[PATCH v11 07/24] kasan: rename kasan_zero_page to kasan_early_shadow_page

Andrey Konovalov
2018-11-19T17:27:11Z

With tag based KASAN mode the early shadow value is 0xff and not 0x00,
so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to
kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
arch/arm64/mm/kasan_init.c | 43 ++++++++++++---------
arch/s390/mm/dump_pagetables.c | 16 ++++----
arch/s390/mm/kasan_init.c | 33 +++++++++-------
arch/x86/mm/dump_pagetables.c | 11 +++---
arch/x86/mm/kasan_init_64.c | 55 +++++++++++++-------------
arch/xtensa/mm/kasan_init.c | 18 +++++----
include/linux/kasan.h | 12 +++---
mm/kasan/init.c | 70 +++++++++++++++++++---------------
8 files changed, 144 insertions(+), 114 deletions(-)

diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index 63527e585aac..4ebc19422931 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -47,8 +47,9 @@ static pte_t *__init kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node,
bool early)
{
if (pmd_none(READ_ONCE(*pmdp))) {
- phys_addr_t pte_phys = early ? __pa_symbol(kasan_zero_pte)
- : kasan_alloc_zeroed_page(node);
+ phys_addr_t pte_phys = early ?
+ __pa_symbol(kasan_early_shadow_pte)
+ : kasan_alloc_zeroed_page(node);
__pmd_populate(pmdp, pte_phys, PMD_TYPE_TABLE);
}

@@ -60,8 +61,9 @@ static pmd_t *__init kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node,
bool early)
{
if (pud_none(READ_ONCE(*pudp))) {
- phys_addr_t pmd_phys = early ? __pa_symbol(kasan_zero_pmd)
- : kasan_alloc_zeroed_page(node);
+ phys_addr_t pmd_phys = early ?
+ __pa_symbol(kasan_early_shadow_pmd)
+ : kasan_alloc_zeroed_page(node);
__pud_populate(pudp, pmd_phys, PMD_TYPE_TABLE);
}

@@ -72,8 +74,9 @@ static pud_t *__init kasan_pud_offset(pgd_t *pgdp, unsigned long addr, int node,
bool early)
{
if (pgd_none(READ_ONCE(*pgdp))) {
- phys_addr_t pud_phys = early ? __pa_symbol(kasan_zero_pud)
- : kasan_alloc_zeroed_page(node);
+ phys_addr_t pud_phys = early ?
+ __pa_symbol(kasan_early_shadow_pud)
+ : kasan_alloc_zeroed_page(node);
__pgd_populate(pgdp, pud_phys, PMD_TYPE_TABLE);
}

@@ -87,8 +90,9 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr,
pte_t *ptep = kasan_pte_offset(pmdp, addr, node, early);

do {
- phys_addr_t page_phys = early ? __pa_symbol(kasan_zero_page)
- : kasan_alloc_zeroed_page(node);
+ phys_addr_t page_phys = early ?
+ __pa_symbol(kasan_early_shadow_page)
+ : kasan_alloc_zeroed_page(node);
next = addr + PAGE_SIZE;
set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL));
} while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep)));
@@ -205,14 +209,14 @@ void __init kasan_init(void)
kasan_map_populate(kimg_shadow_start, kimg_shadow_end,
early_pfn_to_nid(virt_to_pfn(lm_alias(_text))));

- kasan_populate_zero_shadow((void *)KASAN_SHADOW_START,
- (void *)mod_shadow_start);
- kasan_populate_zero_shadow((void *)kimg_shadow_end,
- kasan_mem_to_shadow((void *)PAGE_OFFSET));
+ kasan_populate_early_shadow((void *)KASAN_SHADOW_START,
+ (void *)mod_shadow_start);
+ kasan_populate_early_shadow((void *)kimg_shadow_end,
+ kasan_mem_to_shadow((void *)PAGE_OFFSET));

if (kimg_shadow_start > mod_shadow_end)
- kasan_populate_zero_shadow((void *)mod_shadow_end,
- (void *)kimg_shadow_start);
+ kasan_populate_early_shadow((void *)mod_shadow_end,
+ (void *)kimg_shadow_start);

for_each_memblock(memory, reg) {
void *start = (void *)__phys_to_virt(reg->base);
@@ -227,14 +231,15 @@ void __init kasan_init(void)
}

