#ifndef _ARCH_POWERPC_UACCESS_H #define _ARCH_POWERPC_UACCESS_H #ifdef __KERNEL__ #ifndef __ASSEMBLY__ #include <linux/sched.h> #include <linux/errno.h> #include <asm/processor.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. * * The fs/ds values are now the highest legal address in the "segment". * This simplifies the checking in the routines below. */ #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) #define KERNEL_DS MAKE_MM_SEG(~0UL) #ifdef __powerpc64__ /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ #define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1) #else #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) #endif #define get_ds() (KERNEL_DS) #define get_fs() (current->thread.fs) #define set_fs(val) (current->thread.fs = (val)) #define segment_eq(a, b) ((a).seg == (b).seg) #ifdef __powerpc64__ /* * This check is sufficient because there is a large enough * gap between user addresses and the kernel addresses */ #define __access_ok(addr, size, segment) \ (((addr) <= (segment).seg) && ((size) <= (segment).seg)) #else #define __access_ok(addr, size, segment) \ (((addr) <= (segment).seg) && \ (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) #endif #define access_ok(type, addr, size) \ (__chk_user_ptr(addr), \ __access_ok((__force unsigned long)(addr), (size), get_fs())) /* * 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; unsigned long 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 the * PowerPC, we can just do these as direct assignments. (Of course, the * exception handling means that it's no longer "just"...) * * The "user64" versions of the user access functions are versions that * allow access of 64-bit data. The "get_user" functions do not * properly handle 64-bit data because the value gets down cast to a long. * The "put_user" functions already handle 64-bit data properly but we add * "user64" versions for completeness */ #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))) #ifndef __powerpc64__ #define __get_user64(x, ptr) \ __get_user64_nocheck((x), (ptr), sizeof(*(ptr))) #define __put_user64(x, ptr) __put_user(x, ptr) #endif #define __get_user_unaligned __get_user #define __put_user_unaligned __put_user extern long __put_user_bad(void); /* * We don't tell gcc that we are accessing memory, but this is OK * because we do not write to any memory gcc knows about, so there * are no aliasing issues. */ #define __put_user_asm(x, addr, err, op) \ __asm__ __volatile__( \ "1: " op " %1,0(%2) # put_user\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ "3: li %0,%3\n" \ " b 2b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign %5\n" \ PPC_LONG "1b,3b\n" \ ".previous" \ : "=r" (err) \ : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\ "i"(sizeof(unsigned long))) #ifdef __powerpc64__ #define __put_user_asm2(x, ptr, retval) \ __put_user_asm(x, ptr, retval, "std") #else /* __powerpc64__ */ #define __put_user_asm2(x, addr, err) \ __asm__ __volatile__( \ "1: stw %1,0(%2)\n" \ "2: stw %1+1,4(%2)\n" \ "3:\n" \ ".section .fixup,\"ax\"\n" \ "4: li %0,%3\n" \ " b 3b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign %5\n" \ PPC_LONG "1b,4b\n" \ PPC_LONG "2b,4b\n" \ ".previous" \ : "=r" (err) \ : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\ "i"(sizeof(unsigned long))) #endif /* __powerpc64__ */ #define __put_user_size(x, ptr, size, retval) \ do { \ retval = 0; \ switch (size) { \ case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ case 8: __put_user_asm2(x, ptr, retval); break; \ default: __put_user_bad(); \ } \ } while (0) #define __put_user_nocheck(x, ptr, size) \ ({ \ long __pu_err; \ __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ if (!is_kernel_addr((unsigned long)__pu_addr)) \ might_sleep(); \ __chk_user_ptr(ptr); \ __put_user_size((x), __pu_addr, (size), __pu_err); \ __pu_err; \ }) #define __put_user_check(x, ptr, size) \ ({ \ long __pu_err = -EFAULT; \ __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ might_sleep(); \ if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ __put_user_size((x), __pu_addr, (size), __pu_err); \ __pu_err; \ }) extern long __get_user_bad(void); #define __get_user_asm(x, addr, err, op) \ __asm__ __volatile__( \ "1: "op" %1,0(%2) # get_user\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ "3: li %0,%3\n" \ " li %1,0\n" \ " b 2b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign %5\n" \ PPC_LONG "1b,3b\n" \ ".previous" \ : "=r" (err), "=r" (x) \ : "b" (addr), "i" (-EFAULT), "0" (err), \ "i"(sizeof(unsigned long))) #ifdef __powerpc64__ #define __get_user_asm2(x, addr, err) \ __get_user_asm(x, addr, err, "ld") #else /* __powerpc64__ */ #define __get_user_asm2(x, addr, err) \ __asm__ __volatile__( \ "1: lwz %1,0(%2)\n" \ "2: lwz %1+1,4(%2)\n" \ "3:\n" \ ".section .fixup,\"ax\"\n" \ "4: li %0,%3\n" \ " li %1,0\n" \ " li %1+1,0\n" \ " b 3b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .balign %5\n" \ PPC_LONG "1b,4b\n" \ PPC_LONG "2b,4b\n" \ ".previous" \ : "=r" (err), "=&r" (x) \ : "b" (addr), "i" (-EFAULT), "0" (err), \ "i"(sizeof(unsigned long))) #endif /* __powerpc64__ */ #define __get_user_size(x, ptr, size, retval) \ do { \ retval = 0; \ __chk_user_ptr(ptr); \ if (size > sizeof(x)) \ (x) = __get_user_bad(); \ switch (size) { \ case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ case 8: __get_user_asm2(x, ptr, retval); break; \ default: (x) = __get_user_bad(); \ } \ } while (0) #define __get_user_nocheck(x, ptr, size) \ ({ \ long __gu_err; \ unsigned long __gu_val; \ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ __chk_user_ptr(ptr); \ if (!is_kernel_addr((unsigned long)__gu_addr)) \ might_sleep(); \ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ (x) = (__typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) #ifndef __powerpc64__ #define __get_user64_nocheck(x, ptr, size) \ ({ \ long __gu_err; \ long long __gu_val; \ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ __chk_user_ptr(ptr); \ if (!is_kernel_addr((unsigned long)__gu_addr)) \ might_sleep(); \ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ (x) = (__typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) #endif /* __powerpc64__ */ #define __get_user_check(x, ptr, size) \ ({ \ long __gu_err = -EFAULT; \ unsigned long __gu_val = 0; \ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ might_sleep(); \ 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; \ }) /* more complex routines */ extern unsigned long __copy_tofrom_user(void __user *to, const void __user *from, unsigned long size); #ifndef __powerpc64__ extern inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n) { unsigned long over; if (access_ok(VERIFY_READ, from, n)) return __copy_tofrom_user((__force void __user *)to, from, n); if ((unsigned long)from < TASK_SIZE) { over = (unsigned long)from + n - TASK_SIZE; return __copy_tofrom_user((__force void __user *)to, from, n - over) + over; } return n; } extern inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n) { unsigned long over; if (access_ok(VERIFY_WRITE, to, n)) return __copy_tofrom_user(to, (__force void __user *)from, n); if ((unsigned long)to < TASK_SIZE) { over = (unsigned long)to + n - TASK_SIZE; return __copy_tofrom_user(to, (__force void __user *)from, n - over) + over; } return n; } #else /* __powerpc64__ */ #define __copy_in_user(to, from, size) \ __copy_tofrom_user((to), (from), (size)) extern unsigned long copy_from_user(void *to, const void __user *from, unsigned long n); extern unsigned long copy_to_user(void __user *to, const void *from, unsigned long n); extern unsigned long copy_in_user(void __user *to, const void __user *from, unsigned long n); #endif /* __powerpc64__ */ static inline unsigned long __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) { if (__builtin_constant_p(n) && (n <= 8)) { unsigned long ret; switch (n) { case 1: __get_user_size(*(u8 *)to, from, 1, ret); break; case 2: __get_user_size(*(u16 *)to, from, 2, ret); break; case 4: __get_user_size(*(u32 *)to, from, 4, ret); break; case 8: __get_user_size(*(u64 *)to, from, 8, ret); break; } if (ret == 0) return 0; } return __copy_tofrom_user((__force void __user *)to, from, n); } static inline unsigned long __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) { if (__builtin_constant_p(n) && (n <= 8)) { unsigned long ret; switch (n) { case 1: __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); break; case 2: __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); break; case 4: __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); break; case 8: __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); break; } if (ret == 0) return 0; } return __copy_tofrom_user(to, (__force const void __user *)from, n); } static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long size) { might_sleep(); return __copy_from_user_inatomic(to, from, size); } static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long size) { might_sleep(); return __copy_to_user_inatomic(to, from, size); } extern unsigned long __clear_user(void __user *addr, unsigned long size); static inline unsigned long clear_user(void __user *addr, unsigned long size) { might_sleep(); if (likely(access_ok(VERIFY_WRITE, addr, size))) return __clear_user(addr, size); if ((unsigned long)addr < TASK_SIZE) { unsigned long over = (unsigned long)addr + size - TASK_SIZE; return __clear_user(addr, size - over) + over; } return size; } extern int __strncpy_from_user(char *dst, const char __user *src, long count); static inline long strncpy_from_user(char *dst, const char __user *src, long count) { might_sleep(); if (likely(access_ok(VERIFY_READ, src, 1))) return __strncpy_from_user(dst, src, count); return -EFAULT; } /* * Return the size of a string (including the ending 0) * * Return 0 for error */ extern int __strnlen_user(const char __user *str, long len, unsigned long top); /* * Returns the length of the string at str (including the null byte), * or 0 if we hit a page we can't access, * or something > len if we didn't find a null byte. * * The `top' parameter to __strnlen_user is to make sure that * we can never overflow from the user area into kernel space. */ static inline int strnlen_user(const char __user *str, long len) { unsigned long top = current->thread.fs.seg; if ((unsigned long)str > top) return 0; return __strnlen_user(str, len, top); } #define strlen_user(str) strnlen_user((str), 0x7ffffffe) #endif /* __ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _ARCH_POWERPC_UACCESS_H */