From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A9B66657; Thu, 12 Oct 2023 01:45:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="lL+Z9oNP" Received: from mailout4.samsung.com (mailout4.samsung.com [203.254.224.34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A444E98; Wed, 11 Oct 2023 18:45:18 -0700 (PDT) Received: from epcas2p2.samsung.com (unknown [182.195.41.54]) by mailout4.samsung.com (KnoxPortal) with ESMTP id 20231012014516epoutp04c3ac5cb2248aba0ef58fba6a05c5bd6f~NONO2GwH41763017630epoutp04Z; Thu, 12 Oct 2023 01:45:16 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20231012014516epoutp04c3ac5cb2248aba0ef58fba6a05c5bd6f~NONO2GwH41763017630epoutp04Z DKIM-Signature: v=1; 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Thu, 12 Oct 2023 01:45:14 +0000 (GMT) Received: from epsmgms1p1new.samsung.com (unknown [182.195.42.41]) by epsmtrp1.samsung.com (KnoxPortal) with ESMTP id 20231012014514epsmtrp11618661b71bca5b44530bba8ce23a48e~NONNO1nP52141621416epsmtrp1C; Thu, 12 Oct 2023 01:45:14 +0000 (GMT) X-AuditID: b6c32a46-1c3eaa80000025b1-42-65274fab2c6b Received: from epsmtip1.samsung.com ( [182.195.34.30]) by epsmgms1p1new.samsung.com (Symantec Messaging Gateway) with SMTP id 04.0F.08742.AAF47256; Thu, 12 Oct 2023 10:45:14 +0900 (KST) Received: from tiffany (unknown [10.229.95.142]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20231012014514epsmtip1831e5824c182001ced8785e96c927f36~NONM7MXAT1906819068epsmtip1g; Thu, 12 Oct 2023 01:45:14 +0000 (GMT) Date: Thu, 12 Oct 2023 10:35:05 +0900 From: Hyesoo Yu To: Alexandru Elisei Cc: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com, pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH RFC 17/37] arm64: mte: Disable dynamic tag storage management if HW KASAN is enabled Message-ID: <20231012013505.GB2426387@tiffany> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20230823131350.114942-18-alexandru.elisei@arm.com> X-Brightmail-Tracker: H4sIAAAAAAAAA02TeTBdVxzHe+69777H9MW1JDmRSapPs9BanvWQEJOit1uqk6SdyXTCG+54 guflLdJEJ0UREbUbJYiloRFCbEksr5YXW1UbirG2KBPEUmlIKOnjaif/fX7f8/2e3zm/M4eH 6/3CNeT5SRSMTCIKEJDaRHWziZ3Z7U8OMZZ/9+qgzNJiEqXd6iGRqs0brSe1cFH3RK9Gmg4j 0EJBLEDPSldxNJlQhaPGnHkCTS7FEeh3VSGGRuJTCXRvag5DM5XNBIqueUag8ok+DqqrbydQ T00miUaLX3KQuvRnAj3IbOeg5PkpgPILD6LuhhwMpb54QqL44X4StX7bgCFV9B+YxnsPQ2Hq BRKlDw0BFK1exlH9xgsCVT1c4aKIYVs0cLOM63KALs4uBvTaahKgI1SDXDqnXElHqOc4dMUP