Re: [PATCH v3 4/7] arm64: mte: Lock a page for MTE tag initialisation
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2022-09-02 16:30:17
Also in:
kvm, kvmarm
On Fri, Sep 02, 2022 at 03:47:33PM +0100, Steven Price wrote:
On 10/08/2022 20:30, Peter Collingbourne wrote:quoted
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c index a78c1db23c68..cd5ad0936e16 100644 --- a/arch/arm64/mm/mteswap.c +++ b/arch/arm64/mm/mteswap.c@@ -53,6 +53,9 @@ bool mte_restore_tags(swp_entry_t entry, struct page *page) if (!tags) return false; + /* racing tag restoring? */ + if (!try_page_mte_tagging(page)) + return false; mte_restore_page_tags(page_address(page), tags);I feel like adding a "set_page_mte_tagged(page);" in here would avoid the need for the comments about mte_restore_tags() taking the lock.
Good point. I think I blindly followed the set_bit() places but it makes sense to move the bit setting to mte_restore_tags(). Thanks for the review. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel