uaccess_32.h revision 7c12d81134b130ccd4c286b434ca48c4cda71a2f
11da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#ifndef __i386_UACCESS_H 21da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __i386_UACCESS_H 31da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 41da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 51da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * User space memory access functions 61da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 71da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/errno.h> 81da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/thread_info.h> 91da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/prefetch.h> 101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/string.h> 111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <asm/page.h> 121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define VERIFY_READ 0 141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define VERIFY_WRITE 1 151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The fs value determines whether argument validity checking should be 181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * performed or not. If get_fs() == USER_DS, checking is performed, with 191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * get_fs() == KERNEL_DS, checking is bypassed. 201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * For historical reasons, these macros are grossly misnamed. 221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFUL) 281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define USER_DS MAKE_MM_SEG(PAGE_OFFSET) 291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define get_ds() (KERNEL_DS) 311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define get_fs() (current_thread_info()->addr_limit) 321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define set_fs(x) (current_thread_info()->addr_limit = (x)) 331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define segment_eq(a,b) ((a).seg == (b).seg) 351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * movsl can be slow when source and dest are not both 8-byte aligned 381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#ifdef CONFIG_X86_INTEL_USERCOPY 401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern struct movsl_mask { 411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int mask; 421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} ____cacheline_aligned_in_smp movsl_mask; 431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif 441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __addr_ok(addr) ((unsigned long __force)(addr) < (current_thread_info()->addr_limit.seg)) 461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Test whether a block of memory is a valid user space address. 491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns 0 if the range is valid, nonzero otherwise. 501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This is equivalent to the following test: 521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * (u33)addr + (u33)size >= (u33)current->addr_limit.seg 531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This needs 33-bit arithmetic. We have a carry... 551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __range_ok(addr,size) ({ \ 571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long flag,sum; \ 581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __chk_user_ptr(addr); \ 591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0" \ 601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds :"=&r" (flag), "=r" (sum) \ 61722f4f5b2600b8930b63a096e48b878cd6e0e15aRoman Zippel :"1" (addr),"g" ((int)(size)),"rm" (current_thread_info()->addr_limit.seg)); \ 621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds flag; }) 631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * access_ok: - Checks if a user space pointer is valid 661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that 671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe 681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * to write to a block, it is always safe to read from it. 691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @addr: User space pointer to start of block to check 701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @size: Size of block to check 711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Context: User context only. This function may sleep. 731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Checks if a pointer to a block of memory in user space is valid. 751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns true (nonzero) if the memory block may be valid, false (zero) 771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * if it is definitely invalid. 781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Note that, depending on architecture, this function probably just 801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * checks that the pointer is in the user space range - after calling 811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * this function, memory access functions may still return -EFAULT. 821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0)) 841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The exception table consists of pairs of addresses: the first is the 871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * address of an instruction that is allowed to fault, and the second is 881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the address at which the program should continue. No registers are 891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * modified, so it is entirely up to the continuation code to figure out 901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * what to do. 911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * All the routines below use bits of fixup code that are out of line 931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * with the main instruction path. This means when everything is well, 941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * we don't even have to jump over them. Further, they do not intrude 951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * on our cache or tlb entries. 961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstruct exception_table_entry 991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long insn, fixup; 1011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 1021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern int fixup_exception(struct pt_regs *regs); 1041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * These are the main single-value transfer routines. They automatically 1071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * use the right size if we just have the right pointer type. 1081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This gets kind of ugly. We want to return _two_ values in "get_user()" 1101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * and yet we don't want to do any pointers, because that is too much 1111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * of a performance impact. Thus we have a few rather ugly macros here, 1121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * and hide all the ugliness from the user. 1131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The "__xxx" versions of the user access functions are versions that 1151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * do not verify the address space, that must have been done previously 1161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * with a separate "access_ok()" call (this is used when we do multiple 1171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * accesses to the same area of user memory). 1181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern void __get_user_1(void); 1211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern void __get_user_2(void); 1221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern void __get_user_4(void); 1231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __get_user_x(size,ret,x,ptr) \ 1251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __asm__ __volatile__("call __get_user_" #size \ 1261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds :"=a" (ret),"=d" (x) \ 1271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds :"0" (ptr)) 1281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* Careful: we have to cast the result to the type of the pointer for sign reasons */ 1311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 1321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * get_user: - Get a simple variable from user space. 