diff options
Diffstat (limited to 'include/asm-ppc64/uaccess.h')
| -rw-r--r-- | include/asm-ppc64/uaccess.h | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/include/asm-ppc64/uaccess.h b/include/asm-ppc64/uaccess.h new file mode 100644 index 000000000000..05b5943ab1ee --- /dev/null +++ b/include/asm-ppc64/uaccess.h @@ -0,0 +1,346 @@ +#ifndef _PPC64_UACCESS_H +#define _PPC64_UACCESS_H + +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef __ASSEMBLY__ +#include <linux/sched.h> +#include <linux/errno.h> +#include <asm/processor.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(0UL) +#define USER_DS MAKE_MM_SEG(0xf000000000000000UL) + +#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) + +/* + * Use the alpha trick for checking ranges: + * + * 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 + * - OR we are in kernel mode. + * + * We dont have to check for high bits in (addr+size) because the first + * two checks force the maximum result to be below the start of the + * kernel region. + */ +#define __access_ok(addr,size,segment) \ + (((segment).seg & (addr | size )) == 0) + +#define access_ok(type,addr,size) \ + __access_ok(((__force unsigned long)(addr)),(size),get_fs()) + +/* this function will go away soon - use access_ok() instead */ +static inline int __deprecated verify_area(int type, const void __user *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. + * + * 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"...) + */ +#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))) + +#define __get_user_unaligned __get_user +#define __put_user_unaligned __put_user + +extern long __put_user_bad(void); + +#define __put_user_nocheck(x,ptr,size) \ +({ \ + long __pu_err; \ + might_sleep(); \ + __chk_user_ptr(ptr); \ + __put_user_size((x),(ptr),(size),__pu_err,-EFAULT); \ + __pu_err; \ +}) + +#define __put_user_check(x,ptr,size) \ +({ \ + long __pu_err = -EFAULT; \ + void __user *__pu_addr = (ptr); \ + might_sleep(); \ + if (access_ok(VERIFY_WRITE,__pu_addr,size)) \ + __put_user_size((x),__pu_addr,(size),__pu_err,-EFAULT); \ + __pu_err; \ +}) + +#define __put_user_size(x,ptr,size,retval,errret) \ +do { \ + retval = 0; \ + switch (size) { \ + case 1: __put_user_asm(x,ptr,retval,"stb",errret); break; \ + case 2: __put_user_asm(x,ptr,retval,"sth",errret); break; \ + case 4: __put_user_asm(x,ptr,retval,"stw",errret); break; \ + case 8: __put_user_asm(x,ptr,retval,"std",errret); break; \ + default: __put_user_bad(); \ + } \ +} while (0) + +/* + * 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, errret) \ + __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" \ + " .align 3\n" \ + " .llong 1b,3b\n" \ + ".previous" \ + : "=r"(err) \ + : "r"(x), "b"(addr), "i"(errret), "0"(err)) + + +#define __get_user_nocheck(x,ptr,size) \ +({ \ + long __gu_err, __gu_val; \ + might_sleep(); \ + __get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\ + (x) = (__typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +#define __get_user_check(x,ptr,size) \ +({ \ + long __gu_err = -EFAULT, __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,-EFAULT);\ + (x) = (__typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +extern long __get_user_bad(void); + +#define __get_user_size(x,ptr,size,retval,errret) \ +do { \ + retval = 0; \ + __chk_user_ptr(ptr); \ + switch (size) { \ + case 1: __get_user_asm(x,ptr,retval,"lbz",errret); break; \ + case 2: __get_user_asm(x,ptr,retval,"lhz",errret); break; \ + case 4: __get_user_asm(x,ptr,retval,"lwz",errret); break; \ + case 8: __get_user_asm(x,ptr,retval,"ld",errret); break; \ + default: (x) = __get_user_bad(); \ + } \ +} while (0) + +#define __get_user_asm(x, addr, err, op, errret) \ + __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" \ + " .align 3\n" \ + " .llong 1b,3b\n" \ + ".previous" \ + : "=r"(err), "=r"(x) \ + : "b"(addr), "i"(errret), "0"(err)) + +/* more complex routines */ + +extern unsigned long __copy_tofrom_user(void __user *to, const void __user *from, + unsigned long size); + +static inline unsigned long +__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) +{ + if (__builtin_constant_p(n)) { + unsigned long ret; + + switch (n) { + case 1: + __get_user_size(*(u8 *)to, from, 1, ret, 1); + return ret; + case 2: + __get_user_size(*(u16 *)to, from, 2, ret, 2); + return ret; + case 4: + __get_user_size(*(u32 *)to, from, 4, ret, 4); + return ret; + case 8: + __get_user_size(*(u64 *)to, from, 8, ret, 8); + return ret; + } + } + return __copy_tofrom_user((__force void __user *) to, from, n); +} + +static inline unsigned long +__copy_from_user(void *to, const void __user *from, unsigned long n) +{ + might_sleep(); + return __copy_from_user_inatomic(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)) { + unsigned long ret; + + switch (n) { + case 1: + __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1); + return ret; + case 2: + __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2); + return ret; + case 4: + __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4); + return ret; + case 8: + __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret, 8); + return ret; + } + } + return __copy_tofrom_user(to, (__force const void __user *) from, n); +} + +static inline unsigned long +__copy_to_user(void __user *to, const void *from, unsigned long n) +{ + might_sleep(); + return __copy_to_user_inatomic(to, from, n); +} + +#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); + +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))) + size = __clear_user(addr, size); + 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); + +/* + * 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. + */ +static inline int strnlen_user(const char __user *str, long len) +{ + might_sleep(); + if (likely(access_ok(VERIFY_READ, str, 1))) + return __strnlen_user(str, len); + return 0; +} + +#define strlen_user(str) strnlen_user((str), 0x7ffffffe) + +#endif /* __ASSEMBLY__ */ + +#endif /* _PPC64_UACCESS_H */ |