diff options
Diffstat (limited to 'include/asm-ppc/uaccess.h')
| -rw-r--r-- | include/asm-ppc/uaccess.h | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/include/asm-ppc/uaccess.h b/include/asm-ppc/uaccess.h new file mode 100644 index 000000000000..b044ae03ac56 --- /dev/null +++ b/include/asm-ppc/uaccess.h @@ -0,0 +1,400 @@ +#ifdef __KERNEL__ +#ifndef _PPC_UACCESS_H +#define _PPC_UACCESS_H + +#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. + * + * The fs/ds values are now the highest legal address in the "segment". + * This simplifies the checking in the routines below. + */ + +#define KERNEL_DS ((mm_segment_t) { ~0UL }) +#define USER_DS ((mm_segment_t) { TASK_SIZE - 1 }) + +#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) + +#define __access_ok(addr,size) \ + ((addr) <= current->thread.fs.seg \ + && ((size) == 0 || (size) - 1 <= current->thread.fs.seg - (addr))) + +#define access_ok(type, addr, size) \ + (__chk_user_ptr(addr),__access_ok((unsigned long)(addr),(size))) + +/* this function will go away soon - use access_ok() instead */ +extern 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; +}; + +/* + * 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 get_user64(x,ptr) \ + __get_user64_check((x),(ptr),sizeof(*(ptr))) +#define put_user(x,ptr) \ + __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) +#define put_user64(x,ptr) put_user(x,ptr) + +#define __get_user(x,ptr) \ + __get_user_nocheck((x),(ptr),sizeof(*(ptr))) +#define __get_user64(x,ptr) \ + __get_user64_nocheck((x),(ptr),sizeof(*(ptr))) +#define __put_user(x,ptr) \ + __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) +#define __put_user64(x,ptr) __put_user(x,ptr) + +extern long __put_user_bad(void); + +#define __put_user_nocheck(x,ptr,size) \ +({ \ + long __pu_err; \ + __chk_user_ptr(ptr); \ + __put_user_size((x),(ptr),(size),__pu_err); \ + __pu_err; \ +}) + +#define __put_user_check(x,ptr,size) \ +({ \ + long __pu_err = -EFAULT; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + if (access_ok(VERIFY_WRITE,__pu_addr,size)) \ + __put_user_size((x),__pu_addr,(size),__pu_err); \ + __pu_err; \ +}) + +#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) + +/* + * 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)\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: li %0,%3\n" \ + " b 2b\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,3b\n" \ + ".previous" \ + : "=r" (err) \ + : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) + +#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" \ + " .align 2\n" \ + " .long 1b,4b\n" \ + " .long 2b,4b\n" \ + ".previous" \ + : "=r" (err) \ + : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) + +#define __get_user_nocheck(x, ptr, size) \ +({ \ + long __gu_err; \ + unsigned long __gu_val; \ + __chk_user_ptr(ptr); \ + __get_user_size(__gu_val, (ptr), (size), __gu_err); \ + (x) = (__typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +#define __get_user64_nocheck(x, ptr, size) \ +({ \ + long __gu_err; \ + long long __gu_val; \ + __chk_user_ptr(ptr); \ + __get_user_size64(__gu_val, (ptr), (size), __gu_err); \ + (x) = (__typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +#define __get_user_check(x, ptr, size) \ +({ \ + long __gu_err = -EFAULT; \ + unsigned long __gu_val = 0; \ + const __typeof__(*(ptr)) __user *__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; \ +}) + +#define __get_user64_check(x, ptr, size) \ +({ \ + long __gu_err = -EFAULT; \ + long long __gu_val = 0; \ + const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ + if (access_ok(VERIFY_READ, __gu_addr, (size))) \ + __get_user_size64(__gu_val, __gu_addr, (size), __gu_err); \ + (x) = (__typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +extern long __get_user_bad(void); + +#define __get_user_size(x, ptr, size, retval) \ +do { \ + retval = 0; \ + 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; \ + default: \ + x = __get_user_bad(); \ + } \ +} while (0) + +#define __get_user_size64(x, ptr, size, retval) \ +do { \ + retval = 0; \ + 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_asm(x, addr, err, op) \ + __asm__ __volatile__( \ + "1: "op" %1,0(%2)\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 2\n" \ + " .long 1b,3b\n" \ + ".previous" \ + : "=r"(err), "=r"(x) \ + : "b"(addr), "i"(-EFAULT), "0"(err)) + +#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" \ + " .align 2\n" \ + " .long 1b,4b\n" \ + " .long 2b,4b\n" \ + ".previous" \ + : "=r"(err), "=&r"(x) \ + : "b"(addr), "i"(-EFAULT), "0"(err)) + +/* more complex routines */ + +extern int __copy_tofrom_user(void __user *to, const void __user *from, + unsigned long size); + +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; +} + +static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long size) +{ + return __copy_tofrom_user((__force void __user *)to, from, size); +} + +static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long size) +{ + return __copy_tofrom_user(to, (__force void __user *)from, size); +} + +#define __copy_to_user_inatomic __copy_to_user +#define __copy_from_user_inatomic __copy_from_user + +extern unsigned long __clear_user(void __user *addr, unsigned long size); + +extern inline unsigned long +clear_user(void __user *addr, unsigned long size) +{ + if (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); + +extern inline long +strncpy_from_user(char *dst, const char __user *src, long count) +{ + if (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. + */ +extern __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 /* _PPC_UACCESS_H */ +#endif /* __KERNEL__ */ |