1331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @x: Variable to store result. 1341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @ptr: Source address, in user space. 1351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Context: User context only. This function may sleep. 1371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This macro copies a single simple variable from user space to kernel 1391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * space. It supports simple types like char and int, but not larger 1401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * data types like structures or arrays. 1411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @ptr must have pointer-to-simple-variable type, and the result of 1431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * dereferencing @ptr must be assignable to @x without a cast. 1441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns zero on success, or -EFAULT on error. 1461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * On error, the variable @x is set to zero. 1471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define get_user(x,ptr) \ 1491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds({ int __ret_gu; \ 1501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long __val_gu; \ 1511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __chk_user_ptr(ptr); \ 1521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds switch(sizeof (*(ptr))) { \ 1531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \ 1541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \ 1551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \ 1561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds default: __get_user_x(X,__ret_gu,__val_gu,ptr); break; \ 1571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } \ 1581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds (x) = (__typeof__(*(ptr)))__val_gu; \ 1591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __ret_gu; \ 1601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}) 1611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern void __put_user_bad(void); 1631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Strange magic calling convention: pointer in %ecx, 1661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * value in %eax(:%edx), return value in %eax, no clobbers. 1671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern void __put_user_1(void); 1691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern void __put_user_2(void); 1701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern void __put_user_4(void); 1711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern void __put_user_8(void); 1721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_1(x, ptr) __asm__ __volatile__("call __put_user_1":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) 1741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_2(x, ptr) __asm__ __volatile__("call __put_user_2":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) 1751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_4(x, ptr) __asm__ __volatile__("call __put_user_4":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) 1761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_8(x, ptr) __asm__ __volatile__("call __put_user_8":"=a" (__ret_pu):"A" ((typeof(*(ptr)))(x)), "c" (ptr)) 1771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_X(x, ptr) __asm__ __volatile__("call __put_user_X":"=a" (__ret_pu):"c" (ptr)) 1781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 1801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * put_user: - Write a simple value into user space. 1811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @x: Value to copy to user space. 1821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @ptr: Destination address, in user space. 1831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Context: User context only. This function may sleep. 1851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This macro copies a single simple value from kernel space to user 1871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * space. It supports simple types like char and int, but not larger 1881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * data types like structures or arrays. 1891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @ptr must have pointer-to-simple-variable type, and @x must be assignable 1911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * to the result of dereferencing @ptr. 1921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns zero on success, or -EFAULT on error. 1941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#ifdef CONFIG_X86_WP_WORKS_OK 1961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define put_user(x,ptr) \ 1981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds({ int __ret_pu; \ 19930e931d4092713cecd6b8c2fd70f268efaa6e428Eric W. Biederman __typeof__(*(ptr)) __pu_val; \ 2001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __chk_user_ptr(ptr); \ 20130e931d4092713cecd6b8c2fd70f268efaa6e428Eric W. Biederman __pu_val = x; \ 2021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds switch(sizeof(*(ptr))) { \ 20330e931d4092713cecd6b8c2fd70f268efaa6e428Eric W. Biederman case 1: __put_user_1(__pu_val, ptr); break; \ 20430e931d4092713cecd6b8c2fd70f268efaa6e428Eric W. Biederman case 2: __put_user_2(__pu_val, ptr); break; \ 20530e931d4092713cecd6b8c2fd70f268efaa6e428Eric W. Biederman case 4: __put_user_4(__pu_val, ptr); break; \ 20630e931d4092713cecd6b8c2fd70f268efaa6e428Eric W. Biederman case 8: __put_user_8(__pu_val, ptr); break; \ 20730e931d4092713cecd6b8c2fd70f268efaa6e428Eric W. Biederman default:__put_user_X(__pu_val, ptr); break; \ 2081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } \ 2091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __ret_pu; \ 2101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}) 2111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#else 2131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define put_user(x,ptr) \ 2141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds({ \ 2151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int __ret_pu; \ 2161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __typeof__(*(ptr)) __pus_tmp = x; \ 2171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __ret_pu=0; \ 2181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, \ 2191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds sizeof(*(ptr))) != 0)) \ 2201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __ret_pu=-EFAULT; \ 2211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __ret_pu; \ 2221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds }) 2231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif 2261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 2281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * __get_user: - Get a simple variable from user space, with less checking. 2291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @x: Variable to store result. 2301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @ptr: Source address, in user space. 2311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Context: User context only. This function may sleep. 2331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This macro copies a single simple variable from user space to kernel 2351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * space. It supports simple types like char and int, but not larger 2361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * data types like structures or arrays. 2371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @ptr must have pointer-to-simple-variable type, and the result of 2391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * dereferencing @ptr must be assignable to @x without a cast. 2401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Caller must check the pointer with access_ok() before calling this 2421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * function. 