| /* |
| * User address space access functions. |
| * The non inlined parts of asm-i386/uaccess.h are here. |
| * |
| * Copyright 1997 Andi Kleen <ak@muc.de> |
| * Copyright 1997 Linus Torvalds |
| */ |
| #include <linux/config.h> |
| #include <linux/mm.h> |
| #include <linux/highmem.h> |
| #include <linux/blkdev.h> |
| #include <linux/module.h> |
| #include <asm/uaccess.h> |
| #include <asm/mmx.h> |
| |
| static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n) |
| { |
| #ifdef CONFIG_X86_INTEL_USERCOPY |
| if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask)) |
| return 0; |
| #endif |
| return 1; |
| } |
| #define movsl_is_ok(a1,a2,n) \ |
| __movsl_is_ok((unsigned long)(a1),(unsigned long)(a2),(n)) |
| |
| /* |
| * Copy a null terminated string from userspace. |
| */ |
| |
| #define __do_strncpy_from_user(dst,src,count,res) \ |
| do { \ |
| int __d0, __d1, __d2; \ |
| might_sleep(); \ |
| __asm__ __volatile__( \ |
| " testl %1,%1\n" \ |
| " jz 2f\n" \ |
| "0: lodsb\n" \ |
| " stosb\n" \ |
| " testb %%al,%%al\n" \ |
| " jz 1f\n" \ |
| " decl %1\n" \ |
| " jnz 0b\n" \ |
| "1: subl %1,%0\n" \ |
| "2:\n" \ |
| ".section .fixup,\"ax\"\n" \ |
| "3: movl %5,%0\n" \ |
| " jmp 2b\n" \ |
| ".previous\n" \ |
| ".section __ex_table,\"a\"\n" \ |
| " .align 4\n" \ |
| " .long 0b,3b\n" \ |
| ".previous" \ |
| : "=d"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1), \ |
| "=&D" (__d2) \ |
| : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \ |
| : "memory"); \ |
| } while (0) |
| |
| /** |
| * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking. |
| * @dst: Destination address, in kernel space. This buffer must be at |
| * least @count bytes long. |
| * @src: Source address, in user space. |
| * @count: Maximum number of bytes to copy, including the trailing NUL. |
| * |
| * Copies a NUL-terminated string from userspace to kernel space. |
| * Caller must check the specified block with access_ok() before calling |
| * this function. |
| * |
| * On success, returns the length of the string (not including the trailing |
| * NUL). |
| * |
| * If access to userspace fails, returns -EFAULT (some data may have been |
| * copied). |
| * |
| * If @count is smaller than the length of the string, copies @count bytes |
| * and returns @count. |
| */ |
| long |
| __strncpy_from_user(char *dst, const char __user *src, long count) |
| { |
| long res; |
| __do_strncpy_from_user(dst, src, count, res); |
| return res; |
| } |
| |
| /** |
| * strncpy_from_user: - Copy a NUL terminated string from userspace. |
| * @dst: Destination address, in kernel space. This buffer must be at |
| * least @count bytes long. |
| * @src: Source address, in user space. |
| * @count: Maximum number of bytes to copy, including the trailing NUL. |
| * |
| * Copies a NUL-terminated string from userspace to kernel space. |
| * |
| * On success, returns the length of the string (not including the trailing |
