865e5b7650
Merge versions of getuser from uaccess_32.h and uaccess_64.h into uaccess.h. There is a part which is 64-bit only (for now), and for that, we use a __get_user_8 macro. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
477 lines
14 KiB
C
477 lines
14 KiB
C
#ifndef __i386_UACCESS_H
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#define __i386_UACCESS_H
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/*
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* User space memory access functions
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*/
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#include <linux/errno.h>
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#include <linux/thread_info.h>
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#include <linux/prefetch.h>
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#include <linux/string.h>
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#include <asm/asm.h>
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#include <asm/page.h>
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/*
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* movsl can be slow when source and dest are not both 8-byte aligned
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*/
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#ifdef CONFIG_X86_INTEL_USERCOPY
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extern struct movsl_mask {
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int mask;
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} ____cacheline_aligned_in_smp movsl_mask;
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#endif
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#define __addr_ok(addr) \
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((unsigned long __force)(addr) < \
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(current_thread_info()->addr_limit.seg))
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extern void __put_user_bad(void);
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/*
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* Strange magic calling convention: pointer in %ecx,
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* value in %eax(:%edx), return value in %eax, no clobbers.
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*/
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extern void __put_user_1(void);
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extern void __put_user_2(void);
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extern void __put_user_4(void);
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extern void __put_user_8(void);
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#define __put_user_x(size, x, ptr) \
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asm volatile("call __put_user_" #size : "=a" (__ret_pu) \
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:"0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
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#define __put_user_8(x, ptr) \
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asm volatile("call __put_user_8" : "=a" (__ret_pu) \
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: "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
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/**
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* put_user: - Write a simple value into user space.
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* @x: Value to copy to user space.
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* @ptr: Destination address, in user space.
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*
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* Context: User context only. This function may sleep.
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*
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* This macro copies a single simple value from kernel space to user
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and @x must be assignable
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* to the result of dereferencing @ptr.
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*
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* Returns zero on success, or -EFAULT on error.
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*/
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#ifdef CONFIG_X86_WP_WORKS_OK
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#define put_user(x, ptr) \
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({ \
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int __ret_pu; \
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__typeof__(*(ptr)) __pu_val; \
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__chk_user_ptr(ptr); \
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__pu_val = x; \
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switch (sizeof(*(ptr))) { \
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case 1: \
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__put_user_x(1, __pu_val, ptr); \
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break; \
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case 2: \
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__put_user_x(2, __pu_val, ptr); \
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break; \
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case 4: \
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__put_user_x(4, __pu_val, ptr); \
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break; \
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case 8: \
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__put_user_8(__pu_val, ptr); \
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break; \
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default: \
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__put_user_x(X, __pu_val, ptr); \
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break; \
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} \
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__ret_pu; \
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})
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#else
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#define put_user(x, ptr) \
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({ \
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int __ret_pu; \
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__typeof__(*(ptr))__pus_tmp = x; \
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__ret_pu = 0; \
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if (unlikely(__copy_to_user_ll(ptr, &__pus_tmp, \
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sizeof(*(ptr))) != 0)) \
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__ret_pu = -EFAULT; \
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__ret_pu; \
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})
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#endif
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/**
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* __get_user: - Get a simple variable from user space, with less checking.
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* @x: Variable to store result.
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* @ptr: Source address, in user space.
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*
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* Context: User context only. This function may sleep.
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*
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* This macro copies a single simple variable from user space to kernel
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and the result of
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* dereferencing @ptr must be assignable to @x without a cast.
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*
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* Caller must check the pointer with access_ok() before calling this
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* function.
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*
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* Returns zero on success, or -EFAULT on error.
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* On error, the variable @x is set to zero.
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*/
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#define __get_user(x, ptr) \
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__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
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/**
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* __put_user: - Write a simple value into user space, with less checking.
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* @x: Value to copy to user space.
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* @ptr: Destination address, in user space.
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*
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* Context: User context only. This function may sleep.
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*
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* This macro copies a single simple value from kernel space to user
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and @x must be assignable
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* to the result of dereferencing @ptr.
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*
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* Caller must check the pointer with access_ok() before calling this
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* function.
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*
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* Returns zero on success, or -EFAULT on error.
