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kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN
KASAN learns about hotadded memory via the memory hotplug notifier.
devm_memremap_pages() intentionally skips calling memory hotplug
notifiers. So KASAN doesn't know anything about new memory added by
devm_memremap_pages(). This causes a crash when KASAN tries to access
non-existent shadow memory:
BUG: unable to handle kernel paging request at ffffed0078000000
RIP: 0010:check_memory_region+0x82/0x1e0
Call Trace:
memcpy+0x1f/0x50
pmem_do_bvec+0x163/0x720
pmem_make_request+0x305/0xac0
generic_make_request+0x54f/0xcf0
submit_bio+0x9c/0x370
submit_bh_wbc+0x4c7/0x700
block_read_full_page+0x5ef/0x870
do_read_cache_page+0x2b8/0xb30
read_dev_sector+0xbd/0x3f0
read_lba.isra.0+0x277/0x670
efi_partition+0x41a/0x18f0
check_partition+0x30d/0x5e9
rescan_partitions+0x18c/0x840
__blkdev_get+0x859/0x1060
blkdev_get+0x23f/0x810
__device_add_disk+0x9c8/0xde0
pmem_attach_disk+0x9a8/0xf50
nvdimm_bus_probe+0xf3/0x3c0
driver_probe_device+0x493/0xbd0
bus_for_each_drv+0x118/0x1b0
__device_attach+0x1cd/0x2b0
bus_probe_device+0x1ac/0x260
device_add+0x90d/0x1380
nd_async_device_register+0xe/0x50
async_run_entry_fn+0xc3/0x5d0
process_one_work+0xa0a/0x1810
worker_thread+0x87/0xe80
kthread+0x2d7/0x390
ret_from_fork+0x3a/0x50
Add kasan_add_zero_shadow()/kasan_remove_zero_shadow() - post mm_init()
interface to map/unmap kasan_zero_page at requested virtual addresses.
And use it to add/remove the shadow memory for hotplugged/unplugged
device memory.
Link: http://lkml.kernel.org/r/20180629164932.740-1-aryabinin@virtuozzo.com
Fixes: 41e94a8513 ("add devm_memremap_pages")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrey Ryabinin
Linus Torvalds
parent
50f8b92f21
commit
0207df4fa1
@ -20,7 +20,7 @@ extern pmd_t kasan_zero_pmd[PTRS_PER_PMD];
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extern pud_t kasan_zero_pud[PTRS_PER_PUD];
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extern p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D];
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void kasan_populate_zero_shadow(const void *shadow_start,
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int kasan_populate_zero_shadow(const void *shadow_start,
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const void *shadow_end);
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static inline void *kasan_mem_to_shadow(const void *addr)
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@ -71,6 +71,9 @@ struct kasan_cache {
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int kasan_module_alloc(void *addr, size_t size);
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void kasan_free_shadow(const struct vm_struct *vm);
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int kasan_add_zero_shadow(void *start, unsigned long size);
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void kasan_remove_zero_shadow(void *start, unsigned long size);
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size_t ksize(const void *);
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static inline void kasan_unpoison_slab(const void *ptr) { ksize(ptr); }
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size_t kasan_metadata_size(struct kmem_cache *cache);
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@ -124,6 +127,14 @@ static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
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static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
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static inline void kasan_free_shadow(const struct vm_struct *vm) {}
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static inline int kasan_add_zero_shadow(void *start, unsigned long size)
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{
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return 0;
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}
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static inline void kasan_remove_zero_shadow(void *start,
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unsigned long size)
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{}
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static inline void kasan_unpoison_slab(const void *ptr) { }
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static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
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@ -5,6 +5,7 @@
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#include <linux/types.h>
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#include <linux/pfn_t.h>
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#include <linux/io.h>
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#include <linux/kasan.h>
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#include <linux/mm.h>
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#include <linux/memory_hotplug.h>
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#include <linux/swap.h>
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@ -137,6 +138,7 @@ static void devm_memremap_pages_release(void *data)
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mem_hotplug_begin();
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arch_remove_memory(align_start, align_size, pgmap->altmap_valid ?
