/* * include/asm-s390/uaccess.h * * S390 version * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation * Author(s): Hartmut Penner (hpenner@de.ibm.com), * Martin Schwidefsky (schwidefsky@de.ibm.com) * * Derived from "include/asm-i386/uaccess.h" */ #ifndef __S390_UACCESS_H #define __S390_UACCESS_H /* * User space memory access functions */ #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) }) #define KERNEL_DS MAKE_MM_SEG(0) #define USER_DS MAKE_MM_SEG(1) #define get_ds() (KERNEL_DS) #define get_fs() (current->addr_limit) #define set_fs(x) ({asm volatile("sar 4,%0"::"a" ((x).ar4));\ current->addr_limit = (x);}) #define segment_eq(a,b) ((a).ar4 == (b).ar4) #define __access_ok(addr,size) (1) #define access_ok(type,addr,size) __access_ok(addr,size) extern inline int verify_area(int type, const void * 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; }; /* Returns 0 if exception not found and fixup otherwise. */ extern unsigned long search_exception_table(unsigned long); /* * These are the main single-value transfer routines. They automatically * use the right size if we just have the right pointer type. */ extern inline int __put_user_asm_8(__u64 x, void *ptr) { int err; __asm__ __volatile__ ( " sr %1,%1\n" " la 4,%0\n" " sacf 512\n" "0: stg %2,0(4)\n" "1: sacf 0\n" ".section .fixup,\"ax\"\n" "2: lhi %1,%h3\n" " jg 1b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 8\n" " .quad 0b,2b\n" ".previous" : "=m" (*((__u64*) ptr)) , "=&d" (err) : "d" (x), "K" (-EFAULT) : "cc", "4" ); return err; } extern inline int __put_user_asm_4(__u32 x, void *ptr) { int err; __asm__ __volatile__ ( " sr %1,%1\n" " la 4,%0\n" " sacf 512\n" "0: st %2,0(4)\n" "1: sacf 0\n" ".section .fixup,\"ax\"\n" "2: lhi %1,%h3\n" " jg 1b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 8\n" " .quad 0b,2b\n" ".previous" : "=m" (*((__u32*) ptr)) , "=&d" (err) : "d" (x), "K" (-EFAULT) : "cc", "4" ); return err; } extern inline int __put_user_asm_2(__u16 x, void *ptr) { int err; __asm__ __volatile__ ( " sr %1,%1\n" " la 4,%0\n" " sacf 512\n" "0: sth %2,0(4)\n" "1: sacf 0\n" ".section .fixup,\"ax\"\n" "2: lhi %1,%h3\n" " jg 1b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 8\n" " .quad 0b,2b\n" ".previous" : "=m" (*((__u16*) ptr)) , "=&d" (err) : "d" (x), "K" (-EFAULT) : "cc", "4" ); return err; } extern inline int __put_user_asm_1(__u8 x, void *ptr) { int err; __asm__ __volatile__ ( " sr %1,%1\n" " la 4,%0\n" " sacf 512\n" "0: stc %2,0(4)\n" "1: sacf 0\n" ".section .fixup,\"ax\"\n" "2: lhi %1,%h3\n" " jg 1b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 8\n" " .quad 0b,2b\n" ".previous" : "=m" (*((__u8*) ptr)) , "=&d" (err) : "d" (x), "K" (-EFAULT) : "cc", "1", "4" ); return err; } /* * (u?)