ACK: [SRU][N][PATCH 0/1] powerpc/64s/radix/kfence: map __kfence_pool at page granularity (LP: 2060039)

[Kuan-Ying Lee]

On Wed, Aug 28, 2024 at 03:46:43PM -0300, patricia.domingues at canonical.com wrote:
> BugLink: https://bugs.launchpad.net/bugs/2060039
> 
> SRU Justification:
> 
> [Impact]
>  * L1 host hangs when triggering FADump with recommended crash
> 
> [Fix]
>  * 353d7a84c214f184d5a6b62acdec8b4424159b7c 353d7a84c214 "powerpc/64s/radix/kfence: map __kfence_pool at page granularity"
> 
> [Test Case]
>  * Have a Ubuntu Server 24.04 LTS installation on ppc64el.
>  * Enable FADump with 1GB: fadump=on crashkernel=1024M
>  * A kernel panic will happen when dump got triggered
> 
> [Regression Potential]
> * There is a certain risk of a regression, but it is mapping only the memory
>   allocated for KFENCE pool at page granularity, reducing memory consumption
>   when KFENCE is used. 
> 
> * On top the commit is already upstream reviewed and accepted.
> 
> * The modifications were done and tested by IBM.
> 
> * The fadump feature is supported only on IBM POWER systems. 
> 
> [Other]
> * The fix/commit got upstream accepted with kernel v6.11-rc4,
>   hence Oracular (with a planned kernel of 6.11) is not affected.
> 
> Hari Bathini (1):
>   powerpc/64s/radix/kfence: map __kfence_pool at page granularity
> 
>  arch/powerpc/include/asm/kfence.h        | 11 +++-
>  arch/powerpc/mm/book3s64/radix_pgtable.c | 84 ++++++++++++++++++++++--
>  arch/powerpc/mm/init-common.c            |  3 +
>  3 files changed, 93 insertions(+), 5 deletions(-)

Acked-by: Kuan-Ying Lee <kuan-ying.lee at canonical.com>