v4.19.13 snapshot.
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
new file mode 100644
index 0000000..5451e1f
--- /dev/null
+++ b/arch/arm/include/asm/uaccess.h
@@ -0,0 +1,536 @@
+/*
+ * arch/arm/include/asm/uaccess.h
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef _ASMARM_UACCESS_H
+#define _ASMARM_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/string.h>
+#include <asm/memory.h>
+#include <asm/domain.h>
+#include <asm/unified.h>
+#include <asm/compiler.h>
+
+#include <asm/extable.h>
+
+/*
+ * These two functions allow hooking accesses to userspace to increase
+ * system integrity by ensuring that the kernel can not inadvertantly
+ * perform such accesses (eg, via list poison values) which could then
+ * be exploited for priviledge escalation.
+ */
+static inline unsigned int uaccess_save_and_enable(void)
+{
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+ unsigned int old_domain = get_domain();
+
+ /* Set the current domain access to permit user accesses */
+ set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
+ domain_val(DOMAIN_USER, DOMAIN_CLIENT));
+
+ return old_domain;
+#else
+ return 0;
+#endif
+}
+
+static inline void uaccess_restore(unsigned int flags)
+{
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+ /* Restore the user access mask */
+ set_domain(flags);
+#endif
+}
+
+/*
+ * These two are intentionally not defined anywhere - if the kernel
+ * code generates any references to them, that's a bug.
+ */
+extern int __get_user_bad(void);
+extern int __put_user_bad(void);
+
+/*
+ * Note that this is actually 0x1,0000,0000
+ */
+#define KERNEL_DS 0x00000000
+#define get_ds() (KERNEL_DS)
+
+#ifdef CONFIG_MMU
+
+#define USER_DS TASK_SIZE
+#define get_fs() (current_thread_info()->addr_limit)
+
+static inline void set_fs(mm_segment_t fs)
+{
+ current_thread_info()->addr_limit = fs;
+ modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
+}
+
+#define segment_eq(a, b) ((a) == (b))
+
+/* We use 33-bit arithmetic here... */
+#define __range_ok(addr, size) ({ \
+ unsigned long flag, roksum; \
+ __chk_user_ptr(addr); \
+ __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
+ : "=&r" (flag), "=&r" (roksum) \
+ : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
+ : "cc"); \
+ flag; })
+
+/*
+ * This is a type: either unsigned long, if the argument fits into
+ * that type, or otherwise unsigned long long.
+ */
+#define __inttype(x) \
+ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
+
+/*
+ * Single-value transfer routines. They automatically use the right
+ * size if we just have the right pointer type. Note that the functions
+ * which read from user space (*get_*) need to take care not to leak
+ * kernel data even if the calling code is buggy and fails to check
+ * the return value. This means zeroing out the destination variable
+ * or buffer on error. Normally this is done out of line by the
+ * fixup code, but there are a few places where it intrudes on the
+ * main code path. When we only write to user space, there is no
+ * problem.
+ */
+extern int __get_user_1(void *);
+extern int __get_user_2(void *);
+extern int __get_user_4(void *);
+extern int __get_user_32t_8(void *);
+extern int __get_user_8(void *);
+extern int __get_user_64t_1(void *);
+extern int __get_user_64t_2(void *);
+extern int __get_user_64t_4(void *);
+
+#define __GUP_CLOBBER_1 "lr", "cc"
+#ifdef CONFIG_CPU_USE_DOMAINS
+#define __GUP_CLOBBER_2 "ip", "lr", "cc"
+#else
+#define __GUP_CLOBBER_2 "lr", "cc"
+#endif
+#define __GUP_CLOBBER_4 "lr", "cc"
+#define __GUP_CLOBBER_32t_8 "lr", "cc"
+#define __GUP_CLOBBER_8 "lr", "cc"
+
+#define __get_user_x(__r2, __p, __e, __l, __s) \
+ __asm__ __volatile__ ( \