(u64) ... autsch, but that the only way we can suppress the * warnings when compiling binfmt_elf.c */ #define __put_user(x, ptr) \ ({ \ int __pu_err; \ switch (sizeof (*(ptr))) { \ case 1: \ __pu_err = __put_user_asm_1((__u8)(__u64)(x),(ptr));\ break; \ case 2: \ __pu_err = __put_user_asm_2((__u16)(__u64)(x),(ptr));\ break; \ case 4: \ __pu_err = __put_user_asm_4((__u32)(__u64)(x),(ptr));\ break; \ case 8: \ __pu_err = __put_user_asm_8((__u64)(x),(ptr));\ break; \ default: \ __pu_err = __put_user_bad(); \ break; \ } \ __pu_err; \ }) #define put_user(x, ptr) \ ({ \ long __pu_err = -EFAULT; \ __typeof__(*(ptr)) *__pu_addr = (ptr); \ __typeof__(*(ptr)) __x = (x); \ if (__access_ok((long)__pu_addr,sizeof(*(ptr)))) { \ __pu_err = 0; \ __put_user((__x), (__pu_addr)); \ } \ __pu_err; \ }) extern int __put_user_bad(void); #define __get_user_asm_8(x, ptr, err) \ ({ \ __asm__ __volatile__ ( " sr %1,%1\n" \ " la 4,%2\n" \ " sacf 512\n" \ "0: lg %0,0(4)\n" \ "1: sacf 0\n" \ ".section .fixup,\"ax\"\n" \ "2: lhi %1,%h3\n" \ " jg 1b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .align 8\n" \ " .quad 0b,2b\n" \ ".previous" \ : "=d" (x) , "=&d" (err) \ : "m" (*(const __u64*)(ptr)),"K" (-EFAULT) \ : "cc", "4" ); \ }) #define __get_user_asm_4(x, ptr, err) \ ({ \ __asm__ __volatile__ ( " sr %1,%1\n" \ " la 4,%2\n" \ " sacf 512\n" \ "0: l %0,0(4)\n" \ "1: sacf 0\n" \ ".section .fixup,\"ax\"\n" \ "2: lhi %1,%h3\n" \ " jg 1b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .align 8\n" \ " .quad 0b,2b\n" \ ".previous" \ : "=d" (x) , "=&d" (err) \ : "m" (*(const __u32*)(ptr)),"K" (-EFAULT) \ : "cc", "4" ); \ }) #define __get_user_asm_2(x, ptr, err) \ ({ \ __asm__ __volatile__ ( " sr %1,%1\n" \ " la 4,%2\n" \ " sacf 512\n" \ "0: lh %0,0(4)\n" \ "1: sacf 0\n" \ ".section .fixup,\"ax\"\n" \ "2: lhi %1,%h3\n" \ " jg 1b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .align 8\n" \ " .quad 0b,2b\n" \ ".previous" \ : "=d" (x) , "=&d" (err) \ : "m" (*(const __u16*)(ptr)),"K" (-EFAULT) \ : "cc", "4" ); \ }) #define __get_user_asm_1(x, ptr, err) \ ({ \ __asm__ __volatile__ ( " sr %1,%1\n" \ " la 4,%2\n" \ " sr %0,%0\n" \ " sacf 512\n" \ "0: ic %0,0(4)\n" \ "1: sacf 0\n" \ ".section .fixup,\"ax\"\n" \ "2: lhi %1,%h3\n" \ " jg 1b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .align 8\n" \ " .quad 0b,2b\n" \ ".previous" \ : "=d" (x) , "=&d" (err) \ : "m" (*(const __u8*)(ptr)),"K" (-EFAULT) \ : "cc", "4" ); \ }) #define __get_user(x, ptr) \ ({ \ int __gu_err; \ switch (sizeof(*(ptr))) { \ case 1: \ __get_user_asm_1(x,ptr,__gu_err); \ break; \ case 2: \ __get_user_asm_2(x,ptr,__gu_err); \ break; \ case 4: \ __get_user_asm_4(x,ptr,__gu_err); \ break; \ case 8: \ __get_user_asm_8(x,ptr,__gu_err); \ break; \ default: \ (x) = 0; \ __gu_err = __get_user_bad(); \ break; \ } \ __gu_err; \ }) #define get_user(x, ptr) \ ({ \ long __gu_err = -EFAULT; \ __typeof__(ptr) __gu_addr = (ptr); \ __typeof__(*(ptr)) __x; \ if (__access_ok((long)__gu_addr,sizeof(*(ptr)))) { \ __gu_err = 0; \ __get_user((__x), (__gu_addr)); \ (x) = __x; \ } \ else \ (x) = 0; \ __gu_err; \ }) extern int __get_user_bad(void); /* * access register are set up, that 4 points to secondary (user) , 2 to primary (kernel) */ extern long __copy_to_user_asm(const void *from, long n, void *to); #define __copy_to_user(to, from, n) \ ({ \ __copy_to_user_asm(from, n, to); \ }) #define copy_to_user(to, from, n) \ ({ \ long err = 0; \ __typeof__(n) __n = (n); \ if (__access_ok(to,__n)) { \ err = __copy_to_user_asm(from, __n, to); \ } \ else \ err = __n; \ err; \ }) extern long __copy_from_user_asm(void *to, long n, const void *from); #define __copy_from_user(to, from, n) \ ({ \ __copy_from_user_asm(to, n, from); \ }) #define copy_from_user(to, from, n) \ ({ \ long err = 0; \ __typeof__(n) __n = (n); \ if (__access_ok(from,__n)) { \ err = __copy_from_user_asm(to, __n, from); \ } \ else \ err = __n; \ err; \ }) /* * Copy a null terminated string from userspace. */ static inline long __strncpy_from_user(char *dst, const char *src, long count) { long len; __asm__ __volatile__ ( " slgr %0,%0\n" " lgr 2,%1\n" " lgr 4,%2\n" " slr 3,3\n" " sacf 512\n" "0: ic 3,0(%0,4)\n" "1: stc 3,0(%0,2)\n" " ltr 3,3\n" " jz 2f\n" " aghi %0,1\n" " cgr %0,%3\n" " jl 0b\n" "2: sacf 0\n" ".section .fixup,\"ax\"\n" "3: lghi %0,%h4\n" " jg 2b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 8\n" " .quad 0b,3b\n" " .quad 1b,3b\n" ".previous" : "=&a" (len) : "a" (dst), "d" (src), "d" (count), "K" (-EFAULT) : "cc", "2" ,"3", "4" ); return len; } static inline long strncpy_from_user(char *dst, const char *src, long count) { long res = -EFAULT; if (access_ok(VERIFY_READ, src, 1)) res = __strncpy_from_user(dst, src, count); return res; } /* * Return the size of a string (including the ending 0) * * Return 0 for error */ static inline unsigned long strnlen_user(const char * src, unsigned long n) { #if 0 __asm__ __volatile__ (" algr %0,%1\n" " slgr 0,0\n" " lgr 4,%1\n" " sacf 512\n" "0: srst %0,4\n" " jo 0b\n" " slgr %0,%1\n" " aghi %0,1\n" "1: sacf 0\n" ".section .fixup,\"ax\"\n" "2: slgr %0,%0\n" " jg 1b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 8\n" " .quad 0b,2b\n" ".previous" : "+&a" (n) : "d" (src) : "cc", "0", "4" ); #else __asm__ __volatile__ (" lgr 4,%1\n" " sacf 512\n" "0: cli 0(4),0x00\n" " la 4,1(4)\n" " je 1f\n" " brctg %0,0b\n" "1: lgr %0,4\n" " slgr %0,%1\n" "2: sacf 0\n" ".section .fixup,\"ax\"\n" "3: slgr %0,%0\n" " jg 2b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 8\n" " .quad 0b,3b\n" ".previous" : "+&a" (n) : "d" (src) : "cc", "4" ); #endif return n; } #define strlen_user(str) strnlen_user(str, ~0UL) /* * Zero Userspace */ extern long __clear_user_asm(void *to, long n); #define __clear_user(to, n) \ ({ \ __clear_user_asm(to, n); \ }) static inline unsigned long clear_user(void *to, unsigned long n) { if (access_ok(VERIFY_WRITE, to, n)) n = __clear_user(to, n); return n; } #endif /* _S390_UACCESS_H */