[Crash-utility] [PATCH 1/2] crash-utility/arm64: rename ARM64_PAGE_OFFSET_ACTUAL as ARM64_FLIP_PAGE_OFFSET_ACTUAL

[Bhupesh Sharma]

Hi Pingfan,

On Thu, 25 Mar 2021 at 08:37, Pingfan Liu <piliu at redhat.com> wrote:
>
> Renaming, so it is better to reflect the flip layout of kernel VA, which
> is introduced by kernel commit 14c127c957c1 ("arm64: mm: Flip kernel VA space")
>
> Signed-off-by: Pingfan Liu <piliu at redhat.com>
> Cc: HAGIO KAZUHITO <k-hagio-ab at nec.com>
> Cc: Lianbo Jiang <lijiang at redhat.com>
> Cc: Mark Salter <msalter at redhat.com>
> Cc: Mark Langsdorf <mlangsdo at redhat.com>
> Cc: Jeremy Linton <jlinton at redhat.com>
> To: crash-utility at redhat.com
> ---
>  arm64.c | 8 ++++----
>  defs.h  | 3 ++-
>  2 files changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/arm64.c b/arm64.c
> index a0bee62..132a39d 100644
> --- a/arm64.c
> +++ b/arm64.c
> @@ -221,9 +221,9 @@ arm64_init(int when)
>                 arm64_calc_KERNELPACMASK();
>                 ms = machdep->machspec;
>                 if (ms->VA_BITS_ACTUAL) {
> -                       ms->page_offset = ARM64_PAGE_OFFSET_ACTUAL;
> -                       machdep->identity_map_base = ARM64_PAGE_OFFSET_ACTUAL;
> -                       machdep->kvbase = ARM64_PAGE_OFFSET_ACTUAL;
> +                       ms->page_offset = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
> +                       machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
> +                       machdep->kvbase = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
>                         ms->userspace_top = ARM64_USERSPACE_TOP_ACTUAL;
>                 } else {
>                         ms->page_offset = ARM64_PAGE_OFFSET;
> @@ -404,7 +404,7 @@ arm64_init(int when)
>                                 fprintf(fp, "CONFIG_ARM64_VA_BITS: %ld\n", ms->CONFIG_ARM64_VA_BITS);
>                                 fprintf(fp, "      VA_BITS_ACTUAL: %ld\n", ms->VA_BITS_ACTUAL);
>                                 fprintf(fp, "(calculated) VA_BITS: %ld\n", ms->VA_BITS);
> -                               fprintf(fp, " PAGE_OFFSET: %lx\n", ARM64_PAGE_OFFSET_ACTUAL);
> +                               fprintf(fp, " PAGE_OFFSET: %lx\n", ARM64_FLIP_PAGE_OFFSET_ACTUAL);
>                                 fprintf(fp, "    VA_START: %lx\n", ms->VA_START);
>                                 fprintf(fp, "     modules: %lx - %lx\n", ms->modules_vaddr, ms->modules_end);
>                                 fprintf(fp, "     vmalloc: %lx - %lx\n", ms->vmalloc_start_addr, ms->vmalloc_end);
> diff --git a/defs.h b/defs.h
> index 64f2bcb..d8e0f30 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -3219,7 +3219,8 @@ typedef signed int s32;
>
>  #define ARM64_PAGE_OFFSET    ((0xffffffffffffffffUL) \
>                                         << (machdep->machspec->VA_BITS - 1))
> -#define ARM64_PAGE_OFFSET_ACTUAL ((0xffffffffffffffffUL) \
> +/* after kernel commit 14c127c957c1 ("arm64: mm: Flip kernel VA space") */

Normally, we use kernel versions instead of the kernel commit in
comments. So something like, for kernels > v5.4 the kernel VA space is
flipped.

> +#define ARM64_FLIP_PAGE_OFFSET_ACTUAL ((0xffffffffffffffffUL) \
>                                         - ((1UL) << machdep->machspec->VA_BITS_ACTUAL) + 1)

Thanks,
Bhupesh

>  #define ARM64_USERSPACE_TOP  ((1UL) << machdep->machspec->VA_BITS)
> --
> 2.29.2
>
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