637 lines
18 KiB
C
637 lines
18 KiB
C
/*
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* User address space access functions.
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* The non inlined parts of asm-i386/uaccess.h are here.
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*
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* Copyright 1997 Andi Kleen <ak@muc.de>
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* Copyright 1997 Linus Torvalds
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*/
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#include <linux/config.h>
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#include <linux/mm.h>
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#include <linux/highmem.h>
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#include <linux/blkdev.h>
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#include <linux/module.h>
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#include <asm/uaccess.h>
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#include <asm/mmx.h>
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static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
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{
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#ifdef CONFIG_X86_INTEL_USERCOPY
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if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
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return 0;
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#endif
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return 1;
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}
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#define movsl_is_ok(a1,a2,n) \
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__movsl_is_ok((unsigned long)(a1),(unsigned long)(a2),(n))
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/*
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* Copy a null terminated string from userspace.
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*/
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#define __do_strncpy_from_user(dst,src,count,res) \
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do { \
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int __d0, __d1, __d2; \
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might_sleep(); \
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__asm__ __volatile__( \
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" testl %1,%1\n" \
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" jz 2f\n" \
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"0: lodsb\n" \
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" stosb\n" \
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" testb %%al,%%al\n" \
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" jz 1f\n" \
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" decl %1\n" \
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" jnz 0b\n" \
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"1: subl %1,%0\n" \
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"2:\n" \
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".section .fixup,\"ax\"\n" \
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"3: movl %5,%0\n" \
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" jmp 2b\n" \
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".previous\n" \
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".section __ex_table,\"a\"\n" \
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" .align 4\n" \
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" .long 0b,3b\n" \
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".previous" \
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: "=d"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1), \
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"=&D" (__d2) \
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: "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
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: "memory"); \
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} while (0)
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/**
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* __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
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* @dst: Destination address, in kernel space. This buffer must be at
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* least @count bytes long.
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* @src: Source address, in user space.
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* @count: Maximum number of bytes to copy, including the trailing NUL.
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*
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* Copies a NUL-terminated string from userspace to kernel space.
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* Caller must check the specified block with access_ok() before calling
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* this function.
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*
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* On success, returns the length of the string (not including the trailing
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* NUL).
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*
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* If access to userspace fails, returns -EFAULT (some data may have been
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* copied).
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*
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* If @count is smaller than the length of the string, copies @count bytes
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* and returns @count.
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*/
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long
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__strncpy_from_user(char *dst, const char __user *src, long count)
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{
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long res;
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__do_strncpy_from_user(dst, src, count, res);
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return res;
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}
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/**
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* strncpy_from_user: - Copy a NUL terminated string from userspace.
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* @dst: Destination address, in kernel space. This buffer must be at
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* least @count bytes long.
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* @src: Source address, in user space.
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* @count: Maximum number of bytes to copy, including the trailing NUL.
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*
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* Copies a NUL-terminated string from userspace to kernel space.
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*
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* On success, returns the length of the string (not including the trailing
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* NUL).
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*
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* If access to userspace fails, returns -EFAULT (some data may have been
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* copied).
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*
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* If @count is smaller than the length of the string, copies @count bytes
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* and returns @count.
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*/
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long
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strncpy_from_user(char *dst, const char __user *src, long count)
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{
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long res = -EFAULT;
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if (access_ok(VERIFY_READ, src, 1))
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__do_strncpy_from_user(dst, src, count, res);
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return res;
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}
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/*
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* Zero Userspace
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*/
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#define __do_clear_user(addr,size) \
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do { \
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int __d0; \
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might_sleep(); \
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__asm__ __volatile__( \
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"0: rep; stosl\n" \
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" movl %2,%0\n" \
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"1: rep; stosb\n" \
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"2:\n" \
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".section .fixup,\"ax\"\n" \
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"3: lea 0(%2,%0,4),%0\n" \
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" jmp 2b\n" \
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".previous\n" \
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".section __ex_table,\"a\"\n" \
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" .align 4\n" \
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" .long 0b,3b\n" \
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" .long 1b,2b\n" \
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".previous" \
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: "=&c"(size), "=&D" (__d0) \
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: "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
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} while (0)
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/**
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* clear_user: - Zero a block of memory in user space.