/*
- * KAsan may reuse the contents of kasan_zero_pte directly, so we
- * should make sure that it maps the zero page read-only.
+ * KAsan may reuse the contents of kasan_early_shadow_pte directly,
+ * so we should make sure that it maps the zero page read-only.
*/
for (i = 0; i < PTRS_PER_PTE; i++)
- set_pte(&kasan_zero_pte[i],
- pfn_pte(sym_to_pfn(kasan_zero_page), PAGE_KERNEL_RO));
+ set_pte(&kasan_early_shadow_pte[i],
+ pfn_pte(sym_to_pfn(kasan_early_shadow_page),
+ PAGE_KERNEL_RO));

- memset(kasan_zero_page, 0, PAGE_SIZE);
+ memset(kasan_early_shadow_page, 0, PAGE_SIZE);
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));

/* At this point kasan is fully initialized. Enable error messages */
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index 363f6470d742..43cdaf96f79f 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -111,11 +111,11 @@ static void note_page(struct seq_file *m, struct pg_state *st,
}

#ifdef CONFIG_KASAN
-static void note_kasan_zero_page(struct seq_file *m, struct pg_state *st)
+static void note_kasan_early_shadow_page(struct seq_file *m, struct pg_state *st)
{
unsigned int prot;

- prot = pte_val(*kasan_zero_pte) &
+ prot = pte_val(*kasan_early_shadow_pte) &
(_PAGE_PROTECT | _PAGE_INVALID | _PAGE_NOEXEC);
note_page(m, st, prot, 4);
}
@@ -154,8 +154,8 @@ static void walk_pmd_level(struct seq_file *m, struct pg_state *st,
int i;

#ifdef CONFIG_KASAN
- if ((pud_val(*pud) & PAGE_MASK) == __pa(kasan_zero_pmd)) {
- note_kasan_zero_page(m, st);
+ if ((pud_val(*pud) & PAGE_MASK) == __pa(kasan_early_shadow_pmd)) {
+ note_kasan_early_shadow_page(m, st);
return;
}
#endif
@@ -185,8 +185,8 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st,
int i;

#ifdef CONFIG_KASAN
- if ((p4d_val(*p4d) & PAGE_MASK) == __pa(kasan_zero_pud)) {
- note_kasan_zero_page(m, st);
+ if ((p4d_val(*p4d) & PAGE_MASK) == __pa(kasan_early_shadow_pud)) {
+ note_kasan_early_shadow_page(m, st);
return;
}
#endif
@@ -215,8 +215,8 @@ static void walk_p4d_level(struct seq_file *m, struct pg_state *st,
int i;

