From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) by kanga.kvack.org (Postfix) with ESMTP id 88175280310 for ; Thu, 3 Aug 2017 17:25:02 -0400 (EDT) Received: by mail-it0-f71.google.com with SMTP id 7so24605578ita.0 for ; Thu, 03 Aug 2017 14:25:02 -0700 (PDT) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id 128si15842811ion.73.2017.08.03.14.24.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 Aug 2017 14:24:59 -0700 (PDT) From: Pavel Tatashin Subject: [v5 11/15] arm64/kasan: explicitly zero kasan shadow memory Date: Thu, 3 Aug 2017 17:23:49 -0400 Message-Id: <1501795433-982645-12-git-send-email-pasha.tatashin@oracle.com> In-Reply-To: <1501795433-982645-1-git-send-email-pasha.tatashin@oracle.com> References: <1501795433-982645-1-git-send-email-pasha.tatashin@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, mhocko@kernel.org To optimize the performance of struct page initialization, vmemmap_populate() will no longer zero memory. We must explicitly zero the memory that is allocated by vmemmap_populate() for kasan, as this memory does not go through struct page initialization path. Signed-off-by: Pavel Tatashin Reviewed-by: Steven Sistare Reviewed-by: Daniel Jordan Reviewed-by: Bob Picco --- arch/arm64/mm/kasan_init.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 81f03959a4ab..a57104bc54b8 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -135,6 +135,31 @@ static void __init clear_pgds(unsigned long start, set_pgd(pgd_offset_k(start), __pgd(0)); } +/* + * Memory that was allocated by vmemmap_populate is not zeroed, so we must + * zero it here explicitly. + */ +static void +zero_vemmap_populated_memory(void) +{ + struct memblock_region *reg; + u64 start, end; + + for_each_memblock(memory, reg) { + start = __phys_to_virt(reg->base); + end = __phys_to_virt(reg->base + reg->size); + + if (start >= end) + break; + + memset((void *)start, 0, end - start); + } + + start = (u64)kasan_mem_to_shadow(_stext); + end = (u64)kasan_mem_to_shadow(_end); + memset((void *)start, 0, end - start); +} + void __init kasan_init(void) { u64 kimg_shadow_start, kimg_shadow_end; @@ -205,6 +230,13 @@ void __init kasan_init(void) pfn_pte(sym_to_pfn(kasan_zero_page), PAGE_KERNEL_RO)); memset(kasan_zero_page, 0, PAGE_SIZE); + + /* + * vmemmap_populate does not zero the memory, so we need to zero it + * explicitly + */ + zero_vemmap_populated_memory(); + cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); /* At this point kasan is fully initialized. Enable error messages */ -- 2.13.4 -- 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