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Diffstat (limited to 'include/asm-powerpc/uaccess.h')
| -rw-r--r-- | include/asm-powerpc/uaccess.h | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/include/asm-powerpc/uaccess.h b/include/asm-powerpc/uaccess.h new file mode 100644 index 00000000000..33af730f0d1 --- /dev/null +++ b/include/asm-powerpc/uaccess.h @@ -0,0 +1,468 @@ +#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> + +#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); + +#ifdef __powerpc64__ +#define __EX_TABLE_ALIGN "3" +#define __EX_TABLE_TYPE "llong" +#else +#define __EX_TABLE_ALIGN "2" +#define __EX_TABLE_TYPE "long" +#endif + +/* + * 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" \ + " .align " __EX_TABLE_ALIGN "\n" \ + " ."__EX_TABLE_TYPE" 1b,3b\n" \ + ".previous" \ + : "=r" (err) \ + : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) + +#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" \ + " .align " __EX_TABLE_ALIGN "\n" \ + " ." __EX_TABLE_TYPE " 1b,4b\n" \ + " ." __EX_TABLE_TYPE " 2b,4b\n" \ + ".previous" \ + : "=r" (err) \ + : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) +#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; \ + might_sleep(); \ + __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); \ + 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" \ + " .align "__EX_TABLE_ALIGN "\n" \ + " ." __EX_TABLE_TYPE " 1b,3b\n" \ + ".previous" \ + : "=r" (err), "=r" (x) \ + : "b" (addr), "i" (-EFAULT), "0" (err)) + +#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" \ + " .align " __EX_TABLE_ALIGN "\n" \ + " ." __EX_TABLE_TYPE " 1b,4b\n" \ + " ." __EX_TABLE_TYPE " 2b,4b\n" \ + ".previous" \ + : "=r" (err), "=&r" (x) \ + : "b" (addr), "i" (-EFAULT), "0" (err)) +#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; \ + __chk_user_ptr(ptr); \ + might_sleep(); \ + __get_user_size(__gu_val, (ptr), (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; \ + __chk_user_ptr(ptr); \ + might_sleep(); \ + __get_user_size(__gu_val, (ptr), (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 */ |