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-rw-r--r--arch/arm64/include/asm/uaccess.h44
1 files changed, 32 insertions, 12 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index b2ede967fe7d..f973bdce8410 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -64,6 +64,16 @@ extern int fixup_exception(struct pt_regs *regs);
static inline void set_fs(mm_segment_t fs)
{
current_thread_info()->addr_limit = fs;
+
+ /*
+ * Enable/disable UAO so that copy_to_user() etc can access
+ * kernel memory with the unprivileged instructions.
+ */
+ if (IS_ENABLED(CONFIG_ARM64_UAO) && fs == KERNEL_DS)
+ asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO));
+ else
+ asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO,
+ CONFIG_ARM64_UAO));
}
#define segment_eq(a, b) ((a) == (b))
@@ -113,9 +123,10 @@ static inline void set_fs(mm_segment_t fs)
* The "__xxx_error" versions set the third argument to -EFAULT if an error
* occurs, and leave it unchanged on success.
*/
-#define __get_user_asm(instr, reg, x, addr, err) \
+#define __get_user_asm(instr, alt_instr, reg, x, addr, err, feature) \
asm volatile( \
- "1: " instr " " reg "1, [%2]\n" \
+ "1:"ALTERNATIVE(instr " " reg "1, [%2]\n", \
+ alt_instr " " reg "1, [%2]\n", feature) \
"2:\n" \
" .section .fixup, \"ax\"\n" \
" .align 2\n" \
@@ -138,16 +149,20 @@ do { \
CONFIG_ARM64_PAN)); \
switch (sizeof(*(ptr))) { \
case 1: \
- __get_user_asm("ldrb", "%w", __gu_val, (ptr), (err)); \
+ __get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \
+ (err), ARM64_HAS_UAO); \
break; \
case 2: \
- __get_user_asm("ldrh", "%w", __gu_val, (ptr), (err)); \
+ __get_user_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr), \
+ (err), ARM64_HAS_UAO); \
break; \
case 4: \
- __get_user_asm("ldr", "%w", __gu_val, (ptr), (err)); \
+ __get_user_asm("ldr", "ldtr", "%w", __gu_val, (ptr), \
+ (err), ARM64_HAS_UAO); \
break; \
case 8: \
- __get_user_asm("ldr", "%", __gu_val, (ptr), (err)); \
+ __get_user_asm("ldr", "ldtr", "%", __gu_val, (ptr), \
+ (err), ARM64_HAS_UAO); \
break; \
default: \
BUILD_BUG(); \
@@ -181,9 +196,10 @@ do { \
((x) = 0, -EFAULT); \
})
-#define __put_user_asm(instr, reg, x, addr, err) \
+#define __put_user_asm(instr, alt_instr, reg, x, addr, err, feature) \
asm volatile( \
- "1: " instr " " reg "1, [%2]\n" \
+ "1:"ALTERNATIVE(instr " " reg "1, [%2]\n", \
+ alt_instr " " reg "1, [%2]\n", feature) \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
@@ -205,16 +221,20 @@ do { \
CONFIG_ARM64_PAN)); \
switch (sizeof(*(ptr))) { \
case 1: \
- __put_user_asm("strb", "%w", __pu_val, (ptr), (err)); \
+ __put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \
+ (err), ARM64_HAS_UAO); \
break; \
case 2: \
- __put_user_asm("strh", "%w", __pu_val, (ptr), (err)); \
+ __put_user_asm("strh", "sttrh", "%w", __pu_val, (ptr), \
+ (err), ARM64_HAS_UAO); \
break; \
case 4: \
- __put_user_asm("str", "%w", __pu_val, (ptr), (err)); \
+ __put_user_asm("str", "sttr", "%w", __pu_val, (ptr), \
+ (err), ARM64_HAS_UAO); \
break; \
case 8: \
- __put_user_asm("str", "%", __pu_val, (ptr), (err)); \
+ __put_user_asm("str", "sttr", "%", __pu_val, (ptr), \
+ (err), ARM64_HAS_UAO); \
break; \
default: \
BUILD_BUG(); \