pnR50VWSLl9K4tLDfXUk3fbdGkHnhqbidMX3X9OPK9IBvaDqJemKn0Lop+X7Pagz/kfFjMiH kRkxEu8gHz+Jr5Pgw5Oe73ra2lkKzYQOyF5gJBEFMk4C1488zNz9AjTDFBgFiwKUGslDJJcL LJyPyoKUCsZIHCRXOAkYqU+A1F5qLhcFypUSX3MJo3AUWlpa2WqMXv7ilIxeTKqivpy+cTwU VPBjgBYPUjaw7PojbgzQ5ulR9wHsyr2CscUSgCMlidvFMoBj9QlkDOBtRYYGHFm9HsCohLZt 0ySA4U9XOJv7EtQBOHe3mNxkkjoE2yoLwCYbUBZwvGoGbAZwqoOEI9c7sc0FfeoczI0f2zLx KXNYVn8XY1kXtqf/SWyyFuUCo0ZvbnWDVKo2rK1eBOyRXOHq8jH2QvpwprWSy7IhnI6P2mZ/ OPJXAsmyAt7pDN3WrWHG1JWtvjglhr9OjW9vaQzVgwQr74DRzetcVubD6Cg9NmkMfyzIJlje A8dLrnBYCw07Vz5mR9KmmdvsGpYA9me8cpmMV5qx/A7MqV0iMzRxnNoLCzd4LJrA0hqLHMAp ArsYqTzQl5FbSa3+f17voMBysPWzTN3vg5S5RfMmgPFAE4A8XGDAH/d7i9Hj+4guXmJkQZ4y ZQAjbwK2mqdJxA13egdpvqZE4Sm0cbC0sbMT2lvZWtoLdvNHI7N89ChfkYLxZxgpI/svh/G0 DEOxq5FGR6y/Mnw473YmrGeuZfW9UwOL/bbG/5zsH53MG7vVJHZFs+cKq17qmLXmRQccPu/T Mb3v2FKk/nN8IS3rdnNdBflm8jW5uIV6NOTWqB4pCQ3mhaZXZc8njtYKqXBl3I1vdh6kmd2w 2nP9cs1ojdfnyfgdXXXI6dff+O1wHD/rU8n4ieSUwRwP7Emavcfsjj6XDX/nyvOxWUO0g1G+ e5GN6bX3g5X5tVZ7HY/I7DpCpmoiL5xuUD8w4cTqhhuUYF5dzt6fdbs1nhhjXrOemN/3BUel Y4hdsHhunKg8e3FPwSXM5u0qeojK0/tgsvlxdXXXogt+1gnXh5fzrU+t7FLWCwi5WCQ0xWVy 0b9Bj5x04gQAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA02SbUxTZxiG855zenpaqZ4VXN9KxpKiEpqtiMzszbZs/PDHu2SOhWSQACqV nvBZ7FpwfiwR0iIMQQgMhbZxMOVjXSdSyscQOgZV2lijwVhFGGxAGeqQQcMWZHSjkGX+u3Pf 15U8Px6GFF/k7WKy8ws4bb4yT0YLqe5hWcSbloQobp9pOBqZ2600uvTtfRo5XBloveYWH43O PNionhRTaLGlAqCV9hck8lV3keinxucU8i1foNCUo5VAP1fVUahnboFAT+3DFCrrW6GQbcbL Q/0Dbgrd7zPTaNL6Dw852+9Q6Aezm4dqn88BdKV1LxodbCRQ3ervNKqaeEijkcpBAjnKfiE2 2B4CFTsXadQwPg5QmfNPEg0EVinUdfMvPjJMHEBjzdf58Xuw9bIV4LUXNQAbHI/5uNFWiA3O BR7ubJNjm+VLGtuWa/h4wttPY1f9GoWbiupI3Hn1LJ7vbAB40fGAxp23z2C/LeITNkX4norL yz7BaWPeTxdmTX2jJzQB0UnrlB8UgYpt5YBhIPsWHB97pxwIGTF7A0BLST0oB4KNXgqNfjex lUPhlMHJ24JmALxrD5DBgWL3wIUOKx3MNBsFXfaWTTmMjYHTXU9BUCBZDw0vfGfkBYdQNgc2 Vf26CYlYBbw+0EEErxCzBVBfK9qqX4HuhlkqmElWDh8FnmwiJBsOWwNMsBaw8fDcZDNRDVjj S4bxJcP4v9EISAuQchqdOlOti9XE5nOfK3RKta4wP1ORcVxtA5uvI4/uBT2WPxRDgGDAEIAM KQsTTWfv5sQilfLUaU57/Ki2MI/TDYFwhpJJRJL5SpWYzVQWcLkcp+G0/60EI9hVRMSFnXkj cvCerfZgmSFxzd53Iydt6d2UuI/2dvSmSrtDtk/7S1xelSMQ+Oqknb+UViKMbOanpNbw5o79 XembK8SPdl6r6Ikylcadkh1jCi67Rkeks55cRfiY6aCkzRvx0H3r427VgSZJbtehBP2aMKX/ cG/S+dX4bfvPSfZHmNXL5ntHDt3JOJ2V5kl+tXof/fVOI/3Mr5+tf2xIf126FH1TEBKT4LCk wuJk/Wt3L04mj6234IyFxMVr9fGmUO9Rwacn5GmXPDk+ZkWnbJvf0Xk4cfKIZbtL4ytNoj7j cW+nG5IyvxgK2WG+vV561bEya4r11H448uMHv0V+bzp7Hj+TUbosZayc1OqU/wIpMteEqQMA