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*/
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#define __put_user(x, ptr) \
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__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
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#define __put_user_nocheck(x, ptr, size) \
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({ \
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long __pu_err; \
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__put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \
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__pu_err; \
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})
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#define __put_user_u64(x, addr, err) \
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asm volatile("1: movl %%eax,0(%2)\n" \
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"2: movl %%edx,4(%2)\n" \
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"3:\n" \
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".section .fixup,\"ax\"\n" \
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"4: movl %3,%0\n" \
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" jmp 3b\n" \
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".previous\n" \
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_ASM_EXTABLE(1b, 4b) \
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_ASM_EXTABLE(2b, 4b) \
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: "=r" (err) \
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: "A" (x), "r" (addr), "i" (-EFAULT), "0" (err))
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#ifdef CONFIG_X86_WP_WORKS_OK
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#define __put_user_size(x, ptr, size, retval, errret) \
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do { \
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retval = 0; \
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__chk_user_ptr(ptr); \
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switch (size) { \
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case 1: \
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__put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \
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break; \
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case 2: \
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__put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \
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break; \
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case 4: \
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__put_user_asm(x, ptr, retval, "l", "", "ir", errret); \
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break; \
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case 8: \
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__put_user_u64((__typeof__(*ptr))(x), ptr, retval); \
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break; \
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default: \
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__put_user_bad(); \
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} \
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} while (0)
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#else
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#define __put_user_size(x, ptr, size, retval, errret) \
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do { \
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__typeof__(*(ptr))__pus_tmp = x; \
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retval = 0; \
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\
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if (unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0)) \
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retval = errret; \
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} while (0)
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#endif
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struct __large_struct { unsigned long buf[100]; };
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#define __m(x) (*(struct __large_struct __user *)(x))
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/*
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* Tell gcc we read from memory instead of writing: this is because
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* we do not write to any memory gcc knows about, so there are no
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* aliasing issues.
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*/
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#define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \
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asm volatile("1: mov"itype" %"rtype"1,%2\n" \
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"2:\n" \
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".section .fixup,\"ax\"\n" \
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"3: movl %3,%0\n" \
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" jmp 2b\n" \
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".previous\n" \
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_ASM_EXTABLE(1b, 3b) \
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: "=r"(err) \
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: ltype (x), "m" (__m(addr)), "i" (errret), "0" (err))
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#define __get_user_nocheck(x, ptr, size) \
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({ \
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long __gu_err; \
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unsigned long __gu_val; \
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__get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \
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(x) = (__typeof__(*(ptr)))__gu_val; \
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__gu_err; \
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})
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#define __get_user_size(x, ptr, size, retval, errret) \
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do { \
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retval = 0; \
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__chk_user_ptr(ptr); \
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switch (size) { \
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case 1: \
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__get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \
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break; \
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case 2: \
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__get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \
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break; \
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case 4: \
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__get_user_asm(x, ptr, retval, "l", "", "=r", errret); \
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break; \
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default: \
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(x) = __get_user_bad(); \
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} \
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} while (0)
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#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \
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asm volatile("1: mov"itype" %2,%"rtype"1\n" \
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"2:\n" \
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".section .fixup,\"ax\"\n" \
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"3: movl %3,%0\n" \
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" xor"itype" %"rtype"1,%"rtype"1\n" \
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" jmp 2b\n" \
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".previous\n" \
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_ASM_EXTABLE(1b, 3b) \
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: "=r" (err), ltype (x) \
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: "m" (__m(addr)), "i" (errret), "0" (err))
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unsigned long __must_check __copy_to_user_ll
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(void __user *to, const void *from, unsigned long n);
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unsigned long __must_check __copy_from_user_ll
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(void *to, const void __user *from, unsigned long n);
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unsigned long __must_check __copy_from_user_ll_nozero
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(void *to, const void __user *from, unsigned long n);
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unsigned long __must_check __copy_from_user_ll_nocache
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(void *to, const void __user *from, unsigned long n);
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unsigned long __must_check __copy_from_user_ll_nocache_nozero
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(void *to, const void __user *from, unsigned long n);
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/**
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* __copy_to_user_inatomic: - Copy a block of data into user space, with less checking.
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* @to: Destination address, in user space.
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* @from: Source address, in kernel space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only.
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*
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* Copy data from kernel space to user space. Caller must check
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* the specified block with access_ok() before calling this function.
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* The caller should also make sure he pins the user space address
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* so that the we don't result in page fault and sleep.
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*
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* Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault
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* we return the initial request size (1, 2 or 4), as copy_*_user should do.
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* If a store crosses a page boundary and gets a fault, the x86 will not write
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* anything, so this is accurate.
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*/
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static __always_inline unsigned long __must_check
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__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
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{
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if (__builtin_constant_p(n)) {
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unsigned long ret;
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switch (n) {
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case 1:
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__put_user_size(*(u8 *)from, (u8 __user *)to,
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1, ret, 1);
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return ret;
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case 2:
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__put_user_size(*(u16 *)from, (u16 __user *)to,
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2, ret, 2);
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return ret;
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case 4:
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__put_user_size(*(u32 *)from, (u32 __user *)to,
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4, ret, 4);
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return ret;
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}
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}
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return __copy_to_user_ll(to, from, n);
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}
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/**
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* __copy_to_user: - Copy a block of data into user space, with less checking.