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* @to: Destination address, in user space.
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* @n: Number of bytes to zero.
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*
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* Zero a block of memory in user space.
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*
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* Returns number of bytes that could not be cleared.
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* On success, this will be zero.
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*/
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unsigned long
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clear_user(void __user *to, unsigned long n)
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{
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might_sleep();
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if (access_ok(VERIFY_WRITE, to, n))
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__do_clear_user(to, n);
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return n;
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}
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/**
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* __clear_user: - Zero a block of memory in user space, with less checking.
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* @to: Destination address, in user space.
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* @n: Number of bytes to zero.
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*
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* Zero a block of memory in 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 cleared.
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* On success, this will be zero.
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*/
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unsigned long
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__clear_user(void __user *to, unsigned long n)
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{
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__do_clear_user(to, n);
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return n;
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}
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/**
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* strlen_user: - Get the size of a string in user space.
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* @s: The string to measure.
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* @n: The maximum valid length
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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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* If the string is too long, returns a value greater than @n.
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*/
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long strnlen_user(const char __user *s, long n)
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{
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unsigned long mask = -__addr_ok(s);
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unsigned long res, tmp;
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might_sleep();
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__asm__ __volatile__(
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" testl %0, %0\n"
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" jz 3f\n"
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" andl %0,%%ecx\n"
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"0: repne; scasb\n"
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" setne %%al\n"
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" subl %%ecx,%0\n"
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" addl %0,%%eax\n"
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"1:\n"
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".section .fixup,\"ax\"\n"
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"2: xorl %%eax,%%eax\n"
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" jmp 1b\n"
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"3: movb $1,%%al\n"
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" jmp 1b\n"
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".previous\n"
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".section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 0b,2b\n"
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".previous"
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:"=r" (n), "=D" (s), "=a" (res), "=c" (tmp)
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:"0" (n), "1" (s), "2" (0), "3" (mask)
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:"cc");
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return res & mask;
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}
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#ifdef CONFIG_X86_INTEL_USERCOPY
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static unsigned long
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__copy_user_intel(void __user *to, const void *from, unsigned long size)
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{
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int d0, d1;
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__asm__ __volatile__(
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" .align 2,0x90\n"
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"1: movl 32(%4), %%eax\n"
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" cmpl $67, %0\n"
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" jbe 3f\n"
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"2: movl 64(%4), %%eax\n"
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" .align 2,0x90\n"
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"3: movl 0(%4), %%eax\n"
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"4: movl 4(%4), %%edx\n"
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"5: movl %%eax, 0(%3)\n"
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"6: movl %%edx, 4(%3)\n"
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"7: movl 8(%4), %%eax\n"
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"8: movl 12(%4),%%edx\n"
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"9: movl %%eax, 8(%3)\n"
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"10: movl %%edx, 12(%3)\n"
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"11: movl 16(%4), %%eax\n"
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"12: movl 20(%4), %%edx\n"
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"13: movl %%eax, 16(%3)\n"
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"14: movl %%edx, 20(%3)\n"
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"15: movl 24(%4), %%eax\n"
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"16: movl 28(%4), %%edx\n"
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"17: movl %%eax, 24(%3)\n"
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"18: movl %%edx, 28(%3)\n"
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"19: movl 32(%4), %%eax\n"
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"20: movl 36(%4), %%edx\n"
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"21: movl %%eax, 32(%3)\n"
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"22: movl %%edx, 36(%3)\n"
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"23: movl 40(%4), %%eax\n"
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"24: movl 44(%4), %%edx\n"
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"25: movl %%eax, 40(%3)\n"
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"26: movl %%edx, 44(%3)\n"
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"27: movl 48(%4), %%eax\n"
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"28: movl 52(%4), %%edx\n"
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"29: movl %%eax, 48(%3)\n"
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"30: movl %%edx, 52(%3)\n"