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&pgmap->altmap : NULL);
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kasan_remove_zero_shadow(__va(align_start), align_size);
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mem_hotplug_done();
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untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
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@ -239,6 +241,12 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
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goto err_pfn_remap;
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mem_hotplug_begin();
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error = kasan_add_zero_shadow(__va(align_start), align_size);
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if (error) {
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mem_hotplug_done();
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goto err_kasan;
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}
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error = arch_add_memory(nid, align_start, align_size, altmap, false);
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if (!error)
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move_pfn_range_to_zone(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
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@ -267,6 +275,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
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return __va(res->start);
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err_add_memory:
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kasan_remove_zero_shadow(__va(align_start), align_size);
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err_kasan:
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untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
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err_pfn_remap:
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err_radix:
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@ -17,10 +17,13 @@
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#include <linux/memblock.h>
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#include <linux/mm.h>
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#include <linux/pfn.h>
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#include <linux/slab.h>
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#include <asm/page.h>
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#include <asm/pgalloc.h>
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#include "kasan.h"
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/*
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* This page serves two purposes:
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* - It used as early shadow memory. The entire shadow region populated
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@ -32,22 +35,59 @@ unsigned char kasan_zero_page[PAGE_SIZE] __page_aligned_bss;
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#if CONFIG_PGTABLE_LEVELS > 4
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p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D] __page_aligned_bss;
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static inline bool kasan_p4d_table(pgd_t pgd)
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{
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return pgd_page(pgd) == virt_to_page(lm_alias(kasan_zero_p4d));
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}
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#else
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static inline bool kasan_p4d_table(pgd_t pgd)
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{
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return 0;
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}
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#endif
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#if CONFIG_PGTABLE_LEVELS > 3
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pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss;
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static inline bool kasan_pud_table(p4d_t p4d)
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{
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return p4d_page(p4d) == virt_to_page(lm_alias(kasan_zero_pud));
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}
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#else
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static inline bool kasan_pud_table(p4d_t p4d)
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{
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return 0;
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}
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#endif
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#if CONFIG_PGTABLE_LEVELS > 2
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pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss;
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static inline bool kasan_pmd_table(pud_t pud)
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{
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return pud_page(pud) == virt_to_page(lm_alias(kasan_zero_pmd));
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}
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#else
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static inline bool kasan_pmd_table(pud_t pud)
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{
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return 0;
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}
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#endif
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pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss;
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static inline bool kasan_pte_table(pmd_t pmd)
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{
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return pmd_page(pmd) == virt_to_page(lm_alias(kasan_zero_pte));
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}
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static inline bool kasan_zero_page_entry(pte_t pte)
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{
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return pte_page(pte) == virt_to_page(lm_alias(kasan_zero_page));
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}
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static __init void *early_alloc(size_t size, int node)
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{
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return memblock_virt_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS),
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BOOTMEM_ALLOC_ACCESSIBLE, node);
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}
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static void __init zero_pte_populate(pmd_t *pmd, unsigned long addr,
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static void __ref zero_pte_populate(pmd_t *pmd, unsigned long addr,
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unsigned long end)
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{
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pte_t *pte = pte_offset_kernel(pmd, addr);
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@ -63,7 +103,7 @@ static void __init zero_pte_populate(pmd_t *pmd, unsigned long addr,
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}
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}
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static void __init zero_pmd_populate(pud_t *pud, unsigned long addr,
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static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr,
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unsigned long end)
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{
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pmd_t *pmd = pmd_offset(pud, addr);
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@ -78,14 +118,24 @@ static void __init zero_pmd_populate(pud_t *pud, unsigned long addr,
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}
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if (pmd_none(*pmd)) {
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pmd_populate_kernel(&init_mm, pmd,
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early_alloc(PAGE_SIZE, NUMA_NO_NODE));
