[PATCH 13/19] csky: User access
From: Guo Ren
Date: Sun Mar 18 2018 - 15:53:12 EST
Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
---
arch/csky/include/asm/uaccess.h | 408 ++++++++++++++++++++++++++++++++++++++++
arch/csky/include/asm/user.h | 102 ++++++++++
2 files changed, 510 insertions(+)
create mode 100644 arch/csky/include/asm/uaccess.h
create mode 100644 arch/csky/include/asm/user.h
diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h
new file mode 100644
index 0000000..b3c3599
--- /dev/null
+++ b/arch/csky/include/asm/uaccess.h
@@ -0,0 +1,408 @@
+// 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)
+{
+ return (((unsigned long)addr < current_thread_info()->addr_limit.seg) &&
+ ((unsigned long)(addr + size) < current_thread_info()->addr_limit.seg));
+}
+
+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" /* 4W */ \
+ " 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" /* 1W */ \
+ " 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" /* 1B */ \
+ " 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" /* zero */ \
+ " 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);
+
+#ifdef COMPAT_KERNEL_4_9
+#define __copy_from_user(to, from, n) raw_copy_from_user(to, from, n)
+#define __copy_to_user(to, from, n) raw_copy_to_user(to, from, n)
+
+#define __copy_from_user_inatomic __copy_from_user
+#define __copy_to_user_inatomic __copy_to_user
+
+#define copy_from_user __copy_from_user
+#define copy_to_user __copy_to_user
+#endif
+
+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 */
diff --git a/arch/csky/include/asm/user.h b/arch/csky/include/asm/user.h
new file mode 100644
index 0000000..8ca8a12
--- /dev/null
+++ b/arch/csky/include/asm/user.h
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#ifndef __ASM_CSKY_USER_H
+#define __ASM_CSKY_USER_H
+
+#include <asm/page.h>
+#include <asm/ptrace.h>
+/*
+ * Core file format: The core file is written in such a way that gdb
+ * can understand it and provide useful information to the user (under
+ * linux we use the 'trad-core' bfd). There are quite a number of
+ * obstacles to being able to view the contents of the floating point
+ * registers, and until these are solved you will not be able to view the
+ * contents of them. Actually, you can read in the core file and look at
+ * the contents of the user struct to find out what the floating point
+ * registers contain.
+ * The actual file contents are as follows:
+ * UPAGE: 1 page consisting of a user struct that tells gdb what is present
+ * in the file. Directly after this is a copy of the task_struct, which
+ * is currently not used by gdb, but it may come in useful at some point.
+ * All of the registers are stored as part of the upage. The upage should
+ * always be only one page.
+ * DATA: The data area is stored. We use current->end_text to
+ * current->brk to pick up all of the user variables, plus any memory
+ * that may have been malloced. No attempt is made to determine if a page
+ * is demand-zero or if a page is totally unused, we just cover the entire
+ * range. All of the addresses are rounded in such a way that an integral
+ * number of pages is written.
+ * STACK: We need the stack information in order to get a meaningful
+ * backtrace. We need to write the data from (esp) to
+ * current->start_stack, so we round each of these off in order to be able
+ * to write an integer number of pages.
+ * The minimum core file size is 3 pages, or 12288 bytes.
+ */
+
+struct user_cskyfp_struct {
+ unsigned long fcr; /* fpu control reg */
+ unsigned long fsr; /* fpu status reg, nothing in CPU_CSKYV2 */
+ unsigned long fesr; /* fpu exception status reg */
+ unsigned long fp[32]; /* fpu general regs */
+};
+
+/*
+ * This is the old layout of "struct pt_regs" as of Linux 1.x, and
+ * is still the layout used by user (the new pt_regs doesn't have
+ * all registers).
+ *
+ * In this struct, both ABIV1 & ABIV2 have the same general regs:
+ * CSKY ABIv1: r0 ~ r31, psr, pc, hi, lo
+ * CSKY ABIv2: r0 ~ r31, psr, pc, hi, lo
+ * but in CSKY ABIV1, r16 ~ r31 don't exist, so in ABIV1, they are zero.
+ */
+struct user_regs_struct {
+ unsigned long gregs[32]; // ABIV1, usp = r0; ABIV2, usp = r14
+ unsigned long psr;
+ unsigned long pc;
+ unsigned long hi;
+ unsigned long lo;
+};
+
+/* user_regs_struct->gregs[REG_WHY].
+ * flag: 0: enter system call
+ * 1: leave system call
+ */
+#define REG_WHY 9
+
+/*
+ * When the kernel dumps core, it starts by dumping the user struct -
+ * this will be used by gdb to figure out where the data and stack segments
+ * are within the file, and what virtual addresses to use.
+ */
+struct user{
+/* We start with the registers, to mimic the way that "memory" is returned
+ from the ptrace(3,...) function. */
+ struct user_regs_struct regs; /* Where the registers are actually stored */
+ int u_fpvalid; /* True if math co-processor being used. */
+
+/* The rest of this junk is to help gdb figure out what goes where */
+ unsigned long int u_tsize; /* Text segment size (pages). */
+ unsigned long int u_dsize; /* Data segment size (pages). */
+ unsigned long int u_ssize; /* Stack segment size (pages). */
+ unsigned long start_code; /* Starting virtual address of text. */
+ unsigned long start_stack;/* Starting virtual address of stack area.
+ This is actually the bottom of the stack,
+ the top of the stack is always found in
+ the esp register. */
+ long int signal; /* Signal that caused the core dump. */
+ int reserved; /* No longer used */
+ unsigned long u_ar0; /* Used by gdb to help find the values
+ for the registers. */
+ unsigned long magic; /* To uniquely identify a core file */
+ char u_comm[32]; /* User command that was responsible */
+ struct user_cskyfp_struct u_fp; /* Floating point registers */
+ struct user_cskyfp_struct* u_fpstate; /* Math Co-processor pointer. */
+};
+
+#define NBPG 4096
+#define UPAGES 1
+#define HOST_TEXT_START_ADDR (u.start_code)
+#define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG)
+
+#endif /* __ASM_CSKY_USER_H */
--
2.7.4