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authorGuo Ren <ren_guo@c-sky.com>2018-09-05 09:25:18 +0300
committerGuo Ren <ren_guo@c-sky.com>2018-10-25 19:54:25 +0300
commitda551281947cb2c0ab6e0045529a706af5d79584 (patch)
treeed1366aaec2841a0de7c2d114376abfe0c3cd7c6 /arch/csky/include
parentc5af58b769113c4045209973052db3e3a543ee43 (diff)
downloadlinux-da551281947cb2c0ab6e0045529a706af5d79584.tar.xz
csky: User access
The patch adds "user access from kernel" codes. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/csky/include')
-rw-r--r--arch/csky/include/asm/uaccess.h416
1 files changed, 416 insertions, 0 deletions
diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h
new file mode 100644
index 000000000000..acaf0e210d81
--- /dev/null
+++ b/arch/csky/include/asm/uaccess.h
@@ -0,0 +1,416 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_UACCESS_H
+#define __ASM_CSKY_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/version.h>
+#include <asm/segment.h>
+
+#define VERIFY_READ 0
+#define VERIFY_WRITE 1
+
+static inline int access_ok(int type, const void *addr, unsigned long size)
+{
+ unsigned long limit = current_thread_info()->addr_limit.seg;
+
+ return (((unsigned long)addr < limit) &&
+ ((unsigned long)(addr + size) < limit));
+}
+
+static inline int verify_area(int type, const void *addr, unsigned long size)
+{
+ return access_ok(type, addr, size) ? 0 : -EFAULT;
+}
+
+#define __addr_ok(addr) (access_ok(VERIFY_READ, addr, 0))
+
+extern int __put_user_bad(void);
+
+/*
+ * Tell gcc we read from memory instead of writing: this is because
+ * we do not write to any memory gcc knows about, so there are no
+ * aliasing issues.
+ */
+
+/*
+ * These are the main single-value transfer routines. They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * This gets kind of ugly. We want to return _two_ values in "get_user()"
+ * and yet we don't want to do any pointers, because that is too much
+ * of a performance impact. Thus we have a few rather ugly macros here,
+ * and hide all the ugliness from the user.
+ *
+ * The "__xxx" versions of the user access functions are versions that
+ * do not verify the address space, that must have been done previously
+ * with a separate "access_ok()" call (this is used when we do multiple
+ * accesses to the same area of user memory).
+ *
+ * As we use the same address space for kernel and user data on
+ * Ckcore, we can just do these as direct assignments. (Of course, the
+ * exception handling means that it's no longer "just"...)
+ */
+
+#define put_user(x, ptr) \
+ __put_user_check((x), (ptr), sizeof(*(ptr)))
+
+#define __put_user(x, ptr) \
+ __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#define __ptr(x) ((unsigned long *)(x))
+
+#define get_user(x, ptr) \
+ __get_user_check((x), (ptr), sizeof(*(ptr)))
+
+#define __get_user(x, ptr) \
+ __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#define __put_user_nocheck(x, ptr, size) \
+({ \
+ long __pu_err = 0; \
+ typeof(*(ptr)) *__pu_addr = (ptr); \
+ typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x); \
+ if (__pu_addr) \
+ __put_user_size(__pu_val, (__pu_addr), (size), \
+ __pu_err); \
+ __pu_err; \
+})
+
+#define __put_user_check(x, ptr, size) \
+({ \
+ long __pu_err = -EFAULT; \
+ typeof(*(ptr)) *__pu_addr = (ptr); \
+ typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x); \
+ if (access_ok(VERIFY_WRITE, __pu_addr, size) && __pu_addr) \
+ __put_user_size(__pu_val, __pu_addr, (size), __pu_err); \
+ __pu_err; \
+})
+
+#define __put_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: \
+ __put_user_asm_b(x, ptr, retval); \
+ break; \
+ case 2: \
+ __put_user_asm_h(x, ptr, retval); \
+ break; \
+ case 4: \
+ __put_user_asm_w(x, ptr, retval); \
+ break; \
+ case 8: \
+ __put_user_asm_64(x, ptr, retval); \
+ break; \
+ default: \
+ __put_user_bad(); \
+ } \
+} while (0)
+
+/*
+ * We don't tell gcc that we are accessing memory, but this is OK
+ * because we do not write to any memory gcc knows about, so there
+ * are no aliasing issues.
+ *
+ * Note that PC at a fault is the address *after* the faulting
+ * instruction.
