1 files changed, 590 insertions, 0 deletions

diff --git a/include/asm-x86/uaccess_32.h b/include/asm-x86/uaccess_32.h
new file mode 100644
index 000000000000..d2a4f7be9c2c
--- /dev/null
+++ b/include/asm-x86/uaccess_32.h
@@ -0,0 +1,590 @@
+#ifndef __i386_UACCESS_H
+#define __i386_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/errno.h>
+#include <linux/thread_info.h>
+#include <linux/prefetch.h>
+#include <linux/string.h>
+#include <asm/page.h>
+
+#define VERIFY_READ 0
+#define VERIFY_WRITE 1
+
+/*
+ * 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.
+ */
+
+#define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
+
+
+#define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFFUL)
+#define USER_DS         MAKE_MM_SEG(PAGE_OFFSET)
+
+#define get_ds()        (KERNEL_DS)
+#define get_fs()        (current_thread_info()->addr_limit)
+#define set_fs(x)       (current_thread_info()->addr_limit = (x))
+
+#define segment_eq(a,b) ((a).seg == (b).seg)
+
+/*
+ * movsl can be slow when source and dest are not both 8-byte aligned
+ */
+#ifdef CONFIG_X86_INTEL_USERCOPY
+extern struct movsl_mask {
+        int mask;
+} ____cacheline_aligned_in_smp movsl_mask;
+#endif
+
+#define __addr_ok(addr) ((unsigned long __force)(addr) < (current_thread_info()->addr_limit.seg))
+
+/*
+ * Test whether a block of memory is a valid user space address.
+ * Returns 0 if the range is valid, nonzero otherwise.
+ *
+ * This is equivalent to the following test:
+ * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
+ *
+ * This needs 33-bit arithmetic. We have a carry...
+ */
+#define __range_ok(addr,size) ({ \
+        unsigned long flag,roksum; \
+        __chk_user_ptr(addr); \
+        asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0" \
+                :"=&r" (flag), "=r" (roksum) \
+                :"1" (addr),"g" ((int)(size)),"rm" (current_thread_info()->addr_limit.seg)); \
+        flag; })
+
+/**
+ * access_ok: - Checks if a user space pointer is valid
+ * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
+ *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
+ *        to write to a block, it is always safe to read from it.
+ * @addr: User space pointer to start of block to check
+ * @size: Size of block to check
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Checks if a pointer to a block of memory in user space is valid.
+ *
+ * Returns true (nonzero) if the memory block may be valid, false (zero)
+ * if it is definitely invalid.
+ *
+ * Note that, depending on architecture, this function probably just
+ * checks that the pointer is in the user space range - after calling
+ * this function, memory access functions may still return -EFAULT.
+ */
+#define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
+
+/*
+ * The exception table consists of pairs of addresses: the first is the
+ * address of an instruction that is allowed to fault, and the second is
+ * the address at which the program should continue.  No registers are
+ * modified, so it is entirely up to the continuation code to figure out
+ * what to do.
+ *
+ * All the routines below use bits of fixup code that are out of line
+ * with the main instruction path.  This means when everything is well,
+ * we don't even have to jump over them.  Further, they do not intrude
+ * on our cache or tlb entries.
+ */
+
+struct exception_table_entry
+{
+        unsigned long insn, fixup;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+/*
+ * 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).
+ */
+
+extern void __get_user_1(void);
+extern void __get_user_2(void);
+extern void __get_user_4(void);
+
+#define __get_user_x(size,ret,x,ptr) \
+        __asm__ __volatile__("call __get_user_" #size \
+                :"=a" (ret),"=d" (x) \
+                :"0" (ptr))
+
+
+/* Careful: we have to cast the result to the type of the pointer for sign reasons */
+/**
+ * get_user: - Get a simple variable from user space.
+ * @x:   Variable to store result.
+ * @ptr: Source address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple variable from user space to kernel
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and the result of
+ * dereferencing @ptr must be assignable to @x without a cast.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ * On error, the variable @x is set to zero.
+ */
+#define get_user(x,ptr)                                                 \
+({      int __ret_gu;                                                   \
+        unsigned long __val_gu;                                         \
+        __chk_user_ptr(ptr);                                            \
+        switch(sizeof (*(ptr))) {                                       \
+        case 1:  __get_user_x(1,__ret_gu,__val_gu,ptr); break;          \
+        case 2:  __get_user_x(2,__ret_gu,__val_gu,ptr); break;          \
+        case 4:  __get_user_x(4,__ret_gu,__val_gu,ptr); break;          \
+        default: __get_user_x(X,__ret_gu,__val_gu,ptr); break;          \
+        }                                                               \
+        (x) = (__typeof__(*(ptr)))__val_gu;                             \
+        __ret_gu;                                                       \
+})
+
+extern void __put_user_bad(void);
+
+/*
+ * Strange magic calling convention: pointer in %ecx,
+ * value in %eax(:%edx), return value in %eax, no clobbers.
