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Date:   Wed, 5 Jul 2023 19:15:48 +0200
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Subject: Re: [PATCH v3 2/2] mm: disable CONFIG_PER_VMA_LOCK until its fixed
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To:     Suren Baghdasaryan <surenb@google.com>, akpm@linux-foundation.org
Cc:     jirislaby@kernel.org, jacobly.alt@gmail.com,
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References: <20230705171213.2843068-1-surenb@google.com>
 <20230705171213.2843068-3-surenb@google.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20230705171213.2843068-3-surenb@google.com>
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On 05.07.23 19:12, Suren Baghdasaryan wrote:
> A memory corruption was reported in [1] with bisection pointing to the
> patch [2] enabling per-VMA locks for x86.
> Disable per-VMA locks config to prevent this issue while the problem is
> being investigated. This is expected to be a temporary measure.
> 
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=217624
> [2] https://lore.kernel.org/all/20230227173632.3292573-30-surenb@google.com
> 
> Reported-by: Jiri Slaby <jirislaby@kernel.org>
> Closes: https://lore.kernel.org/all/dbdef34c-3a07-5951-e1ae-e9c6e3cdf51b@kernel.org/
> Reported-by: Jacob Young <jacobly.alt@gmail.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217624
> Fixes: 0bff0aaea03e ("x86/mm: try VMA lock-based page fault handling first")
> Cc: stable@vger.kernel.org
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> ---
>   mm/Kconfig | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 09130434e30d..0abc6c71dd89 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -1224,8 +1224,9 @@ config ARCH_SUPPORTS_PER_VMA_LOCK
>          def_bool n
>   
>   config PER_VMA_LOCK
> -	def_bool y
> +	bool "Enable per-vma locking during page fault handling."
>   	depends on ARCH_SUPPORTS_PER_VMA_LOCK && MMU && SMP
> +	depends on BROKEN
>   	help
>   	  Allow per-vma locking during page fault handling.
>   
Do we have any testing results (that don't reveal other issues :) ) for 
patch #1? Not sure if we really want to mark it broken if patch #1 fixes 
the issue.

-- 
Cheers,

David / dhildenb