File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/tile/include/asm/uaccess.h b/arch/tile/include/asm/uaccess.h
new file mode 100644
index 0000000..0a9c426
--- /dev/null
+++ b/arch/tile/include/asm/uaccess.h
@@ -0,0 +1,565 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#ifndef _ASM_TILE_UACCESS_H
+#define _ASM_TILE_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <asm-generic/uaccess-unaligned.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+
+#define VERIFY_READ	0
+#define VERIFY_WRITE	1
+
+/*
+ * The fs value determines whether argument validity checking should be
+ * performed or not.  If get_fs() == USER_DS, checking is performed, with
+ * get_fs() == KERNEL_DS, checking is bypassed.
+ *
+ * For historical reasons, these macros are grossly misnamed.
+ */
+#define MAKE_MM_SEG(a)  ((mm_segment_t) { (a) })
+
+#define KERNEL_DS	MAKE_MM_SEG(-1UL)
+#define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)
+
+#define get_ds()	(KERNEL_DS)
+#define get_fs()	(current_thread_info()->addr_limit)
+#define set_fs(x)	(current_thread_info()->addr_limit = (x))
+
+#define segment_eq(a, b) ((a).seg == (b).seg)
+
+#ifndef __tilegx__
+/*
+ * We could allow mapping all 16 MB at 0xfc000000, but we set up a
+ * special hack in arch_setup_additional_pages() to auto-create a mapping
+ * for the first 16 KB, and it would seem strange to have different
+ * user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
+ */
+static inline int is_arch_mappable_range(unsigned long addr,
+					 unsigned long size)
+{
+	return (addr >= MEM_USER_INTRPT &&
+		addr < (MEM_USER_INTRPT + INTRPT_SIZE) &&
+		size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr);
+}
+#define is_arch_mappable_range is_arch_mappable_range
+#else
+#define is_arch_mappable_range(addr, size) 0
+#endif
+
+/*
+ * Note that using this definition ignores is_arch_mappable_range(),
+ * so on tilepro code that uses user_addr_max() is constrained not
+ * to reference the tilepro user-interrupt region.
+ */
+#define user_addr_max() (current_thread_info()->addr_limit.seg)
+
+/*
+ * Test whether a block of memory is a valid user space address.
+ * Returns 0 if the range is valid, nonzero otherwise.
+ */
+int __range_ok(unsigned long addr, unsigned long size);
+
+/**
+ * access_ok: - Checks if a user space pointer is valid
+ * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
+ *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
+ *        to write to a block, it is always safe to read from it.
+ * @addr: User space pointer to start of block to check
+ * @size: Size of block to check
+ *
+ * Context: User context only. This function may sleep if pagefaults are
+ *          enabled.
+ *
+ * Checks if a pointer to a block of memory in user space is valid.
+ *
+ * Returns true (nonzero) if the memory block may be valid, false (zero)
+ * if it is definitely invalid.
+ *
+ * Note that, depending on architecture, this function probably just
+ * checks that the pointer is in the user space range - after calling
+ * this function, memory access functions may still return -EFAULT.
+ */
+#define access_ok(type, addr, size) ({ \
+	__chk_user_ptr(addr); \
+	likely(__range_ok((unsigned long)(addr), (size)) == 0);	\
+})
+
+/*
+ * The exception table consists of pairs of addresses: the first is the
+ * address of an instruction that is allowed to fault, and the second is
+ * the address at which the program should continue.  No registers are
+ * modified, so it is entirely up to the continuation code to figure out
+ * what to do.
+ *
+ * All the routines below use bits of fixup code that are out of line
+ * with the main instruction path.  This means when everything is well,
+ * we don't even have to jump over them.  Further, they do not intrude
+ * on our cache or tlb entries.
+ */
+
+struct exception_table_entry {
+	unsigned long insn, fixup;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+/*
+ * 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))
+
+/*
+ * Support macros for __get_user().
+ * Note that __get_user() and __put_user() assume proper alignment.
