On Tue, Nov 24, 2020 at 11:59:40AM -0800, Sami Tolvanen wrote:
> Use scs_alloc() to allocate also IRQ and SDEI shadow stacks instead of
> using statically allocated stacks.
>
> Signed-off-by: Sami Tolvanen <[email protected]>
> ---
> arch/arm64/kernel/Makefile | 1 -
> arch/arm64/kernel/entry.S | 6 ++--
> arch/arm64/kernel/irq.c | 19 ++++++++++
> arch/arm64/kernel/scs.c | 16 ---------
> arch/arm64/kernel/sdei.c | 71 +++++++++++++++++++++++++++++++-------
> include/linux/scs.h | 4 ---
> 6 files changed, 81 insertions(+), 36 deletions(-)
> delete mode 100644 arch/arm64/kernel/scs.c
[...]
> @@ -70,18 +97,40 @@ static int _init_sdei_stack(unsigned long * __percpu
> *ptr, int cpu)
> return 0;
> }
>
> +static int _init_sdei_scs(unsigned long * __percpu *ptr, int cpu)
> +{
> + void *s;
> +
> + s = scs_alloc(cpu_to_node(cpu));
> + if (!s)
> + return -ENOMEM;
> + per_cpu(*ptr, cpu) = s;
> +
> + return 0;
> +}
> +
> static int init_sdei_stacks(void)
> {
> int cpu;
> int err = 0;
>
> for_each_possible_cpu(cpu) {
> - err = _init_sdei_stack(&sdei_stack_normal_ptr, cpu);
> - if (err)
> - break;
> - err = _init_sdei_stack(&sdei_stack_critical_ptr, cpu);
> - if (err)
> - break;
> + if (IS_ENABLED(CONFIG_VMAP_STACK)) {
> + err = _init_sdei_stack(&sdei_stack_normal_ptr, cpu);
> + if (err)
> + break;
> + err = _init_sdei_stack(&sdei_stack_critical_ptr, cpu);
> + if (err)
> + break;
> + }
> + if (IS_ENABLED(CONFIG_SHADOW_CALL_STACK)) {
> + err =
> _init_sdei_scs(&sdei_shadow_call_stack_normal_ptr, cpu);
> + if (err)
> + break;
> + err =
> _init_sdei_scs(&sdei_shadow_call_stack_critical_ptr, cpu);
> + if (err)
> + break;
This looks ok to me, but I think it would be better to follow the same
approach as you have for the IRQ stacks and instead have a separate
init_sdei_scs() function (similarly for the free() path), which means
you can simply the IS_ENABLED() checks too.
Either way:
Acked-by: Will Deacon <[email protected]>
Will
