Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/csky/lib/usercopy.c b/arch/csky/lib/usercopy.c
new file mode 100644
index 0000000..647a239
--- /dev/null
+++ b/arch/csky/lib/usercopy.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/uaccess.h>
+#include <linux/types.h>
+
+unsigned long raw_copy_from_user(void *to, const void *from,
+ unsigned long n)
+{
+ if (access_ok(from, n))
+ __copy_user_zeroing(to, from, n);
+ else
+ memset(to, 0, n);
+ return n;
+}
+EXPORT_SYMBOL(raw_copy_from_user);
+
+unsigned long raw_copy_to_user(void *to, const void *from,
+ unsigned long n)
+{
+ if (access_ok(to, n))
+ __copy_user(to, from, n);
+ return n;
+}
+EXPORT_SYMBOL(raw_copy_to_user);
+
+
+/*
+ * copy a null terminated string from userspace.
+ */
+#define __do_strncpy_from_user(dst, src, count, res) \
+do { \
+ int tmp; \
+ long faultres; \
+ asm volatile( \
+ " cmpnei %3, 0 \n" \
+ " bf 4f \n" \
+ "1: cmpnei %1, 0 \n" \
+ " bf 5f \n" \
+ "2: ldb %4, (%3, 0) \n" \
+ " stb %4, (%2, 0) \n" \
+ " cmpnei %4, 0 \n" \
+ " bf 3f \n" \
+ " addi %3, 1 \n" \
+ " addi %2, 1 \n" \
+ " subi %1, 1 \n" \
+ " br 1b \n" \
+ "3: subu %0, %1 \n" \
+ " br 5f \n" \
+ "4: mov %0, %5 \n" \
+ " br 5f \n" \
+ ".section __ex_table, \"a\" \n" \
+ ".align 2 \n" \
+ ".long 2b, 4b \n" \
+ ".previous \n" \
+ "5: \n" \
+ : "=r"(res), "=r"(count), "=r"(dst), \
+ "=r"(src), "=r"(tmp), "=r"(faultres) \
+ : "5"(-EFAULT), "0"(count), "1"(count), \
+ "2"(dst), "3"(src) \
+ : "memory", "cc"); \
+} while (0)
+
+/*
+ * __strncpy_from_user: - Copy a NUL terminated string from userspace,
+ * with less checking.
+ * @dst: Destination address, in kernel space. This buffer must be at
+ * least @count bytes long.
+ * @src: Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ * Caller must check the specified block with access_ok() before calling
+ * this function.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+long __strncpy_from_user(char *dst, const char *src, long count)
+{
+ long res;
+
+ __do_strncpy_from_user(dst, src, count, res);
+ return res;
+}
+EXPORT_SYMBOL(__strncpy_from_user);
+
+/*
+ * strncpy_from_user: - Copy a NUL terminated string from userspace.
+ * @dst: Destination address, in kernel space. This buffer must be at
+ * least @count bytes long.
+ * @src: Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+long strncpy_from_user(char *dst, const char *src, long count)
+{
+ long res = -EFAULT;
+
+ if (access_ok(src, 1))
+ __do_strncpy_from_user(dst, src, count, res);
+ return res;
+}
+EXPORT_SYMBOL(strncpy_from_user);
+
+/*
+ * strlen_user: - Get the size of a string in user space.
+ * @str: The string to measure.
+ * @n: The maximum valid length
+ *
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ * If the string is too long, returns a value greater than @n.