+ */
+
+#ifdef __LP64__
+#define _ASM_PTR	".quad"
+#define _ASM_ALIGN	".align 8"
+#else
+#define _ASM_PTR	".long"
+#define _ASM_ALIGN	".align 4"
+#endif
+
+#define __get_user_asm(OP, x, ptr, ret)					\
+	asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n"		\
+		     ".pushsection .fixup,\"ax\"\n"			\
+		     "0: { movei %1, 0; movei %0, %3 }\n"		\
+		     "j 9f\n"						\
+		     ".section __ex_table,\"a\"\n"			\
+		     _ASM_ALIGN "\n"					\
+		     _ASM_PTR " 1b, 0b\n"				\
+		     ".popsection\n"					\
+		     "9:"						\
+		     : "=r" (ret), "=r" (x)				\
+		     : "r" (ptr), "i" (-EFAULT))
+
+#ifdef __tilegx__
+#define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret)
+#define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret)
+#define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret)
+#define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret)
+#else
+#define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret)
+#define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret)
+#define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret)
+#ifdef __LITTLE_ENDIAN
+#define __lo32(a, b) a
+#define __hi32(a, b) b
+#else
+#define __lo32(a, b) b
+#define __hi32(a, b) a
+#endif
+#define __get_user_8(x, ptr, ret)					\
+	({								\
+		unsigned int __a, __b;					\
+		asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n"	\
+			     "2: { lw %2, %2; movei %0, 0 }\n"		\
+			     ".pushsection .fixup,\"ax\"\n"		\
+			     "0: { movei %1, 0; movei %2, 0 }\n"	\
+			     "{ movei %0, %4; j 9f }\n"			\
+			     ".section __ex_table,\"a\"\n"		\
+			     ".align 4\n"				\
+			     ".word 1b, 0b\n"				\
+			     ".word 2b, 0b\n"				\
+			     ".popsection\n"				\
+			     "9:"					\
+			     : "=r" (ret), "=r" (__a), "=&r" (__b)	\
+			     : "r" (ptr), "i" (-EFAULT));		\
+		(x) = (__force __typeof(x))(__inttype(x))		\
+			(((u64)__hi32(__a, __b) << 32) |		\
+			 __lo32(__a, __b));				\
+	})
+#endif
+
+extern int __get_user_bad(void)
+  __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8")));
+
+/**
+ * __get_user: - Get a simple variable from user space, with less checking.
+ * @x:   Variable to store result.
+ * @ptr: Source address, in user space.
+ *
+ * Context: User context only. This function may sleep if pagefaults are
+ *          enabled.
+ *
+ * This macro copies a single simple variable from user space to kernel
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and the result of
+ * dereferencing @ptr must be assignable to @x without a cast.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ * On error, the variable @x is set to zero.
+ *
+ * Caller must check the pointer with access_ok() before calling this
+ * function.
+ */
+#define __get_user(x, ptr)						\
+	({								\
+		int __ret;						\
+		typeof(x) _x;						\
+		__chk_user_ptr(ptr);					\
+		switch (sizeof(*(ptr))) {				\
+		case 1: __get_user_1(_x, ptr, __ret); break;		\
+		case 2: __get_user_2(_x, ptr, __ret); break;		\
+		case 4: __get_user_4(_x, ptr, __ret); break;		\
+		case 8: __get_user_8(_x, ptr, __ret); break;		\
+		default: __ret = __get_user_bad(); break;		\
+		}							\
+		(x) = (typeof(*(ptr))) _x;				\
+		__ret;							\
+	})
+
+/* Support macros for __put_user(). */
+
+#define __put_user_asm(OP, x, ptr, ret)			\
+	asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n"		\
+		     ".pushsection .fixup,\"ax\"\n"			\
+		     "0: { movei %0, %3; j 9f }\n"			\
+		     ".section __ex_table,\"a\"\n"			\
+		     _ASM_ALIGN "\n"					\
+		     _ASM_PTR " 1b, 0b\n"				\
+		     ".popsection\n"					\
+		     "9:"						\
+		     : "=r" (ret)					\
+		     : "r" (ptr), "r" (x), "i" (-EFAULT))
+
+#ifdef __tilegx__
+#define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret)
+#define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret)
+#define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret)
+#define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret)
+#else
+#define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret)
+#define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret)
+#define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret)
+#define __put_user_8(x, ptr, ret)					\
+	({								\
+		u64 __x = (__force __inttype(x))(x);			\
+		int __lo = (int) __x, __hi = (int) (__x >> 32);		\
+		asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n"	\
+			     "2: { sw %0, %3; movei %0, 0 }\n"		\
+			     ".pushsection .fixup,\"ax\"\n"		\
+			     "0: { movei %0, %4; j 9f }\n"		\
+			     ".section __ex_table,\"a\"\n"		\
+			     ".align 4\n"				\
+			     ".word 1b, 0b\n"				\
+			     ".word 2b, 0b\n"				\
+			     ".popsection\n"				\
+			     "9:"					\
+			     : "=&r" (ret)				\
+			     : "r" (ptr), "r" (__lo32(__lo, __hi)),	\
+			     "r" (__hi32(__lo, __hi)), "i" (-EFAULT));	\
+	})
+#endif
+
+extern int __put_user_bad(void)
+  __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8")));
+
+/**
+ * __put_user: - Write a simple value into user space, with less checking.
