Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 320 insertions, 0 deletions

diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h
new file mode 100644
index 000000000..5c9fb8005
--- /dev/null
+++ b/arch/xtensa/include/asm/uaccess.h
@@ -0,0 +1,320 @@
+/*
+ * include/asm-xtensa/uaccess.h
+ *
+ * User space memory access functions
+ *
+ * These routines provide basic accessing functions to the user memory
+ * space for the kernel. This header file provides functions such as:
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_UACCESS_H
+#define _XTENSA_UACCESS_H
+
+#include <linux/prefetch.h>
+#include <asm/types.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 (Data Segment Register?), these macros are
+ * grossly misnamed.
+ */
+
+#define KERNEL_DS	((mm_segment_t) { 0 })
+#define USER_DS		((mm_segment_t) { 1 })
+
+#define get_fs()	(current->thread.current_ds)
+#define set_fs(val)	(current->thread.current_ds = (val))
+
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
+
+#define __kernel_ok (uaccess_kernel())
+#define __user_ok(addr, size) \
+		(((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size)))
+#define __access_ok(addr, size) (__kernel_ok || __user_ok((addr), (size)))
+#define access_ok(addr, size) __access_ok((unsigned long)(addr), (size))
+
+#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_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.
+ *
+ * Careful to not
+ * (a) re-use the arguments for side effects (sizeof is ok)
+ * (b) require any knowledge of processes at this stage
+ */
+#define put_user(x, ptr)	__put_user_check((x), (ptr), sizeof(*(ptr)))
+#define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
+
+/*
+ * 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).
+ */
+#define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
+#define __get_user(x, ptr) __get_user_nocheck((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)) __user *__pu_addr = (ptr);			\
+	if (access_ok(__pu_addr, size))			\
+		__put_user_size((x), __pu_addr, (size), __pu_err);	\
+	__pu_err;							\
+})
+
+#define __put_user_size(x, ptr, size, retval)				\
+do {									\
+	int __cb;							\
+	retval = 0;							\
+	switch (size) {							\
+	case 1: __put_user_asm(x, ptr, retval, 1, "s8i", __cb);  break;	\
+	case 2: __put_user_asm(x, ptr, retval, 2, "s16i", __cb); break;	\
+	case 4: __put_user_asm(x, ptr, retval, 4, "s32i", __cb); break;	\
+	case 8: {							\
+		     __typeof__(*ptr) __v64 = x;			\
+		     retval = __copy_to_user(ptr, &__v64, 8) ? -EFAULT : 0;	\
+		     break;						\
+	        }							\
+	default: __put_user_bad();					\
+	}								\
+} while (0)
+
+
+/*
+ * Consider a case of a user single load/store would cause both an
+ * unaligned exception and an MMU-related exception (unaligned
+ * exceptions happen first):
+ *
+ * User code passes a bad variable ptr to a system call.
+ * Kernel tries to access the variable.
+ * Unaligned exception occurs.
+ * Unaligned exception handler tries to make aligned accesses.
+ * Double exception occurs for MMU-related cause (e.g., page not mapped).
+ * do_page_fault() thinks the fault address belongs to the kernel, not the
+ * user, and panics.
+ *
+ * The kernel currently prohibits user unaligned accesses.  We use the
+ * __check_align_* macros to check for unaligned addresses before
+ * accessing user space so we don't crash the kernel.  Both
+ * __put_user_asm and __get_user_asm use these alignment macros, so
+ * macro-specific labels such as 0f, 1f, %0, %2, and %3 must stay in
+ * sync.
+ */
+
+#define __check_align_1  ""
+
+#define __check_align_2				\
+	"   _bbci.l %[mem] * 0, 1f	\n"	\
+	"   movi    %[err], %[efault]	\n"	\
+	"   _j      2f			\n"
+
+#define __check_align_4				\
+	"   _bbsi.l %[mem] * 0, 0f	\n"	\
+	"   _bbci.l %[mem] * 0 + 1, 1f	\n"	\
+	"0: movi    %[err], %[efault]	\n"	\
+	"   _j      2f			\n"
+
+
+/*
+ * 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.
+ *
+ * WARNING: If you modify this macro at all, verify that the
+ * __check_align_* macros still work.
