[PATCH 5.16 0349/1017] uaccess: fix nios2 and microblaze get_user_8()

Greg Kroah-Hartman
2022-04-05T12:19:56Z

From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit a97b693c3712f040c5802f32b2d685352e08cefa ]

These two architectures implement 8-byte get_user() through
a memcpy() into a four-byte variable, which won't fit.

Use a temporary 64-bit variable instead here, and use a double
cast the way that risc-v and openrisc do to avoid compile-time
warnings.

Fixes: 6a090e97972d ("arch/microblaze: support get_user() of size 8 bytes")
Fixes: 5ccc6af5e88e ("nios2: Memory management")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/microblaze/include/asm/uaccess.h | 18 +++++++++---------
arch/nios2/include/asm/uaccess.h | 26 ++++++++++++++++----------
2 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index 5b6e0e7788f4..3fe96979d2c6 100644
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -130,27 +130,27 @@ extern long __user_bad(void);

#define __get_user(x, ptr) \
({ \
- unsigned long __gu_val = 0; \
long __gu_err; \
switch (sizeof(*(ptr))) { \
case 1: \
- __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \
+ __get_user_asm("lbu", (ptr), x, __gu_err); \
break; \
case 2: \
- __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \
+ __get_user_asm("lhu", (ptr), x, __gu_err); \
break; \
case 4: \
- __get_user_asm("lw", (ptr), __gu_val, __gu_err); \
+ __get_user_asm("lw", (ptr), x, __gu_err); \
break; \
- case 8: \
- __gu_err = __copy_from_user(&__gu_val, ptr, 8); \
- if (__gu_err) \
- __gu_err = -EFAULT; \
+ case 8: { \
+ __u64 __x = 0; \
+ __gu_err = raw_copy_from_user(&__x, ptr, 8) ? \
+ -EFAULT : 0; \
+ (x) = (typeof(x))(typeof((x) - (x)))__x; \
break; \
+ } \
default: \
/* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
} \
- x = (__force __typeof__(*(ptr))) __gu_val; \
__gu_err; \
})

diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h
index ba9340e96fd4..ca9285a915ef 100644
--- a/arch/nios2/include/asm/uaccess.h
+++ b/arch/nios2/include/asm/uaccess.h
@@ -88,6 +88,7 @@ extern __must_check long strnlen_user(const char __user *s, long n);
/* Optimized macros */
#define __get_user_asm(val, insn, addr, err) \
{ \
+ unsigned long __gu_val; \
__asm__ __volatile__( \
" movi %0, %3\n" \
"1: " insn " %1, 0(%2)\n" \
@@ -96,14 +97,20 @@ extern __must_check long strnlen_user(const char __user *s, long n);
" .section __ex_table,\"a\"\n" \
" .word 1b, 2b\n" \
" .previous" \
- : "=&r" (err), "=r" (val) \
+ : "=&r" (err), "=r" (__gu_val) \
: "r" (addr), "i" (-EFAULT)); \
+ val = (__force __typeof__(*(addr)))__gu_val; \
}

-#define __get_user_unknown(val, size, ptr, err) do { \
+extern void __get_user_unknown(void);
+
+#define __get_user_8(val, ptr, err) do { \
+ u64 __val = 0; \
err = 0; \
- if (__copy_from_user(&(val), ptr, size)) { \
+ if (raw_copy_from_user(&(__val), ptr, sizeof(val))) { \
err = -EFAULT; \
+ } else { \
+ val = (typeof(val))(typeof((val) - (val)))__val; \
} \
} while (0)

@@ -119,8 +126,11 @@ do { \
case 4: \
__get_user_asm(val, "ldw", ptr, err); \
break; \
+ case 8: \
+ __get_user_8(val, ptr, err); \
+ break; \
default: \
- __get_user_unknown(val, size, ptr, err); \
+ __get_user_unknown(); \
break; \
} \
} while (0)
@@ -129,9 +139,7 @@ do { \
({ \
long __gu_err = -EFAULT; \
const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
- unsigned long __gu_val = 0; \
- __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
- (x) = (__force __typeof__(x))__gu_val; \
+ __get_user_common(x, sizeof(*(ptr)), __gu_ptr, __gu_err); \
__gu_err; \
})

@@ -139,11 +147,9 @@ do { \
({ \
long __gu_err = -EFAULT; \
const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
- unsigned long __gu_val = 0; \
if (access_ok( __gu_ptr, sizeof(*__gu_ptr))) \
- __get_user_common(__gu_val, sizeof(*__gu_ptr), \
+ __get_user_common(x, sizeof(*__gu_ptr), \
__gu_ptr, __gu_err); \
- (x) = (__force __typeof__(x))__gu_val; \
__gu_err; \
})

--
2.34.1