+ */
+#define __put_user_asm_b(x, ptr, err) \
+do { \
+ int errcode; \
+ asm volatile( \
+ "1: stb %1, (%2,0) \n" \
+ " br 3f \n" \
+ "2: mov %0, %3 \n" \
+ " br 3f \n" \
+ ".section __ex_table, \"a\" \n" \
+ ".align 2 \n" \
+ ".long 1b,2b \n" \
+ ".previous \n" \
+ "3: \n" \
+ : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \
+ : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \
+ : "memory"); \
+} while (0)
+
+#define __put_user_asm_h(x, ptr, err) \
+do { \
+ int errcode; \
+ asm volatile( \
+ "1: sth %1, (%2,0) \n" \
+ " br 3f \n" \
+ "2: mov %0, %3 \n" \
+ " br 3f \n" \
+ ".section __ex_table, \"a\" \n" \
+ ".align 2 \n" \
+ ".long 1b,2b \n" \
+ ".previous \n" \
+ "3: \n" \
+ : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \
+ : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \
+ : "memory"); \
+} while (0)
+
+#define __put_user_asm_w(x, ptr, err) \
+do { \
+ int errcode; \
+ asm volatile( \
+ "1: stw %1, (%2,0) \n" \
+ " br 3f \n" \
+ "2: mov %0, %3 \n" \
+ " br 3f \n" \
+ ".section __ex_table,\"a\" \n" \
+ ".align 2 \n" \
+ ".long 1b, 2b \n" \
+ ".previous \n" \
+ "3: \n" \
+ : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \
+ : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \
+ : "memory"); \
+} while (0)
+
+#define __put_user_asm_64(x, ptr, err) \
+do { \
+ int tmp; \
+ int errcode; \
+ typeof(*(ptr))src = (typeof(*(ptr)))x; \
+ typeof(*(ptr))*psrc = &src; \
+ \
+ asm volatile( \
+ " ldw %3, (%1, 0) \n" \
+ "1: stw %3, (%2, 0) \n" \
+ " ldw %3, (%1, 4) \n" \
+ "2: stw %3, (%2, 4) \n" \
+ " br 4f \n" \
+ "3: mov %0, %4 \n" \
+ " br 4f \n" \
+ ".section __ex_table, \"a\" \n" \
+ ".align 2 \n" \
+ ".long 1b, 3b \n" \
+ ".long 2b, 3b \n" \
+ ".previous \n" \
+ "4: \n" \
+ : "=r"(err), "=r"(psrc), "=r"(ptr), \
+ "=r"(tmp), "=r"(errcode) \
+ : "0"(err), "1"(psrc), "2"(ptr), "3"(0), "4"(-EFAULT) \
+ : "memory"); \
+} while (0)
+
+#define __get_user_nocheck(x, ptr, size) \
+({ \
+ long __gu_err; \
+ __get_user_size(x, (ptr), (size), __gu_err); \
+ __gu_err; \
+})
+
+#define __get_user_check(x, ptr, size) \
+({ \
+ int __gu_err = -EFAULT; \
+ const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
+ if (access_ok(VERIFY_READ, __gu_ptr, size) && __gu_ptr) \
+ __get_user_size(x, __gu_ptr, size, __gu_err); \
+ __gu_err; \
+})
+
+#define __get_user_size(x, ptr, size, retval) \
+do { \
+ switch (size) { \
+ case 1: \
+ __get_user_asm_common((x), ptr, "ldb", retval); \
+ break; \
+ case 2: \
+ __get_user_asm_common((x), ptr, "ldh", retval); \
+ break; \
+ case 4: \
+ __get_user_asm_common((x), ptr, "ldw", retval); \
+ break; \
+ default: \
+ x = 0; \
+ (retval) = __get_user_bad(); \
+ } \
+} while (0)
+
+#define __get_user_asm_common(x, ptr, ins, err) \
+do { \
+ int errcode; \
+ asm volatile( \
+ "1: " ins " %1, (%4,0) \n" \
+ " br 3f \n" \
+ /* Fix up codes */ \
+ "2: mov %0, %2 \n" \
+ " movi %1, 0 \n" \
+ " br 3f \n" \
+ ".section __ex_table,\"a\" \n" \
+ ".align 2 \n" \
+ ".long 1b, 2b \n" \
+ ".previous \n" \
+ "3: \n" \
+ : "=r"(err), "=r"(x), "=r"(errcode) \
+ : "0"(0), "r"(ptr), "2"(-EFAULT) \
+ : "memory"); \
+} while (0)
+
+extern int __get_user_bad(void);
+
+#define __copy_user(to, from, n) \
+do { \
+ int w0, w1, w2, w3; \
+ asm volatile( \
+ "0: cmpnei %1, 0 \n" \
+ " bf 8f \n" \
+ " mov %3, %1 \n" \
+ " or %3, %2 \n" \
+ " andi %3, 3 \n" \
+ " cmpnei %3, 0 \n" \
