#ifndef __ALPHA_UACCESS_H #define __ALPHA_UACCESS_H #include <linux/errno.h> #include <linux/sched.h> /* * 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. * * Or at least it did once upon a time. Nowadays it is a mask that * defines which bits of the address space are off limits. This is a * wee bit faster than the above. * * For historical reasons, these macros are grossly misnamed. */ #define KERNEL_DS ((mm_segment_t) { 0UL }) #define USER_DS ((mm_segment_t) { -0x40000000000UL }) #define VERIFY_READ 0 #define VERIFY_WRITE 1 #define get_fs() (current_thread_info()->addr_limit) #define get_ds() (KERNEL_DS) #define set_fs(x) (current_thread_info()->addr_limit = (x)) #define segment_eq(a,b) ((a).seg == (b).seg) /* * Is a address valid? This does a straightforward calculation rather * than tests. * * Address valid if: * - "addr" doesn't have any high-bits set * - AND "size" doesn't have any high-bits set * - AND "addr+size" doesn't have any high-bits set * - OR we are in kernel mode. */ #define __access_ok(addr,size,segment) \ (((segment).seg & (addr | size | (addr+size))) == 0) #define access_ok(type,addr,size) \ ({ \ __chk_user_ptr(addr); \ __access_ok(((unsigned long)(addr)),(size),get_fs()); \ }) /* * These are the main single-value transfer routines. They automatically * use the right size if we just have the right pointer type. * * As the alpha uses the same address space for kernel and user * data, we can just do these as direct assignments. (Of course, the * exception handling means that it's no longer "just"...) * * Careful to not * (a) re-use the arguments for side effects (sizeof/typeof is ok) * (b) require any knowledge of processes at this stage */ #define put_user(x,ptr) \ __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)),get_fs()) #define get_user(x,ptr) \ __get_user_check((x),(ptr),sizeof(*(ptr)),get_fs()) /* * The "__xxx" versions do not do address space checking, useful when * doing multiple accesses to the same area (the programmer has to do the * checks by hand with "access_ok()") */ #define __put_user(x,ptr) \ __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) #define __get_user(x,ptr) \ __get_user_nocheck((x),(ptr),sizeof(*(ptr))) /* * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to * encode the bits we need for resolving the exception. See the * more extensive comments with fixup_inline_exception below for * more information. */ extern void __get_user_unknown(void); #define __get_user_nocheck(x,ptr,size) \ ({ \ long __gu_err = 0; \ unsigned long __gu_val; \ __chk_user_ptr(ptr); \ switch (size) { \ case 1: __get_user_8(ptr); break; \ case 2: __get_user_16(ptr); break; \ case 4: __get_user_32(ptr); break; \ case 8: __get_user_64(ptr); break; \ default: __get_user_unknown(); break; \ } \ (x) = (__typeof__(*(ptr))) __gu_val; \ __gu_err; \ }) #define __get_user_check(x,ptr,size,segment) \ ({ \ long __gu_err = -EFAULT; \ unsigned long __gu_val = 0; \ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ if (__access_ok((unsigned long)__gu_addr,size,segment)) { \ __gu_err = 0; \ switch (size) { \ case 1: __get_user_8(__gu_addr); break; \ case 2: __get_user_16(__gu_addr); break; \ case 4: __get_user_32(__gu_addr); break; \ case 8: __get_user_64(__gu_addr); break; \ default: __get_user_unknown(); break; \ } \ } \ (x) = (__typeof__(*(ptr))) __gu_val; \ __gu_err; \ }) struct __large_struct { unsigned long buf[100]; }; #define __m(x) (*(struct __large_struct __user *)(x)) #define __get_user_64(addr) \ __asm__("1: ldq %0,%2\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda %0, 2b-1b(%1)\n" \ ".previous" \ : "=r"(__gu_val), "=r"(__gu_err) \ : "m"(__m(addr)), "1"(__gu_err)) #define __get_user_32(addr) \ __asm__("1: ldl %0,%2\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda %0, 2b-1b(%1)\n" \ ".previous" \ : "=r"(__gu_val), "=r"(__gu_err) \ : "m"(__m(addr)), "1"(__gu_err)) #ifdef __alpha_bwx__ /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ #define __get_user_16(addr) \ __asm__("1: ldwu %0,%2\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda %0, 2b-1b(%1)\n" \ ".previous" \ : "=r"(__gu_val), "=r"(__gu_err) \ : "m"(__m(addr)), "1"(__gu_err)) #define __get_user_8(addr) \ __asm__("1: ldbu %0,%2\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda %0, 2b-1b(%1)\n" \ ".previous" \ : "=r"(__gu_val), "=r"(__gu_err) \ : "m"(__m(addr)), "1"(__gu_err)) #else /* Unfortunately, we can't get an unaligned access trap for the sub-word load, so we have to do a general unaligned operation. */ #define __get_user_16(addr) \ { \ long __gu_tmp; \ __asm__("1: ldq_u %0,0(%3)\n" \ "2: ldq_u %1,1(%3)\n" \ " extwl %0,%3,%0\n" \ " extwh %1,%3,%1\n" \ " or %0,%1,%0\n" \ "3:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda %0, 3b-1b(%2)\n" \ " .long 2b - .