#ifdef CONFIG_KASAN
- if ((pgd_val(*pgd) & PAGE_MASK) == __pa(kasan_zero_p4d)) {
- note_kasan_zero_page(m, st);
+ if ((pgd_val(*pgd) & PAGE_MASK) == __pa(kasan_early_shadow_p4d)) {
+ note_kasan_early_shadow_page(m, st);
return;
}
#endif
diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c
index acb9645b762b..bac5c27d11fc 100644
--- a/arch/s390/mm/kasan_init.c
+++ b/arch/s390/mm/kasan_init.c
@@ -107,7 +107,8 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PGDIR_SIZE) &&
end - address >= PGDIR_SIZE) {
- pgd_populate(&init_mm, pg_dir, kasan_zero_p4d);
+ pgd_populate(&init_mm, pg_dir,
+ kasan_early_shadow_p4d);
address = (address + PGDIR_SIZE) & PGDIR_MASK;
continue;
}
@@ -120,7 +121,8 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, P4D_SIZE) &&
end - address >= P4D_SIZE) {
- p4d_populate(&init_mm, p4_dir, kasan_zero_pud);
+ p4d_populate(&init_mm, p4_dir,
+ kasan_early_shadow_pud);
address = (address + P4D_SIZE) & P4D_MASK;
continue;
}
@@ -133,7 +135,8 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PUD_SIZE) &&
end - address >= PUD_SIZE) {
- pud_populate(&init_mm, pu_dir, kasan_zero_pmd);
+ pud_populate(&init_mm, pu_dir,
+ kasan_early_shadow_pmd);
address = (address + PUD_SIZE) & PUD_MASK;
continue;
}
@@ -146,7 +149,8 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PMD_SIZE) &&
end - address >= PMD_SIZE) {
- pmd_populate(&init_mm, pm_dir, kasan_zero_pte);
+ pmd_populate(&init_mm, pm_dir,
+ kasan_early_shadow_pte);
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
@@ -188,7 +192,7 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
pte_val(*pt_dir) = __pa(page) | pgt_prot;
break;
case POPULATE_ZERO_SHADOW:
- page = kasan_zero_page;
+ page = kasan_early_shadow_page;
pte_val(*pt_dir) = __pa(page) | pgt_prot_zero;
break;
}
@@ -256,14 +260,14 @@ void __init kasan_early_init(void)
unsigned long vmax;
unsigned long pgt_prot = pgprot_val(PAGE_KERNEL_RO);
pte_t pte_z;
- pmd_t pmd_z = __pmd(__pa(kasan_zero_pte) | _SEGMENT_ENTRY);
- pud_t pud_z = __pud(__pa(kasan_zero_pmd) | _REGION3_ENTRY);
- p4d_t p4d_z = __p4d(__pa(kasan_zero_pud) | _REGION2_ENTRY);
+ pmd_t pmd_z = __pmd(__pa(kasan_early_shadow_pte) | _SEGMENT_ENTRY);
+ pud_t pud_z = __pud(__pa(kasan_early_shadow_pmd) | _REGION3_ENTRY);
+ p4d_t p4d_z = __p4d(__pa(kasan_early_shadow_pud) | _REGION2_ENTRY);

kasan_early_detect_facilities();
if (!has_nx)
pgt_prot &= ~_PAGE_NOEXEC;
- pte_z = __pte(__pa(kasan_zero_page) | pgt_prot);
+ pte_z = __pte(__pa(kasan_early_shadow_page) | pgt_prot);

memsize = get_mem_detect_end();
if (!memsize)
@@ -292,10 +296,13 @@ void __init kasan_early_init(void)
}

/* init kasan zero shadow */
- crst_table_init((unsigned long *)kasan_zero_p4d, p4d_val(p4d_z));
- crst_table_init((unsigned long *)kasan_zero_pud, pud_val(pud_z));
- crst_table_init((unsigned long *)kasan_zero_pmd, pmd_val(pmd_z));
- memset64((u64 *)kasan_zero_pte, pte_val(pte_z), PTRS_PER_PTE);
+ crst_table_init((unsigned long *)kasan_early_shadow_p4d,
+ p4d_val(p4d_z));
+ crst_table_init((unsigned long *)kasan_early_shadow_pud,
+ pud_val(pud_z));
+ crst_table_init((unsigned long *)kasan_early_shadow_pmd,
+ pmd_val(pmd_z));
+ memset64((u64 *)kasan_early_shadow_pte, pte_val(pte_z), PTRS_PER_PTE);

shadow_alloc_size = memsize >> KASAN_SHADOW_SCALE_SHIFT;
pgalloc_low = round_up((unsigned long)_end, _SEGMENT_SIZE);
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index fc37bbd23eb8..c4696ab9a72b 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -380,7 +380,7 @@ static void walk_pte_level(struct seq_file *m, struct pg_state *st, pmd_t addr,

