On 10/11/2017 01:22 AM, Abbott Liu wrote:
> From: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
>
> This patch initializes KASan shadow region's page table and memory.
> There are two stage for KASan initializing:
> 1. At early boot stage the whole shadow region is mapped to just
> one physical page (kasan_zero_page). It's finished by the function
> kasan_early_init which is called by __mmap_switched(arch/arm/kernel/
> head-common.S)
>
> 2. After the calling of paging_init, we use kasan_zero_page as zero
> shadow for some memory that KASan don't need to track, and we alloc
> new shadow space for the other memory that KASan need to track. These
> issues are finished by the function kasan_init which is call by setup_arch.
>
> Cc: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
> Signed-off-by: Abbott Liu <liuwenliang@xxxxxxxxxx>
> ---
[snip]
\
> @@ -140,6 +149,30 @@ extern void cpu_resume(void);
> pg &= ~0x3fff; \
> (pgd_t *)phys_to_virt(pg); \
> })
> +
> +#define cpu_set_ttbr(nr, val) \
> + do { \
> + u64 ttbr = val; \
> + __asm__("mcr p15, 0, %0, c2, c0, 0" \
> + : : "r" (ttbr)); \
> + } while (0)
nr seems to be unused here?
> +
> +#define cpu_get_ttbr(nr) \
> + ({ \
> + unsigned long ttbr; \
> + __asm__("mrc p15, 0, %0, c2, c0, 0" \
> + : "=r" (ttbr)); \
> + ttbr; \
> + })
> +
> +#define cpu_set_ttbr0(val) \
> + do { \
> + u64 ttbr = val; \
> + __asm__("mcr p15, 0, %0, c2, c0, 0" \
> + : : "r" (ttbr)); \
> + } while (0)
> +
Why is not cpu_set_ttbr0() not using cpu_set_ttbr()?
> +
> #endif
>
> #else /*!CONFIG_MMU */
> diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
> index 1d468b5..52c4858 100644
> --- a/arch/arm/include/asm/thread_info.h
> +++ b/arch/arm/include/asm/thread_info.h
> @@ -16,7 +16,11 @@
> #include <asm/fpstate.h>
> #include <asm/page.h>
>
> +#ifdef CONFIG_KASAN
> +#define THREAD_SIZE_ORDER 2
> +#else
> #define THREAD_SIZE_ORDER 1
> +#endif
> #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
> #define THREAD_START_SP (THREAD_SIZE - 8)
>
> diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
> index 8733012..c17f4a2 100644
> --- a/arch/arm/kernel/head-common.S
> +++ b/arch/arm/kernel/head-common.S
> @@ -101,7 +101,11 @@ __mmap_switched:
> str r2, [r6] @ Save atags pointer
> cmp r7, #0
> strne r0, [r7] @ Save control register values
> +#ifdef CONFIG_KASAN
> + b kasan_early_init
> +#else
> b start_kernel
> +#endif
Please don't make this "exclusive" just conditionally call
kasan_early_init(), remove the call to start_kernel from
kasan_early_init and keep the call to start_kernel here.
> ENDPROC(__mmap_switched)
>
> .align 2
[snip]
> +void __init kasan_early_init(void)
> +{
> + struct proc_info_list *list;
> +
> + /*
> + * locate processor in the list of supported processor
> + * types. The linker builds this table for us from the
> + * entries in arch/arm/mm/proc-*.S
> + */
> + list = lookup_processor_type(read_cpuid_id());
> + if (list) {
> +#ifdef MULTI_CPU
> + processor = *list->proc;
> +#endif
> + }
I could not quite spot in your patch series when do you need this
information?
--
Florian
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