From: Catalin Marinas <catalin.marinas@arm.com>
To: Ryan Roberts <ryan.roberts@arm.com>
Cc: Will Deacon <will@kernel.org>,
Pasha Tatashin <pasha.tatashin@soleen.com>,
Andrew Morton <akpm@linux-foundation.org>,
Uladzislau Rezki <urezki@gmail.com>,
Christoph Hellwig <hch@infradead.org>,
David Hildenbrand <david@redhat.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Mark Rutland <mark.rutland@arm.com>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Alexandre Ghiti <alexghiti@rivosinc.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 08/14] mm/vmalloc: Warn on improper use of vunmap_range()
Date: Mon, 24 Feb 2025 12:04:18 +0000 [thread overview]
Message-ID: <Z7xgQr7_xivV849V@arm.com> (raw)
In-Reply-To: <20250217140809.1702789-9-ryan.roberts@arm.com>
On Mon, Feb 17, 2025 at 02:08:00PM +0000, Ryan Roberts wrote:
> A call to vmalloc_huge() may cause memory blocks to be mapped at pmd or
> pud level. But it is possible to subsequently call vunmap_range() on a
> sub-range of the mapped memory, which partially overlaps a pmd or pud.
> In this case, vmalloc unmaps the entire pmd or pud so that the
> no-overlapping portion is also unmapped. Clearly that would have a bad
> outcome, but it's not something that any callers do today as far as I
> can tell. So I guess it's just expected that callers will not do this.
>
> However, it would be useful to know if this happened in future; let's
> add a warning to cover the eventuality.
>
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
next prev parent reply other threads:[~2025-02-24 12:17 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-17 14:07 [PATCH v2 00/14] Perf improvements for hugetlb and vmalloc on arm64 Ryan Roberts
2025-02-17 14:07 ` [PATCH v2 01/14] arm64: hugetlb: Cleanup huge_pte size discovery mechanisms Ryan Roberts
2025-02-17 14:07 ` [PATCH v2 02/14] arm64: hugetlb: Refine tlb maintenance scope Ryan Roberts
2025-02-17 14:07 ` [PATCH v2 03/14] mm/page_table_check: Batch-check pmds/puds just like ptes Ryan Roberts
2025-02-17 14:07 ` [PATCH v2 04/14] arm64/mm: Refactor __set_ptes() and __ptep_get_and_clear() Ryan Roberts
2025-02-17 14:07 ` [PATCH v2 05/14] arm64: hugetlb: Use set_ptes_anysz() and ptep_get_and_clear_anysz() Ryan Roberts
2025-02-17 14:07 ` [PATCH v2 06/14] arm64/mm: Hoist barriers out of set_ptes_anysz() loop Ryan Roberts
2025-02-22 11:56 ` Catalin Marinas
2025-02-24 12:18 ` Ryan Roberts
2025-02-17 14:07 ` [PATCH v2 07/14] arm64/mm: Avoid barriers for invalid or userspace mappings Ryan Roberts
2025-02-20 16:54 ` Kevin Brodsky
2025-02-24 12:26 ` Ryan Roberts
2025-02-22 13:17 ` Catalin Marinas
2025-02-25 16:41 ` Ryan Roberts
2025-02-17 14:08 ` [PATCH v2 08/14] mm/vmalloc: Warn on improper use of vunmap_range() Ryan Roberts
2025-02-20 7:02 ` Anshuman Khandual
2025-02-24 12:03 ` Catalin Marinas
2025-02-24 12:04 ` Catalin Marinas [this message]
2025-02-17 14:08 ` [PATCH v2 09/14] mm/vmalloc: Gracefully unmap huge ptes Ryan Roberts
2025-02-20 12:05 ` Uladzislau Rezki
2025-02-24 12:04 ` Catalin Marinas
2025-02-17 14:08 ` [PATCH v2 10/14] arm64/mm: Support huge pte-mapped pages in vmap Ryan Roberts
2025-02-24 12:03 ` Catalin Marinas
2025-02-25 16:57 ` Ryan Roberts
2025-02-17 14:08 ` [PATCH v2 11/14] mm/vmalloc: Batch arch_sync_kernel_mappings() more efficiently Ryan Roberts
2025-02-25 15:37 ` Catalin Marinas
2025-02-25 16:58 ` Ryan Roberts
2025-02-17 14:08 ` [PATCH v2 12/14] mm: Generalize arch_sync_kernel_mappings() Ryan Roberts
2025-02-25 17:10 ` Ryan Roberts
2025-02-25 17:52 ` Catalin Marinas
2025-02-17 14:08 ` [PATCH v2 13/14] mm: Only call arch_update_kernel_mappings_[begin|end]() for kernel mappings Ryan Roberts
2025-02-17 14:08 ` [PATCH v2 14/14] arm64/mm: Batch barriers when updating " Ryan Roberts
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