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pte_t *p;
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if (slab_is_available())
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p = pte_alloc_one_kernel(&init_mm, addr);
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else
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p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
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if (!p)
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return -ENOMEM;
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pmd_populate_kernel(&init_mm, pmd, p);
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}
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zero_pte_populate(pmd, addr, next);
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} while (pmd++, addr = next, addr != end);
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return 0;
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}
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static void __init zero_pud_populate(p4d_t *p4d, unsigned long addr,
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static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr,
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unsigned long end)
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{
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pud_t *pud = pud_offset(p4d, addr);
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@ -103,14 +153,24 @@ static void __init zero_pud_populate(p4d_t *p4d, unsigned long addr,
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}
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if (pud_none(*pud)) {
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pud_populate(&init_mm, pud,
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early_alloc(PAGE_SIZE, NUMA_NO_NODE));
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pmd_t *p;
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if (slab_is_available()) {
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p = pmd_alloc(&init_mm, pud, addr);
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if (!p)
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return -ENOMEM;
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} else {
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pud_populate(&init_mm, pud,
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early_alloc(PAGE_SIZE, NUMA_NO_NODE));
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}
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}
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zero_pmd_populate(pud, addr, next);
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} while (pud++, addr = next, addr != end);
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return 0;
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}
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static void __init zero_p4d_populate(pgd_t *pgd, unsigned long addr,
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static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr,
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unsigned long end)
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{
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p4d_t *p4d = p4d_offset(pgd, addr);
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@ -132,11 +192,21 @@ static void __init zero_p4d_populate(pgd_t *pgd, unsigned long addr,
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}
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if (p4d_none(*p4d)) {
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p4d_populate(&init_mm, p4d,
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early_alloc(PAGE_SIZE, NUMA_NO_NODE));
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pud_t *p;
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if (slab_is_available()) {
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p = pud_alloc(&init_mm, p4d, addr);
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if (!p)
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return -ENOMEM;
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} else {
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p4d_populate(&init_mm, p4d,
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early_alloc(PAGE_SIZE, NUMA_NO_NODE));
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}
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}
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zero_pud_populate(p4d, addr, next);
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} while (p4d++, addr = next, addr != end);
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return 0;
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}
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/**
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@ -145,7 +215,7 @@ static void __init zero_p4d_populate(pgd_t *pgd, unsigned long addr,
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* @shadow_start - start of the memory range to populate
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* @shadow_end - end of the memory range to populate
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*/
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void __init kasan_populate_zero_shadow(const void *shadow_start,
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int __ref kasan_populate_zero_shadow(const void *shadow_start,
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const void *shadow_end)
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{
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unsigned long addr = (unsigned long)shadow_start;
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@ -191,9 +261,229 @@ void __init kasan_populate_zero_shadow(const void *shadow_start,
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}
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if (pgd_none(*pgd)) {
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pgd_populate(&init_mm, pgd,
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early_alloc(PAGE_SIZE, NUMA_NO_NODE));
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p4d_t *p;
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if (slab_is_available()) {
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p = p4d_alloc(&init_mm, pgd, addr);
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if (!p)
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return -ENOMEM;
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} else {
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pgd_populate(&init_mm, pgd,
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early_alloc(PAGE_SIZE, NUMA_NO_NODE));
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}
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}
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zero_p4d_populate(pgd, addr, next);
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} while (pgd++, addr = next, addr != end);
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return 0;
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}
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static void kasan_free_pte(pte_t *pte_start, pmd_t *pmd)
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{
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pte_t *pte;
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int i;
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for (i = 0; i < PTRS_PER_PTE; i++) {
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pte = pte_start + i;
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if (!pte_none(*pte))
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return;
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}
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pte_free_kernel(&init_mm, (pte_t *)page_to_virt(pmd_page(*pmd)));
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pmd_clear(pmd);
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}
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static void kasan_free_pmd(pmd_t *pmd_start, pud_t *pud)
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{
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pmd_t *pmd;
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int i;
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for (i = 0; i < PTRS_PER_PMD; i++) {
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pmd = pmd_start + i;
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if (!pmd_none(*pmd))