\n" \ " lda %0, 3b-2b(%2)\n" \ ".previous" \ : "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \ : "r"(addr), "2"(__gu_err)); \ } #define __get_user_8(addr) \ __asm__("1: ldq_u %0,0(%2)\n" \ " extbl %0,%2,%0\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda %0, 2b-1b(%1)\n" \ ".previous" \ : "=&r"(__gu_val), "=r"(__gu_err) \ : "r"(addr), "1"(__gu_err)) #endif extern void __put_user_unknown(void); #define __put_user_nocheck(x,ptr,size) \ ({ \ long __pu_err = 0; \ __chk_user_ptr(ptr); \ switch (size) { \ case 1: __put_user_8(x,ptr); break; \ case 2: __put_user_16(x,ptr); break; \ case 4: __put_user_32(x,ptr); break; \ case 8: __put_user_64(x,ptr); break; \ default: __put_user_unknown(); break; \ } \ __pu_err; \ }) #define __put_user_check(x,ptr,size,segment) \ ({ \ long __pu_err = -EFAULT; \ __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ if (__access_ok((unsigned long)__pu_addr,size,segment)) { \ __pu_err = 0; \ switch (size) { \ case 1: __put_user_8(x,__pu_addr); break; \ case 2: __put_user_16(x,__pu_addr); break; \ case 4: __put_user_32(x,__pu_addr); break; \ case 8: __put_user_64(x,__pu_addr); break; \ default: __put_user_unknown(); break; \ } \ } \ __pu_err; \ }) /* * The "__put_user_xx()" macros tell gcc they read from memory * instead of writing: this is because they do not write to * any memory gcc knows about, so there are no aliasing issues */ #define __put_user_64(x,addr) \ __asm__ __volatile__("1: stq %r2,%1\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda $31,2b-1b(%0)\n" \ ".previous" \ : "=r"(__pu_err) \ : "m" (__m(addr)), "rJ" (x), "0"(__pu_err)) #define __put_user_32(x,addr) \ __asm__ __volatile__("1: stl %r2,%1\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda $31,2b-1b(%0)\n" \ ".previous" \ : "=r"(__pu_err) \ : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) #ifdef __alpha_bwx__ /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ #define __put_user_16(x,addr) \ __asm__ __volatile__("1: stw %r2,%1\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda $31,2b-1b(%0)\n" \ ".previous" \ : "=r"(__pu_err) \ : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) #define __put_user_8(x,addr) \ __asm__ __volatile__("1: stb %r2,%1\n" \ "2:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda $31,2b-1b(%0)\n" \ ".previous" \ : "=r"(__pu_err) \ : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) #else /* Unfortunately, we can't get an unaligned access trap for the sub-word write, so we have to do a general unaligned operation. */ #define __put_user_16(x,addr) \ { \ long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \ __asm__ __volatile__( \ "1: ldq_u %2,1(%5)\n" \ "2: ldq_u %1,0(%5)\n" \ " inswh %6,%5,%4\n" \ " inswl %6,%5,%3\n" \ " mskwh %2,%5,%2\n" \ " mskwl %1,%5,%1\n" \ " or %2,%4,%2\n" \ " or %1,%3,%1\n" \ "3: stq_u %2,1(%5)\n" \ "4: stq_u %1,0(%5)\n" \ "5:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda $31, 5b-1b(%0)\n" \ " .long 2b - .\n" \ " lda $31, 5b-2b(%0)\n" \ " .long 3b - .\n" \ " lda $31, 5b-3b(%0)\n" \ " .long 4b - .\n" \ " lda $31, 5b-4b(%0)\n" \ ".previous" \ : "=r"(__pu_err), "=&r"(__pu_tmp1), \ "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \ "=&r"(__pu_tmp4) \ : "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \ } #define __put_user_8(x,addr) \ { \ long __pu_tmp1, __pu_tmp2; \ __asm__ __volatile__( \ "1: ldq_u %1,0(%4)\n" \ " insbl %3,%4,%2\n" \ " mskbl %1,%4,%1\n" \ " or %1,%2,%1\n" \ "2: stq_u %1,0(%4)\n" \ "3:\n" \ ".section __ex_table,\"a\"\n" \ " .long 1b - .\n" \ " lda $31, 3b-1b(%0)\n" \ " .long 2b - .