On Wed, 26 Jun 2019 at 22:51, Kees Cook <keesc...@chromium.org> wrote:
>
> While jump_label_init() was moved earlier in the boot process in commit
> efd9e03facd0 ("arm64: Use static keys for CPU features"), it wasn't
> early enough for early params to use it. The old state of things was as
> described here...
>
> init/main.c calls out to arch-specific things before general jump
> label and early param handling:
>
> asmlinkage __visible void __init start_kernel(void)
> {
> ...
> setup_arch(&command_line);
> ...
> smp_prepare_boot_cpu();
> ...
> /* parameters may set static keys */
> jump_label_init();
> parse_early_param();
> ...
> }
>
> x86 setup_arch() wants those earlier, so it handles jump label and
> early param:
>
> void __init setup_arch(char **cmdline_p)
> {
> ...
> jump_label_init();
> ...
> parse_early_param();
> ...
> }
>
> arm64 setup_arch() only had early param:
>
> void __init setup_arch(char **cmdline_p)
> {
> ...
> parse_early_param();
> ...
> }
>
> with jump label later in smp_prepare_boot_cpu():
>
> void __init smp_prepare_boot_cpu(void)
> {
> ...
> jump_label_init();
> ...
> }
>
> This moves arm64 jump_label_init() from smp_prepare_boot_cpu() to
> setup_arch(), as done already on x86, in preparation from early param
> usage in the init_on_alloc/free() series:
> https://lkml.kernel.org/r/1561572949.5154.81.ca...@lca.pw
>
> Signed-off-by: Kees Cook <keesc...@chromium.org>
Acked-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
> ---
> arch/arm64/kernel/setup.c | 5 +++++
> arch/arm64/kernel/smp.c | 5 -----
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index 7e541f947b4c..9c4bad7d7131 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -283,6 +283,11 @@ void __init setup_arch(char **cmdline_p)
>
> setup_machine_fdt(__fdt_pointer);
>
> + /*
> + * Initialise the static keys early as they may be enabled by the
> + * cpufeature code and early parameters.
> + */
> + jump_label_init();
> parse_early_param();
>
> /*
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index 6dcf9607d770..20c456b3862c 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -424,11 +424,6 @@ void __init smp_cpus_done(unsigned int max_cpus)
> void __init smp_prepare_boot_cpu(void)
> {
> set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
> - /*
> - * Initialise the static keys early as they may be enabled by the
> - * cpufeature code.
> - */
> - jump_label_init();
> cpuinfo_store_boot_cpu();
>
> /*
> --
> 2.17.1
>
>
> --
> Kees Cook
