From: Tejun Heo <tj@kernel.org>
To: bot+bpf-ci@kernel.org, void@manifault.com, arighi@nvidia.com,
changwoo@igalia.com, ast@kernel.org, andrii@kernel.org,
daniel@iogearbox.net, martin.lau@linux.dev, memxor@gmail.com
Cc: peterz@infradead.org, catalin.marinas@arm.com, will@kernel.org,
tglx@kernel.org, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, akpm@linux-foundation.org,
david@kernel.org, rppt@kernel.org, emil@etsalapatis.com,
sched-ext@lists.linux.dev, bpf@vger.kernel.org, x86@kernel.org,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, eddyz87@gmail.com,
yonghong.song@linux.dev, clm@meta.com, ihor.solodrai@linux.dev
Subject: Re: [PATCH bpf-next] bpf: Replace scratch PTE atomically when allocating arena pages
Date: Tue, 02 Jun 2026 12:09:11 -1000 [thread overview]
Message-ID: <8f133924fbf8d259340f3057e505f663@kernel.org> (raw)
In-Reply-To: <f45f02410d23c99d14f3577da9b27a327816b5a0904bdeefc8e229eac760d1cf@mail.kernel.org>
On Mon, Jun 01, 2026 at 08:15:34PM +0000, bot+bpf-ci@kernel.org wrote:
> After the real page is installed without a flush, can that stale
> kaddr -> scratch_page translation persist, so that later kernel-side
> accesses at kaddr reach the shared per-arena scratch page instead of
> the freshly allocated page?
It can on x86, but it's harmless: that CPU faulted on an unallocated
address and got scratch-recovered, so reaching either the scratch or the
real page is fine. No flush needed.
Thanks.
--
tejun
next prev parent reply other threads:[~2026-06-02 22:09 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-01 18:37 [PATCH bpf-next] bpf: Replace scratch PTE atomically when allocating arena pages Tejun Heo
2026-06-01 20:15 ` bot+bpf-ci
2026-06-02 22:09 ` Tejun Heo [this message]
2026-06-02 22:29 ` Kumar Kartikeya Dwivedi
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