| * NUL). |
| * |
| * If access to userspace fails, returns -EFAULT (some data may have been |
| * copied). |
| * |
| * If @count is smaller than the length of the string, copies @count bytes |
| * and returns @count. |
| */ |
| long |
| strncpy_from_user(char *dst, const char __user *src, long count) |
| { |
| long res = -EFAULT; |
| if (access_ok(VERIFY_READ, src, 1)) |
| __do_strncpy_from_user(dst, src, count, res); |
| return res; |
| } |
| |
| |
| /* |
| * Zero Userspace |
| */ |
| |
| #define __do_clear_user(addr,size) \ |
| do { \ |
| int __d0; \ |
| might_sleep(); \ |
| __asm__ __volatile__( \ |
| "0: rep; stosl\n" \ |
| " movl %2,%0\n" \ |
| "1: rep; stosb\n" \ |
| "2:\n" \ |
| ".section .fixup,\"ax\"\n" \ |
| "3: lea 0(%2,%0,4),%0\n" \ |
| " jmp 2b\n" \ |
| ".previous\n" \ |
| ".section __ex_table,\"a\"\n" \ |
| " .align 4\n" \ |
| " .long 0b,3b\n" \ |
| " .long 1b,2b\n" \ |
| ".previous" \ |
| : "=&c"(size), "=&D" (__d0) \ |
| : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \ |
| } while (0) |
| |
| /** |
| * clear_user: - Zero a block of memory in user space. |
| * @to: Destination address, in user space. |
| * @n: Number of bytes to zero. |
| * |
| * Zero a block of memory in user space. |
| * |
| * Returns number of bytes that could not be cleared. |
| * On success, this will be zero. |
| */ |
| unsigned long |
| clear_user(void __user *to, unsigned long n) |
| { |
| might_sleep(); |
| if (access_ok(VERIFY_WRITE, to, n)) |
| __do_clear_user(to, n); |
| return n; |
| } |
| |
| /** |
| * __clear_user: - Zero a block of memory in user space, with less checking. |
| * @to: Destination address, in user space. |
| * @n: Number of bytes to zero. |
| * |
| * Zero a block of memory in user space. Caller must check |
| * the specified block with access_ok() before calling this function. |
| * |
| * Returns number of bytes that could not be cleared. |
| * On success, this will be zero. |
| */ |
| unsigned long |
| __clear_user(void __user *to, unsigned long n) |
| { |
| __do_clear_user(to, n); |
| return n; |
| } |
| |
| /** |
| * strlen_user: - Get the size of a string in user space. |
| * @s: The string to measure. |
| * @n: The maximum valid length |
| * |
| * 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 the string is too long, returns a value greater than @n. |
| */ |
| long strnlen_user(const char __user *s, long n) |
| { |
| unsigned long mask = -__addr_ok(s); |
| unsigned long res, tmp; |
| |
| might_sleep(); |
| |
| __asm__ __volatile__( |
| " testl %0, %0\n" |
| " jz 3f\n" |
| " andl %0,%%ecx\n" |
| "0: repne; scasb\n" |
| " setne %%al\n" |
| " subl %%ecx,%0\n" |
| " addl %0,%%eax\n" |
| "1:\n" |
| ".section .fixup,\"ax\"\n" |
| "2: xorl %%eax,%%eax\n" |
| " jmp 1b\n" |
| "3: movb $1,%%al\n" |
| " jmp 1b\n" |
| ".previous\n" |
| ".section __ex_table,\"a\"\n" |
| " .align 4\n" |
| " .long 0b,2b\n" |
| ".previous" |
| :"=r" (n), "=D" (s), "=a" (res), "=c" (tmp) |