+ */
+extern void __put_user_1(void);
+extern void __put_user_2(void);
+extern void __put_user_4(void);
+extern void __put_user_8(void);
+
+#define __put_user_1(x, ptr) __asm__ __volatile__("call __put_user_1":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
+#define __put_user_2(x, ptr) __asm__ __volatile__("call __put_user_2":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
+#define __put_user_4(x, ptr) __asm__ __volatile__("call __put_user_4":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
+#define __put_user_8(x, ptr) __asm__ __volatile__("call __put_user_8":"=a" (__ret_pu):"A" ((typeof(*(ptr)))(x)), "c" (ptr))
+#define __put_user_X(x, ptr) __asm__ __volatile__("call __put_user_X":"=a" (__ret_pu):"c" (ptr))
+
+/**
+ * put_user: - Write a simple value into user space.
+ * @x:   Value to copy to user space.
+ * @ptr: Destination address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple value from kernel space to user
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and @x must be assignable
+ * to the result of dereferencing @ptr.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ */
+#ifdef CONFIG_X86_WP_WORKS_OK
+
+#define put_user(x,ptr)                                         \
+({      int __ret_pu;                                           \
+        __typeof__(*(ptr)) __pu_val;                            \
+        __chk_user_ptr(ptr);                                    \
+        __pu_val = x;                                           \
+        switch(sizeof(*(ptr))) {                                \
+        case 1: __put_user_1(__pu_val, ptr); break;             \
+        case 2: __put_user_2(__pu_val, ptr); break;             \
+        case 4: __put_user_4(__pu_val, ptr); break;             \
+        case 8: __put_user_8(__pu_val, ptr); break;             \
+        default:__put_user_X(__pu_val, ptr); break;             \
+        }                                                       \
+        __ret_pu;                                               \
+})
+
+#else
+#define put_user(x,ptr)                                         \
+({                                                              \
+        int __ret_pu;                                           \
+        __typeof__(*(ptr)) __pus_tmp = x;                       \
+        __ret_pu=0;                                             \
+        if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp,          \
+                                sizeof(*(ptr))) != 0))          \
+                __ret_pu=-EFAULT;                               \
+        __ret_pu;                                               \
+ })
+
+
+#endif
+
+/**
+ * __get_user: - Get a simple variable from user space, with less checking.
+ * @x:   Variable to store result.
+ * @ptr: Source address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple variable from user space to kernel
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and the result of
+ * dereferencing @ptr must be assignable to @x without a cast.
+ *
+ * Caller must check the pointer with access_ok() before calling this
+ * function.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ * On error, the variable @x is set to zero.
+ */
+#define __get_user(x,ptr) \
+  __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
+
+
+/**
+ * __put_user: - Write a simple value into user space, with less checking.
+ * @x:   Value to copy to user space.
+ * @ptr: Destination address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple value from kernel space to user
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and @x must be assignable
+ * to the result of dereferencing @ptr.
+ *
+ * Caller must check the pointer with access_ok() before calling this
+ * function.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ */
+#define __put_user(x,ptr) \
+  __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
+
+#define __put_user_nocheck(x,ptr,size)                          \
+({                                                              \
+        long __pu_err;                                          \
+        __put_user_size((x),(ptr),(size),__pu_err,-EFAULT);     \
+        __pu_err;                                               \
+})
+
+
+#define __put_user_u64(x, addr, err)                            \
+        __asm__ __volatile__(                                   \
+                "1:     movl %%eax,0(%2)\n"                     \
+                "2:     movl %%edx,4(%2)\n"                     \
+                "3:\n"                                          \
+                ".section .fixup,\"ax\"\n"                      \
+                "4:     movl %3,%0\n"                           \
+                "       jmp 3b\n"                               \
+                ".previous\n"                                   \
+                ".section __ex_table,\"a\"\n"                   \
+                "       .align 4\n"                             \
+                "       .long 1b,4b\n"                          \
+                "       .long 2b,4b\n"                          \
+                ".previous"                                     \
+                : "=r"(err)                                     \
+                : "A" (x), "r" (addr), "i"(-EFAULT), "0"(err))
+
+#ifdef CONFIG_X86_WP_WORKS_OK
+
+#define __put_user_size(x,ptr,size,retval,errret)                       \
+do {                                                                    \
+        retval = 0;                                                     \
+        __chk_user_ptr(ptr);                                            \
+        switch (size) {                                                 \
+        case 1: __put_user_asm(x,ptr,retval,"b","b","iq",errret);break; \
+        case 2: __put_user_asm(x,ptr,retval,"w","w","ir",errret);break; \
+        case 4: __put_user_asm(x,ptr,retval,"l","","ir",errret); break; \
+        case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
+          default: __put_user_bad();                                    \
+        }                                                               \
+} while (0)
+
+#else
+
+#define __put_user_size(x,ptr,size,retval,errret)                       \
+do {                                                                    \
+        __typeof__(*(ptr)) __pus_tmp = x;                               \
+        retval = 0;                                                     \
+                                                                        \
+        if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0))     \
+                retval = errret;                                        \
+} while (0)
+
+#endif
+struct __large_struct { unsigned long buf[100]; };
+#define __m(x) (*(struct __large_struct __user *)(x))
+
+/*
+ * 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.
