diff options
Diffstat (limited to 'arch/csky/lib/usercopy.c')
| -rw-r--r-- | arch/csky/lib/usercopy.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/arch/csky/lib/usercopy.c b/arch/csky/lib/usercopy.c new file mode 100644 index 000000000..3c9bd645e --- /dev/null +++ b/arch/csky/lib/usercopy.c @@ -0,0 +1,258 @@ +// 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) +{ + ___copy_from_user(to, from, n); + return n; +} +EXPORT_SYMBOL(raw_copy_from_user); + +unsigned long raw_copy_to_user(void *to, const void *from, + unsigned long n) +{ + ___copy_to_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); |