\n" \ " lda $31, 3b-2b(%0)\n" \ ".previous" \ : "=r"(__pu_err), \ "=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \ : "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \ } #endif /* * Complex access routines */ /* This little bit of silliness is to get the GP loaded for a function that ordinarily wouldn't. Otherwise we could have it done by the macro directly, which can be optimized the linker. */ #ifdef MODULE #define __module_address(sym) "r"(sym), #define __module_call(ra, arg, sym) "jsr $" #ra ",(%" #arg ")," #sym #else #define __module_address(sym) #define __module_call(ra, arg, sym) "bsr $" #ra "," #sym " !samegp" #endif extern void __copy_user(void); extern inline long __copy_tofrom_user_nocheck(void *to, const void *from, long len) { register void * __cu_to __asm__("$6") = to; register const void * __cu_from __asm__("$7") = from; register long __cu_len __asm__("$0") = len; __asm__ __volatile__( __module_call(28, 3, __copy_user) : "=r" (__cu_len), "=r" (__cu_from), "=r" (__cu_to) : __module_address(__copy_user) "0" (__cu_len), "1" (__cu_from), "2" (__cu_to) : "$1","$2","$3","$4","$5","$28","memory"); return __cu_len; } extern inline long __copy_tofrom_user(void *to, const void *from, long len, const void __user *validate) { if (__access_ok((unsigned long)validate, len, get_fs())) len = __copy_tofrom_user_nocheck(to, from, len); return len; } #define __copy_to_user(to,from,n) \ ({ \ __chk_user_ptr(to); \ __copy_tofrom_user_nocheck((__force void *)(to),(from),(n)); \ }) #define __copy_from_user(to,from,n) \ ({ \ __chk_user_ptr(from); \ __copy_tofrom_user_nocheck((to),(__force void *)(from),(n)); \ }) #define __copy_to_user_inatomic __copy_to_user #define __copy_from_user_inatomic __copy_from_user extern inline long copy_to_user(void __user *to, const void *from, long n) { return __copy_tofrom_user((__force void *)to, from, n, to); } extern inline long copy_from_user(void *to, const void __user *from, long n) { return __copy_tofrom_user(to, (__force void *)from, n, from); } extern void __do_clear_user(void); extern inline long __clear_user(void __user *to, long len) { register void __user * __cl_to __asm__("$6") = to; register long __cl_len __asm__("$0") = len; __asm__ __volatile__( __module_call(28, 2, __do_clear_user) : "=r"(__cl_len), "=r"(__cl_to) : __module_address(__do_clear_user) "0"(__cl_len), "1"(__cl_to) : "$1","$2","$3","$4","$5","$28","memory"); return __cl_len; } extern inline long clear_user(void __user *to, long len) { if (__access_ok((unsigned long)to, len, get_fs())) len = __clear_user(to, len); return len; } #undef __module_address #undef __module_call /* Returns: -EFAULT if exception before terminator, N if the entire buffer filled, else strlen. */ extern long __strncpy_from_user(char *__to, const char __user *__from, long __to_len); extern inline long strncpy_from_user(char *to, const char __user *from, long n) { long ret = -EFAULT; if (__access_ok((unsigned long)from, 0, get_fs())) ret = __strncpy_from_user(to, from, n); return ret; } /* Returns: 0 if bad, string length+1 (memory size) of string if ok */ extern long __strlen_user(const char __user *); extern inline long strlen_user(const char __user *str) { return access_ok(VERIFY_READ,str,0) ? __strlen_user(str) : 0; } /* Returns: 0 if exception before NUL or reaching the supplied limit (N), * a value greater than N if the limit would be exceeded, else strlen. */ extern long __strnlen_user(const char __user *, long); extern inline long strnlen_user(const char __user *str, long n) { return access_ok(VERIFY_READ,str,0) ? __strnlen_user(str, n) : 0; } /* * About the exception table: * * - insn is a 32-bit pc-relative offset from the faulting insn. * - nextinsn is a 16-bit offset off of the faulting instruction * (not off of the *next* instruction as branches are). * - errreg is the register in which to place -EFAULT. * - valreg is the final target register for the load sequence * and will be zeroed. * * Either errreg or valreg may be $31, in which case nothing happens. * * The exception fixup information "just so happens" to be arranged * as in a MEM format instruction. This lets us emit our three * values like so: * * lda valreg, nextinsn(errreg) * */ struct exception_table_entry { signed int insn; union exception_fixup { unsigned unit; struct { signed int nextinsn : 16; unsigned int errreg : 5; unsigned int valreg : 5; } bits; } fixup; }; /* Returns the new pc */ #define fixup_exception(map_reg, fixup, pc) \ ({ \ if ((fixup)->fixup.bits.valreg != 31) \ map_reg((fixup)->fixup.bits.valreg) = 0; \ if ((fixup)->fixup.bits.errreg != 31) \ map_reg((fixup)->fixup.bits.errreg) = -EFAULT; \ (pc) + (fixup)->fixup.bits.nextinsn; \ }) #endif /* __ALPHA_UACCESS_H */