_index); void pmp_update_rule_nums(CPURISCVState *env); +uint32_t pmp_get_num_rules(CPURISCVState *env); #endif