+ * @x:   Value to copy to user space.
+ * @ptr: Destination address, in user space.
+ *
+ * Context: User context only. This function may sleep if pagefaults are
+ *          enabled.
+ *
+ * This macro copies a single simple value from kernel space to user
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and @x must be assignable
+ * to the result of dereferencing @ptr.
+ *
+ * Caller must check the pointer with access_ok() before calling this
+ * function.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ */
+#define __put_user(x, ptr)						\
+({									\
+	int __ret;							\
+	typeof(*(ptr)) _x = (x);					\
+	__chk_user_ptr(ptr);						\
+	switch (sizeof(*(ptr))) {					\
+	case 1: __put_user_1(_x, ptr, __ret); break;			\
+	case 2: __put_user_2(_x, ptr, __ret); break;			\
+	case 4: __put_user_4(_x, ptr, __ret); break;			\
+	case 8: __put_user_8(_x, ptr, __ret); break;			\
+	default: __ret = __put_user_bad(); break;			\
+	}								\
+	__ret;								\
+})
+
+/*
+ * The versions of get_user and put_user without initial underscores
+ * check the address of their arguments to make sure they are not
+ * in kernel space.
+ */
+#define put_user(x, ptr)						\
+({									\
+	__typeof__(*(ptr)) __user *__Pu_addr = (ptr);			\
+	access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ?	\
+		__put_user((x), (__Pu_addr)) :				\
+		-EFAULT;						\
+})
+
+#define get_user(x, ptr)						\
+({									\
+	__typeof__(*(ptr)) const __user *__Gu_addr = (ptr);		\
+	access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ?	\
+		__get_user((x), (__Gu_addr)) :				\
+		((x) = 0, -EFAULT);					\
+})
+
+/**
+ * __copy_to_user() - copy data into user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @from: Source address, in kernel space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only. This function may sleep if pagefaults are
+ *          enabled.
+ *
+ * Copy data from kernel space to user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ *
+ * An alternate version - __copy_to_user_inatomic() - is designed
+ * to be called from atomic context, typically bracketed by calls
+ * to pagefault_disable() and pagefault_enable().
+ */
+extern unsigned long __must_check __copy_to_user_inatomic(
+	void __user *to, const void *from, unsigned long n);
+
+static inline unsigned long __must_check
+__copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	might_fault();
+	return __copy_to_user_inatomic(to, from, n);
+}
+
+static inline unsigned long __must_check
+copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	if (access_ok(VERIFY_WRITE, to, n))
+		n = __copy_to_user(to, from, n);
+	return n;
+}
+
+/**
+ * __copy_from_user() - copy data from user space, with less checking.
+ * @to:   Destination address, in kernel space.
+ * @from: Source address, in user space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only. This function may sleep if pagefaults are
+ *          enabled.
+ *
+ * Copy data from user space to kernel space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ *
+ * If some data could not be copied, this function will pad the copied
+ * data to the requested size using zero bytes.
+ *
+ * An alternate version - __copy_from_user_inatomic() - is designed
+ * to be called from atomic context, typically bracketed by calls
+ * to pagefault_disable() and pagefault_enable().  This version
+ * does *NOT* pad with zeros.
