266 lines
8.1 KiB
Diff
266 lines
8.1 KiB
Diff
From 95ee3aee92e32b90ff10f47cb6cfc414e1fd92b2 Mon Sep 17 00:00:00 2001
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From: Andrey Ryabinin <aryabinin@virtuozzo.com>
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Date: Wed, 15 Nov 2017 17:36:35 -0800
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Subject: [PATCH 127/241] x86/mm/kasan: Don't use vmemmap_populate() to
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initialize shadow
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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CVE-2017-5754
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[ Note, this is a Git cherry-pick of the following commit:
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d17a1d97dc20: ("x86/mm/kasan: don't use vmemmap_populate() to initialize shadow")
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... for easier x86 PTI code testing and back-porting. ]
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The KASAN shadow is currently mapped using vmemmap_populate() since that
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provides a semi-convenient way to map pages into init_top_pgt. However,
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since that no longer zeroes the mapped pages, it is not suitable for
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KASAN, which requires zeroed shadow memory.
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Add kasan_populate_shadow() interface and use it instead of
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vmemmap_populate(). Besides, this allows us to take advantage of
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gigantic pages and use them to populate the shadow, which should save us
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some memory wasted on page tables and reduce TLB pressure.
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Link: http://lkml.kernel.org/r/20171103185147.2688-2-pasha.tatashin@oracle.com
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Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
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Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
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Cc: Andy Lutomirski <luto@kernel.org>
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Cc: Steven Sistare <steven.sistare@oracle.com>
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Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
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Cc: Bob Picco <bob.picco@oracle.com>
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Cc: Michal Hocko <mhocko@suse.com>
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Cc: Alexander Potapenko <glider@google.com>
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Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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Cc: Catalin Marinas <catalin.marinas@arm.com>
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Cc: Christian Borntraeger <borntraeger@de.ibm.com>
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Cc: David S. Miller <davem@davemloft.net>
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Cc: Dmitry Vyukov <dvyukov@google.com>
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Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
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Cc: "H. Peter Anvin" <hpa@zytor.com>
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Cc: Ingo Molnar <mingo@redhat.com>
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Cc: Mark Rutland <mark.rutland@arm.com>
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Cc: Matthew Wilcox <willy@infradead.org>
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Cc: Mel Gorman <mgorman@techsingularity.net>
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Cc: Michal Hocko <mhocko@kernel.org>
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Cc: Sam Ravnborg <sam@ravnborg.org>
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Cc: Thomas Gleixner <tglx@linutronix.de>
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Cc: Will Deacon <will.deacon@arm.com>
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Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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(cherry picked from commit 2aeb07365bcd489620f71390a7d2031cd4dfb83e)
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Signed-off-by: Andy Whitcroft <apw@canonical.com>
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Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
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(cherry picked from commit f60ab0015a57d9fbf659b212d504682f069b0590)
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Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
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---
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arch/x86/mm/kasan_init_64.c | 143 +++++++++++++++++++++++++++++++++++++++++---
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arch/x86/Kconfig | 2 +-
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2 files changed, 137 insertions(+), 8 deletions(-)
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diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
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index 464089f33e80..3d7341986e13 100644
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--- a/arch/x86/mm/kasan_init_64.c
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+++ b/arch/x86/mm/kasan_init_64.c
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@@ -3,12 +3,14 @@
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#include <linux/bootmem.h>
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#include <linux/kasan.h>
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#include <linux/kdebug.h>
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+#include <linux/memblock.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/sched/task.h>
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#include <linux/vmalloc.h>
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#include <asm/e820/types.h>
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+#include <asm/pgalloc.h>
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#include <asm/tlbflush.h>
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#include <asm/sections.h>
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@@ -17,7 +19,134 @@ extern struct range pfn_mapped[E820_MAX_ENTRIES];
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static p4d_t tmp_p4d_table[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
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-static int __init map_range(struct range *range)
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+static __init void *early_alloc(size_t size, int nid)
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+{
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+ return memblock_virt_alloc_try_nid_nopanic(size, size,
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+ __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid);
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+}
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+
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+static void __init kasan_populate_pmd(pmd_t *pmd, unsigned long addr,
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+ unsigned long end, int nid)
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+{
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+ pte_t *pte;
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+
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+ if (pmd_none(*pmd)) {
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+ void *p;
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+
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+ if (boot_cpu_has(X86_FEATURE_PSE) &&
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+ ((end - addr) == PMD_SIZE) &&
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+ IS_ALIGNED(addr, PMD_SIZE)) {
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+ p = early_alloc(PMD_SIZE, nid);
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+ if (p && pmd_set_huge(pmd, __pa(p), PAGE_KERNEL))
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+ return;
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+ else if (p)
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+ memblock_free(__pa(p), PMD_SIZE);
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+ }
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+
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+ p = early_alloc(PAGE_SIZE, nid);
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+ pmd_populate_kernel(&init_mm, pmd, p);
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+ }
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+
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+ pte = pte_offset_kernel(pmd, addr);
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+ do {
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+ pte_t entry;
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+ void *p;
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+
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+ if (!pte_none(*pte))
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+ continue;
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+
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+ p = early_alloc(PAGE_SIZE, nid);
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+ entry = pfn_pte(PFN_DOWN(__pa(p)), PAGE_KERNEL);
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+ set_pte_at(&init_mm, addr, pte, entry);
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+ } while (pte++, addr += PAGE_SIZE, addr != end);
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+}
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+
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+static void __init kasan_populate_pud(pud_t *pud, unsigned long addr,
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+ unsigned long end, int nid)
