#ifndef _ASM_IA64_UACCESS_H #define _ASM_IA64_UACCESS_H /* * This file defines various macros to transfer memory areas across * the user/kernel boundary. This needs to be done carefully because * this code is executed in kernel mode and uses user-specified * addresses. Thus, we need to be careful not to let the user to * trick us into accessing kernel memory that would normally be * inaccessible. This code is also fairly performance sensitive, * so we want to spend as little time doing safety checks as * possible. * * To make matters a bit more interesting, these macros sometimes also * called from within the kernel itself, in which case the address * validity check must be skipped. The get_fs() macro tells us what * to do: if get_fs()==USER_DS, checking is performed, if * get_fs()==KERNEL_DS, checking is bypassed. * * Note that even if the memory area specified by the user is in a * valid address range, it is still possible that we'll get a page * fault while accessing it. This is handled by filling out an * exception handler fixup entry for each instruction that has the * potential to fault. When such a fault occurs, the page fault * handler checks to see whether the faulting instruction has a fixup * associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and * then resumes execution at the continuation point. * * Based on <asm-alpha/uaccess.h>. * * Copyright (C) 1998, 1999, 2001-2004 Hewlett-Packard Co * David Mosberger-Tang <davidm@hpl.hp.com> */ #include <linux/compiler.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/page-flags.h> #include <linux/mm.h> #include <asm/intrinsics.h> #include <asm/pgtable.h> #include <asm/io.h> /* * For historical reasons, the following macros are grossly misnamed: */ #define KERNEL_DS ((mm_segment_t) { ~0UL }) /* cf. access_ok() */ #define USER_DS ((mm_segment_t) { TASK_SIZE-1 }) /* cf. access_ok() */ #define VERIFY_READ 0 #define VERIFY_WRITE 1 #define get_ds() (KERNEL_DS) #define get_fs() (current_thread_info()->addr_limit) #define set_fs(x) (current_thread_info()->addr_limit = (x)) #define segment_eq(a, b) ((a).seg == (b).seg) /* * When accessing user memory, we need to make sure the entire area really is in * user-level space. In order to do this efficiently, we make sure that the page at * address TASK_SIZE is never valid. We also need to make sure that the address doesn't * point inside the virtually mapped linear page table. */ #define __access_ok(addr, size, segment) \ ({ \ __chk_user_ptr(addr); \ (likely((unsigned long) (addr) <= (segment).seg) \ && ((segment).seg == KERNEL_DS.seg \ || likely(REGION_OFFSET((unsigned long) (addr)) < RGN_MAP_LIMIT))); \ }) #define access_ok(type, addr, size) __access_ok((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; } /* * These are the main single-value transfer routines. They automatically * use the right size if we just have the right pointer type. * * Careful to not * (a) re-use the arguments for side effects (sizeof/typeof is ok) * (b) require any knowledge of processes at this stage */ #define put_user(x, ptr) __put_user_check((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)), get_fs()) #define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)), get_fs()) /* * The "__xxx" versions do not do address space checking, useful when * doing multiple accesses to the same area (the programmer 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))) extern long __put_user_unaligned_unknown (void); #define __put_user_unaligned(x, ptr) \ ({ \ long __ret; \ switch (sizeof(*(ptr))) { \ case 1: __ret = __put_user((x), (ptr)); break; \ case 2: __ret = (__put_user((x), (u8 __user *)(ptr))) \ | (__put_user((x) >> 8, ((u8 __user *)(ptr) + 1))); break; \ case 4: __ret = (__put_user((x), (u16 __user *)(ptr))) \ | (__put_user((x) >> 16, ((u16 __user *)(ptr) + 1))); break; \ case 8: __ret = (__put_user((x), (u32 __user *)(ptr))) \ | (__put_user((x) >> 32, ((u32 __user *)(ptr) + 1))); break; \ default: __ret = __put_user_unaligned_unknown(); \ } \ __ret; \ }) extern long __get_user_unaligned_unknown (void); #define __get_user_unaligned(x, ptr) \ ({ \ long __ret; \ switch (sizeof(*(ptr))) { \ case 1: __ret = __get_user((x), (ptr)); break; \ case 2: __ret = (__get_user((x), (u8 __user *)(ptr))) \ | (__get_user((x) >> 8, ((u8 __user *)(ptr) + 1))); break; \ case 4: __ret = (__get_user((x), (u16 __user *)(ptr))) \ | (__get_user((x) >> 16, ((u16 __user *)(ptr) + 1))); break; \ case 8: __ret = (__get_user((x), (u32 __user *)(ptr))) \ | (__get_user((x) >> 32, ((u32 __user *)(ptr) + 1))); break; \ default: __ret = __get_user_unaligned_unknown(); \ } \ __ret; \ }) #ifdef ASM_SUPPORTED struct __large_struct { unsigned long buf[100]; }; # define __m(x) (*(struct __large_struct __user *)(x)) /* We need to declare the __ex_table section before we can use it in .xdata. */ asm (".section \"__ex_table\", \"a\"\n\t.previous"); # define __get_user_size(val, addr, n, err) \ do { \ register long __gu_r8 asm ("r8") = 0; \ register long __gu_r9 asm ("r9"); \ asm ("\n[1:]\tld"#n" %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \ "\t.xdata4 \"__ex_table\", 1b-., 1f-.