From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B897C433E1 for ; Mon, 24 Aug 2020 18:29:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A65E20738 for ; Mon, 24 Aug 2020 18:29:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727792AbgHXS3J (ORCPT ); Mon, 24 Aug 2020 14:29:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:36076 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727776AbgHXS3E (ORCPT ); Mon, 24 Aug 2020 14:29:04 -0400 Received: from localhost.localdomain (unknown [95.146.230.145]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CF65320738; Mon, 24 Aug 2020 18:29:01 +0000 (UTC) From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, Will Deacon , Dave P Martin , Vincenzo Frascino , Szabolcs Nagy , Kevin Brodsky , Andrey Konovalov , Peter Collingbourne , Andrew Morton , Steven Price , James Morse Subject: [PATCH v8 26/28] arm64: mte: Save tags when hibernating Date: Mon, 24 Aug 2020 19:27:56 +0100 Message-Id: <20200824182758.27267-27-catalin.marinas@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200824182758.27267-1-catalin.marinas@arm.com> References: <20200824182758.27267-1-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org From: Steven Price When hibernating the contents of all pages in the system are written to disk, however the MTE tags are not visible to the generic hibernation code. So just before the hibernation image is created copy the tags out of the physical tag storage into standard memory so they will be included in the hibernation image. After hibernation apply the tags back into the physical tag storage. Signed-off-by: Steven Price Signed-off-by: Catalin Marinas Cc: James Morse Cc: Will Deacon --- Notes: New in v4. arch/arm64/kernel/hibernate.c | 118 ++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index 68e14152d6e9..23467092e24d 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -285,6 +286,117 @@ static int create_safe_exec_page(void *src_start, size_t length, #define dcache_clean_range(start, end) __flush_dcache_area(start, (end - start)) +#ifdef CONFIG_ARM64_MTE + +static DEFINE_XARRAY(mte_pages); + +static int save_tags(struct page *page, unsigned long pfn) +{ + void *tag_storage, *ret; + + tag_storage = mte_allocate_tag_storage(); + if (!tag_storage) + return -ENOMEM; + + mte_save_page_tags(page_address(page), tag_storage); + + ret = xa_store(&mte_pages, pfn, tag_storage, GFP_KERNEL); + if (WARN(xa_is_err(ret), "Failed to store MTE tags")) { + mte_free_tag_storage(tag_storage); + return xa_err(ret); + } else if (WARN(ret, "swsusp: %s: Duplicate entry", __func__)) { + mte_free_tag_storage(ret); + } + + return 0; +} + +static void swsusp_mte_free_storage(void) +{ + XA_STATE(xa_state, &mte_pages, 0); + void *tags; + + xa_lock(&mte_pages); + xas_for_each(&xa_state, tags, ULONG_MAX) { + mte_free_tag_storage(tags); + } + xa_unlock(&mte_pages); + + xa_destroy(&mte_pages); +} + +static int swsusp_mte_save_tags(void) +{ + struct zone *zone; + unsigned long pfn, max_zone_pfn; + int ret = 0; + int n = 0; + + if (!system_supports_mte()) + return 0; + + for_each_populated_zone(zone) { + max_zone_pfn = zone_end_pfn(zone); + for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { + struct page *page = pfn_to_online_page(pfn); + + if (!page) + continue; + + if (!test_bit(PG_mte_tagged, &page->flags)) + continue; + + ret = save_tags(page, pfn); + if (ret) { + swsusp_mte_free_storage(); + goto out; + } + + n++; + } + } + pr_info("Saved %d MTE pages\n", n); + +out: + return ret; +} + +static void swsusp_mte_restore_tags(void) +{ + XA_STATE(xa_state, &mte_pages, 0); + int n = 0; + void *tags; + + xa_lock(&mte_pages); + xas_for_each(&xa_state, tags, ULONG_MAX) { + unsigned long pfn = xa_state.xa_index; + struct page *page = pfn_to_online_page(pfn); + + mte_restore_page_tags(page_address(page), tags); + + mte_free_tag_storage(tags); + n++; + } + xa_unlock(&mte_pages); + + pr_info("Restored %d MTE pages\n", n); + + xa_destroy(&mte_pages); +} + +#else /* CONFIG_ARM64_MTE */ + +static int swsusp_mte_save_tags(void) +{ + return 0; +} + +static void swsusp_mte_restore_tags(void) +{ +} + +#endif /* CONFIG_ARM64_MTE */ + int swsusp_arch_suspend(void) { int ret = 0; @@ -302,6 +414,10 @@ int swsusp_arch_suspend(void) /* make the crash dump kernel image visible/saveable */ crash_prepare_suspend(); + ret = swsusp_mte_save_tags(); + if (ret) + return ret; + sleep_cpu = smp_processor_id(); ret = swsusp_save(); } else { @@ -315,6 +431,8 @@ int swsusp_arch_suspend(void) dcache_clean_range(__hyp_text_start, __hyp_text_end); } + swsusp_mte_restore_tags(); + /* make the crash dump kernel image protected again */ crash_post_resume();