2431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns zero on success, or -EFAULT on error. 2451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * On error, the variable @x is set to zero. 2461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 2471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __get_user(x,ptr) \ 2481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __get_user_nocheck((x),(ptr),sizeof(*(ptr))) 2491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 2521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * __put_user: - Write a simple value into user space, with less checking. 2531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @x: Value to copy to user space. 2541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @ptr: Destination address, in user space. 2551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Context: User context only. This function may sleep. 2571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This macro copies a single simple value from kernel space to user 2591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * space. It supports simple types like char and int, but not larger 2601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * data types like structures or arrays. 2611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @ptr must have pointer-to-simple-variable type, and @x must be assignable 2631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * to the result of dereferencing @ptr. 2641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Caller must check the pointer with access_ok() before calling this 2661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * function. 2671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns zero on success, or -EFAULT on error. 2691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 2701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user(x,ptr) \ 2711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) 2721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_nocheck(x,ptr,size) \ 2741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds({ \ 2751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds long __pu_err; \ 2761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __put_user_size((x),(ptr),(size),__pu_err,-EFAULT); \ 2771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __pu_err; \ 2781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}) 2791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_u64(x, addr, err) \ 2821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __asm__ __volatile__( \ 2831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "1: movl %%eax,0(%2)\n" \ 2841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "2: movl %%edx,4(%2)\n" \ 2851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "3:\n" \ 2861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".section .fixup,\"ax\"\n" \ 2871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "4: movl %3,%0\n" \ 2881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " jmp 3b\n" \ 2891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".previous\n" \ 2901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".section __ex_table,\"a\"\n" \ 2911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " .align 4\n" \ 2921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " .long 1b,4b\n" \ 2931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " .long 2b,4b\n" \ 2941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".previous" \ 2951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds : "=r"(err) \ 2961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds : "A" (x), "r" (addr), "i"(-EFAULT), "0"(err)) 2971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#ifdef CONFIG_X86_WP_WORKS_OK 2991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_size(x,ptr,size,retval,errret) \ 3011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsdo { \ 3021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds retval = 0; \ 3031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __chk_user_ptr(ptr); \ 3041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds switch (size) { \ 3051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 1: __put_user_asm(x,ptr,retval,"b","b","iq",errret);break; \ 3061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 2: __put_user_asm(x,ptr,retval,"w","w","ir",errret);break; \ 3071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 4: __put_user_asm(x,ptr,retval,"l","","ir",errret); break; \ 3081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\ 3091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds default: __put_user_bad(); \ 3101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } \ 3111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} while (0) 3121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#else 3141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_size(x,ptr,size,retval,errret) \ 3161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsdo { \ 3171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __typeof__(*(ptr)) __pus_tmp = x; \ 3181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds retval = 0; \ 3191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds \ 3201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0)) \ 3211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds retval = errret; \ 3221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} while (0) 3231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif 3251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstruct __large_struct { unsigned long buf[100]; }; 3261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __m(x) (*(struct __large_struct __user *)(x)) 3271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 3291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Tell gcc we read from memory instead of writing: this is because 3301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * we do not write to any memory gcc knows about, so there are no 3311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * aliasing issues. 3321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \ 3341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __asm__ __volatile__( \ 3351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "1: mov"itype" %"rtype"1,%2\n" \ 3361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "2:\n" \ 3371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".section .fixup,\"ax\"\n" \ 3381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "3: movl %3,%0\n" \ 3391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " jmp 2b\n" \ 3401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".previous\n" \ 3411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".section __ex_table,\"a\"\n" \ 3421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " .align 4\n" \ 3431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " .long 1b,3b\n" \ 3441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".previous" \ 3451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds : "=r"(err) \ 3461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds : ltype (x), "m"(__m(addr)), "i"(errret), "0"(err)) 3471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __get_user_nocheck(x,ptr,size) \ 3501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds({ \ 3511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds long __gu_err; \ 3521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long __gu_val; \ 3531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\ 3541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds (x) = (__typeof__(*(ptr)))__gu_val; \ 3551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __gu_err; \ 3561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}) 3571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsextern long __get_user_bad(void); 3591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __get_user_size(x,ptr,size,retval,errret) \ 3611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsdo { \ 3621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds retval = 0; \ 3631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __chk_user_ptr(ptr); \ 3641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds switch (size) { \ 3651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 1: __get_user_asm(x,ptr,retval,"b","b","=q",errret);break; \ 3661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 