target/riscv: Smepmp: Return error when access permission not allowed…

… in PMP

On an address match, skip checking for default permissions and return error
based on access defined in PMP configuration.

v3 Changes:
o Removed explicit return of boolean value from comparision
  of priv/allowed_priv

v2 Changes:
o Removed goto to return in place when address matches
o Call pmp_hart_has_privs_default at the end of the loop

Fixes: 90b1faf ("target/riscv: Smepmp: Skip applying default rules when address matches")
Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-Id: <20230605164548.715336-1-hchauhan@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/pmp.c

@@ -291,7 +291,6 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr,
                         pmp_priv_t *allowed_privs, target_ulong mode)
 {
     int i = 0;
-    bool ret = false;
     int pmp_size = 0;
     target_ulong s = 0;
     target_ulong e = 0;
@@ -435,17 +434,12 @@ 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;
+            return (privs & *allowed_privs) == privs;
         }
     }
 
     /* No rule matched */
-    if (!ret) {
-        ret = pmp_hart_has_privs_default(env, privs, allowed_privs, mode);
-    }
-
-    return ret;
+    return pmp_hart_has_privs_default(env, privs, allowed_privs, mode);
 }
 
 /*