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"31: movl 56(%4), %%eax\n"
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"32: movl 60(%4), %%edx\n"
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"33: movl %%eax, 56(%3)\n"
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"34: movl %%edx, 60(%3)\n"
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" addl $-64, %0\n"
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" addl $64, %4\n"
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" addl $64, %3\n"
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" cmpl $63, %0\n"
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" ja 1b\n"
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"35: movl %0, %%eax\n"
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" shrl $2, %0\n"
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" andl $3, %%eax\n"
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" cld\n"
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"99: rep; movsl\n"
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"36: movl %%eax, %0\n"
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"37: rep; movsb\n"
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"100:\n"
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".section .fixup,\"ax\"\n"
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"101: lea 0(%%eax,%0,4),%0\n"
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" jmp 100b\n"
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".previous\n"
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".section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 1b,100b\n"
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" .long 2b,100b\n"
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" .long 3b,100b\n"
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" .long 4b,100b\n"
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" .long 5b,100b\n"
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" .long 6b,100b\n"
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" .long 7b,100b\n"
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" .long 8b,100b\n"
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" .long 9b,100b\n"
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" .long 10b,100b\n"
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" .long 11b,100b\n"
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" .long 12b,100b\n"
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" .long 13b,100b\n"
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" .long 14b,100b\n"
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" .long 15b,100b\n"
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" .long 16b,100b\n"
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" .long 17b,100b\n"
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" .long 18b,100b\n"
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" .long 19b,100b\n"
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" .long 20b,100b\n"
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" .long 21b,100b\n"
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" .long 22b,100b\n"
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" .long 23b,100b\n"
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" .long 24b,100b\n"
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" .long 25b,100b\n"
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" .long 26b,100b\n"
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" .long 27b,100b\n"
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" .long 28b,100b\n"
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" .long 29b,100b\n"
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" .long 30b,100b\n"
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" .long 31b,100b\n"
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" .long 32b,100b\n"
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" .long 33b,100b\n"
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" .long 34b,100b\n"
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" .long 35b,100b\n"
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" .long 36b,100b\n"
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" .long 37b,100b\n"
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" .long 99b,101b\n"
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".previous"
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: "=&c"(size), "=&D" (d0), "=&S" (d1)
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: "1"(to), "2"(from), "0"(size)
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: "eax", "edx", "memory");
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return size;
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}
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static unsigned long
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__copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
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{
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int d0, d1;
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__asm__ __volatile__(
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" .align 2,0x90\n"
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"0: movl 32(%4), %%eax\n"
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" cmpl $67, %0\n"
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" jbe 2f\n"
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"1: movl 64(%4), %%eax\n"
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" .align 2,0x90\n"
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"2: movl 0(%4), %%eax\n"
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"21: movl 4(%4), %%edx\n"
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" movl %%eax, 0(%3)\n"
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" movl %%edx, 4(%3)\n"
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"3: movl 8(%4), %%eax\n"
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"31: movl 12(%4),%%edx\n"
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" movl %%eax, 8(%3)\n"
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" movl %%edx, 12(%3)\n"
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"4: movl 16(%4), %%eax\n"
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"41: movl 20(%4), %%edx\n"
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" movl %%eax, 16(%3)\n"
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" movl %%edx, 20(%3)\n"
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"10: movl 24(%4), %%eax\n"
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"51: movl 28(%4), %%edx\n"
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" movl %%eax, 24(%3)\n"
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" movl %%edx, 28(%3)\n"
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"11: movl 32(%4), %%eax\n"
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"61: movl 36(%4), %%edx\n"
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" movl %%eax, 32(%3)\n"
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" movl %%edx, 36(%3)\n"
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"12: movl 40(%4), %%eax\n"
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"71: movl 44(%4), %%edx\n"
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" movl %%eax, 40(%3)\n"
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" movl %%edx, 44(%3)\n"
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"13: movl 48(%4), %%eax\n"
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"81: movl 52(%4), %%edx\n"
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" movl %%eax, 48(%3)\n"
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" movl %%edx, 52(%3)\n"
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"14: movl 56(%4), %%eax\n"
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"91: movl 60(%4), %%edx\n"
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" movl %%eax, 56(%3)\n"