2: __get_user_asm(x,ptr,retval,"w","w","=r",errret);break; \ 3671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 4: __get_user_asm(x,ptr,retval,"l","","=r",errret);break; \ 3681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds default: (x) = __get_user_bad(); \ 3691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } \ 3701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} while (0) 3711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \ 3731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __asm__ __volatile__( \ 3741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "1: mov"itype" %2,%"rtype"1\n" \ 3751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "2:\n" \ 3761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".section .fixup,\"ax\"\n" \ 3771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds "3: movl %3,%0\n" \ 3781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " xor"itype" %"rtype"1,%"rtype"1\n" \ 3791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " jmp 2b\n" \ 3801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".previous\n" \ 3811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".section __ex_table,\"a\"\n" \ 3821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " .align 4\n" \ 3831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds " .long 1b,3b\n" \ 3841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ".previous" \ 3851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds : "=r"(err), ltype (x) \ 3861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds : "m"(__m(addr)), "i"(errret), "0"(err)) 3871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsunsigned long __must_check __copy_to_user_ll(void __user *to, 3901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds const void *from, unsigned long n); 3911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsunsigned long __must_check __copy_from_user_ll(void *to, 3921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds const void __user *from, unsigned long n); 3937c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrownunsigned long __must_check __copy_from_user_ll_nozero(void *to, 3947c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown const void __user *from, unsigned long n); 395c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshiokaunsigned long __must_check __copy_from_user_ll_nocache(void *to, 396c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka const void __user *from, unsigned long n); 3977c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrownunsigned long __must_check __copy_from_user_ll_nocache_nozero(void *to, 3987c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown const void __user *from, unsigned long n); 3991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 4011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault 4021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * we return the initial request size (1, 2 or 4), as copy_*_user should do. 4031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * If a store crosses a page boundary and gets a fault, the x86 will not write 4041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * anything, so this is accurate. 4051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 4061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 4081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * __copy_to_user: - Copy a block of data into user space, with less checking. 4091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @to: Destination address, in user space. 4101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @from: Source address, in kernel space. 4111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @n: Number of bytes to copy. 4121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Context: User context only. This function may sleep. 4141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Copy data from kernel space to user space. Caller must check 4161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the specified block with access_ok() before calling this function. 4171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns number of bytes that could not be copied. 4191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * On success, this will be zero. 4201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 421652050aec936fdd70ed9cbce1cd1ef30a7c9d117Ingo Molnarstatic __always_inline unsigned long __must_check 4221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) 4231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 4241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (__builtin_constant_p(n)) { 4251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long ret; 4261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds switch (n) { 4281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 1: 4291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1); 4301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return ret; 4311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 2: 4321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2); 4331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return ret; 4341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 4: 4351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4); 4361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return ret; 4371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 4381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 4391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return __copy_to_user_ll(to, from, n); 4401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 4411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 442652050aec936fdd70ed9cbce1cd1ef30a7c9d117Ingo Molnarstatic __always_inline unsigned long __must_check 4431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds__copy_to_user(void __user *to, const void *from, unsigned long n) 4441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 4451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds might_sleep(); 4461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return __copy_to_user_inatomic(to, from, n); 4471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 4481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 4501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * __copy_from_user: - Copy a block of data from user space, with less checking. 4511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @to: Destination address, in kernel space. 4521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @from: Source address, in user space. 4531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @n: Number of bytes to copy. 4541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Context: User context only. This function may sleep. 4561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Copy data from user space to kernel space. Caller must check 4581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the specified block with access_ok() before calling this function. 4591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns number of bytes that could not be copied. 4611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * On success, this will be zero. 4621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * If some data could not be copied, this function will pad the copied 4641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * data to the requested size using zero bytes. 46501408c4939479ec46c15aa7ef6e2406be50eeecaNeilBrown * 46601408c4939479ec46c15aa7ef6e2406be50eeecaNeilBrown * An alternate version - __copy_from_user_inatomic() - may be called from 46701408c4939479ec46c15aa7ef6e2406be50eeecaNeilBrown * atomic context and will fail rather than sleep. In this case the 46801408c4939479ec46c15aa7ef6e2406be50eeecaNeilBrown * uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h 46901408c4939479ec46c15aa7ef6e2406be50eeecaNeilBrown * for explanation of why this is needed. 4701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 471652050aec936fdd70ed9cbce1cd1ef30a7c9d117Ingo Molnarstatic __always_inline unsigned long 4721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) 4731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 4747c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown /* Avoid zeroing the tail if the copy fails.. 