| :"0" (n), "1" (s), "2" (0), "3" (mask) |
| :"cc"); |
| return res & mask; |
| } |
| |
| #ifdef CONFIG_X86_INTEL_USERCOPY |
| static unsigned long |
| __copy_user_intel(void __user *to, const void *from, unsigned long size) |
| { |
| int d0, d1; |
| __asm__ __volatile__( |
| " .align 2,0x90\n" |
| "1: movl 32(%4), %%eax\n" |
| " cmpl $67, %0\n" |
| " jbe 3f\n" |
| "2: movl 64(%4), %%eax\n" |
| " .align 2,0x90\n" |
| "3: movl 0(%4), %%eax\n" |
| "4: movl 4(%4), %%edx\n" |
| "5: movl %%eax, 0(%3)\n" |
| "6: movl %%edx, 4(%3)\n" |
| "7: movl 8(%4), %%eax\n" |
| "8: movl 12(%4),%%edx\n" |
| "9: movl %%eax, 8(%3)\n" |
| "10: movl %%edx, 12(%3)\n" |
| "11: movl 16(%4), %%eax\n" |
| "12: movl 20(%4), %%edx\n" |
| "13: movl %%eax, 16(%3)\n" |
| "14: movl %%edx, 20(%3)\n" |
| "15: movl 24(%4), %%eax\n" |
| "16: movl 28(%4), %%edx\n" |
| "17: movl %%eax, 24(%3)\n" |
| "18: movl %%edx, 28(%3)\n" |
| "19: movl 32(%4), %%eax\n" |
| "20: movl 36(%4), %%edx\n" |
| "21: movl %%eax, 32(%3)\n" |
| "22: movl %%edx, 36(%3)\n" |
| "23: movl 40(%4), %%eax\n" |
| "24: movl 44(%4), %%edx\n" |
| "25: movl %%eax, 40(%3)\n" |
| "26: movl %%edx, 44(%3)\n" |
| "27: movl 48(%4), %%eax\n" |
| "28: movl 52(%4), %%edx\n" |
| "29: movl %%eax, 48(%3)\n" |
| "30: movl %%edx, 52(%3)\n" |
| "31: movl 56(%4), %%eax\n" |
| "32: movl 60(%4), %%edx\n" |
| "33: movl %%eax, 56(%3)\n" |
| "34: movl %%edx, 60(%3)\n" |
| " addl $-64, %0\n" |
| " addl $64, %4\n" |
| " addl $64, %3\n" |
| " cmpl $63, %0\n" |
| " ja 1b\n" |
| "35: movl %0, %%eax\n" |
| " shrl $2, %0\n" |
| " andl $3, %%eax\n" |
| " cld\n" |
| "99: rep; movsl\n" |
| "36: movl %%eax, %0\n" |
| "37: rep; movsb\n" |
| "100:\n" |
| ".section .fixup,\"ax\"\n" |
| "101: lea 0(%%eax,%0,4),%0\n" |
| " jmp 100b\n" |
| ".previous\n" |
| ".section __ex_table,\"a\"\n" |
| " .align 4\n" |
| " .long 1b,100b\n" |
| " .long 2b,100b\n" |
| " .long 3b,100b\n" |
| " .long 4b,100b\n" |
| " .long 5b,100b\n" |
| " .long 6b,100b\n" |
| " .long 7b,100b\n" |
| " .long 8b,100b\n" |
| " .long 9b,100b\n" |
| " .long 10b,100b\n" |
| " .long 11b,100b\n" |
| " .long 12b,100b\n" |
| " .long 13b,100b\n" |
| " .long 14b,100b\n" |
| " .long 15b,100b\n" |
| " .long 16b,100b\n" |
| " .long 17b,100b\n" |
| " .long 18b,100b\n" |
| " .long 19b,100b\n" |
| " .long 20b,100b\n" |
| " .long 21b,100b\n" |
| " .long 22b,100b\n" |
| " .long 23b,100b\n" |
| " .long 24b,100b\n" |
| " .long 25b,100b\n" |
| " .long 26b,100b\n" |
| " .long 27b,100b\n" |
| " .long 28b,100b\n" |
| " .long 29b,100b\n" |
| " .long 30b,100b\n" |
| " .long 31b,100b\n" |
| " .long 32b,100b\n" |
| " .long 33b,100b\n" |
| " .long 34b,100b\n" |
| " .long 35b,100b\n" |
| " .long 36b,100b\n" |
| " .long 37b,100b\n" |
| " .long 99b,101b\n" |
| ".previous" |
| : "=&c"(size), "=&D" (d0), "=&S" (d1) |
| : "1"(to), "2"(from), "0"(size) |
| : "eax", "edx", "memory"); |
| return size; |
| } |
| |
| static unsigned long |
