/* * Authors: Bjorn Wesen (bjornw@axis.com) * Hans-Peter Nilsson (hp@axis.com) * * $Log: uaccess.h,v $ * Revision 1.8 2001/10/29 13:01:48 bjornw * Removed unused variable tmp2 in strnlen_user * * Revision 1.7 2001/10/02 12:44:52 hp * Add support for 64-bit put_user/get_user * * Revision 1.6 2001/10/01 14:51:17 bjornw * Added register prefixes and removed underscores * * Revision 1.5 2000/10/25 03:33:21 hp * - Provide implementation for everything else but get_user and put_user; * copying inline to/from user for constant length 0..16, 20, 24, and * clearing for 0..4, 8, 12, 16, 20, 24, strncpy_from_user and strnlen_user * always inline. * - Constraints for destination addr in get_user cannot be memory, only reg. * - Correct labels for PC at expected fault points. * - Nits with assembly code. * - Don't use statement expressions without value; use "do {} while (0)". * - Return correct values from __generic_... functions. * * Revision 1.4 2000/09/12 16:28:25 bjornw * * Removed comments from the get/put user asm code * * Constrains for destination addr in put_user cannot be memory, only reg * * Revision 1.3 2000/09/12 14:30:20 bjornw * MAX_ADDR_USER does not exist anymore * * Revision 1.2 2000/07/13 15:52:48 bjornw * New user-access functions * * Revision 1.1.1.1 2000/07/10 16:32:31 bjornw * CRIS architecture, working draft * * * */ /* Asm:s have been tweaked (within the domain of correctness) to give satisfactory results for "gcc version 2.96 20000427 (experimental)". Check regularly... Register $r9 is chosen for temporaries, being a call-clobbered register first in line to be used (notably for local blocks), not colliding with parameter registers. */ #ifndef _CRIS_UACCESS_H #define _CRIS_UACCESS_H #ifndef __ASSEMBLY__ #include #include #include #include #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) }) /* addr_limit is the maximum accessible address for the task. we misuse * the KERNEL_DS and USER_DS values to both assign and compare the * addr_limit values through the equally misnamed get/set_fs macros. * (see above) */ #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) #define USER_DS MAKE_MM_SEG(TASK_SIZE) #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 __kernel_ok (segment_eq(get_fs(), KERNEL_DS)) #define __user_ok(addr,size) (((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size))) #define __access_ok(addr,size) (__kernel_ok || __user_ok((addr),(size))) #define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size)) #include /* * 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; }; /* * 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). * * As we use the same address space for kernel and user data on * CRIS, we can just do these as direct assignments. (Of course, the * exception handling means that it's no longer "just"...) */ #define get_user(x,ptr) \ __get_user_check((x),(ptr),sizeof(*(ptr))) #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))) extern long __put_user_bad(void); #define __put_user_size(x,ptr,size,retval) \ do { \ retval = 0; \ switch (size) { \ case 1: __put_user_asm(x,ptr,retval,"move.b"); break; \ case 2: __put_user_asm(x,ptr,retval,"move.w"); break; \ case 4: __put_user_asm(x,ptr,retval,"move.d"); break; \ case 8: __put_user_asm_64(x,ptr,retval); break; \ default: __put_user_bad(); \ } \ } while (0) #define __get_user_size(x,ptr,size,retval) \ do { \ retval = 0; \ switch (size) { \ case 1: __get_user_asm(x,ptr,retval,"move.b"); break; \ case 2: __get_user_asm(x,ptr,retval,"move.w"); break; \ case 4: __get_user_asm(x,ptr,retval,"move.d"); break; \ case 8: __get_user_asm_64(x,ptr,retval); break; \ default: (x) = __get_user_bad(); \ } \ } while (0) #define __put_user_nocheck(x,ptr,size) \ ({ \ long __pu_err; \ __put_user_size((x),(ptr),(size),__pu_err); \ __pu_err; \ }) #define __put_user_check(x,ptr,size) \ ({ \ long __pu_err = -EFAULT; \ __typeof__(*(ptr)) *__pu_addr = (ptr); \ if (access_ok(VERIFY_WRITE,__pu_addr,size)) \ __put_user_size((x),__pu_addr,(size),__pu_err); \ __pu_err; \ }) struct __large_struct { unsigned long buf[100]; }; #define __m(x) (*(struct __large_struct *)(x)) #define __get_user_nocheck(x,ptr,size) \ ({ \ long __gu_err, __gu_val; \ __get_user_size(__gu_val,(ptr),(size),__gu_err); \ (x) = (__typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) #define __get_user_check(x,ptr,size) \ ({ \ long __gu_err = -EFAULT, __gu_val = 0; \ const __typeof__(*(ptr)) *__gu_addr = (ptr); \ if (access_ok(VERIFY_READ,__gu_addr,size)) \ __get_user_size(__gu_val,__gu_addr,(size),__gu_err); \ (x) = (__typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) extern long __get_user_bad(void); /* More complex functions. Most are inline, but some call functions that live in lib/usercopy.c */ extern unsigned long __copy_user(void *to, const void *from, unsigned long n); extern unsigned long __copy_user_zeroing(void *to, const void *from, unsigned long n); extern unsigned long __do_clear_user(void *to, unsigned long n); static inline unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n) { if (access_ok(VERIFY_WRITE, to, n)) return __copy_user(to,from,n); return n; } static inline unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n) { if (access_ok(VERIFY_READ, from, n)) return __copy_user_zeroing(to,from,n); return n; } static inline unsigned long __generic_clear_user(void __user *to, unsigned long n) { if (access_ok(VERIFY_WRITE, to, n)) return __do_clear_user(to,n); return n; } static inline long __strncpy_from_user(char *dst, const char __user *src, long count) { return __do_strncpy_from_user(dst, src, count); } static inline long strncpy_from_user(char *dst, const char __user *src, long count) { long res = -EFAULT; if (access_ok(VERIFY_READ, src, 1)) res = __do_strncpy_from_user(dst, src, count); return res; } /* Note that if these expand awfully if made into switch constructs, so don't do that. */ static inline unsigned long __constant_copy_from_user(void *to, const void __user *from, unsigned long n) { unsigned long ret = 0; if (n == 0) ; else if (n == 1) __asm_copy_from_user_1(to, from, ret); else if (n == 2) __asm_copy_from_user_2(to, from, ret); else if (n == 3) __asm_copy_from_user_3(to, from, ret); else if (n == 4) __asm_copy_from_user_4(to, from, ret); else if (n == 5) __asm_copy_from_user_5(to, from, ret); else if (n == 6) __asm_copy_from_user_6(to, from, ret); else if (n == 7) __asm_copy_from_user_7(to, from, ret); else if (n == 8) __asm_copy_from_user_8(to, from, ret); else if (n == 9) __asm_copy_from_user_9(to, from, ret); else if (n == 10) __asm_copy_from_user_10(to, from, ret); else if (n == 11) __asm_copy_from_user_11(to, from, ret); else if (n == 12) __asm_copy_from_user_12(to, from, ret); else if (n == 13) __asm_copy_from_user_13(to, from, ret); else if (n == 14) __asm_copy_from_user_14(to, from, ret); else if (n == 15) __asm_copy_from_user_15(to, from, ret); else if (n == 16) __asm_copy_from_user_16(to, from, ret); else if (n == 20) __asm_copy_from_user_20(to, from, ret); else if (n == 24) __asm_copy_from_user_24(to, from, ret); else ret = __generic_copy_from_user(to, from, n); return ret; } /* Ditto, don't make a switch out of this. */ static inline unsigned long __constant_copy_to_user(void __user *to, const void *from, unsigned long n) { unsigned long ret = 0; if (n == 0) ; else if (n == 1) __asm_copy_to_user_1(to, from, ret); else if (n == 2) __asm_copy_to_user_2(to, from, ret); else if (n == 3) __asm_copy_to_user_3(to, from, ret); else if (n == 4) __asm_copy_to_user_4(to, from, ret); else if (n == 5) __asm_copy_to_user_5(to, from, ret); else if (n == 6) __asm_copy_to_user_6(to, from, ret); else if (n == 7) __asm_copy_to_user_7(to, from, ret); else if (n == 8) __asm_copy_to_user_8(to, from, ret); else if (n == 9) __asm_copy_to_user_9(to, from, ret); else if (n == 10) __asm_copy_to_user_10(to, from, ret); else if (n == 11) __asm_copy_to_user_11(to, from, ret); else if (n == 12) __asm_copy_to_user_12(to, from, ret); else if (n == 13) __asm_copy_to_user_13(to, from, ret); else if (n == 14) __asm_copy_to_user_14(to, from, ret); else if (n == 15) __asm_copy_to_user_15(to, from, ret); else if (n == 16) __asm_copy_to_user_16(to, from, ret); else if (n == 20) __asm_copy_to_user_20(to, from, ret); else if (n == 24) __asm_copy_to_user_24(to, from, ret); else ret = __generic_copy_to_user(to, from, n); return ret; } /* No switch, please. */ static inline unsigned long __constant_clear_user(void __user *to, unsigned long n) { unsigned long ret = 0; if (n == 0) ; else if (n == 1) __asm_clear_1(to, ret); else if (n == 2) __asm_clear_2(to, ret); else if (n == 3) __asm_clear_3(to, ret); else if (n == 4) __asm_clear_4(to, ret); else if (n == 8) __asm_clear_8(to, ret); else if (n == 12) __asm_clear_12(to, ret); else if (n == 16) __asm_clear_16(to, ret); else if (n == 20) __asm_clear_20(to, ret); else if (n == 24) __asm_clear_24(to, ret); else ret = __generic_clear_user(to, n); return ret; } #define clear_user(to, n) \ (__builtin_constant_p(n) ? \ __constant_clear_user(to, n) : \ __generic_clear_user(to, n)) #define copy_from_user(to, from, n) \ (__builtin_constant_p(n) ? \ __constant_copy_from_user(to, from, n) : \ __generic_copy_from_user(to, from, n)) #define copy_to_user(to, from, n) \ (__builtin_constant_p(n) ? \ __constant_copy_to_user(to, from, n) : \ __generic_copy_to_user(to, from, n)) /* We let the __ versions of copy_from/to_user inline, because they're often * used in fast paths and have only a small space overhead. */ static inline unsigned long __generic_copy_from_user_nocheck(void *to, const void *from, unsigned long n) { return __copy_user_zeroing(to,from,n); } static inline unsigned long __generic_copy_to_user_nocheck(void *to, const void *from, unsigned long n) { return __copy_user(to,from,n); } static inline unsigned long __generic_clear_user_nocheck(void *to, unsigned long n) { return __do_clear_user(to,n); } /* without checking */ #define __copy_to_user(to,from,n) __generic_copy_to_user_nocheck((to),(from),(n)) #define __copy_from_user(to,from,n) __generic_copy_from_user_nocheck((to),(from),(n)) #define __copy_to_user_inatomic __copy_to_user #define __copy_from_user_inatomic __copy_from_user #define __clear_user(to,n) __generic_clear_user_nocheck((to),(n)) #define strlen_user(str) strnlen_user((str), 0x7ffffffe) #endif /* __ASSEMBLY__ */ #endif /* _CRIS_UACCESS_H */