From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id 5F40A6B02FC for ; Thu, 7 Sep 2017 13:37:12 -0400 (EDT) Received: by mail-it0-f70.google.com with SMTP id c195so260605itb.5 for ; Thu, 07 Sep 2017 10:37:12 -0700 (PDT) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id p197sor16285itp.120.2017.09.07.10.37.11 for (Google Transport Security); Thu, 07 Sep 2017 10:37:11 -0700 (PDT) From: Tycho Andersen Subject: [PATCH v6 07/11] arm64/mm, xpfo: temporarily map dcache regions Date: Thu, 7 Sep 2017 11:36:05 -0600 Message-Id: <20170907173609.22696-8-tycho@docker.com> In-Reply-To: <20170907173609.22696-1-tycho@docker.com> References: <20170907173609.22696-1-tycho@docker.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, kernel-hardening@lists.openwall.com, Marco Benatto , Juerg Haefliger , linux-arm-kernel@lists.infradead.org, Tycho Andersen From: Juerg Haefliger If the page is unmapped by XPFO, a data cache flush results in a fatal page fault, so let's temporarily map the region, flush the cache, and then unmap it. v6: actually flush in the face of xpfo, and temporarily map the underlying memory so it can be flushed correctly CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Juerg Haefliger Signed-off-by: Tycho Andersen --- arch/arm64/mm/flush.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index 21a8d828cbf4..e335e3fd4fca 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -28,9 +29,15 @@ void sync_icache_aliases(void *kaddr, unsigned long len) { unsigned long addr = (unsigned long)kaddr; + unsigned long num_pages = XPFO_NUM_PAGES(addr, len); + void *mapping[num_pages]; if (icache_is_aliasing()) { + xpfo_temp_map(kaddr, len, mapping, + sizeof(mapping[0]) * num_pages); __clean_dcache_area_pou(kaddr, len); + xpfo_temp_unmap(kaddr, len, mapping, + sizeof(mapping[0]) * num_pages); __flush_icache_all(); } else { flush_icache_range(addr, addr + len); -- 2.11.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org