From: Pavel Tatashin <pasha.tatashin@oracle.com>
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,
ard.biesheuvel@linaro.org, will.deacon@arm.com,
catalin.marinas@arm.com, sam@ravnborg.org
Subject: [v6 11/15] arm64/kasan: explicitly zero kasan shadow memory
Date: Mon, 7 Aug 2017 16:38:45 -0400 [thread overview]
Message-ID: <1502138329-123460-12-git-send-email-pasha.tatashin@oracle.com> (raw)
In-Reply-To: <1502138329-123460-1-git-send-email-pasha.tatashin@oracle.com>
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 <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
---
arch/arm64/mm/kasan_init.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index 81f03959a4ab..e78a9ecbb687 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -135,6 +135,41 @@ 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_vmemmap_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;
+
+ start = (u64)kasan_mem_to_shadow((void *)start);
+ end = (u64)kasan_mem_to_shadow((void *)end);
+
+ /* Round to the start end of the mapped pages */
+ start = round_down(start, SWAPPER_BLOCK_SIZE);
+ end = round_up(end, SWAPPER_BLOCK_SIZE);
+ memset((void *)start, 0, end - start);
+ }
+
+ start = (u64)kasan_mem_to_shadow(_text);
+ end = (u64)kasan_mem_to_shadow(_end);
+
+ /* Round to the start end of the mapped pages */
+ start = round_down(start, SWAPPER_BLOCK_SIZE);
+ end = round_up(end, SWAPPER_BLOCK_SIZE);
+ memset((void *)start, 0, end - start);
+}
+
void __init kasan_init(void)
{
u64 kimg_shadow_start, kimg_shadow_end;
@@ -205,8 +240,15 @@ void __init kasan_init(void)
pfn_pte(sym_to_pfn(kasan_zero_page), PAGE_KERNEL_RO));
memset(kasan_zero_page, 0, PAGE_SIZE);
+
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
+ /*
+ * vmemmap_populate does not zero the memory, so we need to zero it
+ * explicitly
+ */
+ zero_vmemmap_populated_memory();
+
/* At this point kasan is fully initialized. Enable error messages */
init_task.kasan_depth = 0;
pr_info("KernelAddressSanitizer initialized\n");
--
2.14.0
next prev parent reply other threads:[~2017-08-07 20:40 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-07 20:38 [v6 00/15] complete deferred page initialization Pavel Tatashin
2017-08-07 20:38 ` [v6 01/15] x86/mm: reserve only exiting low pages Pavel Tatashin
2017-08-11 8:07 ` Michal Hocko
2017-08-11 15:24 ` Pasha Tatashin
2017-08-14 11:40 ` Michal Hocko
2017-08-14 13:30 ` Pasha Tatashin
2017-08-14 13:55 ` Michal Hocko
2017-08-17 15:37 ` Pasha Tatashin
2017-08-07 20:38 ` [v6 02/15] x86/mm: setting fields in deferred pages Pavel Tatashin
2017-08-11 9:02 ` Michal Hocko
2017-08-11 15:39 ` Pasha Tatashin
2017-08-14 11:43 ` Michal Hocko
2017-08-14 13:32 ` Pasha Tatashin
2017-08-07 20:38 ` [v6 03/15] sparc64/mm: " Pavel Tatashin
2017-08-07 20:38 ` [v6 04/15] mm: discard memblock data later Pavel Tatashin
2017-08-11 9:32 ` Michal Hocko
2017-08-11 9:50 ` Mel Gorman
2017-08-11 15:49 ` Pasha Tatashin
2017-08-11 16:04 ` Michal Hocko
2017-08-11 16:22 ` Pasha Tatashin
2017-08-14 11:36 ` Michal Hocko
2017-08-14 13:35 ` Pasha Tatashin
2017-08-11 19:00 ` Pasha Tatashin
2017-08-14 11:34 ` Michal Hocko
2017-08-14 13:39 ` Pasha Tatashin
2017-08-14 13:42 ` Michal Hocko
2017-08-07 20:38 ` [v6 05/15] mm: don't accessed uninitialized struct pages Pavel Tatashin
2017-08-11 9:37 ` Michal Hocko
2017-08-11 15:55 ` Pasha Tatashin
2017-08-14 11:47 ` Michal Hocko
2017-08-14 13:51 ` Pasha Tatashin
2017-08-17 15:28 ` Pasha Tatashin
2017-08-17 15:43 ` Michal Hocko
2017-08-15 9:33 ` Michal Hocko
2017-08-07 20:38 ` [v6 06/15] sparc64: simplify vmemmap_populate Pavel Tatashin
2017-08-07 20:38 ` [v6 07/15] mm: defining memblock_virt_alloc_try_nid_raw Pavel Tatashin
2017-08-11 12:39 ` Michal Hocko
2017-08-11 15:58 ` Pasha Tatashin
2017-08-11 16:06 ` Michal Hocko
2017-08-11 16:24 ` Pasha Tatashin
2017-08-07 20:38 ` [v6 08/15] mm: zero struct pages during initialization Pavel Tatashin
2017-08-11 12:50 ` Michal Hocko
2017-08-11 16:03 ` Pasha Tatashin
2017-08-07 20:38 ` [v6 09/15] sparc64: optimized struct page zeroing Pavel Tatashin
2017-08-11 12:53 ` Michal Hocko
2017-08-11 16:04 ` Pasha Tatashin
2017-08-07 20:38 ` [v6 10/15] x86/kasan: explicitly zero kasan shadow memory Pavel Tatashin
2017-08-07 20:38 ` Pavel Tatashin [this message]
2017-08-08 9:07 ` [v6 11/15] arm64/kasan: " Will Deacon
2017-08-08 11:49 ` Pasha Tatashin
2017-08-08 12:30 ` Will Deacon
2017-08-08 12:49 ` Pasha Tatashin
2017-08-08 13:15 ` David Laight
2017-08-08 13:30 ` Pasha Tatashin
2017-08-07 20:38 ` [v6 12/15] mm: explicitly zero pagetable memory Pavel Tatashin
2017-08-07 20:38 ` [v6 13/15] mm: stop zeroing memory during allocation in vmemmap Pavel Tatashin
2017-08-11 13:04 ` Michal Hocko
2017-08-11 16:11 ` Pasha Tatashin
2017-08-07 20:38 ` [v6 14/15] mm: optimize early system hash allocations Pavel Tatashin
2017-08-11 13:05 ` Michal Hocko
2017-08-11 16:13 ` Pasha Tatashin
2017-08-07 20:38 ` [v6 15/15] mm: debug for raw alloctor Pavel Tatashin
2017-08-11 13:08 ` Michal Hocko
2017-08-11 16:18 ` Pasha Tatashin
2017-08-14 11:50 ` Michal Hocko
2017-08-14 14:01 ` Pasha Tatashin
2017-08-15 9:36 ` Michal Hocko
2017-08-11 7:58 ` [v6 00/15] complete deferred page initialization Michal Hocko
2017-08-11 15:13 ` Pasha Tatashin
2017-08-11 15:22 ` Michal Hocko
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