diff mbox series

[qemu,v2,1/3] target/arm: Unify checking for M Main Extension in MRS/MSR

Message ID 167398464577.10345.18365355650640365165-1@git.sr.ht
State New
Headers show
Series ARM: Add support for V8M special registers in GDB stub | expand

Commit Message

~dreiss-meta Jan. 9, 2023, 11:05 p.m. UTC 
From: David Reiss <dreiss@meta.com>

BASEPRI, FAULTMASK, and their _NS equivalents only exist on devices with
the Main Extension.  However, the MRS instruction did not check this,
and the MSR instruction handled it inconsistently (warning BASEPRI, but
silently ignoring writes to BASEPRI_NS).  Unify this behavior and always
warn when reading or writing any of these registers if the extension is
not present.

Signed-off-by: David Reiss <dreiss@meta.com>
---
 target/arm/m_helper.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/target/arm/m_helper.c b/target/arm/m_helper.c
index 033a4d9261..d87b9ecd12 100644
--- a/target/arm/m_helper.c
+++ b/target/arm/m_helper.c
@@ -2465,11 +2465,17 @@  uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
             }
             return env->v7m.primask[M_REG_NS];
         case 0x91: /* BASEPRI_NS */
+            if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+                goto bad_reg;
+            }
             if (!env->v7m.secure) {
                 return 0;
             }
             return env->v7m.basepri[M_REG_NS];
         case 0x93: /* FAULTMASK_NS */
+            if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+                goto bad_reg;
+            }
             if (!env->v7m.secure) {
                 return 0;
             }
@@ -2515,8 +2521,14 @@  uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
         return env->v7m.primask[env->v7m.secure];
     case 17: /* BASEPRI */
     case 18: /* BASEPRI_MAX */
+        if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+            goto bad_reg;
+        }
         return env->v7m.basepri[env->v7m.secure];
     case 19: /* FAULTMASK */
+        if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+            goto bad_reg;
+        }
         return env->v7m.faultmask[env->v7m.secure];
     default:
     bad_reg:
@@ -2581,13 +2593,19 @@  void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val)
             env->v7m.primask[M_REG_NS] = val & 1;
             return;
         case 0x91: /* BASEPRI_NS */
-            if (!env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_MAIN)) {
+            if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+                goto bad_reg;
+            }
+            if (!env->v7m.secure) {
                 return;
             }
             env->v7m.basepri[M_REG_NS] = val & 0xff;
             return;
         case 0x93: /* FAULTMASK_NS */
-            if (!env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_MAIN)) {
+            if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+                goto bad_reg;
+            }
+            if (!env->v7m.secure) {
                 return;
             }
             env->v7m.faultmask[M_REG_NS] = val & 1;