Re: [Qemu-arm] [PATCH 7/7] target/arm: Rename 'type' to 'excret' in do_v7m_exception_exit()

[Philippe Mathieu-Daudé]

On 09/11/2017 10:52 AM, Peter Maydell wrote:
> In the v7M and v8M ARM ARM, the magic exception return values are
> referred to as EXC_RETURN values, and in QEMU we use V7M_EXCRET_*
> constants to define bits within them. Rename the 'type' variable
> which holds the exception return value in do_v7m_exception_exit()
> to excret, making it clearer that it does hold an EXC_RETURN value.
>
> Signed-off-by: Peter Maydell <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>   target/arm/helper.c | 23 ++++++++++++-----------
>   1 file changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index a502e4e..4f41841 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -6212,7 +6212,7 @@ static void v7m_push_stack(ARMCPU *cpu)
>   static void do_v7m_exception_exit(ARMCPU *cpu)
>   {
>       CPUARMState *env = &cpu->env;
> -    uint32_t type;
> +    uint32_t excret;
>       uint32_t xpsr;
>       bool ufault = false;
>       bool return_to_sp_process = false;
> @@ -6233,18 +6233,19 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
>        * the target value up between env->regs[15] and env->thumb in
>        * gen_bx(). Reconstitute it.
>        */
> -    type = env->regs[15];
> +    excret = env->regs[15];
>       if (env->thumb) {
> -        type |= 1;
> +        excret |= 1;
>       }
>   
>       qemu_log_mask(CPU_LOG_INT, "Exception return: magic PC %" PRIx32
>                     " previous exception %d\n",
> -                  type, env->v7m.exception);
> +                  excret, env->v7m.exception);
>   
> -    if ((type & R_V7M_EXCRET_RES1_MASK) != R_V7M_EXCRET_RES1_MASK) {
> +    if ((excret & R_V7M_EXCRET_RES1_MASK) != R_V7M_EXCRET_RES1_MASK) {
>           qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero high bits in exception 
> "
> -                      "exit PC value 0x%" PRIx32 " are UNPREDICTABLE\n", type);
> +                      "exit PC value 0x%" PRIx32 " are UNPREDICTABLE\n",
> +                      excret);
>       }
>   
>       if (env->v7m.exception != ARMV7M_EXCP_NMI) {
> @@ -6255,7 +6256,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
>            * which security state's faultmask to clear. (v8M ARM ARM R_KBNF.)
>            */
>           if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
> -            int es = type & R_V7M_EXCRET_ES_MASK;
> +            int es = excret & R_V7M_EXCRET_ES_MASK;
>               if (armv7m_nvic_raw_execution_priority(env->nvic) >= 0) {
>                   env->v7m.faultmask[es] = 0;
>               }
> @@ -6283,7 +6284,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
>           g_assert_not_reached();
>       }
>   
> -    switch (type & 0xf) {
> +    switch (excret & 0xf) {
>       case 1: /* Return to Handler */
>           return_to_handler = true;
>           break;
> @@ -6306,7 +6307,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
>            */
>           env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
>           armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE);
> -        v7m_exception_taken(cpu, type);
> +        v7m_exception_taken(cpu, excret);
>           qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing "
>                         "stackframe: failed exception return integrity 
> check\n");
>           return;
> @@ -6341,14 +6342,14 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
>   
>       /* The restored xPSR exception field will be zero if we're
>        * resuming in Thread mode. If that doesn't match what the
> -     * exception return type specified then this is a UsageFault.
> +     * exception return excret specified then this is a UsageFault.
>        */
>       if (return_to_handler != arm_v7m_is_handler_mode(env)) {
>           /* Take an INVPC UsageFault by pushing the stack again. */
>           armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE);
>           env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
>           v7m_push_stack(cpu);
> -        v7m_exception_taken(cpu, type);
> +        v7m_exception_taken(cpu, excret);
>           qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on new stackframe: "
>                         "failed exception return integrity check\n");
>           return;