Re: [PATCH] target/riscv: Smepmp: Return error when access permission not allowed in PMP

[Weiwei Li]

On 2023/6/5 15:51, Himanshu Chauhan wrote:
On an address match, skip checking for default permissions and return error
based on access defined in PMP configuration.

Fixes: 90b1fafce06 ("target/riscv: Smepmp: Skip applying default rules when address 
matches")
Signed-off-by: Himanshu Chauhan <hchau...@ventanamicro.com>
---
  target/riscv/pmp.c | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index 418738afd8..6238528282 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -435,8 +435,8 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong 
addr,
               * defined with PMP must be used. We shouldn't fallback on
               * finding default privileges.
               */
-            ret = true;
-            break;
+            ret = ((privs & *allowed_privs) == privs ? true : false);
+            goto _address_matched;

goto seems unnecessary. We can directly return (privs & *allowed_privs) 
== privs here.

And then we can directly return pmp_hart_has_privs_default(env, privs, 
allowed_privs, mode) after this loop.

Regards,

Weiwei Li

          }
      }
  
@@ -445,6 +445,7 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr,
          ret = pmp_hart_has_privs_default(env, privs, allowed_privs, mode);

      }
  
+ _address_matched:
      return ret;
  }