From: Dave Hansen <dave.hansen@intel.com>
To: Maciej Wieczor-Retman <m.wieczorretman@pm.me>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Cc: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v10 07/13] x86/mm: Use physical address comparisons in fill_p*d/pte
Date: Mon, 23 Feb 2026 12:36:00 -0800 [thread overview]
Message-ID: <04c4544b-6acc-4bf4-942e-fc1e02c1f60d@intel.com> (raw)
In-Reply-To: <b2a0dedfa1d51aa28f20ca8ff91d942415cc86dd.1770232424.git.m.wieczorretman@pm.me>
On 2/4/26 11:20, Maciej Wieczor-Retman wrote:
> From: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
>
> Calculating page offset returns a pointer without a tag. When comparing
> the calculated offset to a tagged page pointer an error is raised
> because they are not equal.
>
> Change pointer comparisons to physical address comparisons as to avoid
> issues with tagged pointers that pointer arithmetic would create. Open
> code pte_offset_kernel(), pmd_offset(), pud_offset() and p4d_offset().
> Because one parameter is always zero and the rest of the function
> insides are enclosed inside __va(), removing that layer lowers the
> complexity of final assembly.
These are a little ugly, but it's better than defining three more
helpers that only get used once.
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
next prev parent reply other threads:[~2026-02-23 20:35 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-04 19:18 [PATCH v10 00/13] kasan: x86: arm64: KASAN tag-based mode for x86 Maciej Wieczor-Retman
2026-02-04 19:19 ` [PATCH v10 01/13] kasan: sw_tags: Use arithmetic shift for shadow computation Maciej Wieczor-Retman
2026-03-05 19:05 ` Andrey Ryabinin
2026-03-05 20:18 ` Maciej Wieczor-Retman
2026-03-05 21:22 ` Andrey Ryabinin
2026-03-05 21:25 ` Maciej Wieczor-Retman
2026-02-04 19:19 ` [PATCH v10 02/13] kasan: arm64: x86: Make special tags arch specific Maciej Wieczor-Retman
2026-02-04 19:19 ` [PATCH v10 03/13] kasan: Fix inline mode for x86 tag-based mode Maciej Wieczor-Retman
2026-02-04 19:19 ` [PATCH v10 04/13] x86/kasan: Add arch specific kasan functions Maciej Wieczor-Retman
2026-02-04 19:19 ` [PATCH v10 05/13] x86/mm: Reset tag for virtual to physical address conversions Maciej Wieczor-Retman
2026-02-04 19:20 ` [PATCH v10 06/13] mm/execmem: Untag addresses in EXECMEM_ROX related pointer arithmetic Maciej Wieczor-Retman
2026-02-04 19:20 ` [PATCH v10 07/13] x86/mm: Use physical address comparisons in fill_p*d/pte Maciej Wieczor-Retman
2026-02-23 20:36 ` Dave Hansen [this message]
2026-02-04 19:20 ` [PATCH v10 08/13] x86/kasan: Initialize KASAN raw shadow memory Maciej Wieczor-Retman
2026-02-04 19:20 ` [PATCH v10 09/13] x86/mm: Reset tags in a canonical address helper call Maciej Wieczor-Retman
2026-02-23 20:39 ` Dave Hansen
2026-02-24 8:57 ` Maciej Wieczor-Retman
2026-02-26 19:39 ` Dave Hansen
2026-02-27 8:24 ` Maciej Wieczor-Retman
2026-02-04 19:20 ` [PATCH v10 10/13] x86/mm: Initialize LAM_SUP Maciej Wieczor-Retman
2026-02-23 20:43 ` Dave Hansen
2026-02-24 9:05 ` Maciej Wieczor-Retman
2026-02-04 19:20 ` [PATCH v10 11/13] x86: Increase minimal SLAB alignment for KASAN Maciej Wieczor-Retman
2026-02-04 19:20 ` [PATCH v10 12/13] x86/kasan: Use a logical bit shift for kasan_mem_to_shadow Maciej Wieczor-Retman
2026-02-04 19:20 ` [PATCH v10 13/13] x86/kasan: Make software tag-based kasan available Maciej Wieczor-Retman
2026-02-23 20:52 ` Dave Hansen
2026-02-24 9:10 ` Maciej Wieczor-Retman
2026-02-26 23:29 ` Dave Hansen
2026-02-27 8:27 ` Maciej Wieczor-Retman
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