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+{
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+ pmd_t *pmd;
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+ unsigned long next;
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+
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+ if (pud_none(*pud)) {
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+ void *p;
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+
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+ if (boot_cpu_has(X86_FEATURE_GBPAGES) &&
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+ ((end - addr) == PUD_SIZE) &&
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+ IS_ALIGNED(addr, PUD_SIZE)) {
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+ p = early_alloc(PUD_SIZE, nid);
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+ if (p && pud_set_huge(pud, __pa(p), PAGE_KERNEL))
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+ return;
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+ else if (p)
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+ memblock_free(__pa(p), PUD_SIZE);
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+ }
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+
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+ p = early_alloc(PAGE_SIZE, nid);
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+ pud_populate(&init_mm, pud, p);
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+ }
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+
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+ pmd = pmd_offset(pud, addr);
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+ do {
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+ next = pmd_addr_end(addr, end);
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+ if (!pmd_large(*pmd))
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+ kasan_populate_pmd(pmd, addr, next, nid);
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+ } while (pmd++, addr = next, addr != end);
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+}
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+
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+static void __init kasan_populate_p4d(p4d_t *p4d, unsigned long addr,
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+ unsigned long end, int nid)
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+{
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+ pud_t *pud;
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+ unsigned long next;
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+
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+ if (p4d_none(*p4d)) {
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+ void *p = early_alloc(PAGE_SIZE, nid);
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+
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+ p4d_populate(&init_mm, p4d, p);
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+ }
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+
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+ pud = pud_offset(p4d, addr);
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+ do {
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+ next = pud_addr_end(addr, end);
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+ if (!pud_large(*pud))
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+ kasan_populate_pud(pud, addr, next, nid);
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+ } while (pud++, addr = next, addr != end);
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+}
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+
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+static void __init kasan_populate_pgd(pgd_t *pgd, unsigned long addr,
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+ unsigned long end, int nid)
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+{
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+ void *p;
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+ p4d_t *p4d;
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+ unsigned long next;
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+
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+ if (pgd_none(*pgd)) {
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+ p = early_alloc(PAGE_SIZE, nid);
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+ pgd_populate(&init_mm, pgd, p);
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+ }
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+
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+ p4d = p4d_offset(pgd, addr);
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+ do {
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+ next = p4d_addr_end(addr, end);
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+ kasan_populate_p4d(p4d, addr, next, nid);
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+ } while (p4d++, addr = next, addr != end);
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+}
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+
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+static void __init kasan_populate_shadow(unsigned long addr, unsigned long end,
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+ int nid)
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+{
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+ pgd_t *pgd;
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+ unsigned long next;
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+
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+ addr = addr & PAGE_MASK;
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+ end = round_up(end, PAGE_SIZE);
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+ pgd = pgd_offset_k(addr);
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+ do {
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+ next = pgd_addr_end(addr, end);
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+ kasan_populate_pgd(pgd, addr, next, nid);
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+ } while (pgd++, addr = next, addr != end);
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+}
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+
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+static void __init map_range(struct range *range)
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{
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unsigned long start;
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unsigned long end;
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@@ -25,7 +154,7 @@ static int __init map_range(struct range *range)
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start = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->start));
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end = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->end));
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- return vmemmap_populate(start, end, NUMA_NO_NODE);
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+ kasan_populate_shadow(start, end, early_pfn_to_nid(range->start));
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}
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static void __init clear_pgds(unsigned long start,
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@@ -188,16 +317,16 @@ void __init kasan_init(void)
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if (pfn_mapped[i].end == 0)
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break;
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- if (map_range(&pfn_mapped[i]))
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- panic("kasan: unable to allocate shadow!");
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+ map_range(&pfn_mapped[i]);
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}
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+
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kasan_populate_zero_shadow(
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kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
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kasan_mem_to_shadow((void *)__START_KERNEL_map));
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- vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext),
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- (unsigned long)kasan_mem_to_shadow(_end),
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- NUMA_NO_NODE);
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+ kasan_populate_shadow((unsigned long)kasan_mem_to_shadow(_stext),
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+ (unsigned long)kasan_mem_to_shadow(_end),
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+ early_pfn_to_nid(__pa(_stext)));
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kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
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(void *)KASAN_SHADOW_END);
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diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
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index 67d07802ae95..8b5499bb24bb 100644
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--- a/arch/x86/Kconfig
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+++ b/arch/x86/Kconfig
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@@ -106,7 +106,7 @@ config X86
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select HAVE_ARCH_AUDITSYSCALL
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select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
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select HAVE_ARCH_JUMP_LABEL
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- select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
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+ select HAVE_ARCH_KASAN if X86_64
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select HAVE_ARCH_KGDB
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select HAVE_ARCH_KMEMCHECK
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select HAVE_ARCH_MMAP_RND_BITS if MMU
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--
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2.14.2
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