#ifndef __X86_64_UACCESS_H #define __X86_64_UACCESS_H /* * User space memory access functions */ #include <linux/compiler.h> #include <linux/errno.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,roksum; \ __chk_user_ptr(addr); \ asm("# range_ok\n\r" \ "addq %3,%1 ; sbbq %0,%0 ; cmpq %1,%4 ; sbbq $0,%0" \ :"=&r" (flag), "=r" (roksum) \ :"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) /* * 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) = (__force 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","","Zr",-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) = (__force 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 */ __must_check unsigned long copy_user_generic(void *to, const void *from, unsigned len); __must_check unsigned long copy_to_user(void __user *to, const void *from, unsigned len); __must_check unsigned long copy_from_user(void *to, const void __user *from, unsigned len); __must_check unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len); static __always_inline __must_check 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 __always_inline __must_check 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 __always_inline __must_check 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); } } __must_check long strncpy_from_user(char *dst, const char __user *src, long count); __must_check long __strncpy_from_user(char *dst, const char __user *src, long count); __must_check long strnlen_user(const char __user *str, long n); __must_check long __strnlen_user(const char __user *str, long n); __must_check long strlen_user(const char __user *str); __must_check unsigned long clear_user(void __user *mem, unsigned long len); __must_check unsigned long __clear_user(void __user *mem, unsigned long len); __must_check long __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size); static __must_check __always_inline int __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size) { return copy_user_generic((__force void *)dst, src, size); } #define ARCH_HAS_NOCACHE_UACCESS 1 extern long __copy_user_nocache(void *dst, const void __user *src, unsigned size, int zerorest); static inline int __copy_from_user_nocache(void *dst, const void __user *src, unsigned size) { might_sleep(); return __copy_user_nocache(dst, src, size, 1); } static inline int __copy_from_user_inatomic_nocache(void *dst, const void __user *src, unsigned size) { return __copy_user_nocache(dst, src, size, 0); } #endif /* __X86_64_UACCESS_H */