| /* |
| * uaccess.h: User space memore access functions. |
| * |
| * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) |
| * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) |
| */ |
| #ifndef _ASM_UACCESS_H |
| #define _ASM_UACCESS_H |
| |
| #include <linux/compiler.h> |
| #include <linux/string.h> |
| |
| #include <asm/processor.h> |
| |
| #define ARCH_HAS_SORT_EXTABLE |
| #define ARCH_HAS_SEARCH_EXTABLE |
| |
| /* Sparc is not segmented, however we need to be able to fool access_ok() |
| * when doing system calls from kernel mode legitimately. |
| * |
| * "For historical reasons, these macros are grossly misnamed." -Linus |
| */ |
| |
| #define KERNEL_DS ((mm_segment_t) { 0 }) |
| #define USER_DS ((mm_segment_t) { -1 }) |
| |
| #define get_ds() (KERNEL_DS) |
| #define get_fs() (current->thread.current_ds) |
| #define set_fs(val) ((current->thread.current_ds) = (val)) |
| |
| #define segment_eq(a, b) ((a).seg == (b).seg) |
| |
| /* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test |
| * can be fairly lightweight. |
| * No one can read/write anything from userland in the kernel space by setting |
| * large size and address near to PAGE_OFFSET - a fault will break his intentions. |
| */ |
| #define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; }) |
| #define __kernel_ok (uaccess_kernel()) |
| #define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size))) |
| #define access_ok(type, addr, size) \ |
| ({ (void)(type); __access_ok((unsigned long)(addr), size); }) |
| |
| /* |
| * 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. |
| * |
| * There is a special way how to put a range of potentially faulting |
| * insns (like twenty ldd/std's with now intervening other instructions) |
| * You specify address of first in insn and 0 in fixup and in the next |
| * exception_table_entry you specify last potentially faulting insn + 1 |
| * and in fixup the routine which should handle the fault. |
| * That fixup code will get |
| * (faulting_insn_address - first_insn_in_the_range_address)/4 |
| * in %g2 (ie. index of the faulting instruction in the range). |
| */ |
| |
| struct exception_table_entry |
| { |
| unsigned long insn, fixup; |
| }; |
| |
| /* Returns 0 if exception not found and fixup otherwise. */ |
| unsigned long search_extables_range(unsigned long addr, unsigned long *g2); |
| |
| /* Uh, these should become 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. |
| */ |
| #define put_user(x, ptr) ({ \ |
| unsigned long __pu_addr = (unsigned long)(ptr); \ |
| __chk_user_ptr(ptr); \ |
| __put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \ |
| }) |
| |
| #define get_user(x, ptr) ({ \ |
| unsigned long __gu_addr = (unsigned long)(ptr); \ |
| __chk_user_ptr(ptr); \ |
| __get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \ |
| }) |
| |
| /* |
| * The "__xxx" versions do not do address space checking, useful when |
| * doing multiple accesses to the same area (the user 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)), __typeof__(*(ptr))) |
| |
| struct __large_struct { unsigned long buf[100]; }; |
| #define __m(x) ((struct __large_struct __user *)(x)) |
| |
| #define __put_user_check(x, addr, size) ({ \ |
| register int __pu_ret; \ |
| if (__access_ok(addr, size)) { \ |
| switch (size) { \ |
| case 1: \ |
| __put_user_asm(x, b, addr, __pu_ret); \ |
| break; \ |
| case 2: \ |
| __put_user_asm(x, h, addr, __pu_ret); \ |
| break; \ |
| case 4: \ |
| __put_user_asm(x, , addr, __pu_ret); \ |
| break; \ |
| case 8: \ |
| __put_user_asm(x, d, addr, __pu_ret); \ |
| break; \ |
| default: \ |
| __pu_ret = __put_user_bad(); \ |
| break; \ |
| } \ |
| } else { \ |
| __pu_ret = -EFAULT; \ |
| } \ |
| __pu_ret; \ |
| }) |
| |
| #define __put_user_nocheck(x, addr, size) ({ \ |
| register int __pu_ret; \ |
| switch (size) { \ |
| case 1: __put_user_asm(x, b, addr, __pu_ret); break; \ |
