Thank you for review, Lianbo.
Kazu, Can you help improve the patch log.
Thanks
Guanyou
lijiang <lijiang(a)redhat.com> 于2023年9月27日周三 19:35写道:
Thank you for the update, Chen.
On Tue, Sep 26, 2023 at 8:44 PM Guanyou Chen <chenguanyou9338(a)gmail.com>
wrote:
> arm64/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
>
>
We can add the kernel commit to patch log as I mentioned here:
https://listman.redhat.com/archives/crash-utility/2023-September/011010.html
570ef363509b ("arm64/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE")
Otherwise, for the patch: Ack.
BTW: maybe Kazu can help improve the patch log when merging(if the patch
is also fine to him).
Thanks
Lianbo
Let's use one of the type bits: core-mm only supports 5, so there is no
> need to consume 6.
>
> Note that we might be able to reuse bit 1, but reusing bit 1 turned out
> problematic in the past for PROT_NONE handling; so let's play safe and use
> another bit.
>
> Link:
https://lkml.kernel.org/r/20220329164329.208407-5-david@redhat.com
>
> Before:
> crash> vtop 70504000
> VIRTUAL PHYSICAL
> 70504000 (not mapped)
>
> PAGE DIRECTORY: ffffff80f265c000
> PGD: ffffff80f265c008 => 800000141537003
> PMD: ffffff8101537c10 => 800000141538003
> PTE: ffffff8101538820 => 12bc3e04
>
> PTE vtop: cannot determine swap location
>
> After:
> crash> vtop 70504000
> VIRTUAL PHYSICAL
> 70504000 (not mapped)
>
> PAGE DIRECTORY: ffffff80f265c000
> PGD: ffffff80f265c008 => 800000141537003
> PMD: ffffff8101537c10 => 800000141538003
> PTE: ffffff8101538820 => 12bc3e04
>
> PTE SWAP OFFSET
> 12bc3e04 /first_stage_ramdisk/dev/block/zram0 1227838
>
> VMA START END FLAGS FILE
> ffffff80dfe7b578 70504000 707bd000 100073
>
> SWAP: /first_stage_ramdisk/dev/block/zram0 OFFSET: 1227838
>
> Signed-off-by: chenguanyou <chenguanyou(a)xiaomi.com>
> ---
> arm64.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/arm64.c b/arm64.c
> index 39d5f04..ea1b51b 100644
> --- a/arm64.c
> +++ b/arm64.c
> @@ -468,8 +468,16 @@ arm64_init(int when)
> }
> }
>
> -
> - if (THIS_KERNEL_VERSION >= LINUX(4,0,0)) {
> + if (THIS_KERNEL_VERSION >= LINUX(5,19,0)) {
> + ms->__SWP_TYPE_BITS = 5;
> + ms->__SWP_TYPE_SHIFT = 3;
> + ms->__SWP_TYPE_MASK = ((1UL << ms->__SWP_TYPE_BITS) - 1);
> + ms->__SWP_OFFSET_SHIFT = (ms->__SWP_TYPE_BITS +
> ms->__SWP_TYPE_SHIFT);
> + ms->__SWP_OFFSET_BITS = 50;
> + ms->__SWP_OFFSET_MASK = ((1UL << ms->__SWP_OFFSET_BITS) -
1);
> + ms->PTE_PROT_NONE = (1UL << 58);
> + ms->PTE_FILE = 0; /* unused */
> + } else if (THIS_KERNEL_VERSION >= LINUX(4,0,0)) {
> ms->__SWP_TYPE_BITS = 6;
> ms->__SWP_TYPE_SHIFT = 2;
> ms->__SWP_TYPE_MASK = ((1UL << ms->__SWP_TYPE_BITS) - 1);
> --
> 2.39.0
>