Hi, Andrey
On 2023/3/30 上午3:02, Andrey Konovalov wrote:
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index f7ef70661ce2..3b91b941873d 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -54,11 +54,13 @@ extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
int kasan_populate_early_shadow(const void *shadow_start,
const void *shadow_end);
+#ifndef __HAVE_ARCH_SHADOW_MAP
static inline void *kasan_mem_to_shadow(const void *addr)
{
return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
+ KASAN_SHADOW_OFFSET;
}
+#endif
int kasan_add_zero_shadow(void *start, unsigned long size);
void kasan_remove_zero_shadow(void *start, unsigned long size);
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index e5eef670735e..f86194750df5 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -175,6 +175,11 @@ static __always_inline bool check_region_inline(unsigned long addr,
if (unlikely(!addr_has_metadata((void *)addr)))
return !kasan_report(addr, size, write, ret_ip);
+#ifndef __HAVE_ARCH_SHADOW_MAP
+ if (unlikely(kasan_mem_to_shadow((unsigned long *)addr) == NULL))
+ return !kasan_report(addr, size, write, ret_ip);
+#endif
This should have been ifdef, right?
Sorry, it was a clerical error,
Here it is
#ifndef __HAVE_ARCH_SHADOW_MAP
if (unlikely(! addr_has_metadata((void *)addr)))
return ! kasan_report(addr, size, write, ret_ip);
#else
if (unlikely(kasan_mem_to_shadow((void *)addr) == NULL)) {
kasan_report(addr, size, write, ret_ip);
return;
}
#endif
But I don't think you need this check here at all: addr_has_metadata
already checks that shadow exists.
On LongArch, there's a lot of holes between different segments, so kasan
shadow area is some different type of memory that we concatenate, we
can't use if (unlikely((void *)addr <
kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) to determine the
validity, and in arch/loongarch/include/asm/kasan.h I construct invalid
NULL.
+
if (likely(!memory_is_poisoned(addr, size)))
return true;
diff --git a/mm/kasan/init.c b/mm/kasan/init.c
index cc64ed6858c6..860061a22ca9 100644
--- a/mm/kasan/init.c
+++ b/mm/kasan/init.c
@@ -166,8 +166,9 @@ static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr,
if (!p)
return -ENOMEM;
} else {
- pud_populate(&init_mm, pud,
- early_alloc(PAGE_SIZE, NUMA_NO_NODE));
+ p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
+ pmd_init(p);
+ pud_populate(&init_mm, pud, p);
}
}
zero_pmd_populate(pud, addr, next);
@@ -207,8 +208,9 @@ static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr,
if (!p)
return -ENOMEM;
} else {
- p4d_populate(&init_mm, p4d,
- early_alloc(PAGE_SIZE, NUMA_NO_NODE));
+ p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
+ pud_init(p);
+ p4d_populate(&init_mm, p4d, p);
Please explain why these changes are needed in the patch description.
This is because in pagetable_init on loongarch/mips, we populate pmd/pud
with invalid_pmd_table/invalid_pud_table,
So pmd_init/pud_init(p) is required, perhaps we define them as __weak in
mm/kasan/init.c, like mm/sparse-vmemmap.c.
diff --git a/include/linux/mm.h b/include/linux/mm.h
...
+void pmd_init(void *addr);
+void pud_init(void *addr);
...
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
...
+void __weak __meminit pmd_init(void *addr)
+ {
+}
+
@@-203,11 +207,16 @@pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d,
unsigned long addr, int node)
void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
if (! p)
return NULL;
+ pmd_init(p);
pud_populate(&init_mm, pud, p);
}
return pud;
}
+void __weak __meminit pud_init(void *addr)
+ {
+}
+
p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr,
int node)
{
p4d_t *p4d = p4d_offset(pgd, addr);
@@-215,6 +224,7 @@p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd,
unsigned long addr, int node)
void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
if (! p)
return NULL;
+ pud_init(p);
p4d_populate(&init_mm, p4d, p);
}
return p4d;
Thanks,
- Qing
}
}
zero_pud_populate(p4d, addr, next);
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index a61eeee3095a..033335c13b25 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -291,16 +291,22 @@ struct kasan_stack_ring {
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+#ifndef __HAVE_ARCH_SHADOW_MAP
static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
{
return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
<< KASAN_SHADOW_SCALE_SHIFT);
}
+#endif
static __always_inline bool addr_has_metadata(const void *addr)
{
+#ifdef __HAVE_ARCH_SHADOW_MAP
+ return (kasan_mem_to_shadow((void *)addr) != NULL);
+#else
return (kasan_reset_tag(addr) >=
kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
+#endif
}
/**
--
2.20.1