| __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size) |
| { |
| int d0, d1; |
| __asm__ __volatile__( |
| " .align 2,0x90\n" |
| "0: movl 32(%4), %%eax\n" |
| " cmpl $67, %0\n" |
| " jbe 2f\n" |
| "1: movl 64(%4), %%eax\n" |
| " .align 2,0x90\n" |
| "2: movl 0(%4), %%eax\n" |
| "21: movl 4(%4), %%edx\n" |
| " movl %%eax, 0(%3)\n" |
| " movl %%edx, 4(%3)\n" |
| "3: movl 8(%4), %%eax\n" |
| "31: movl 12(%4),%%edx\n" |
| " movl %%eax, 8(%3)\n" |
| " movl %%edx, 12(%3)\n" |
| "4: movl 16(%4), %%eax\n" |
| "41: movl 20(%4), %%edx\n" |
| " movl %%eax, 16(%3)\n" |
| " movl %%edx, 20(%3)\n" |
| "10: movl 24(%4), %%eax\n" |
| "51: movl 28(%4), %%edx\n" |
| " movl %%eax, 24(%3)\n" |
| " movl %%edx, 28(%3)\n" |
| "11: movl 32(%4), %%eax\n" |
| "61: movl 36(%4), %%edx\n" |
| " movl %%eax, 32(%3)\n" |
| " movl %%edx, 36(%3)\n" |
| "12: movl 40(%4), %%eax\n" |
| "71: movl 44(%4), %%edx\n" |
| " movl %%eax, 40(%3)\n" |
| " movl %%edx, 44(%3)\n" |
| "13: movl 48(%4), %%eax\n" |
| "81: movl 52(%4), %%edx\n" |
| " movl %%eax, 48(%3)\n" |
| " movl %%edx, 52(%3)\n" |
| "14: movl 56(%4), %%eax\n" |
| "91: movl 60(%4), %%edx\n" |
| " movl %%eax, 56(%3)\n" |
| " movl %%edx, 60(%3)\n" |
| " addl $-64, %0\n" |
| " addl $64, %4\n" |
| " addl $64, %3\n" |
| " cmpl $63, %0\n" |
| " ja 0b\n" |
| "5: movl %0, %%eax\n" |
| " shrl $2, %0\n" |
| " andl $3, %%eax\n" |
| " cld\n" |
| "6: rep; movsl\n" |
| " movl %%eax,%0\n" |
| "7: rep; movsb\n" |
| "8:\n" |
| ".section .fixup,\"ax\"\n" |
| "9: lea 0(%%eax,%0,4),%0\n" |
| "16: pushl %0\n" |
| " pushl %%eax\n" |
| " xorl %%eax,%%eax\n" |
| " rep; stosb\n" |
| " popl %%eax\n" |
| " popl %0\n" |
| " jmp 8b\n" |
| ".previous\n" |
| ".section __ex_table,\"a\"\n" |
| " .align 4\n" |
| " .long 0b,16b\n" |
| " .long 1b,16b\n" |
| " .long 2b,16b\n" |
| " .long 21b,16b\n" |
| " .long 3b,16b\n" |
| " .long 31b,16b\n" |
| " .long 4b,16b\n" |
| " .long 41b,16b\n" |
| " .long 10b,16b\n" |
| " .long 51b,16b\n" |
| " .long 11b,16b\n" |
| " .long 61b,16b\n" |
| " .long 12b,16b\n" |
| " .long 71b,16b\n" |
| " .long 13b,16b\n" |
| " .long 81b,16b\n" |
| " .long 14b,16b\n" |
| " .long 91b,16b\n" |
| " .long 6b,9b\n" |
| " .long 7b,16b\n" |
| ".previous" |
| : "=&c"(size), "=&D" (d0), "=&S" (d1) |
| : "1"(to), "2"(from), "0"(size) |
| : "eax", "edx", "memory"); |
| return size; |
| } |
| #else |
| /* |
| * Leave these declared but undefined. They should not be any references to |
| * them |
| */ |
| unsigned long |
| __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size); |
| unsigned long |
| __copy_user_intel(void __user *to, const void *from, unsigned long size); |
| #endif /* CONFIG_X86_INTEL_USERCOPY */ |
| |
| /* Generic arbitrary sized copy. */ |
| #define __copy_user(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 2b\n" \ |
| "3: lea 0(%3,%0,4),%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,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); |