+ */
+#define __put_user_asm(x_, addr_, err_, align, insn, cb)\
+__asm__ __volatile__(					\
+	__check_align_##align				\
+	"1: "insn"  %[x], %[mem]	\n"		\
+	"2:				\n"		\
+	"   .section  .fixup,\"ax\"	\n"		\
+	"   .align 4			\n"		\
+	"   .literal_position		\n"		\
+	"5:				\n"		\
+	"   movi   %[tmp], 2b		\n"		\
+	"   movi   %[err], %[efault]	\n"		\
+	"   jx     %[tmp]		\n"		\
+	"   .previous			\n"		\
+	"   .section  __ex_table,\"a\"	\n"		\
+	"   .long	1b, 5b		\n"		\
+	"   .previous"					\
+	:[err] "+r"(err_), [tmp] "=r"(cb), [mem] "=m"(*(addr_))		\
+	:[x] "r"(x_), [efault] "i"(-EFAULT))
+
+#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)					\
+({									\
+	long __gu_err = -EFAULT;					\
+	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
+	if (access_ok(__gu_addr, size))					\
+		__get_user_size((x), __gu_addr, (size), __gu_err);	\
+	else								\
+		(x) = (__typeof__(*(ptr)))0;				\
+	__gu_err;							\
+})
+
+extern long __get_user_bad(void);
+
+#define __get_user_size(x, ptr, size, retval)				\
+do {									\
+	int __cb;							\
+	retval = 0;							\
+	switch (size) {							\
+	case 1: __get_user_asm(x, ptr, retval, 1, "l8ui", __cb);  break;\
+	case 2: __get_user_asm(x, ptr, retval, 2, "l16ui", __cb); break;\
+	case 4: __get_user_asm(x, ptr, retval, 4, "l32i", __cb);  break;\
+	case 8: {							\
+		u64 __x;						\
+		if (unlikely(__copy_from_user(&__x, ptr, 8))) {		\
+			retval = -EFAULT;				\
+			(x) = (__typeof__(*(ptr)))0;			\
+		} else {						\
+			(x) = *(__force __typeof__(*(ptr)) *)&__x;	\
+		}							\
+		break;							\
+	}								\
+	default:							\
+		(x) = (__typeof__(*(ptr)))0;				\
+		__get_user_bad();					\
+	}								\
+} while (0)
+
+
+/*
+ * WARNING: If you modify this macro at all, verify that the
+ * __check_align_* macros still work.
+ */
+#define __get_user_asm(x_, addr_, err_, align, insn, cb) \
+do {							\
+	u32 __x = 0;					\
+	__asm__ __volatile__(				\
+		__check_align_##align			\
+		"1: "insn"  %[x], %[mem]	\n"	\
+		"2:				\n"	\
+		"   .section  .fixup,\"ax\"	\n"	\
+		"   .align 4			\n"	\
+		"   .literal_position		\n"	\
+		"5:				\n"	\
+		"   movi   %[tmp], 2b		\n"	\
+		"   movi   %[err], %[efault]	\n"	\
+		"   jx     %[tmp]		\n"	\
+		"   .previous			\n"	\
+		"   .section  __ex_table,\"a\"	\n"	\
+		"   .long	1b, 5b		\n"	\
+		"   .previous"				\
+		:[err] "+r"(err_), [tmp] "=r"(cb), [x] "+r"(__x) \
+		:[mem] "m"(*(addr_)), [efault] "i"(-EFAULT)); \
+	(x_) = (__force __typeof__(*(addr_)))__x;	\
+} while (0)
+
+
+/*
+ * Copy to/from user space
+ */
+
+extern unsigned __xtensa_copy_user(void *to, const void *from, unsigned n);
+
+static inline unsigned long
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	prefetchw(to);
+	return __xtensa_copy_user(to, (__force const void *)from, n);
+}
+static inline unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	prefetch(from);
+	return __xtensa_copy_user((__force void *)to, from, n);
+}
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
+
+/*
+ * We need to return the number of bytes not cleared.  Our memset()
+ * returns zero if a problem occurs while accessing user-space memory.
+ * In that event, return no memory cleared.  Otherwise, zero for
+ * success.
+ */
+
+static inline unsigned long
+__xtensa_clear_user(void __user *addr, unsigned long size)
+{
+	if (!__memset((void __force *)addr, 0, size))
+		return size;
+	return 0;
+}
+
+static inline unsigned long
+clear_user(void __user *addr, unsigned long size)
+{
+	if (access_ok(addr, size))
+		return __xtensa_clear_user(addr, size);
+	return size ? -EFAULT : 0;
+}
+
+#define __clear_user  __xtensa_clear_user
+
+
+#ifndef CONFIG_GENERIC_STRNCPY_FROM_USER
+
+extern long __strncpy_user(char *dst, const char __user *src, long count);
+
+static inline long
+strncpy_from_user(char *dst, const char __user *src, long count)
+{
+	if (access_ok(src, 1))
+		return __strncpy_user(dst, src, count);
+	return -EFAULT;
+}
+#else
+long strncpy_from_user(char *dst, const char __user *src, long count);
+#endif
+
+/*
+ * Return the size of a string (including the ending 0!)
+ */
+extern long __strnlen_user(const char __user *str, long len);
+
+static inline long strnlen_user(const char __user *str, long len)
+{
+	if (!access_ok(str, 1))
+		return 0;
+	return __strnlen_user(str, len);
+}
+
+#endif	/* _XTENSA_UACCESS_H */