+ __asmeq("%0", "r0") __asmeq("%1", "r2") \
+ __asmeq("%3", "r1") \
+ "bl __get_user_" #__s \
+ : "=&r" (__e), "=r" (__r2) \
+ : "0" (__p), "r" (__l) \
+ : __GUP_CLOBBER_##__s)
+
+/* narrowing a double-word get into a single 32bit word register: */
+#ifdef __ARMEB__
+#define __get_user_x_32t(__r2, __p, __e, __l, __s) \
+ __get_user_x(__r2, __p, __e, __l, 32t_8)
+#else
+#define __get_user_x_32t __get_user_x
+#endif
+
+/*
+ * storing result into proper least significant word of 64bit target var,
+ * different only for big endian case where 64 bit __r2 lsw is r3:
+ */
+#ifdef __ARMEB__
+#define __get_user_x_64t(__r2, __p, __e, __l, __s) \
+ __asm__ __volatile__ ( \
+ __asmeq("%0", "r0") __asmeq("%1", "r2") \
+ __asmeq("%3", "r1") \
+ "bl __get_user_64t_" #__s \
+ : "=&r" (__e), "=r" (__r2) \
+ : "0" (__p), "r" (__l) \
+ : __GUP_CLOBBER_##__s)
+#else
+#define __get_user_x_64t __get_user_x
+#endif
+
+
+#define __get_user_check(x, p) \
+ ({ \
+ unsigned long __limit = current_thread_info()->addr_limit - 1; \
+ register typeof(*(p)) __user *__p asm("r0") = (p); \
+ register __inttype(x) __r2 asm("r2"); \
+ register unsigned long __l asm("r1") = __limit; \
+ register int __e asm("r0"); \
+ unsigned int __ua_flags = uaccess_save_and_enable(); \
+ switch (sizeof(*(__p))) { \
+ case 1: \
+ if (sizeof((x)) >= 8) \
+ __get_user_x_64t(__r2, __p, __e, __l, 1); \
+ else \
+ __get_user_x(__r2, __p, __e, __l, 1); \
+ break; \
+ case 2: \
+ if (sizeof((x)) >= 8) \
+ __get_user_x_64t(__r2, __p, __e, __l, 2); \
+ else \
+ __get_user_x(__r2, __p, __e, __l, 2); \
+ break; \
+ case 4: \
+ if (sizeof((x)) >= 8) \
+ __get_user_x_64t(__r2, __p, __e, __l, 4); \
+ else \
+ __get_user_x(__r2, __p, __e, __l, 4); \
+ break; \
+ case 8: \
+ if (sizeof((x)) < 8) \
+ __get_user_x_32t(__r2, __p, __e, __l, 4); \
+ else \
+ __get_user_x(__r2, __p, __e, __l, 8); \
+ break; \
+ default: __e = __get_user_bad(); break; \
+ } \
+ uaccess_restore(__ua_flags); \
+ x = (typeof(*(p))) __r2; \
+ __e; \
+ })
+
+#define get_user(x, p) \
+ ({ \
+ might_fault(); \
+ __get_user_check(x, p); \
+ })
+
+extern int __put_user_1(void *, unsigned int);
+extern int __put_user_2(void *, unsigned int);
+extern int __put_user_4(void *, unsigned int);
+extern int __put_user_8(void *, unsigned long long);
+
+#define __put_user_check(__pu_val, __ptr, __err, __s) \
+ ({ \
+ unsigned long __limit = current_thread_info()->addr_limit - 1; \
+ register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
+ register const void __user *__p asm("r0") = __ptr; \
+ register unsigned long __l asm("r1") = __limit; \
+ register int __e asm("r0"); \
+ __asm__ __volatile__ ( \
+ __asmeq("%0", "r0") __asmeq("%2", "r2") \
+ __asmeq("%3", "r1") \
+ "bl __put_user_" #__s \
+ : "=&r" (__e) \
+ : "0" (__p), "r" (__r2), "r" (__l) \
+ : "ip", "lr", "cc"); \
+ __err = __e; \
+ })
+
+#else /* CONFIG_MMU */
+
+/*
+ * uClinux has only one addr space, so has simplified address limits.
+ */
+#define USER_DS KERNEL_DS
+
+#define segment_eq(a, b) (1)
+#define __addr_ok(addr) ((void)(addr), 1)
+#define __range_ok(addr, size) ((void)(addr), 0)
+#define get_fs() (KERNEL_DS)
+
+static inline void set_fs(mm_segment_t fs)
+{
+}
+
+#define get_user(x, p) __get_user(x, p)
+#define __put_user_check __put_user_nocheck
+
+#endif /* CONFIG_MMU */
+
+#define access_ok(type, addr, size) (__range_ok(addr, size) == 0)
+
+#define user_addr_max() \
+ (uaccess_kernel() ? ~0UL : get_fs())
+
+#ifdef CONFIG_CPU_SPECTRE
+/*
+ * When mitigating Spectre variant 1, it is not worth fixing the non-
+ * verifying accessors, because we need to add verification of the
+ * address space there. Force these to use the standard get_user()
+ * version instead.