4757c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown * If 'n' is constant and 1, 2, or 4, we do still zero on a failure, 4767c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown * but as the zeroing behaviour is only significant when n is not 4777c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown * constant, that shouldn't be a problem. 4787c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown */ 4797c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown if (__builtin_constant_p(n)) { 4807c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown unsigned long ret; 4817c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown 4827c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown switch (n) { 4837c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown case 1: 4847c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown __get_user_size(*(u8 *)to, from, 1, ret, 1); 4857c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown return ret; 4867c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown case 2: 4877c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown __get_user_size(*(u16 *)to, from, 2, ret, 2); 4887c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown return ret; 4897c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown case 4: 4907c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown __get_user_size(*(u32 *)to, from, 4, ret, 4); 4917c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown return ret; 4927c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown } 4937c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown } 4947c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown return __copy_from_user_ll_nozero(to, from, n); 4957c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown} 4967c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrownstatic __always_inline unsigned long 4977c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown__copy_from_user(void *to, const void __user *from, unsigned long n) 4987c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown{ 4997c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown might_sleep(); 5001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (__builtin_constant_p(n)) { 5011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds unsigned long ret; 5021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds switch (n) { 5041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 1: 5051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __get_user_size(*(u8 *)to, from, 1, ret, 1); 5061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return ret; 5071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 2: 5081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __get_user_size(*(u16 *)to, from, 2, ret, 2); 5091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return ret; 5101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds case 4: 5111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __get_user_size(*(u32 *)to, from, 4, ret, 4); 5121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return ret; 5131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 5141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 5151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return __copy_from_user_ll(to, from, n); 5161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 5171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 518c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka#define ARCH_HAS_NOCACHE_UACCESS 519c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka 5207c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrownstatic __always_inline unsigned long __copy_from_user_nocache(void *to, 521c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka const void __user *from, unsigned long n) 522c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka{ 5237c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown might_sleep(); 524c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka if (__builtin_constant_p(n)) { 525c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka unsigned long ret; 526c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka 527c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka switch (n) { 528c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka case 1: 529c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka __get_user_size(*(u8 *)to, from, 1, ret, 1); 530c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka return ret; 531c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka case 2: 532c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka __get_user_size(*(u16 *)to, from, 2, ret, 2); 533c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka return ret; 534c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka case 4: 535c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka __get_user_size(*(u32 *)to, from, 4, ret, 4); 536c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka return ret; 537c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka } 538c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka } 539c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka return __copy_from_user_ll_nocache(to, from, n); 540c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka} 541c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka 542652050aec936fdd70ed9cbce1cd1ef30a7c9d117Ingo Molnarstatic __always_inline unsigned long 5437c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown__copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long n) 5441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 5457c12d81134b130ccd4c286b434ca48c4cda71a2fNeilBrown return __copy_from_user_ll_nocache_nozero(to, from, n); 546c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka} 547c22ce143d15eb288543fe9873e1c5ac1c01b69a1Hiro Yoshioka 5481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsunsigned long __must_check copy_to_user(void __user *to, 5491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds const void *from, unsigned long n); 5501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsunsigned long __must_check copy_from_user(void *to, 5511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds const void __user *from, unsigned long n); 5521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldslong __must_check strncpy_from_user(char *dst, const char __user *src, 5531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds long count); 5541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldslong __must_check __strncpy_from_user(char *dst, 5551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds const char __user *src, long count); 5561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 5581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * strlen_user: - Get the size of a string in user space. 5591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * @str: The string to measure. 5601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 5611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Context: User context only. This function may sleep. 5621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 5631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Get the size of a NUL-terminated string in user space. 5641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 5651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Returns the size of the string INCLUDING the terminating NUL. 5661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * On exception, returns 0. 5671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 5681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * If there is a limit on the length of a valid string, you may wish to 5691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * consider using strnlen_user() instead. 5701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 5711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define strlen_user(str) strnlen_user(str, ~0UL >> 1) 5721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldslong strnlen_user(const char __user *str, long n); 5741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsunsigned long __must_check clear_user(void __user *mem, unsigned long len); 5751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsunsigned long __must_check __clear_user(void __user *mem, unsigned long len); 5761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#endif /* __i386_UACCESS_H */ 578