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" movl %%edx, 60(%3)\n"
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" addl $-64, %0\n"
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" addl $64, %4\n"
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" addl $64, %3\n"
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" cmpl $63, %0\n"
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" ja 0b\n"
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"5: movl %0, %%eax\n"
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" shrl $2, %0\n"
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" andl $3, %%eax\n"
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" cld\n"
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"6: rep; movsl\n"
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" movl %%eax,%0\n"
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"7: rep; movsb\n"
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"8:\n"
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".section .fixup,\"ax\"\n"
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"9: lea 0(%%eax,%0,4),%0\n"
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"16: pushl %0\n"
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" pushl %%eax\n"
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" xorl %%eax,%%eax\n"
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" rep; stosb\n"
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" popl %%eax\n"
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" popl %0\n"
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" jmp 8b\n"
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".previous\n"
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".section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 0b,16b\n"
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" .long 1b,16b\n"
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" .long 2b,16b\n"
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" .long 21b,16b\n"
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" .long 3b,16b\n"
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" .long 31b,16b\n"
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" .long 4b,16b\n"
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" .long 41b,16b\n"
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" .long 10b,16b\n"
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" .long 51b,16b\n"
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" .long 11b,16b\n"
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" .long 61b,16b\n"
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" .long 12b,16b\n"
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" .long 71b,16b\n"
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" .long 13b,16b\n"
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" .long 81b,16b\n"
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" .long 14b,16b\n"
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" .long 91b,16b\n"
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" .long 6b,9b\n"
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" .long 7b,16b\n"
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".previous"
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: "=&c"(size), "=&D" (d0), "=&S" (d1)
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: "1"(to), "2"(from), "0"(size)
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: "eax", "edx", "memory");
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return size;
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}
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#else
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/*
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* Leave these declared but undefined. They should not be any references to
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* them
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*/
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unsigned long
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__copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size);
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unsigned long
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__copy_user_intel(void __user *to, const void *from, unsigned long size);
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#endif /* CONFIG_X86_INTEL_USERCOPY */
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|
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/* Generic arbitrary sized copy. */
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#define __copy_user(to,from,size) \
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do { \
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int __d0, __d1, __d2; \
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__asm__ __volatile__( \
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" cmp $7,%0\n" \
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" jbe 1f\n" \
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" movl %1,%0\n" \
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" negl %0\n" \
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" andl $7,%0\n" \
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" subl %0,%3\n" \
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"4: rep; movsb\n" \
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" movl %3,%0\n" \
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" shrl $2,%0\n" \
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" andl $3,%3\n" \
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" .align 2,0x90\n" \
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"0: rep; movsl\n" \
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" movl %3,%0\n" \
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"1: rep; movsb\n" \
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"2:\n" \
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".section .fixup,\"ax\"\n" \
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"5: addl %3,%0\n" \
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" jmp 2b\n" \
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"3: lea 0(%3,%0,4),%0\n" \
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" jmp 2b\n" \
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".previous\n" \
|
|
".section __ex_table,\"a\"\n" \
|
|
" .align 4\n" \
|
|
" .long 4b,5b\n" \
|
|
" .long 0b,3b\n" \
|
|
" .long 1b,2b\n" \
|
|
".previous" \
|
|
: "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
|
|
: "3"(size), "0"(size), "1"(to), "2"(from) \
|
|
: "memory"); \
|
|
} while (0)
|
|
|
|
#define __copy_user_zeroing(to,from,size) \
|
|
do { \
|
|
int __d0, __d1, __d2; \
|
|
__asm__ __volatile__( \
|
|
" cmp $7,%0\n" \
|
|
" jbe 1f\n" \
|
|
" movl %1,%0\n" \
|
|
" negl %0\n" \
|
|
" andl $7,%0\n" \
|
|
" subl %0,%3\n" \
|
|
"4: rep; movsb\n" \
|
|
" movl %3,%0\n" \
|
|
" shrl $2,%0\n" \
|
|
" andl $3,%3\n" \
|
|
" .align 2,0x90\n" \
|
|
"0: rep; movsl\n" \
|
|
" movl %3,%0\n" \
|
|
"1: rep; movsb\n" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"5: addl %3,%0\n" \
|
|
" jmp 6f\n" \
|
|
"3: lea 0(%3,%0,4),%0\n" \
|
|
"6: pushl %0\n" \
|
|
" pushl %%eax\n" \
|
|
" xorl %%eax,%%eax\n" \
|
|
" rep; stosb\n" \
|
|
" popl %%eax\n" \
|
|
" popl %0\n" \
|
|
" jmp 2b\n" \
|
|
".previous\n" \
|
|
".section __ex_table,\"a\"\n" \
|
|
" .align 4\n" \
|
|
" .long 4b,5b\n" \
|
|
" .long 0b,3b\n" \
|
|
" .long 1b,6b\n" \
|
|
".previous" \
|
|
: "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
|
|
: "3"(size), "0"(size), "1"(to), "2"(from) \
|
|
: "memory"); \
|
|
} while (0)
|
|
|
|
|
|
unsigned long __copy_to_user_ll(void __user *to, const void *from, unsigned long n)
|
|
{
|
|
BUG_ON((long) n < 0);
|
|
#ifndef CONFIG_X86_WP_WORKS_OK
|
|
if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
|
|
((unsigned long )to) < TASK_SIZE) {
|
|
/*
|
|
* CPU does not honor the WP bit when writing
|
|
* from supervisory mode, and due to preemption or SMP,
|
|
* the page tables can change at any time.
