Re: [Qemu-devel] [RFC v1 2/3] target-microblaze: Allow the stack protection to be disabled

[Peter Crosthwaite]

On Wed, May 13, 2015 at 11:08 PM, Alistair Francis
<address@hidden> wrote:
> Microblaze stack protection is configurable and isn't always enabled.
> This patch allows the stack protection to be disabled from the CPU
> properties.
>
> Signed-off-by: Alistair Francis <address@hidden>
> ---
>
>  target-microblaze/cpu-qom.h   |    5 +++++
>  target-microblaze/cpu.c       |    2 ++
>  target-microblaze/op_helper.c |    4 +++-
>  3 files changed, 10 insertions(+), 1 deletions(-)
>
> diff --git a/target-microblaze/cpu-qom.h b/target-microblaze/cpu-qom.h
> index e3e0701..7bc5b81 100644
> --- a/target-microblaze/cpu-qom.h
> +++ b/target-microblaze/cpu-qom.h
> @@ -59,6 +59,11 @@ typedef struct MicroBlazeCPU {
>      uint32_t base_vectors;
>      /*< public >*/
>
> +    /* Microblaze Configuration Settings */
> +    struct {
> +        bool stackproc;
> +    } cfg;
> +
>      CPUMBState env;
>  } MicroBlazeCPU;
>
> diff --git a/target-microblaze/cpu.c b/target-microblaze/cpu.c
> index 67e3182..c08da19 100644
> --- a/target-microblaze/cpu.c
> +++ b/target-microblaze/cpu.c
> @@ -152,6 +152,8 @@ static const VMStateDescription vmstate_mb_cpu = {
>
>  static Property mb_properties[] = {
>      DEFINE_PROP_UINT32("xlnx.base-vectors", MicroBlazeCPU, base_vectors, 0),
> +    DEFINE_PROP_BOOL("xlnx.use-stack-protection", MicroBlazeCPU, 
> cfg.stackproc,
> +                     true),

This should deposit (at realize time) into pvr[0].SPROT bit.

Regards,
Peter

>      DEFINE_PROP_END_OF_LIST(),
>  };
>
> diff --git a/target-microblaze/op_helper.c b/target-microblaze/op_helper.c
> index d2b3624..24df538 100644
> --- a/target-microblaze/op_helper.c
> +++ b/target-microblaze/op_helper.c
> @@ -467,7 +467,9 @@ void helper_memalign(CPUMBState *env, uint32_t addr, 
> uint32_t dr, uint32_t wr,
>
>  void helper_stackprot(CPUMBState *env, uint32_t addr)
>  {
> -    if (addr < env->slr || addr > env->shr) {
> +    MicroBlazeCPU *cpu = mb_env_get_cpu(env);
> +
> +    if (cpu->cfg.stackproc && (addr < env->slr || addr > env->shr)) {
>          qemu_log("Stack protector violation at %x %x %x\n",
>                   addr, env->slr, env->shr);
>          env->sregs[SR_EAR] = addr;
> --
> 1.7.1
>
>