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arm64: kasan: instrument user memory access API

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The upstream commit 1771c6e1a5
("x86/kasan: instrument user memory access API") added KASAN instrument to
x86 user memory access API, so added such instrument to ARM64 too.

Define __copy_to/from_user in C in order to add kasan_check_read/write call,
rename assembly implementation to __arch_copy_to/from_user.

Tested by test_kasan module.

Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Yang Shi 2016-06-08 14:40:56 -07:00 committed by Catalin Marinas
parent 4674fdb9f1
commit bffe1baff5
4 changed files with 27 additions and 10 deletions
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25
arch/arm64/include/asm/uaccess.h
View File

@ -21,6 +21,7 @@
/*
* User space memory access functions
*/
#include <linux/kasan-checks.h>
#include <linux/string.h>
#include <linux/thread_info.h>
@ -256,15 +257,29 @@ do { \
-EFAULT; \
})
extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
static inline unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n)
{
kasan_check_write(to, n);
return __arch_copy_from_user(to, from, n);
}
static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n)
{
kasan_check_read(from, n);
return __arch_copy_to_user(to, from, n);
}
static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
{
kasan_check_write(to, n);
if (access_ok(VERIFY_READ, from, n))
n = __copy_from_user(to, from, n);
n = __arch_copy_from_user(to, from, n);
else /* security hole - plug it */
memset(to, 0, n);
return n;
@ -272,8 +287,10 @@ static inline unsigned long __must_check copy_from_user(void *to, const void __u
static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
{
kasan_check_read(from, n);
if (access_ok(VERIFY_WRITE, to, n))
n = __copy_to_user(to, from, n);
n = __arch_copy_to_user(to, from, n);
return n;
}

4
arch/arm64/kernel/arm64ksyms.c
View File

@ -34,8 +34,8 @@ EXPORT_SYMBOL(copy_page);
EXPORT_SYMBOL(clear_page);
/* user mem (segment) */
EXPORT_SYMBOL(__copy_from_user);
EXPORT_SYMBOL(__copy_to_user);
EXPORT_SYMBOL(__arch_copy_from_user);
EXPORT_SYMBOL(__arch_copy_to_user);
EXPORT_SYMBOL(__clear_user);
EXPORT_SYMBOL(__copy_in_user);

4
arch/arm64/lib/copy_from_user.S
View File

@ -66,7 +66,7 @@
.endm
end .req x5
ENTRY(__copy_from_user)
ENTRY(__arch_copy_from_user)
ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
CONFIG_ARM64_PAN)
add end, x0, x2
@ -75,7 +75,7 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
CONFIG_ARM64_PAN)
mov x0, #0 // Nothing to copy
ret
ENDPROC(__copy_from_user)
ENDPROC(__arch_copy_from_user)
.section .fixup,"ax"
.align 2

4
arch/arm64/lib/copy_to_user.S
View File

@ -65,7 +65,7 @@
.endm
end .req x5
ENTRY(__copy_to_user)
ENTRY(__arch_copy_to_user)
ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
CONFIG_ARM64_PAN)
add end, x0, x2
@ -74,7 +74,7 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
CONFIG_ARM64_PAN)
mov x0, #0
ret
ENDPROC(__copy_to_user)
ENDPROC(__arch_copy_to_user)
.section .fixup,"ax"
.align 2