/*
* This is an optimization for KASAN=y case. Since all kasan page tables
- * eventually point to the kasan_zero_page we could call note_page()
+ * eventually point to the kasan_early_shadow_page we could call note_page()
* right away without walking through lower level page tables. This saves
* us dozens of seconds (minutes for 5-level config) while checking for
* W+X mapping or reading kernel_page_tables debugfs file.
@@ -388,10 +388,11 @@ static void walk_pte_level(struct seq_file *m, struct pg_state *st, pmd_t addr,
static inline bool kasan_page_table(struct seq_file *m, struct pg_state *st,
void *pt)
{
- if (__pa(pt) == __pa(kasan_zero_pmd) ||
- (pgtable_l5_enabled() && __pa(pt) == __pa(kasan_zero_p4d)) ||
- __pa(pt) == __pa(kasan_zero_pud)) {
- pgprotval_t prot = pte_flags(kasan_zero_pte[0]);
+ if (__pa(pt) == __pa(kasan_early_shadow_pmd) ||
+ (pgtable_l5_enabled() &&
+ __pa(pt) == __pa(kasan_early_shadow_p4d)) ||
+ __pa(pt) == __pa(kasan_early_shadow_pud)) {
+ pgprotval_t prot = pte_flags(kasan_early_shadow_pte[0]);
note_page(m, st, __pgprot(prot), 0, 5);
return true;
}
diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
index 04a9cf6b034f..462fde83b515 100644
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -211,7 +211,8 @@ static void __init kasan_early_p4d_populate(pgd_t *pgd,
unsigned long next;

if (pgd_none(*pgd)) {
- pgd_entry = __pgd(_KERNPG_TABLE | __pa_nodebug(kasan_zero_p4d));
+ pgd_entry = __pgd(_KERNPG_TABLE |
+ __pa_nodebug(kasan_early_shadow_p4d));
set_pgd(pgd, pgd_entry);
}

@@ -222,7 +223,8 @@ static void __init kasan_early_p4d_populate(pgd_t *pgd,
if (!p4d_none(*p4d))
continue;

- p4d_entry = __p4d(_KERNPG_TABLE | __pa_nodebug(kasan_zero_pud));
+ p4d_entry = __p4d(_KERNPG_TABLE |
+ __pa_nodebug(kasan_early_shadow_pud));
set_p4d(p4d, p4d_entry);
} while (p4d++, addr = next, addr != end && p4d_none(*p4d));
}
@@ -261,10 +263,11 @@ static struct notifier_block kasan_die_notifier = {
void __init kasan_early_init(void)
{
int i;
- pteval_t pte_val = __pa_nodebug(kasan_zero_page) | __PAGE_KERNEL | _PAGE_ENC;
- pmdval_t pmd_val = __pa_nodebug(kasan_zero_pte) | _KERNPG_TABLE;
- pudval_t pud_val = __pa_nodebug(kasan_zero_pmd) | _KERNPG_TABLE;
- p4dval_t p4d_val = __pa_nodebug(kasan_zero_pud) | _KERNPG_TABLE;
+ pteval_t pte_val = __pa_nodebug(kasan_early_shadow_page) |
+ __PAGE_KERNEL | _PAGE_ENC;
+ pmdval_t pmd_val = __pa_nodebug(kasan_early_shadow_pte) | _KERNPG_TABLE;
+ pudval_t pud_val = __pa_nodebug(kasan_early_shadow_pmd) | _KERNPG_TABLE;
+ p4dval_t p4d_val = __pa_nodebug(kasan_early_shadow_pud) | _KERNPG_TABLE;