| case 2: __put_user_asm(x, h, addr, __pu_ret); break; \ |
| case 4: __put_user_asm(x, , addr, __pu_ret); break; \ |
| case 8: __put_user_asm(x, d, addr, __pu_ret); break; \ |
| default: __pu_ret = __put_user_bad(); break; \ |
| } \ |
| __pu_ret; \ |
| }) |
| |
| #define __put_user_asm(x, size, addr, ret) \ |
| __asm__ __volatile__( \ |
| "/* Put user asm, inline. */\n" \ |
| "1:\t" "st"#size " %1, %2\n\t" \ |
| "clr %0\n" \ |
| "2:\n\n\t" \ |
| ".section .fixup,#alloc,#execinstr\n\t" \ |
| ".align 4\n" \ |
| "3:\n\t" \ |
| "b 2b\n\t" \ |
| " mov %3, %0\n\t" \ |
| ".previous\n\n\t" \ |
| ".section __ex_table,#alloc\n\t" \ |
| ".align 4\n\t" \ |
| ".word 1b, 3b\n\t" \ |
| ".previous\n\n\t" \ |
| : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \ |
| "i" (-EFAULT)) |
| |
| int __put_user_bad(void); |
| |
| #define __get_user_check(x, addr, size, type) ({ \ |
| register int __gu_ret; \ |
| register unsigned long __gu_val; \ |
| if (__access_ok(addr, size)) { \ |
| switch (size) { \ |
| case 1: \ |
| __get_user_asm(__gu_val, ub, addr, __gu_ret); \ |
| break; \ |
| case 2: \ |
| __get_user_asm(__gu_val, uh, addr, __gu_ret); \ |
| break; \ |
| case 4: \ |
| __get_user_asm(__gu_val, , addr, __gu_ret); \ |
| break; \ |
| case 8: \ |
| __get_user_asm(__gu_val, d, addr, __gu_ret); \ |
| break; \ |
| default: \ |
| __gu_val = 0; \ |
| __gu_ret = __get_user_bad(); \ |
| break; \ |
| } \ |
| } else { \ |
| __gu_val = 0; \ |
| __gu_ret = -EFAULT; \ |
| } \ |
| x = (__force type) __gu_val; \ |
| __gu_ret; \ |
| }) |
| |
| #define __get_user_nocheck(x, addr, size, type) ({ \ |
| register int __gu_ret; \ |
| register unsigned long __gu_val; \ |
| switch (size) { \ |
| case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \ |
| case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \ |
| case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \ |
| case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \ |
| default: \ |
| __gu_val = 0; \ |
| __gu_ret = __get_user_bad(); \ |
| break; \ |
| } \ |
| x = (__force type) __gu_val; \ |
| __gu_ret; \ |
| }) |
| |
| #define __get_user_asm(x, size, addr, ret) \ |
| __asm__ __volatile__( \ |
| "/* Get user asm, inline. */\n" \ |
| "1:\t" "ld"#size " %2, %1\n\t" \ |
| "clr %0\n" \ |
| "2:\n\n\t" \ |
| ".section .fixup,#alloc,#execinstr\n\t" \ |
| ".align 4\n" \ |
| "3:\n\t" \ |
| "clr %1\n\t" \ |
| "b 2b\n\t" \ |
| " mov %3, %0\n\n\t" \ |
| ".previous\n\t" \ |
| ".section __ex_table,#alloc\n\t" \ |
| ".align 4\n\t" \ |
| ".word 1b, 3b\n\n\t" \ |
| ".previous\n\t" \ |
| : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \ |
| "i" (-EFAULT)) |
| |
| int __get_user_bad(void); |
| |
| unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size); |
| |
| static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) |
| { |
| return __copy_user(to, (__force void __user *) from, n); |
| } |
| |
| static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) |
| { |
| return __copy_user((__force void __user *) to, from, n); |
| } |
| |
| #define INLINE_COPY_FROM_USER |
| #define INLINE_COPY_TO_USER |
| |
| static inline unsigned long __clear_user(void __user *addr, unsigned long size) |
| { |
| unsigned long ret; |
| |
| __asm__ __volatile__ ( |
| ".section __ex_table,#alloc\n\t" |
| ".align 4\n\t" |
| ".word 1f,3\n\t" |
| ".previous\n\t" |
| "mov %2, %%o1\n" |
| "1:\n\t" |
| "call __bzero\n\t" |
| " mov %1, %%o0\n\t" |
| "mov %%o0, %0\n" |
| : "=r" (ret) : "r" (addr), "r" (size) : |
| "o0", "o1", "o2", "o3", "o4", "o5", "o7", |
| "g1", "g2", "g3", "g4", "g5", "g7", "cc"); |
| |
| return ret; |
| } |
| |
| static inline unsigned long clear_user(void __user *addr, unsigned long n) |
| { |
| if (n && __access_ok((unsigned long) addr, n)) |
| return __clear_user(addr, n); |
| else |
| return n; |
| } |
| |
| __must_check long strnlen_user(const char __user *str, long n); |
| |
| #endif /* _ASM_UACCESS_H */ |