[PULL 22/46] target/arm: Enforce PAN semantics in get_S1prot

[Peter Maydell <peter.maydell@linaro.org>]

From: Richard Henderson <richard.henderson@linaro.org>

If we have a PAN-enforcing mmu_idx, set prot == 0 if user_rw != 0.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200208125816.14954-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/internals.h | 13 +++++++++++++
 target/arm/helper.c    |  3 +++
 2 files changed, 16 insertions(+)

diff --git a/target/arm/internals.h b/target/arm/internals.h
index f6709a2b08d..4a139644b54 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -893,6 +893,19 @@ static inline bool regime_is_secure(CPUARMState *env, ARMMMUIdx mmu_idx)
     }
 }
 
+static inline bool regime_is_pan(CPUARMState *env, ARMMMUIdx mmu_idx)
+{
+    switch (mmu_idx) {
+    case ARMMMUIdx_Stage1_E1_PAN:
+    case ARMMMUIdx_E10_1_PAN:
+    case ARMMMUIdx_E20_2_PAN:
+    case ARMMMUIdx_SE10_1_PAN:
+        return true;
+    default:
+        return false;
+    }
+}
+
 /* Return the FSR value for a debug exception (watchpoint, hardware
  * breakpoint or BKPT insn) targeting the specified exception level.
  */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index f6a600aa004..178757d2719 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -9569,6 +9569,9 @@ static int get_S1prot(CPUARMState *env, ARMMMUIdx mmu_idx, bool is_aa64,
     if (is_user) {
         prot_rw = user_rw;
     } else {
+        if (user_rw && regime_is_pan(env, mmu_idx)) {
+            return 0;
+        }
         prot_rw = simple_ap_to_rw_prot_is_user(ap, false);
     }
 
-- 
2.20.1