/* Mask out unsupported __PAGE_KERNEL bits: */
pte_val &= __default_kernel_pte_mask;
@@ -273,16 +276,16 @@ void __init kasan_early_init(void)
p4d_val &= __default_kernel_pte_mask;

for (i = 0; i < PTRS_PER_PTE; i++)
- kasan_zero_pte[i] = __pte(pte_val);
+ kasan_early_shadow_pte[i] = __pte(pte_val);

for (i = 0; i < PTRS_PER_PMD; i++)
- kasan_zero_pmd[i] = __pmd(pmd_val);
+ kasan_early_shadow_pmd[i] = __pmd(pmd_val);

for (i = 0; i < PTRS_PER_PUD; i++)
- kasan_zero_pud[i] = __pud(pud_val);
+ kasan_early_shadow_pud[i] = __pud(pud_val);

for (i = 0; pgtable_l5_enabled() && i < PTRS_PER_P4D; i++)
- kasan_zero_p4d[i] = __p4d(p4d_val);
+ kasan_early_shadow_p4d[i] = __p4d(p4d_val);

kasan_map_early_shadow(early_top_pgt);
kasan_map_early_shadow(init_top_pgt);
@@ -326,7 +329,7 @@ void __init kasan_init(void)

clear_pgds(KASAN_SHADOW_START & PGDIR_MASK, KASAN_SHADOW_END);

- kasan_populate_zero_shadow((void *)(KASAN_SHADOW_START & PGDIR_MASK),
+ kasan_populate_early_shadow((void *)(KASAN_SHADOW_START & PGDIR_MASK),
kasan_mem_to_shadow((void *)PAGE_OFFSET));

for (i = 0; i < E820_MAX_ENTRIES; i++) {
@@ -338,41 +341,41 @@ void __init kasan_init(void)

shadow_cpu_entry_begin = (void *)CPU_ENTRY_AREA_BASE;
shadow_cpu_entry_begin = kasan_mem_to_shadow(shadow_cpu_entry_begin);
- shadow_cpu_entry_begin = (void *)round_down((unsigned long)shadow_cpu_entry_begin,
- PAGE_SIZE);
+ shadow_cpu_entry_begin = (void *)round_down(
+ (unsigned long)shadow_cpu_entry_begin, PAGE_SIZE);

shadow_cpu_entry_end = (void *)(CPU_ENTRY_AREA_BASE +
CPU_ENTRY_AREA_MAP_SIZE);
shadow_cpu_entry_end = kasan_mem_to_shadow(shadow_cpu_entry_end);
- shadow_cpu_entry_end = (void *)round_up((unsigned long)shadow_cpu_entry_end,
- PAGE_SIZE);
+ shadow_cpu_entry_end = (void *)round_up(
+ (unsigned long)shadow_cpu_entry_end, PAGE_SIZE);

- kasan_populate_zero_shadow(
+ kasan_populate_early_shadow(
kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
shadow_cpu_entry_begin);

kasan_populate_shadow((unsigned long)shadow_cpu_entry_begin,
(unsigned long)shadow_cpu_entry_end, 0);

- kasan_populate_zero_shadow(shadow_cpu_entry_end,
- kasan_mem_to_shadow((void *)__START_KERNEL_map));
+ kasan_populate_early_shadow(shadow_cpu_entry_end,
+ kasan_mem_to_shadow((void *)__START_KERNEL_map));

kasan_populate_shadow((unsigned long)kasan_mem_to_shadow(_stext),
(unsigned long)kasan_mem_to_shadow(_end),
early_pfn_to_nid(__pa(_stext)));

- kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
- (void *)KASAN_SHADOW_END);
+ kasan_populate_early_shadow(kasan_mem_to_shadow((void *)MODULES_END),
+ (void *)KASAN_SHADOW_END);

load_cr3(init_top_pgt);
__flush_tlb_all();

/*
- * kasan_zero_page has been used as early shadow memory, thus it may
- * contain some garbage. Now we can clear and write protect it, since
- * after the TLB flush no one should write to it.
+ * kasan_early_shadow_page has been used as early shadow memory, thus
+ * it may contain some garbage. Now we can clear and write protect it,
+ * since after the TLB flush no one should write to it.
*/
- memset(kasan_zero_page, 0, PAGE_SIZE);
+ memset(kasan_early_shadow_page, 0, PAGE_SIZE);
for (i = 0; i < PTRS_PER_PTE; i++) {
pte_t pte;
pgprot_t prot;
@@ -380,8 +383,8 @@ void __init kasan_init(void)
prot = __pgprot(__PAGE_KERNEL_RO | _PAGE_ENC);
pgprot_val(prot) &= __default_kernel_pte_mask;

