diff options
| -rw-r--r-- | target-arm/helper.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/target-arm/helper.c b/target-arm/helper.c index ff5f8955a1..24ea48ecdc 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -5200,12 +5200,20 @@ void arm_cp_reset_ignore(CPUARMState *env, const ARMCPRegInfo *opaque) /* Helper coprocessor reset function for do-nothing-on-reset registers */ } -static int bad_mode_switch(CPUARMState *env, int mode) +static int bad_mode_switch(CPUARMState *env, int mode, CPSRWriteType write_type) { /* Return true if it is not valid for us to switch to * this CPU mode (ie all the UNPREDICTABLE cases in * the ARM ARM CPSRWriteByInstr pseudocode). */ + + /* Changes to or from Hyp via MSR and CPS are illegal. */ + if (write_type == CPSRWriteByInstr && + ((env->uncached_cpsr & CPSR_M) == ARM_CPU_MODE_HYP || + mode == ARM_CPU_MODE_HYP)) { + return 1; + } + switch (mode) { case ARM_CPU_MODE_USR: case ARM_CPU_MODE_SYS: @@ -5324,7 +5332,7 @@ void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask, if (write_type != CPSRWriteRaw && (env->uncached_cpsr & CPSR_M) != CPSR_USER && ((env->uncached_cpsr ^ val) & mask & CPSR_M)) { - if (bad_mode_switch(env, val & CPSR_M)) { + if (bad_mode_switch(env, val & CPSR_M, write_type)) { /* Attempt to switch to an invalid mode: this is UNPREDICTABLE in * v7, and has defined behaviour in v8: * + leave CPSR.M untouched |