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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/openrisc/include/asm/uaccess.h
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/openrisc/include/asm/uaccess.h')
-rw-r--r--arch/openrisc/include/asm/uaccess.h273
1 files changed, 273 insertions, 0 deletions
diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h
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+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others. All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __ASM_OPENRISC_UACCESS_H
+#define __ASM_OPENRISC_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/prefetch.h>
+#include <linux/string.h>
+#include <asm/page.h>
+#include <asm/extable.h>
+
+/*
+ * 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.
+ */
+
+/* addr_limit is the maximum accessible address for the task. we misuse
+ * the KERNEL_DS and USER_DS values to both assign and compare the
+ * addr_limit values through the equally misnamed get/set_fs macros.
+ * (see above)
+ */
+
+#define KERNEL_DS (~0UL)
+#define get_ds() (KERNEL_DS)
+
+#define USER_DS (TASK_SIZE)
+#define get_fs() (current_thread_info()->addr_limit)
+#define set_fs(x) (current_thread_info()->addr_limit = (x))
+
+#define segment_eq(a, b) ((a) == (b))
+
+/* Ensure that the range from addr to addr+size is all within the process'
+ * address space
+ */
+#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))
+
+/* Ensure that addr is below task's addr_limit */
+#define __addr_ok(addr) ((unsigned long) addr < get_fs())
+
+#define access_ok(type, addr, size) \
+({ \
+ unsigned long __ao_addr = (unsigned long)(addr); \
+ unsigned long __ao_size = (unsigned long)(size); \
+ __range_ok(__ao_addr, __ao_size); \
+})
+
+/*
+ * 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 uglyness 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 the
+ * PowerPC, we can just do these as direct assignments. (Of course, the
+ * exception handling means that it's no longer "just"...)
+ */
+#define get_user(x, ptr) \
+ __get_user_check((x), (ptr), sizeof(*(ptr)))
+#define put_user(x, ptr) \
+ __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
+#define __get_user(x, ptr) \
+ __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+#define __put_user(x, ptr) \
+ __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
+
+extern long __put_user_bad(void);
+
+#define __put_user_nocheck(x, ptr, size) \
+({ \
+ long __pu_err; \
+ __put_user_size((x), (ptr), (size), __pu_err); \
+ __pu_err; \
+})
+
+#define __put_user_check(x, ptr, size) \
+({ \
+ long __pu_err = -EFAULT; \
+ __typeof__(*(ptr)) *__pu_addr = (ptr); \
+ if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
+ __put_user_size((x), __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(x, ptr, retval, "l.sb"); break; \
+ case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \
+ case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \
+ case 8: __put_user_asm2(x, ptr, retval); break; \
+ default: __put_user_bad(); \
+ } \
+} while (0)
+
+struct __large_struct {
+ unsigned long buf[100];
+};
+#define __m(x) (*(struct __large_struct *)(x))
+
+/*
+ * 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.
+ */
+#define __put_user_asm(x, addr, err, op) \
+ __asm__ __volatile__( \
+ "1: "op" 0(%2),%1\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: l.addi %0,r0,%3\n" \
+ " l.j 2b\n" \
+ " l.nop\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 2\n" \
+ " .long 1b,3b\n" \
+ ".previous" \
+ : "=r"(err) \
+ : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
+
+#define __put_user_asm2(x, addr, err) \
+ __asm__ __volatile__( \
+ "1: l.sw 0(%2),%1\n" \
+ "2: l.sw 4(%2),%H1\n" \
+ "3:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "4: l.addi %0,r0,%3\n" \
+ " l.j 3b\n" \
+ " l.nop\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 2\n" \
+ " .long 1b,4b\n" \
+ " .long 2b,4b\n" \
+ ".previous" \
+ : "=r"(err) \
+ : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
+
+#define __get_user_nocheck(x, ptr, size) \
+({ \
+ long __gu_err, __gu_val; \
+ __get_user_size(__gu_val, (ptr), (size), __gu_err); \
+ (x) = (__force __typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+#define __get_user_check(x, ptr, size) \
+({ \
+ long __gu_err = -EFAULT, __gu_val = 0; \
+ const __typeof__(*(ptr)) * __gu_addr = (ptr); \
+ if (access_ok(VERIFY_READ, __gu_addr, size)) \
+ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
+ (x) = (__force __typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+extern long __get_user_bad(void);
+
+#define __get_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \
+ case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \
+ case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \
+ case 8: __get_user_asm2(x, ptr, retval); break; \
+ default: (x) = __get_user_bad(); \
+ } \
+} while (0)
+
+#define __get_user_asm(x, addr, err, op) \
+ __asm__ __volatile__( \
+ "1: "op" %1,0(%2)\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: l.addi %0,r0,%3\n" \
+ " l.addi %1,r0,0\n" \
+ " l.j 2b\n" \
+ " l.nop\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 2\n" \
+ " .long 1b,3b\n" \
+ ".previous" \
+ : "=r"(err), "=r"(x) \
+ : "r"(addr), "i"(-EFAULT), "0"(err))
+
+#define __get_user_asm2(x, addr, err) \
+ __asm__ __volatile__( \
+ "1: l.lwz %1,0(%2)\n" \
+ "2: l.lwz %H1,4(%2)\n" \
+ "3:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "4: l.addi %0,r0,%3\n" \
+ " l.addi %1,r0,0\n" \
+ " l.addi %H1,r0,0\n" \
+ " l.j 3b\n" \
+ " l.nop\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 2\n" \
+ " .long 1b,4b\n" \
+ " .long 2b,4b\n" \
+ ".previous" \
+ : "=r"(err), "=&r"(x) \
+ : "r"(addr), "i"(-EFAULT), "0"(err))
+
+/* more complex routines */
+
+extern unsigned long __must_check
+__copy_tofrom_user(void *to, const void *from, unsigned long size);
+static inline unsigned long
+raw_copy_from_user(void *to, const void __user *from, unsigned long size)
+{
+ return __copy_tofrom_user(to, (__force const void *)from, size);
+}
+static inline unsigned long
+raw_copy_to_user(void *to, const void __user *from, unsigned long size)
+{
+ return __copy_tofrom_user((__force void *)to, from, size);
+}
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
+
+extern unsigned long __clear_user(void *addr, unsigned long size);
+
+static inline __must_check unsigned long
+clear_user(void *addr, unsigned long size)
+{
+ if (likely(access_ok(VERIFY_WRITE, addr, size)))
+ size = __clear_user(addr, size);
+ return size;
+}
+
+#define user_addr_max() \
+ (uaccess_kernel() ? ~0UL : TASK_SIZE)
+
+extern long strncpy_from_user(char *dest, const char __user *src, long count);
+
+extern __must_check long strnlen_user(const char __user *str, long n);
+
+#endif /* __ASM_OPENRISC_UACCESS_H */