AA== X-CMS-MailID: 20231012014514epcas2p3ca99a067f3044c5753309a08cd0b05c4 X-Msg-Generator: CA Content-Type: multipart/mixed; boundary="----E9vxk1eHFJMo0Hi_Q_rTTD2vXp5VKj0nvvVRz8vbSgBSYVSL=_d92b1_" X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20231012014514epcas2p3ca99a067f3044c5753309a08cd0b05c4 References: <20230823131350.114942-1-alexandru.elisei@arm.com> <20230823131350.114942-18-alexandru.elisei@arm.com> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL, SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net ------E9vxk1eHFJMo0Hi_Q_rTTD2vXp5VKj0nvvVRz8vbSgBSYVSL=_d92b1_ Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline On Wed, Aug 23, 2023 at 02:13:30PM +0100, Alexandru Elisei wrote: > Reserving the tag storage associated with a tagged page requires the > ability to migrate existing data if the tag storage is in use for data. > > The kernel allocates pages, which are now tagged because of HW KASAN, in > non-preemptible contexts, which can make reserving the associate tag > storage impossible. > > Don't expose the tag storage pages to the memory allocator if HW KASAN is > enabled. > > Signed-off-by: Alexandru Elisei > --- > arch/arm64/kernel/mte_tag_storage.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c > index 4a6bfdf88458..f45128d0244e 100644 > --- a/arch/arm64/kernel/mte_tag_storage.c > +++ b/arch/arm64/kernel/mte_tag_storage.c > @@ -314,6 +314,18 @@ static int __init mte_tag_storage_activate_regions(void) > return 0; > } > > + /* > + * The kernel allocates memory in non-preemptible contexts, which makes > + * migration impossible when reserving the associated tag storage. > + * > + * The check is safe to make because KASAN HW tags are enabled before > + * the rest of the init functions are called, in smp_prepare_boot_cpu(). > + */ > + if (kasan_hw_tags_enabled()) { > + pr_info("KASAN HW tags enabled, disabling tag storage"); > + return 0; > + } > + Hi. Is there no plan to enable HW KASAN in the current design ? I wonder if dynamic MTE is only used for user ? Thanks, Hyesoo Yu. > for (i = 0; i < num_tag_regions; i++) { > tag_range = &tag_regions[i].tag_range; > for (pfn = tag_range->start; pfn <= tag_range->end; pfn += pageblock_nr_pages) { > -- > 2.41.0 > > ------E9vxk1eHFJMo0Hi_Q_rTTD2vXp5VKj0nvvVRz8vbSgBSYVSL=_d92b1_ Content-Type: text/plain; charset="utf-8" ------E9vxk1eHFJMo0Hi_Q_rTTD2vXp5VKj0nvvVRz8vbSgBSYVSL=_d92b1_--