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Diffstat (limited to 'include/asm-x86_64/uaccess.h')
| -rw-r--r-- | include/asm-x86_64/uaccess.h | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/include/asm-x86_64/uaccess.h b/include/asm-x86_64/uaccess.h new file mode 100644 index 00000000000..48f292752c9 --- /dev/null +++ b/include/asm-x86_64/uaccess.h @@ -0,0 +1,365 @@ +#ifndef __X86_64_UACCESS_H +#define __X86_64_UACCESS_H + +/* + * User space memory access functions + */ +#include <linux/config.h> +#include <linux/compiler.h> +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/prefetch.h> +#include <asm/page.h> + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +/* + * The fs value determines whether argument validity checking should be + * performed or not. If get_fs() == USER_DS, checking is performed, with + * get_fs() == KERNEL_DS, checking is bypassed. + * + * For historical reasons, these macros are grossly misnamed. + */ + +#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) + +#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFFFFFFFFFUL) +#define USER_DS MAKE_MM_SEG(PAGE_OFFSET) + +#define get_ds() (KERNEL_DS) +#define get_fs() (current_thread_info()->addr_limit) +#define set_fs(x) (current_thread_info()->addr_limit = (x)) + +#define segment_eq(a,b) ((a).seg == (b).seg) + +#define __addr_ok(addr) (!((unsigned long)(addr) & (current_thread_info()->addr_limit.seg))) + +/* + * Uhhuh, this needs 65-bit arithmetic. We have a carry.. + */ +#define __range_not_ok(addr,size) ({ \ + unsigned long flag,sum; \ + __chk_user_ptr(addr); \ + asm("# range_ok\n\r" \ + "addq %3,%1 ; sbbq %0,%0 ; cmpq %1,%4 ; sbbq $0,%0" \ + :"=&r" (flag), "=r" (sum) \ + :"1" (addr),"g" ((long)(size)),"g" (current_thread_info()->addr_limit.seg)); \ + flag; }) + +#define access_ok(type, addr, size) (__range_not_ok(addr,size) == 0) + +/* this function will go away soon - use access_ok() instead */ +extern inline int __deprecated verify_area(int type, const void __user * addr, unsigned long size) +{ + return access_ok(type,addr,size) ? 0 : -EFAULT; +} + + +/* + * The exception table consists of pairs of addresses: the first is the + * address of an instruction that is allowed to fault, and the second is + * the address at which the program should continue. No registers are + * modified, so it is entirely up to the continuation code to figure out + * what to do. + * + * All the routines below use bits of fixup code that are out of line + * with the main instruction path. This means when everything is well, + * we don't even have to jump over them. Further, they do not intrude + * on our cache or tlb entries. + */ + +struct exception_table_entry +{ + unsigned long insn, fixup; +}; + +#define ARCH_HAS_SEARCH_EXTABLE + +/* + * These are the main single-value transfer routines. They automatically + * use the right size if we just have the right pointer type. + * + * This gets kind of ugly. We want to return _two_ values in "get_user()" + * and yet we don't want to do any pointers, because that is too much + * of a performance impact. Thus we have a few rather ugly macros here, + * and hide all the ugliness from the user. + * + * The "__xxx" versions of the user access functions are versions that + * do not verify the address space, that must have been done previously + * with a separate "access_ok()" call (this is used when we do multiple + * accesses to the same area of user memory). + */ + +#define __get_user_x(size,ret,x,ptr) \ + __asm__ __volatile__("call __get_user_" #size \ + :"=a" (ret),"=d" (x) \ + :"c" (ptr) \ + :"r8") + +/* Careful: we have to cast the result to the type of the pointer for sign reasons */ +#define get_user(x,ptr) \ +({ unsigned long __val_gu; \ + int __ret_gu; \ + __chk_user_ptr(ptr); \ + switch(sizeof (*(ptr))) { \ + case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \ + case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \ + case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \ + case 8: __get_user_x(8,__ret_gu,__val_gu,ptr); break; \ + default: __get_user_bad(); break; \ + } \ + (x) = (__typeof__(*(ptr)))__val_gu; \ + __ret_gu; \ +}) + +extern void __put_user_1(void); +extern void __put_user_2(void); +extern void __put_user_4(void); +extern void __put_user_8(void); +extern void __put_user_bad(void); + +#define __put_user_x(size,ret,x,ptr) \ + __asm__ __volatile__("call __put_user_" #size \ + :"=a" (ret) \ + :"c" (ptr),"d" (x) \ + :"r8") + +#define put_user(x,ptr) \ + __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) + +#define __get_user(x,ptr) \ + __get_user_nocheck((x),(ptr),sizeof(*(ptr))) +#define __put_user(x,ptr) \ + __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) + +#define __get_user_unaligned __get_user +#define __put_user_unaligned __put_user + +#define __put_user_nocheck(x,ptr,size) \ +({ \ + int __pu_err; \ + __put_user_size((x),(ptr),(size),__pu_err); \ + __pu_err; \ +}) + + +#define __put_user_check(x,ptr,size) \ +({ \ + int __pu_err; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + switch (size) { \ + case 1: __put_user_x(1,__pu_err,x,__pu_addr); break; \ + case 2: __put_user_x(2,__pu_err,x,__pu_addr); break; \ + case 4: __put_user_x(4,__pu_err,x,__pu_addr); break; \ + case 8: __put_user_x(8,__pu_err,x,__pu_addr); break; \ + default: __put_user_bad(); \ + } \ + __pu_err; \ +}) + +#define __put_user_size(x,ptr,size,retval) \ +do { \ + retval = 0; \ + __chk_user_ptr(ptr); \ + switch (size) { \ + case 1: __put_user_asm(x,ptr,retval,"b","b","iq",-EFAULT); break;\ + case 2: __put_user_asm(x,ptr,retval,"w","w","ir",-EFAULT); break;\ + case 4: __put_user_asm(x,ptr,retval,"l","k","ir",-EFAULT); break;\ + case 8: __put_user_asm(x,ptr,retval,"q","","ir",-EFAULT); break;\ + default: __put_user_bad(); \ + } \ +} while (0) + +/* FIXME: this hack is definitely wrong -AK */ +struct __large_struct { unsigned long buf[100]; }; +#define __m(x) (*(struct __large_struct __user *)(x)) + +/* + * Tell gcc we read from memory instead of writing: this is because + * we do not write to any memory gcc knows about, so there are no + * aliasing issues. + */ +#define __put_user_asm(x, addr, err, itype, rtype, ltype, errno) \ + __asm__ __volatile__( \ + "1: mov"itype" %"rtype"1,%2\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: mov %3,%0\n" \ + " jmp 2b\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 8\n" \ + " .quad 1b,3b\n" \ + ".previous" \ + : "=r"(err) \ + : ltype (x), "m"(__m(addr)), "i"(errno), "0"(err)) + + +#define __get_user_nocheck(x,ptr,size) \ +({ \ + int __gu_err; \ + unsigned long __gu_val; \ + __get_user_size(__gu_val,(ptr),(size),__gu_err); \ + (x) = (__typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +extern int __get_user_1(void); +extern int __get_user_2(void); +extern int __get_user_4(void); +extern int __get_user_8(void); +extern int __get_user_bad(void); + +#define __get_user_size(x,ptr,size,retval) \ +do { \ + retval = 0; \ + __chk_user_ptr(ptr); \ + switch (size) { \ + case 1: __get_user_asm(x,ptr,retval,"b","b","=q",-EFAULT); break;\ + case 2: __get_user_asm(x,ptr,retval,"w","w","=r",-EFAULT); break;\ + case 4: __get_user_asm(x,ptr,retval,"l","k","=r",-EFAULT); break;\ + case 8: __get_user_asm(x,ptr,retval,"q","","=r",-EFAULT); break;\ + default: (x) = __get_user_bad(); \ + } \ +} while (0) + +#define __get_user_asm(x, addr, err, itype, rtype, ltype, errno) \ + __asm__ __volatile__( \ + "1: mov"itype" %2,%"rtype"1\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: mov %3,%0\n" \ + " xor"itype" %"rtype"1,%"rtype"1\n" \ + " jmp 2b\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 8\n" \ + " .quad 1b,3b\n" \ + ".previous" \ + : "=r"(err), ltype (x) \ + : "m"(__m(addr)), "i"(errno), "0"(err)) + +/* + * Copy To/From Userspace + */ + +/* Handles exceptions in both to and from, but doesn't do access_ok */ +extern unsigned long copy_user_generic(void *to, const void *from, unsigned len); + +extern unsigned long copy_to_user(void __user *to, const void *from, unsigned len); +extern unsigned long copy_from_user(void *to, const void __user *from, unsigned len); +extern unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len); + +static inline int __copy_from_user(void *dst, const void __user *src, unsigned size) +{ + int ret = 0; + if (!