+ */
+extern unsigned long __must_check __copy_from_user_inatomic(
+	void *to, const void __user *from, unsigned long n);
+extern unsigned long __must_check __copy_from_user_zeroing(
+	void *to, const void __user *from, unsigned long n);
+
+static inline unsigned long __must_check
+__copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+       might_fault();
+       return __copy_from_user_zeroing(to, from, n);
+}
+
+static inline unsigned long __must_check
+_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	if (access_ok(VERIFY_READ, from, n))
+		n = __copy_from_user(to, from, n);
+	else
+		memset(to, 0, n);
+	return n;
+}
+
+#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
+/*
+ * There are still unprovable places in the generic code as of 2.6.34, so this
+ * option is not really compatible with -Werror, which is more useful in
+ * general.
+ */
+extern void copy_from_user_overflow(void)
+	__compiletime_warning("copy_from_user() size is not provably correct");
+
+static inline unsigned long __must_check copy_from_user(void *to,
+					  const void __user *from,
+					  unsigned long n)
+{
+	int sz = __compiletime_object_size(to);
+
+	if (likely(sz == -1 || sz >= n))
+		n = _copy_from_user(to, from, n);
+	else
+		copy_from_user_overflow();
+
+	return n;
+}
+#else
+#define copy_from_user _copy_from_user
+#endif
+
+#ifdef __tilegx__
+/**
+ * __copy_in_user() - copy data within user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @from: Source address, in user space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only. This function may sleep if pagefaults are
+ *          enabled.
+ *
+ * Copy data from user space to user space.  Caller must check
+ * the specified blocks with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ */
+extern unsigned long __copy_in_user_inatomic(
+	void __user *to, const void __user *from, unsigned long n);
+
+static inline unsigned long __must_check
+__copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+	might_fault();
+	return __copy_in_user_inatomic(to, from, n);
+}
+
+static inline unsigned long __must_check
+copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+	if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
+		n = __copy_in_user(to, from, n);
+	return n;
+}
+#endif
+
+
+extern long strnlen_user(const char __user *str, long n);
+extern long strlen_user(const char __user *str);
+extern long strncpy_from_user(char *dst, const char __user *src, long);
+
+/**
+ * clear_user: - Zero a block of memory in user space.
+ * @mem:   Destination address, in user space.
+ * @len:   Number of bytes to zero.
+ *
+ * Zero a block of memory in user space.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
+extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
+static inline unsigned long __must_check __clear_user(
+	void __user *mem, unsigned long len)
+{
+	might_fault();
+	return clear_user_asm(mem, len);
+}
+static inline unsigned long __must_check clear_user(
+	void __user *mem, unsigned long len)
+{
+	if (access_ok(VERIFY_WRITE, mem, len))
+		return __clear_user(mem, len);
+	return len;
+}
+
+/**
+ * flush_user: - Flush a block of memory in user space from cache.
+ * @mem:   Destination address, in user space.
+ * @len:   Number of bytes to flush.
+ *
+ * Returns number of bytes that could not be flushed.
+ * On success, this will be zero.
+ */
+extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
+static inline unsigned long __must_check __flush_user(
+	void __user *mem, unsigned long len)
+{
+	int retval;
+
+	might_fault();
+	retval = flush_user_asm(mem, len);
+	mb_incoherent();
+	return retval;
+}
+
+static inline unsigned long __must_check flush_user(
+	void __user *mem, unsigned long len)
+{
+	if (access_ok(VERIFY_WRITE, mem, len))
+		return __flush_user(mem, len);
+	return len;
+}
+
+/**
+ * finv_user: - Flush-inval a block of memory in user space from cache.
+ * @mem:   Destination address, in user space.
+ * @len:   Number of bytes to invalidate.
+ *
+ * Returns number of bytes that could not be flush-invalidated.
+ * On success, this will be zero.
+ */
+extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
+static inline unsigned long __must_check __finv_user(
+	void __user *mem, unsigned long len)
+{
+	int retval;
+
+	might_fault();
+	retval = finv_user_asm(mem, len);
+	mb_incoherent();
+	return retval;
+}
+static inline unsigned long __must_check finv_user(
+	void __user *mem, unsigned long len)
+{
+	if (access_ok(VERIFY_WRITE, mem, len))
+		return __finv_user(mem, len);
+	return len;
+}
+
+#endif /* _ASM_TILE_UACCESS_H */