+ */
+#define __get_user(x, ptr) get_user(x, ptr)
+#else
+
+/*
+ * The "__xxx" versions of the user access functions do not verify the
+ * address space - it must have been done previously with a separate
+ * "access_ok()" call.
+ *
+ * The "xxx_error" versions set the third argument to EFAULT if an
+ * error occurs, and leave it unchanged on success. Note that these
+ * versions are void (ie, don't return a value as such).
+ */
+#define __get_user(x, ptr) \
+({ \
+ long __gu_err = 0; \
+ __get_user_err((x), (ptr), __gu_err); \
+ __gu_err; \
+})
+
+#define __get_user_err(x, ptr, err) \
+do { \
+ unsigned long __gu_addr = (unsigned long)(ptr); \
+ unsigned long __gu_val; \
+ unsigned int __ua_flags; \
+ __chk_user_ptr(ptr); \
+ might_fault(); \
+ __ua_flags = uaccess_save_and_enable(); \
+ switch (sizeof(*(ptr))) { \
+ case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
+ case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
+ case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
+ default: (__gu_val) = __get_user_bad(); \
+ } \
+ uaccess_restore(__ua_flags); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+} while (0)
+
+#define __get_user_asm(x, addr, err, instr) \
+ __asm__ __volatile__( \
+ "1: " TUSER(instr) " %1, [%2], #0\n" \
+ "2:\n" \
+ " .pushsection .text.fixup,\"ax\"\n" \
+ " .align 2\n" \
+ "3: mov %0, %3\n" \
+ " mov %1, #0\n" \
+ " b 2b\n" \
+ " .popsection\n" \
+ " .pushsection __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .long 1b, 3b\n" \
+ " .popsection" \
+ : "+r" (err), "=&r" (x) \
+ : "r" (addr), "i" (-EFAULT) \
+ : "cc")
+
+#define __get_user_asm_byte(x, addr, err) \
+ __get_user_asm(x, addr, err, ldrb)
+
+#ifndef __ARMEB__
+#define __get_user_asm_half(x, __gu_addr, err) \
+({ \
+ unsigned long __b1, __b2; \
+ __get_user_asm_byte(__b1, __gu_addr, err); \
+ __get_user_asm_byte(__b2, __gu_addr + 1, err); \
+ (x) = __b1 | (__b2 << 8); \
+})
+#else
+#define __get_user_asm_half(x, __gu_addr, err) \
+({ \
+ unsigned long __b1, __b2; \
+ __get_user_asm_byte(__b1, __gu_addr, err); \
+ __get_user_asm_byte(__b2, __gu_addr + 1, err); \
+ (x) = (__b1 << 8) | __b2; \
+})
+#endif
+
+#define __get_user_asm_word(x, addr, err) \
+ __get_user_asm(x, addr, err, ldr)
+#endif
+
+
+#define __put_user_switch(x, ptr, __err, __fn) \
+ do { \
+ const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
+ __typeof__(*(ptr)) __pu_val = (x); \
+ unsigned int __ua_flags; \
+ might_fault(); \
+ __ua_flags = uaccess_save_and_enable(); \
+ switch (sizeof(*(ptr))) { \
+ case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
+ case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
+ case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
+ case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
+ default: __err = __put_user_bad(); break; \
+ } \
+ uaccess_restore(__ua_flags); \
+ } while (0)
+
+#define put_user(x, ptr) \
+({ \
+ int __pu_err = 0; \
+ __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
+ __pu_err; \
+})
+
+#define __put_user(x, ptr) \
+({ \
+ long __pu_err = 0; \
+ __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
+ __pu_err; \
+})
+
+#define __put_user_error(x, ptr, err) \
+({ \
+ __put_user_switch((x), (ptr), (err), __put_user_nocheck); \
+ (void) 0; \
+})
+
+#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
+ do { \
+ unsigned long __pu_addr = (unsigned long)__pu_ptr; \
+ __put_user_nocheck_##__size(x, __pu_addr, __err); \
+ } while (0)
+
+#define __put_user_nocheck_1 __put_user_asm_byte
+#define __put_user_nocheck_2 __put_user_asm_half
+#define __put_user_nocheck_4 __put_user_asm_word
+#define __put_user_nocheck_8 __put_user_asm_dword
+
+#define __put_user_asm(x, __pu_addr, err, instr) \
+ __asm__ __volatile__( \
+ "1: " TUSER(instr) " %1, [%2], #0\n" \
+ "2:\n" \
+ " .pushsection .text.fixup,\"ax\"\n" \
+ " .align 2\n" \
