From: David Reiss <dre...@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 <dre...@meta.com> --- target/arm/m_helper.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) 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; -- 2.34.5