+ */
+#define __put_user_asm(x, addr, err, itype, rtype, ltype, errret)       \
+        __asm__ __volatile__(                                           \
+                "1:     mov"itype" %"rtype"1,%2\n"                      \
+                "2:\n"                                                  \
+                ".section .fixup,\"ax\"\n"                              \
+                "3:     movl %3,%0\n"                                   \
+                "       jmp 2b\n"                                       \
+                ".previous\n"                                           \
+                ".section __ex_table,\"a\"\n"                           \
+                "       .align 4\n"                                     \
+                "       .long 1b,3b\n"                                  \
+                ".previous"                                             \
+                : "=r"(err)                                             \
+                : ltype (x), "m"(__m(addr)), "i"(errret), "0"(err))
+
+
+#define __get_user_nocheck(x,ptr,size)                          \
+({                                                              \
+        long __gu_err;                                          \
+        unsigned long __gu_val;                                 \
+        __get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\
+        (x) = (__typeof__(*(ptr)))__gu_val;                     \
+        __gu_err;                                               \
+})
+
+extern long __get_user_bad(void);
+
+#define __get_user_size(x,ptr,size,retval,errret)                       \
+do {                                                                    \
+        retval = 0;                                                     \
+        __chk_user_ptr(ptr);                                            \
+        switch (size) {                                                 \
+        case 1: __get_user_asm(x,ptr,retval,"b","b","=q",errret);break; \
+        case 2: __get_user_asm(x,ptr,retval,"w","w","=r",errret);break; \
+        case 4: __get_user_asm(x,ptr,retval,"l","","=r",errret);break;  \
+        default: (x) = __get_user_bad();                                \
+        }                                                               \
+} while (0)
+
+#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret)       \
+        __asm__ __volatile__(                                           \
+                "1:     mov"itype" %2,%"rtype"1\n"                      \
+                "2:\n"                                                  \
+                ".section .fixup,\"ax\"\n"                              \
+                "3:     movl %3,%0\n"                                   \
+                "       xor"itype" %"rtype"1,%"rtype"1\n"               \
+                "       jmp 2b\n"                                       \
+                ".previous\n"                                           \
+                ".section __ex_table,\"a\"\n"                           \
+                "       .align 4\n"                                     \
+                "       .long 1b,3b\n"                                  \
+                ".previous"                                             \
+                : "=r"(err), ltype (x)                                  \
+                : "m"(__m(addr)), "i"(errret), "0"(err))
+
+
+unsigned long __must_check __copy_to_user_ll(void __user *to,
+                                const void *from, unsigned long n);
+unsigned long __must_check __copy_from_user_ll(void *to,
+                                const void __user *from, unsigned long n);
+unsigned long __must_check __copy_from_user_ll_nozero(void *to,
+                                const void __user *from, unsigned long n);
+unsigned long __must_check __copy_from_user_ll_nocache(void *to,
+                                const void __user *from, unsigned long n);
+unsigned long __must_check __copy_from_user_ll_nocache_nozero(void *to,
+                                const void __user *from, unsigned long n);
+
+/**
+ * __copy_to_user_inatomic: - Copy a block of data into user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @from: Source address, in kernel space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.
+ *
+ * Copy data from kernel space to user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ * The caller should also make sure he pins the user space address
+ * so that the we don't result in page fault and sleep.
+ *
+ * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
+ * we return the initial request size (1, 2 or 4), as copy_*_user should do.