+ " bf 1f \n" \
+ " br 5f \n" \
+ "1: cmplti %0, 16 \n" /* 4W */ \
+ " bt 3f \n" \
+ " ldw %3, (%2, 0) \n" \
+ " ldw %4, (%2, 4) \n" \
+ " ldw %5, (%2, 8) \n" \
+ " ldw %6, (%2, 12) \n" \
+ "2: stw %3, (%1, 0) \n" \
+ "9: stw %4, (%1, 4) \n" \
+ "10: stw %5, (%1, 8) \n" \
+ "11: stw %6, (%1, 12) \n" \
+ " addi %2, 16 \n" \
+ " addi %1, 16 \n" \
+ " subi %0, 16 \n" \
+ " br 1b \n" \
+ "3: cmplti %0, 4 \n" /* 1W */ \
+ " bt 5f \n" \
+ " ldw %3, (%2, 0) \n" \
+ "4: stw %3, (%1, 0) \n" \
+ " addi %2, 4 \n" \
+ " addi %1, 4 \n" \
+ " subi %0, 4 \n" \
+ " br 3b \n" \
+ "5: cmpnei %0, 0 \n" /* 1B */ \
+ " bf 8f \n" \
+ " ldb %3, (%2, 0) \n" \
+ "6: stb %3, (%1, 0) \n" \
+ " addi %2, 1 \n" \
+ " addi %1, 1 \n" \
+ " subi %0, 1 \n" \
+ " br 5b \n" \
+ "7: br 8f \n" \
+ ".section __ex_table, \"a\" \n" \
+ ".align 2 \n" \
+ ".long 2b, 7b \n" \
+ ".long 9b, 7b \n" \
+ ".long 10b, 7b \n" \
+ ".long 11b, 7b \n" \
+ ".long 4b, 7b \n" \
+ ".long 6b, 7b \n" \
+ ".previous \n" \
+ "8: \n" \
+ : "=r"(n), "=r"(to), "=r"(from), "=r"(w0), \
+ "=r"(w1), "=r"(w2), "=r"(w3) \
+ : "0"(n), "1"(to), "2"(from) \
+ : "memory"); \
+} while (0)
+
+#define __copy_user_zeroing(to, from, n) \
+do { \
+ int tmp; \
+ int nsave; \
+ asm volatile( \
+ "0: cmpnei %1, 0 \n" \
+ " bf 7f \n" \
+ " mov %3, %1 \n" \
+ " or %3, %2 \n" \
+ " andi %3, 3 \n" \
+ " cmpnei %3, 0 \n" \
+ " bf 1f \n" \
+ " br 5f \n" \
+ "1: cmplti %0, 16 \n" \
+ " bt 3f \n" \
+ "2: ldw %3, (%2, 0) \n" \
+ "10: ldw %4, (%2, 4) \n" \
+ " stw %3, (%1, 0) \n" \
+ " stw %4, (%1, 4) \n" \
+ "11: ldw %3, (%2, 8) \n" \
+ "12: ldw %4, (%2, 12) \n" \
+ " stw %3, (%1, 8) \n" \
+ " stw %4, (%1, 12) \n" \
+ " addi %2, 16 \n" \
+ " addi %1, 16 \n" \
+ " subi %0, 16 \n" \
+ " br 1b \n" \
+ "3: cmplti %0, 4 \n" \
+ " bt 5f \n" \
+ "4: ldw %3, (%2, 0) \n" \
+ " stw %3, (%1, 0) \n" \
+ " addi %2, 4 \n" \
+ " addi %1, 4 \n" \
+ " subi %0, 4 \n" \
+ " br 3b \n" \
+ "5: cmpnei %0, 0 \n" \
+ " bf 7f \n" \
+ "6: ldb %3, (%2, 0) \n" \
+ " stb %3, (%1, 0) \n" \
+ " addi %2, 1 \n" \
+ " addi %1, 1 \n" \
+ " subi %0, 1 \n" \
+ " br 5b \n" \
+ "8: mov %3, %0 \n" \
+ " movi %4, 0 \n" \
+ "9: stb %4, (%1, 0) \n" \
+ " addi %1, 1 \n" \
+ " subi %3, 1 \n" \
+ " cmpnei %3, 0 \n" \
+ " bt 9b \n" \
+ " br 7f \n" \
+ ".section __ex_table, \"a\" \n" \
+ ".align 2 \n" \
+ ".long 2b, 8b \n" \
+ ".long 10b, 8b \n" \
+ ".long 11b, 8b \n" \
+ ".long 12b, 8b \n" \
+ ".long 4b, 8b \n" \
+ ".long 6b, 8b \n" \
+ ".previous \n" \
+ "7: \n" \
+ : "=r"(n), "=r"(to), "=r"(from), "=r"(nsave), \
+ "=r"(tmp) \
+ : "0"(n), "1"(to), "2"(from) \
+ : "memory"); \
+} while (0)
+
+unsigned long raw_copy_from_user(void *to, const void *from, unsigned long n);
+unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n);
+
+unsigned long clear_user(void *to, unsigned long n);
+unsigned long __clear_user(void __user *to, unsigned long n);
+
+long strncpy_from_user(char *dst, const char *src, long count);
+long __strncpy_from_user(char *dst, const char *src, long count);
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 on exception, a value greater than N if too long
+ */
+long strnlen_user(const char *src, long n);
+
+#define strlen_user(str) strnlen_user(str, 32767)
+
+struct exception_table_entry {
+ unsigned long insn;
+ unsigned long nextinsn;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_UACCESS_H */