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return;
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}
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pmd_free(&init_mm, (pmd_t *)page_to_virt(pud_page(*pud)));
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pud_clear(pud);
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}
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static void kasan_free_pud(pud_t *pud_start, p4d_t *p4d)
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{
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pud_t *pud;
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int i;
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for (i = 0; i < PTRS_PER_PUD; i++) {
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pud = pud_start + i;
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if (!pud_none(*pud))
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return;
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}
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pud_free(&init_mm, (pud_t *)page_to_virt(p4d_page(*p4d)));
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p4d_clear(p4d);
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}
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static void kasan_free_p4d(p4d_t *p4d_start, pgd_t *pgd)
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{
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p4d_t *p4d;
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int i;
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for (i = 0; i < PTRS_PER_P4D; i++) {
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p4d = p4d_start + i;
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if (!p4d_none(*p4d))
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return;
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}
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p4d_free(&init_mm, (p4d_t *)page_to_virt(pgd_page(*pgd)));
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pgd_clear(pgd);
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}
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static void kasan_remove_pte_table(pte_t *pte, unsigned long addr,
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unsigned long end)
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{
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unsigned long next;
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for (; addr < end; addr = next, pte++) {
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next = (addr + PAGE_SIZE) & PAGE_MASK;
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if (next > end)
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next = end;
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if (!pte_present(*pte))
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continue;
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if (WARN_ON(!kasan_zero_page_entry(*pte)))
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continue;
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pte_clear(&init_mm, addr, pte);
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}
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}
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static void kasan_remove_pmd_table(pmd_t *pmd, unsigned long addr,
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unsigned long end)
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{
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unsigned long next;
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for (; addr < end; addr = next, pmd++) {
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pte_t *pte;
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next = pmd_addr_end(addr, end);
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if (!pmd_present(*pmd))
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continue;
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if (kasan_pte_table(*pmd)) {
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if (IS_ALIGNED(addr, PMD_SIZE) &&
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IS_ALIGNED(next, PMD_SIZE))
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pmd_clear(pmd);
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continue;
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}
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pte = pte_offset_kernel(pmd, addr);
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kasan_remove_pte_table(pte, addr, next);
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kasan_free_pte(pte_offset_kernel(pmd, 0), pmd);
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}
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}
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static void kasan_remove_pud_table(pud_t *pud, unsigned long addr,
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unsigned long end)
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{
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unsigned long next;
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for (; addr < end; addr = next, pud++) {
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pmd_t *pmd, *pmd_base;
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next = pud_addr_end(addr, end);
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if (!pud_present(*pud))
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continue;
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if (kasan_pmd_table(*pud)) {
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if (IS_ALIGNED(addr, PUD_SIZE) &&
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IS_ALIGNED(next, PUD_SIZE))
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pud_clear(pud);
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continue;
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}
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pmd = pmd_offset(pud, addr);
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pmd_base = pmd_offset(pud, 0);
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kasan_remove_pmd_table(pmd, addr, next);
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kasan_free_pmd(pmd_base, pud);
|
||||
}
|
||||
}
|
||||
|
||||
static void kasan_remove_p4d_table(p4d_t *p4d, unsigned long addr,
|
||||
unsigned long end)
|
||||
{
|
||||
unsigned long next;
|
||||
|
||||
for (; addr < end; addr = next, p4d++) {
|
||||
pud_t *pud;
|
||||
|
||||
next = p4d_addr_end(addr, end);
|
||||
|
||||
if (!p4d_present(*p4d))
|
||||
continue;
|
||||
|
||||
if (kasan_pud_table(*p4d)) {
|
||||
if (IS_ALIGNED(addr, P4D_SIZE) &&
|
||||
IS_ALIGNED(next, P4D_SIZE))
|
||||
p4d_clear(p4d);
|
||||
continue;
|
||||
}
|
||||
pud = pud_offset(p4d, addr);
|
||||
kasan_remove_pud_table(pud, addr, next);
|
||||
kasan_free_pud(pud_offset(p4d, 0), p4d);
|
||||
}
|
||||
}
|
||||
|
||||
void kasan_remove_zero_shadow(void *start, unsigned long size)
|
||||
{
|
||||
unsigned long addr, end, next;
|
||||
pgd_t *pgd;
|
||||
|
||||
addr = (unsigned long)kasan_mem_to_shadow(start);
|
||||
end = addr + (size >> KASAN_SHADOW_SCALE_SHIFT);
|
||||
|
||||
if (WARN_ON((unsigned long)start %
|
||||
(KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) ||
|
||||
WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)))
|
||||
return;
|
||||
|
||||
for (; addr < end; addr = next) {
|
||||
p4d_t *p4d;
|
||||
|
||||
next = pgd_addr_end(addr, end);
|
||||
|
||||
pgd = pgd_offset_k(addr);
|
||||
if (!pgd_present(*pgd))
|
||||
continue;
|
||||
|
||||
if (kasan_p4d_table(*pgd)) {
|
||||
if (IS_ALIGNED(addr, PGDIR_SIZE) &&
|
||||
IS_ALIGNED(next, PGDIR_SIZE))
|
||||
pgd_clear(pgd);
|
||||
continue;
|
||||
}
|
||||
|
||||
p4d = p4d_offset(pgd, addr);
|
||||
kasan_remove_p4d_table(p4d, addr, next);
|
||||
kasan_free_p4d(p4d_offset(pgd, 0), pgd);
|
||||
}
|
||||
}
|
||||
|
||||
int kasan_add_zero_shadow(void *start, unsigned long size)
|
||||
{
|
||||
int ret;
|
||||
void *shadow_start, *shadow_end;
|
||||
|
||||
shadow_start = kasan_mem_to_shadow(start);
|
||||
shadow_end = shadow_start + (size >> KASAN_SHADOW_SCALE_SHIFT);
|
||||
|
||||
if (WARN_ON((unsigned long)start %
|
||||
(KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) ||
|
||||
WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)))
|
||||
return -EINVAL;
|
||||
|
||||
ret = kasan_populate_zero_shadow(shadow_start, shadow_end);
|
||||
if (ret)
|
||||
kasan_remove_zero_shadow(shadow_start,
|
||||
size >> KASAN_SHADOW_SCALE_SHIFT);
|
||||
return ret;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user