+ "3: mov %0, %3\n" \
+ " b 2b\n" \
+ " .popsection\n" \
+ " .pushsection __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .long 1b, 3b\n" \
+ " .popsection" \
+ : "+r" (err) \
+ : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
+ : "cc")
+
+#define __put_user_asm_byte(x, __pu_addr, err) \
+ __put_user_asm(x, __pu_addr, err, strb)
+
+#ifndef __ARMEB__
+#define __put_user_asm_half(x, __pu_addr, err) \
+({ \
+ unsigned long __temp = (__force unsigned long)(x); \
+ __put_user_asm_byte(__temp, __pu_addr, err); \
+ __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
+})
+#else
+#define __put_user_asm_half(x, __pu_addr, err) \
+({ \
+ unsigned long __temp = (__force unsigned long)(x); \
+ __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
+ __put_user_asm_byte(__temp, __pu_addr + 1, err); \
+})
+#endif
+
+#define __put_user_asm_word(x, __pu_addr, err) \
+ __put_user_asm(x, __pu_addr, err, str)
+
+#ifndef __ARMEB__
+#define __reg_oper0 "%R2"
+#define __reg_oper1 "%Q2"
+#else
+#define __reg_oper0 "%Q2"
+#define __reg_oper1 "%R2"
+#endif
+
+#define __put_user_asm_dword(x, __pu_addr, err) \
+ __asm__ __volatile__( \
+ ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
+ ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
+ THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
+ THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
+ "3:\n" \
+ " .pushsection .text.fixup,\"ax\"\n" \
+ " .align 2\n" \
+ "4: mov %0, %3\n" \
+ " b 3b\n" \
+ " .popsection\n" \
+ " .pushsection __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .long 1b, 4b\n" \
+ " .long 2b, 4b\n" \
+ " .popsection" \
+ : "+r" (err), "+r" (__pu_addr) \
+ : "r" (x), "i" (-EFAULT) \
+ : "cc")
+
+
+#ifdef CONFIG_MMU
+extern unsigned long __must_check
+arm_copy_from_user(void *to, const void __user *from, unsigned long n);
+
+static inline unsigned long __must_check
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ unsigned int __ua_flags;
+
+ __ua_flags = uaccess_save_and_enable();
+ n = arm_copy_from_user(to, from, n);
+ uaccess_restore(__ua_flags);
+ return n;
+}
+
+extern unsigned long __must_check
+arm_copy_to_user(void __user *to, const void *from, unsigned long n);
+extern unsigned long __must_check
+__copy_to_user_std(void __user *to, const void *from, unsigned long n);
+
+static inline unsigned long __must_check
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+#ifndef CONFIG_UACCESS_WITH_MEMCPY
+ unsigned int __ua_flags;
+ __ua_flags = uaccess_save_and_enable();
+ n = arm_copy_to_user(to, from, n);
+ uaccess_restore(__ua_flags);
+ return n;
+#else
+ return arm_copy_to_user(to, from, n);
+#endif
+}
+
+extern unsigned long __must_check
+arm_clear_user(void __user *addr, unsigned long n);
+extern unsigned long __must_check
+__clear_user_std(void __user *addr, unsigned long n);
+
+static inline unsigned long __must_check
+__clear_user(void __user *addr, unsigned long n)
+{
+ unsigned int __ua_flags = uaccess_save_and_enable();
+ n = arm_clear_user(addr, n);
+ uaccess_restore(__ua_flags);
+ return n;
+}
+
+#else
+static inline unsigned long
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ memcpy(to, (const void __force *)from, n);
+ return 0;
+}
+static inline unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ memcpy((void __force *)to, from, n);
+ return 0;
+}
+#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
+#endif
+#define INLINE_COPY_TO_USER
+#define INLINE_COPY_FROM_USER
+
+static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
+{
+ if (access_ok(VERIFY_WRITE, to, n))
+ n = __clear_user(to, n);
+ return n;
+}
+
+/* These are from lib/ code, and use __get_user() and friends */
+extern long strncpy_from_user(char *dest, const char __user *src, long count);
+
+extern __must_check long strnlen_user(const char __user *str, long n);
+
+#endif /* _ASMARM_UACCESS_H */