|
|
* Do it manually. Manfred <manfred@colorfullife.com>
|
|
*/
|
|
while (n) {
|
|
unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
|
|
unsigned long len = PAGE_SIZE - offset;
|
|
int retval;
|
|
struct page *pg;
|
|
void *maddr;
|
|
|
|
if (len > n)
|
|
len = n;
|
|
|
|
survive:
|
|
down_read(¤t->mm->mmap_sem);
|
|
retval = get_user_pages(current, current->mm,
|
|
(unsigned long )to, 1, 1, 0, &pg, NULL);
|
|
|
|
if (retval == -ENOMEM && current->pid == 1) {
|
|
up_read(¤t->mm->mmap_sem);
|
|
blk_congestion_wait(WRITE, HZ/50);
|
|
goto survive;
|
|
}
|
|
|
|
if (retval != 1) {
|
|
up_read(¤t->mm->mmap_sem);
|
|
break;
|
|
}
|
|
|
|
maddr = kmap_atomic(pg, KM_USER0);
|
|
memcpy(maddr + offset, from, len);
|
|
kunmap_atomic(maddr, KM_USER0);
|
|
set_page_dirty_lock(pg);
|
|
put_page(pg);
|
|
up_read(¤t->mm->mmap_sem);
|
|
|
|
from += len;
|
|
to += len;
|
|
n -= len;
|
|
}
|
|
return n;
|
|
}
|
|
#endif
|
|
if (movsl_is_ok(to, from, n))
|
|
__copy_user(to, from, n);
|
|
else
|
|
n = __copy_user_intel(to, from, n);
|
|
return n;
|
|
}
|
|
|
|
unsigned long
|
|
__copy_from_user_ll(void *to, const void __user *from, unsigned long n)
|
|
{
|
|
BUG_ON((long)n < 0);
|
|
if (movsl_is_ok(to, from, n))
|
|
__copy_user_zeroing(to, from, n);
|
|
else
|
|
n = __copy_user_zeroing_intel(to, from, n);
|
|
return n;
|
|
}
|
|
|
|
/**
|
|
* copy_to_user: - Copy a block of data into user space.
|
|
* @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.
|
|
*
|
|
* Returns number of bytes that could not be copied.
|
|
* On success, this will be zero.
|
|
*/
|
|
unsigned long
|
|
copy_to_user(void __user *to, const void *from, unsigned long n)
|
|
{
|
|
might_sleep();
|
|
BUG_ON((long) n < 0);
|
|
if (access_ok(VERIFY_WRITE, to, n))
|
|
n = __copy_to_user(to, from, n);
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL(copy_to_user);
|
|
|
|
/**
|
|
* copy_from_user: - Copy a block of data from user space.
|
|
* @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.
|
|
*
|
|
* 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.
|
|
*/
|
|
unsigned long
|
|
copy_from_user(void *to, const void __user *from, unsigned long n)
|
|
{
|
|
might_sleep();
|
|
BUG_ON((long) n < 0);
|
|
if (access_ok(VERIFY_READ, from, n))
|
|
n = __copy_from_user(to, from, n);
|
|
else
|
|
memset(to, 0, n);
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL(copy_from_user);
|