- pte = __pte(__pa(kasan_zero_page) | pgprot_val(prot));
- set_pte(&kasan_zero_pte[i], pte);
+ pte = __pte(__pa(kasan_early_shadow_page) | pgprot_val(prot));
+ set_pte(&kasan_early_shadow_pte[i], pte);
}
/* Flush TLBs again to be sure that write protection applied. */
__flush_tlb_all();
diff --git a/arch/xtensa/mm/kasan_init.c b/arch/xtensa/mm/kasan_init.c
index 6b95ca43aec0..1734cda6bc4a 100644
--- a/arch/xtensa/mm/kasan_init.c
+++ b/arch/xtensa/mm/kasan_init.c
@@ -24,12 +24,13 @@ void __init kasan_early_init(void)
int i;

for (i = 0; i < PTRS_PER_PTE; ++i)
- set_pte(kasan_zero_pte + i,
- mk_pte(virt_to_page(kasan_zero_page), PAGE_KERNEL));
+ set_pte(kasan_early_shadow_pte + i,
+ mk_pte(virt_to_page(kasan_early_shadow_page),
+ PAGE_KERNEL));

for (vaddr = 0; vaddr < KASAN_SHADOW_SIZE; vaddr += PMD_SIZE, ++pmd) {
BUG_ON(!pmd_none(*pmd));
- set_pmd(pmd, __pmd((unsigned long)kasan_zero_pte));
+ set_pmd(pmd, __pmd((unsigned long)kasan_early_shadow_pte));
}
early_trap_init();
}
@@ -80,13 +81,16 @@ void __init kasan_init(void)
populate(kasan_mem_to_shadow((void *)VMALLOC_START),
kasan_mem_to_shadow((void *)XCHAL_KSEG_BYPASS_VADDR));

- /* Write protect kasan_zero_page and zero-initialize it again. */
+ /*
+ * Write protect kasan_early_shadow_page and zero-initialize it again.
+ */
for (i = 0; i < PTRS_PER_PTE; ++i)
- set_pte(kasan_zero_pte + i,
- mk_pte(virt_to_page(kasan_zero_page), PAGE_KERNEL_RO));
+ set_pte(kasan_early_shadow_pte + i,
+ mk_pte(virt_to_page(kasan_early_shadow_page),
+ PAGE_KERNEL_RO));

local_flush_tlb_all();
- memset(kasan_zero_page, 0, PAGE_SIZE);
+ memset(kasan_early_shadow_page, 0, PAGE_SIZE);

/* At this point kasan is fully initialized. Enable error messages. */
current->kasan_depth = 0;
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index b66fdf5ea7ab..ec22d548d0d7 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -14,13 +14,13 @@ struct task_struct;
#include <asm/kasan.h>
#include <asm/pgtable.h>

-extern unsigned char kasan_zero_page[PAGE_SIZE];
-extern pte_t kasan_zero_pte[PTRS_PER_PTE];
-extern pmd_t kasan_zero_pmd[PTRS_PER_PMD];
-extern pud_t kasan_zero_pud[PTRS_PER_PUD];
-extern p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D];
+extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
+extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE];
+extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD];
+extern pud_t kasan_early_shadow_pud[PTRS_PER_PUD];
+extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];

