From: Atish Patra <atish.patra@linux.dev>
To: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
David CARLIER <devnexen@gmail.com>,
David Hildenbrand <david@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Jason Gunthorpe <jgg@ziepe.ca>,
Jiri Slaby <jirislaby@kernel.org>,
Juergen Gross <jgross@suse.com>,
Kevin Tian <kevin.tian@intel.com>,
Kiryl Shutsemau <kas@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Nikunj A Dadhania <nikunj@amd.com>,
Pedro Falcato <pfalcato@suse.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Shakeel Butt <shakeel.butt@linux.dev>,
Steffen Dirkwinkel <lists@steffen.cc>,
Suren Baghdasaryan <surenb@google.com>,
Thomas Gleixner <tglx@kernel.org>,
Toshi Kani <toshi.kani@hpe.com>,
Vishal Moola <vishal.moola@gmail.com>,
Vlastimil Babka <vbabka@kernel.org>,
Will Deacon <will@kernel.org>,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, stable@vger.kernel.org,
syzbot@syzkaller.appspotmail.com, x86@kernel.org
Subject: Re: [PATCH v2 0/5] x86/mm/pat: CPA fixes
Date: Tue, 25 Aug 2026 13:05:37 -0700 [thread overview]
Message-ID: <ddb64a7a-70b2-4c3d-8b80-2c7bcd7f329d@linux.dev> (raw)
In-Reply-To: <ao1EtJG_Gj8f90WQ@gremlin>
On 8/25/26 12:31 AM, Lorenzo Stoakes (ARM) wrote:
> On Tue, Aug 25, 2026 at 12:12:32AM -0700, Atish Patra wrote:
>> Reproduced and verified this series (patches 1-3) on 4vcpu guest running two different kernels
>> 1. mainline (commit: 77ae27fd98f3)
>> 2. Ubuntu Resolute 7.0.0-26 (production kernel hitting the issue in a VM)
>>
>> The Reproducer consisted of
>> 1. A debug patch a cmdline-gated stall between the two *pmd reads in vmalloc_to_page()
>> 2. One taskset-pinned insmod/rmmod worker per module over stock cfg80211/dummy/veth modules
>>
>> With the above reproducer, both BUG within seconds in unpatched kernel.
>> 1. Resolute in 0.71s at alternative.c:2564 (BUG_ON(!pages[0] ...), RAX=0)
>> 2. mainline at alternative.c:2473 (BUG_ON(memcmp(addr, src, len))).
>>
>> With patches 1-3: zero splats across 10 runs each (600s/11,378 module load/unload cycles on mainline and 1200s/55,980 module load/unload cycles on Resolute).
> Amazing, thanks!
>
>>
>> Tested-by: Atish Patra<atishp@meta.com>
> I guess should be applied to patches 1-3 only strictly? Or perhaps 3/5?
Yes. 1-3 sounds good.
>>> --
>>> Sincerely yours,
>>> Mike.
>>>
> --
> Cheers, Lorenzo
prev parent reply other threads:[~2026-08-25 20:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-13 9:01 [PATCH v2 0/5] x86/mm/pat: CPA fixes Mike Rapoport
2026-08-13 9:01 ` [PATCH v2 1/5] x86/mm/pat: acquire init_mm write lock on collapse to avoid UAF Mike Rapoport
2026-08-13 9:01 ` [PATCH v2 2/5] x86/mm/pat: acquire init_mm read lock on attribute change " Mike Rapoport
2026-08-13 9:01 ` [PATCH v2 3/5] x86/alternative: exclude text poking against change_page_attr() Mike Rapoport
2026-08-25 9:37 ` Jiri Slaby
2026-08-13 9:01 ` [PATCH v2 4/5] x86/mm/pat: allocate split page tables as kernel page tables Mike Rapoport
2026-08-13 9:01 ` [PATCH v2 5/5] x86/mm/pat: fix effective RW computation in lookup_address_in_pgd_attr() Mike Rapoport (Microsoft)
2026-08-13 9:45 ` Lorenzo Stoakes (ARM)
2026-08-13 15:05 ` [PATCH v2 0/5] x86/mm/pat: CPA fixes Nikunj A. Dadhania
2026-08-13 15:07 ` Lorenzo Stoakes (ARM)
2026-08-13 15:23 ` Pedro Falcato
2026-08-13 17:13 ` Andrew Morton
2026-08-25 7:12 ` Atish Patra
2026-08-25 7:31 ` Lorenzo Stoakes (ARM)
2026-08-25 20:05 ` Atish Patra [this message]
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