+ * If a store crosses a page boundary and gets a fault, the x86 will not write
+ * anything, so this is accurate.
+ */
+
+static __always_inline unsigned long __must_check
+__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
+{
+        if (__builtin_constant_p(n)) {
+                unsigned long ret;
+
+                switch (n) {
+                case 1:
+                        __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1);
+                        return ret;
+                case 2:
+                        __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2);
+                        return ret;
+                case 4:
+                        __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4);
+                        return ret;
+                }
+        }
+        return __copy_to_user_ll(to, from, n);
+}
+
+/**
+ * __copy_to_user: - Copy a block of data into user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @from: Source address, in kernel space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from kernel space to user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ */
+static __always_inline unsigned long __must_check
+__copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+       might_sleep();
+       return __copy_to_user_inatomic(to, from, n);
+}
+
+static __always_inline unsigned long
+__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
+{
+        /* Avoid zeroing the tail if the copy fails..
+         * If 'n' is constant and 1, 2, or 4, we do still zero on a failure,
+         * but as the zeroing behaviour is only significant when n is not
+         * constant, that shouldn't be a problem.
+         */
+        if (__builtin_constant_p(n)) {
+                unsigned long ret;
+
+                switch (n) {
+                case 1:
+                        __get_user_size(*(u8 *)to, from, 1, ret, 1);
+                        return ret;
+                case 2:
+                        __get_user_size(*(u16 *)to, from, 2, ret, 2);
+                        return ret;
+                case 4:
+                        __get_user_size(*(u32 *)to, from, 4, ret, 4);
+                        return ret;
+                }
+        }
+        return __copy_from_user_ll_nozero(to, from, n);
+}
+
+/**
+ * __copy_from_user: - Copy a block of data from user space, with less checking.
+ * @to:   Destination address, in kernel space.
+ * @from: Source address, in user space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from user space to kernel space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ *
+ * If some data could not be copied, this function will pad the copied
+ * data to the requested size using zero bytes.
+ *
+ * An alternate version - __copy_from_user_inatomic() - may be called from
+ * atomic context and will fail rather than sleep.  In this case the
+ * uncopied bytes will *NOT* be padded with zeros.  See fs/filemap.h
+ * for explanation of why this is needed.
+ */
+static __always_inline unsigned long
+__copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+        might_sleep();
+        if (__builtin_constant_p(n)) {
+                unsigned long ret;
+
+                switch (n) {
+                case 1:
+                        __get_user_size(*(u8 *)to, from, 1, ret, 1);
+                        return ret;
+                case 2:
+                        __get_user_size(*(u16 *)to, from, 2, ret, 2);
+                        return ret;
+                case 4:
+                        __get_user_size(*(u32 *)to, from, 4, ret, 4);
+                        return ret;
+                }
+        }
+        return __copy_from_user_ll(to, from, n);
+}
+
+#define ARCH_HAS_NOCACHE_UACCESS
+
+static __always_inline unsigned long __copy_from_user_nocache(void *to,
+                                const void __user *from, unsigned long n)
+{
+        might_sleep();
+        if (__builtin_constant_p(n)) {
+                unsigned long ret;
+
+                switch (n) {
+                case 1:
+                        __get_user_size(*(u8 *)to, from, 1, ret, 1);
+                        return ret;
+                case 2:
+                        __get_user_size(*(u16 *)to, from, 2, ret, 2);
+                        return ret;
+                case 4:
+                        __get_user_size(*(u32 *)to, from, 4, ret, 4);
+                        return ret;
+                }
+        }
+        return __copy_from_user_ll_nocache(to, from, n);
+}
+
+static __always_inline unsigned long
+__copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long n)
+{
+       return __copy_from_user_ll_nocache_nozero(to, from, n);
+}
+
+unsigned long __must_check copy_to_user(void __user *to,
+                                const void *from, unsigned long n);
+unsigned long __must_check copy_from_user(void *to,
+                                const void __user *from, unsigned long n);
+long __must_check strncpy_from_user(char *dst, const char __user *src,
+                                long count);
+long __must_check __strncpy_from_user(char *dst,
+                                const char __user *src, long count);
+
+/**
+ * strlen_user: - Get the size of a string in user space.
+ * @str: The string to measure.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * 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 there is a limit on the length of a valid string, you may wish to
+ * consider using strnlen_user() instead.
+ */
+#define strlen_user(str) strnlen_user(str, LONG_MAX)
+
+long strnlen_user(const char __user *str, long n);
+unsigned long __must_check clear_user(void __user *mem, unsigned long len);
+unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
+
+#endif /* __i386_UACCESS_H */