__builtin_constant_p(size)) + return copy_user_generic(dst,(__force void *)src,size); + switch (size) { + case 1:__get_user_asm(*(u8*)dst,(u8 __user *)src,ret,"b","b","=q",1); + return ret; + case 2:__get_user_asm(*(u16*)dst,(u16 __user *)src,ret,"w","w","=r",2); + return ret; + case 4:__get_user_asm(*(u32*)dst,(u32 __user *)src,ret,"l","k","=r",4); + return ret; + case 8:__get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",8); + return ret; + case 10: + __get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16); + if (unlikely(ret)) return ret; + __get_user_asm(*(u16*)(8+(char*)dst),(u16 __user *)(8+(char __user *)src),ret,"w","w","=r",2); + return ret; + case 16: + __get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16); + if (unlikely(ret)) return ret; + __get_user_asm(*(u64*)(8+(char*)dst),(u64 __user *)(8+(char __user *)src),ret,"q","","=r",8); + return ret; + default: + return copy_user_generic(dst,(__force void *)src,size); + } +} + +static inline int __copy_to_user(void __user *dst, const void *src, unsigned size) +{ + int ret = 0; + if (!__builtin_constant_p(size)) + return copy_user_generic((__force void *)dst,src,size); + switch (size) { + case 1:__put_user_asm(*(u8*)src,(u8 __user *)dst,ret,"b","b","iq",1); + return ret; + case 2:__put_user_asm(*(u16*)src,(u16 __user *)dst,ret,"w","w","ir",2); + return ret; + case 4:__put_user_asm(*(u32*)src,(u32 __user *)dst,ret,"l","k","ir",4); + return ret; + case 8:__put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",8); + return ret; + case 10: + __put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",10); + if (unlikely(ret)) return ret; + asm("":::"memory"); + __put_user_asm(4[(u16*)src],4+(u16 __user *)dst,ret,"w","w","ir",2); + return ret; + case 16: + __put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",16); + if (unlikely(ret)) return ret; + asm("":::"memory"); + __put_user_asm(1[(u64*)src],1+(u64 __user *)dst,ret,"q","","ir",8); + return ret; + default: + return copy_user_generic((__force void *)dst,src,size); + } +} + + +static inline int __copy_in_user(void __user *dst, const void __user *src, unsigned size) +{ + int ret = 0; + if (!__builtin_constant_p(size)) + return copy_user_generic((__force void *)dst,(__force void *)src,size); + switch (size) { + case 1: { + u8 tmp; + __get_user_asm(tmp,(u8 __user *)src,ret,"b","b","=q",1); + if (likely(!ret)) + __put_user_asm(tmp,(u8 __user *)dst,ret,"b","b","iq",1); + return ret; + } + case 2: { + u16 tmp; + __get_user_asm(tmp,(u16 __user *)src,ret,"w","w","=r",2); + if (likely(!ret)) + __put_user_asm(tmp,(u16 __user *)dst,ret,"w","w","ir",2); + return ret; + } + + case 4: { + u32 tmp; + __get_user_asm(tmp,(u32 __user *)src,ret,"l","k","=r",4); + if (likely(!ret)) + __put_user_asm(tmp,(u32 __user *)dst,ret,"l","k","ir",4); + return ret; + } + case 8: { + u64 tmp; + __get_user_asm(tmp,(u64 __user *)src,ret,"q","","=r",8); + if (likely(!ret)) + __put_user_asm(tmp,(u64 __user *)dst,ret,"q","","ir",8); + return ret; + } + default: + return copy_user_generic((__force void *)dst,(__force void *)src,size); + } +} + +long strncpy_from_user(char *dst, const char __user *src, long count); +long __strncpy_from_user(char *dst, const char __user *src, long count); +long strnlen_user(const char __user *str, long n); +long strlen_user(const char __user *str); +unsigned long clear_user(void __user *mem, unsigned long len); +unsigned long __clear_user(void __user *mem, unsigned long len); + +#define __copy_to_user_inatomic __copy_to_user +#define __copy_from_user_inatomic __copy_from_user + +#endif /* __X86_64_UACCESS_H */ |