-int kasan_populate_zero_shadow(const void *shadow_start,
+int kasan_populate_early_shadow(const void *shadow_start,
const void *shadow_end);

static inline void *kasan_mem_to_shadow(const void *addr)
diff --git a/mm/kasan/init.c b/mm/kasan/init.c
index c7550eb65922..2b21d3717d62 100644
--- a/mm/kasan/init.c
+++ b/mm/kasan/init.c
@@ -30,13 +30,13 @@
* - Latter it reused it as zero shadow to cover large ranges of memory
* that allowed to access, but not handled by kasan (vmalloc/vmemmap ...).
*/
-unsigned char kasan_zero_page[PAGE_SIZE] __page_aligned_bss;
+unsigned char kasan_early_shadow_page[PAGE_SIZE] __page_aligned_bss;

#if CONFIG_PGTABLE_LEVELS > 4
-p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D] __page_aligned_bss;
+p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D] __page_aligned_bss;
static inline bool kasan_p4d_table(pgd_t pgd)
{
- return pgd_page(pgd) == virt_to_page(lm_alias(kasan_zero_p4d));
+ return pgd_page(pgd) == virt_to_page(lm_alias(kasan_early_shadow_p4d));
}
#else
static inline bool kasan_p4d_table(pgd_t pgd)
@@ -45,10 +45,10 @@ static inline bool kasan_p4d_table(pgd_t pgd)
}
#endif
#if CONFIG_PGTABLE_LEVELS > 3
-pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss;
+pud_t kasan_early_shadow_pud[PTRS_PER_PUD] __page_aligned_bss;
static inline bool kasan_pud_table(p4d_t p4d)
{
- return p4d_page(p4d) == virt_to_page(lm_alias(kasan_zero_pud));
+ return p4d_page(p4d) == virt_to_page(lm_alias(kasan_early_shadow_pud));
}
#else
static inline bool kasan_pud_table(p4d_t p4d)
@@ -57,10 +57,10 @@ static inline bool kasan_pud_table(p4d_t p4d)
}
#endif
#if CONFIG_PGTABLE_LEVELS > 2
-pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss;
+pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD] __page_aligned_bss;
static inline bool kasan_pmd_table(pud_t pud)
{
- return pud_page(pud) == virt_to_page(lm_alias(kasan_zero_pmd));
+ return pud_page(pud) == virt_to_page(lm_alias(kasan_early_shadow_pmd));
}
#else
static inline bool kasan_pmd_table(pud_t pud)
@@ -68,16 +68,16 @@ static inline bool kasan_pmd_table(pud_t pud)
return 0;
}
#endif
-pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss;
+pte_t kasan_early_shadow_pte[PTRS_PER_PTE] __page_aligned_bss;

static inline bool kasan_pte_table(pmd_t pmd)
{
- return pmd_page(pmd) == virt_to_page(lm_alias(kasan_zero_pte));
+ return pmd_page(pmd) == virt_to_page(lm_alias(kasan_early_shadow_pte));
}

-static inline bool kasan_zero_page_entry(pte_t pte)
+static inline bool kasan_early_shadow_page_entry(pte_t pte)
{
- return pte_page(pte) == virt_to_page(lm_alias(kasan_zero_page));
+ return pte_page(pte) == virt_to_page(lm_alias(kasan_early_shadow_page));
}

static __init void *early_alloc(size_t size, int node)
@@ -92,7 +92,8 @@ static void __ref zero_pte_populate(pmd_t *pmd, unsigned long addr,
pte_t *pte = pte_offset_kernel(pmd, addr);
pte_t zero_pte;

- zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_zero_page)), PAGE_KERNEL);
+ zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_early_shadow_page)),
+ PAGE_KERNEL);
zero_pte = pte_wrprotect(zero_pte);

while (addr + PAGE_SIZE <= end) {
@@ -112,7 +113,8 @@ static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr,
next = pmd_addr_end(addr, end);

if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) {
- pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
+ pmd_populate_kernel(&init_mm, pmd,
+ lm_alias(kasan_early_shadow_pte));
continue;
}

@@ -145,9 +147,11 @@ static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr,
if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) {
pmd_t *pmd;

- pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
+ pud_populate(&init_mm, pud,
+ lm_alias(kasan_early_shadow_pmd));
pmd = pmd_offset(pud, addr);
- pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
+ pmd_populate_kernel(&init_mm, pmd,
+ lm_alias(kasan_early_shadow_pte));
continue;
}

@@ -181,12 +185,14 @@ static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr,
pud_t *pud;
pmd_t *pmd;

- p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud));
+ p4d_populate(&init_mm, p4d,
+ lm_alias(kasan_early_shadow_pud));
pud = pud_offset(p4d, addr);
- pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
+ pud_populate(&init_mm, pud,
+ lm_alias(kasan_early_shadow_pmd));
pmd = pmd_offset(pud, addr);
pmd_populate_kernel(&init_mm, pmd,
- lm_alias(kasan_zero_pte));
+ lm_alias(kasan_early_shadow_pte));
continue;
}

@@ -209,13 +215,13 @@ static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr,
}

/**
- * kasan_populate_zero_shadow - populate shadow memory region with
- * kasan_zero_page
+ * kasan_populate_early_shadow - populate shadow memory region with
+ * kasan_early_shadow_page
* @shadow_start - start of the memory range to populate
* @shadow_end - end of the memory range to populate
*/
-int __ref kasan_populate_zero_shadow(const void *shadow_start,
- const void *shadow_end)
+int __ref kasan_populate_early_shadow(const void *shadow_start,
+ const void *shadow_end)
{
unsigned long addr = (unsigned long)shadow_start;
unsigned long end = (unsigned long)shadow_end;
@@ -231,7 +237,7 @@ int __ref kasan_populate_zero_shadow(const void *shadow_start,
pmd_t *pmd;

/*
- * kasan_zero_pud should be populated with pmds
+ * kasan_early_shadow_pud should be populated with pmds
* at this moment.
* [pud,pmd]_populate*() below needed only for
* 3,2 - level page tables where we don't have
@@ -241,21 +247,25 @@ int __ref kasan_populate_zero_shadow(const void *shadow_start,
* The ifndef is required to avoid build breakage.
*
* With 5level-fixup.h, pgd_populate() is not nop and
- * we reference kasan_zero_p4d. It's not defined
+ * we reference kasan_early_shadow_p4d. It's not defined
* unless 5-level paging enabled.
*
* The ifndef can be dropped once all KASAN-enabled
* architectures will switch to pgtable-nop4d.h.
*/
#ifndef __ARCH_HAS_5LEVEL_HACK
- pgd_populate(&init_mm, pgd, lm_alias(kasan_zero_p4d));
+ pgd_populate(&init_mm, pgd,
+ lm_alias(kasan_early_shadow_p4d));
#endif
p4d = p4d_offset(pgd, addr);
- p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud));
+ p4d_populate(&init_mm, p4d,
+ lm_alias(kasan_early_shadow_pud));
pud = pud_offset(p4d, addr);
- pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
+ pud_populate(&init_mm, pud,
+ lm_alias(kasan_early_shadow_pmd));
pmd = pmd_offset(pud, addr);
- pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
+ pmd_populate_kernel(&init_mm, pmd,
+ lm_alias(kasan_early_shadow_pte));
continue;
}

@@ -350,7 +360,7 @@ static void kasan_remove_pte_table(pte_t *pte, unsigned long addr,
if (!pte_present(*pte))
continue;

- if (WARN_ON(!kasan_zero_page_entry(*pte)))
+ if (WARN_ON(!kasan_early_shadow_page_entry(*pte)))
continue;
pte_clear(&init_mm, addr, pte);
}
@@ -480,7 +490,7 @@ int kasan_add_zero_shadow(void *start, unsigned long size)
WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)))
return -EINVAL;

- ret = kasan_populate_zero_shadow(shadow_start, shadow_end);
+ ret = kasan_populate_early_shadow(shadow_start, shadow_end);
if (ret)
kasan_remove_zero_shadow(shadow_start,
size >> KASAN_SHADOW_SCALE_SHIFT);
--
2.19.1.1215.g8438c0b245-goog