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* @to: Destination address, in user space.
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* @from: Source address, in kernel space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only. This function may sleep.
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*
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* Copy data from kernel space to user space. Caller must check
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* the specified block with access_ok() before calling this function.
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*
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* Returns number of bytes that could not be copied.
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* On success, this will be zero.
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*/
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static __always_inline unsigned long __must_check
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__copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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might_sleep();
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return __copy_to_user_inatomic(to, from, n);
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}
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static __always_inline unsigned long
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__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
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{
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/* Avoid zeroing the tail if the copy fails..
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* If 'n' is constant and 1, 2, or 4, we do still zero on a failure,
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* but as the zeroing behaviour is only significant when n is not
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* constant, that shouldn't be a problem.
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*/
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if (__builtin_constant_p(n)) {
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unsigned long ret;
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switch (n) {
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case 1:
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__get_user_size(*(u8 *)to, from, 1, ret, 1);
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return ret;
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case 2:
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__get_user_size(*(u16 *)to, from, 2, ret, 2);
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return ret;
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case 4:
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__get_user_size(*(u32 *)to, from, 4, ret, 4);
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return ret;
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}
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}
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return __copy_from_user_ll_nozero(to, from, n);
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}
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/**
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* __copy_from_user: - Copy a block of data from user space, with less checking.
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* @to: Destination address, in kernel space.
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* @from: Source address, in user space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only. This function may sleep.
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*
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* Copy data from user space to kernel space. Caller must check
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* the specified block with access_ok() before calling this function.
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*
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* Returns number of bytes that could not be copied.
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* On success, this will be zero.
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*
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* If some data could not be copied, this function will pad the copied
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* data to the requested size using zero bytes.
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*
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* An alternate version - __copy_from_user_inatomic() - may be called from
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* atomic context and will fail rather than sleep. In this case the
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* uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h
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* for explanation of why this is needed.
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*/
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static __always_inline unsigned long
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__copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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might_sleep();
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if (__builtin_constant_p(n)) {
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unsigned long ret;
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switch (n) {
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case 1:
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__get_user_size(*(u8 *)to, from, 1, ret, 1);
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return ret;
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case 2:
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__get_user_size(*(u16 *)to, from, 2, ret, 2);
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return ret;
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case 4:
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__get_user_size(*(u32 *)to, from, 4, ret, 4);
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return ret;
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}
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}
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return __copy_from_user_ll(to, from, n);
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}
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#define ARCH_HAS_NOCACHE_UACCESS
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static __always_inline unsigned long __copy_from_user_nocache(void *to,
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const void __user *from, unsigned long n)
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{
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might_sleep();
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if (__builtin_constant_p(n)) {
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unsigned long ret;
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switch (n) {
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case 1:
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__get_user_size(*(u8 *)to, from, 1, ret, 1);
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return ret;
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case 2:
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__get_user_size(*(u16 *)to, from, 2, ret, 2);
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return ret;
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case 4:
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__get_user_size(*(u32 *)to, from, 4, ret, 4);
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return ret;
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}
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}
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return __copy_from_user_ll_nocache(to, from, n);
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}
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static __always_inline unsigned long
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__copy_from_user_inatomic_nocache(void *to, const void __user *from,
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unsigned long n)
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{
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return __copy_from_user_ll_nocache_nozero(to, from, n);
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}
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unsigned long __must_check copy_to_user(void __user *to,
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const void *from, unsigned long n);
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unsigned long __must_check copy_from_user(void *to,
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const void __user *from,
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unsigned long n);
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long __must_check strncpy_from_user(char *dst, const char __user *src,
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long count);
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long __must_check __strncpy_from_user(char *dst,
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const char __user *src, long count);
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/**
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* strlen_user: - Get the size of a string in user space.
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* @str: The string to measure.
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*
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* Context: User context only. This function may sleep.
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*
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* Get the size of a NUL-terminated string in user space.
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*
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* Returns the size of the string INCLUDING the terminating NUL.
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* On exception, returns 0.
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*
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* If there is a limit on the length of a valid string, you may wish to
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* consider using strnlen_user() instead.
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*/
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#define strlen_user(str) strnlen_user(str, LONG_MAX)
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long strnlen_user(const char __user *str, long n);
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unsigned long __must_check clear_user(void __user *mem, unsigned long len);
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unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
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#endif /* __i386_UACCESS_H */
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