+ */
+long strnlen_user(const char *s, long n)
+{
+ unsigned long res, tmp;
+
+ if (s == NULL)
+ return 0;
+
+ asm volatile(
+ " cmpnei %1, 0 \n"
+ " bf 3f \n"
+ "1: cmpnei %0, 0 \n"
+ " bf 3f \n"
+ "2: ldb %3, (%1, 0) \n"
+ " cmpnei %3, 0 \n"
+ " bf 3f \n"
+ " subi %0, 1 \n"
+ " addi %1, 1 \n"
+ " br 1b \n"
+ "3: subu %2, %0 \n"
+ " addi %2, 1 \n"
+ " br 5f \n"
+ "4: movi %0, 0 \n"
+ " br 5f \n"
+ ".section __ex_table, \"a\" \n"
+ ".align 2 \n"
+ ".long 2b, 4b \n"
+ ".previous \n"
+ "5: \n"
+ : "=r"(n), "=r"(s), "=r"(res), "=r"(tmp)
+ : "0"(n), "1"(s), "2"(n)
+ : "memory", "cc");
+
+ return res;
+}
+EXPORT_SYMBOL(strnlen_user);
+
+#define __do_clear_user(addr, size) \
+do { \
+ int __d0, zvalue, tmp; \
+ \
+ asm volatile( \
+ "0: cmpnei %1, 0 \n" \
+ " bf 7f \n" \
+ " mov %3, %1 \n" \
+ " andi %3, 3 \n" \
+ " cmpnei %3, 0 \n" \
+ " bf 1f \n" \
+ " br 5f \n" \
+ "1: cmplti %0, 32 \n" /* 4W */ \
+ " bt 3f \n" \
+ "8: stw %2, (%1, 0) \n" \
+ "10: stw %2, (%1, 4) \n" \
+ "11: stw %2, (%1, 8) \n" \
+ "12: stw %2, (%1, 12) \n" \
+ "13: stw %2, (%1, 16) \n" \
+ "14: stw %2, (%1, 20) \n" \
+ "15: stw %2, (%1, 24) \n" \
+ "16: stw %2, (%1, 28) \n" \
+ " addi %1, 32 \n" \
+ " subi %0, 32 \n" \
+ " br 1b \n" \
+ "3: cmplti %0, 4 \n" /* 1W */ \
+ " bt 5f \n" \
+ "4: stw %2, (%1, 0) \n" \
+ " addi %1, 4 \n" \
+ " subi %0, 4 \n" \
+ " br 3b \n" \
+ "5: cmpnei %0, 0 \n" /* 1B */ \
+ "9: bf 7f \n" \
+ "6: stb %2, (%1, 0) \n" \
+ " addi %1, 1 \n" \
+ " subi %0, 1 \n" \
+ " br 5b \n" \
+ ".section __ex_table,\"a\" \n" \
+ ".align 2 \n" \
+ ".long 8b, 9b \n" \
+ ".long 10b, 9b \n" \
+ ".long 11b, 9b \n" \
+ ".long 12b, 9b \n" \
+ ".long 13b, 9b \n" \
+ ".long 14b, 9b \n" \
+ ".long 15b, 9b \n" \
+ ".long 16b, 9b \n" \
+ ".long 4b, 9b \n" \
+ ".long 6b, 9b \n" \
+ ".previous \n" \
+ "7: \n" \
+ : "=r"(size), "=r" (__d0), \
+ "=r"(zvalue), "=r"(tmp) \
+ : "0"(size), "1"(addr), "2"(0) \
+ : "memory", "cc"); \
+} while (0)
+
+/*
+ * clear_user: - Zero a block of memory in user space.
+ * @to: Destination address, in user space.
+ * @n: 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.
+ */
+unsigned long
+clear_user(void __user *to, unsigned long n)
+{
+ if (access_ok(to, n))
+ __do_clear_user(to, n);
+ return n;
+}
+EXPORT_SYMBOL(clear_user);
+
+/*
+ * __clear_user: - Zero a block of memory in user space, with less checking.
+ * @to: Destination address, in user space.
+ * @n: Number of bytes to zero.
+ *
+ * Zero a block of memory in user space. Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
+unsigned long
+__clear_user(void __user *to, unsigned long n)
+{
+ __do_clear_user(to, n);
+ return n;
+}
+EXPORT_SYMBOL(__clear_user);