+4\n" \ "[1:]" \ : "=r"(__gu_r9), "=r"(__gu_r8) : "m"(__m(addr)), "1"(__gu_r8)); \ (err) = __gu_r8; \ (val) = __gu_r9; \ } while (0) /* * The "__put_user_size()" macro tells gcc it reads from memory instead of writing it. This * is because they do not write to any memory gcc knows about, so there are no aliasing * issues. */ # define __put_user_size(val, addr, n, err) \ do { \ register long __pu_r8 asm ("r8") = 0; \ asm volatile ("\n[1:]\tst"#n" %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \ "\t.xdata4 \"__ex_table\", 1b-., 1f-.\n" \ "[1:]" \ : "=r"(__pu_r8) : "m"(__m(addr)), "rO"(val), "0"(__pu_r8)); \ (err) = __pu_r8; \ } while (0) #else /* !ASM_SUPPORTED */ # define RELOC_TYPE 2 /* ip-rel */ # define __get_user_size(val, addr, n, err) \ do { \ __ld_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE); \ (err) = ia64_getreg(_IA64_REG_R8); \ (val) = ia64_getreg(_IA64_REG_R9); \ } while (0) # define __put_user_size(val, addr, n, err) \ do { \ __st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE, (unsigned long) (val)); \ (err) = ia64_getreg(_IA64_REG_R8); \ } while (0) #endif /* !ASM_SUPPORTED */ extern void __get_user_unknown (void); /* * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which * could clobber r8 and r9 (among others). Thus, be careful not to evaluate it while * using r8/r9. */ #define __do_get_user(check, x, ptr, size, segment) \ ({ \ const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ __typeof__ (size) __gu_size = (size); \ long __gu_err = -EFAULT, __gu_val = 0; \ \ if (!check || __access_ok(__gu_ptr, size, segment)) \ switch (__gu_size) { \ case 1: __get_user_size(__gu_val, __gu_ptr, 1, __gu_err); break; \ case 2: __get_user_size(__gu_val, __gu_ptr, 2, __gu_err); break; \ case 4: __get_user_size(__gu_val, __gu_ptr, 4, __gu_err); break; \ case 8: __get_user_size(__gu_val, __gu_ptr, 8, __gu_err); break; \ default: __get_user_unknown(); break; \ } \ (x) = (__typeof__(*(__gu_ptr))) __gu_val; \ __gu_err; \ }) #define __get_user_nocheck(x, ptr, size) __do_get_user(0, x, ptr, size, KERNEL_DS) #define __get_user_check(x, ptr, size, segment) __do_get_user(1, x, ptr, size, segment) extern void __put_user_unknown (void); /* * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which * could clobber r8 (among others). Thus, be careful not to evaluate them while using r8. */ #define __do_put_user(check, x, ptr, size, segment) \ ({ \ __typeof__ (x) __pu_x = (x); \ __typeof__ (*(ptr)) __user *__pu_ptr = (ptr); \ __typeof__ (size) __pu_size = (size); \ long __pu_err = -EFAULT; \ \ if (!check || __access_ok(__pu_ptr, __pu_size, segment)) \ switch (__pu_size) { \ case 1: __put_user_size(__pu_x, __pu_ptr, 1, __pu_err); break; \ case 2: __put_user_size(__pu_x, __pu_ptr, 2, __pu_err); break; \ case 4: __put_user_size(__pu_x, __pu_ptr, 4, __pu_err); break; \ case 8: __put_user_size(__pu_x, __pu_ptr, 8, __pu_err); break; \ default: __put_user_unknown(); break; \ } \ __pu_err; \ }) #define __put_user_nocheck(x, ptr, size) __do_put_user(0, x, ptr, size, KERNEL_DS) #define __put_user_check(x, ptr, size, segment) __do_put_user(1, x, ptr, size, segment) /* * Complex access routines */ extern unsigned long __must_check __copy_user (void __user *to, const void __user *from, unsigned long count); static inline unsigned long __copy_to_user (void __user *to, const void *from, unsigned long count) { return __copy_user(to, (void __user *) from, count); } static inline unsigned long __copy_from_user (void *to, const void __user *from, unsigned long count) { return __copy_user((void __user *) to, from, count); } #define __copy_to_user_inatomic __copy_to_user #define __copy_from_user_inatomic __copy_from_user #define copy_to_user(to, from, n) \ ({ \ void __user *__cu_to = (to); \ const void *__cu_from = (from); \ long __cu_len = (n); \ \ if (__access_ok(__cu_to, __cu_len, get_fs())) \ __cu_len = __copy_user(__cu_to, (void __user *) __cu_from, __cu_len); \ __cu_len; \ }) #define copy_from_user(to, from, n) \ ({ \ void *__cu_to = (to); \ const void __user *__cu_from = (from); \ long __cu_len = (n); \ \ __chk_user_ptr(__cu_from); \ if (__access_ok(__cu_from, __cu_len, get_fs())) \ __cu_len = __copy_user((void __user *) __cu_to, __cu_from, __cu_len); \ __cu_len; \ }) #define __copy_in_user(to, from, size) __copy_user((to), (from), (size)) static inline unsigned long copy_in_user (void __user *to, const void __user *from, unsigned long n) { if (likely(access_ok(VERIFY_READ, from, n) && access_ok(VERIFY_WRITE, to, n))) n = __copy_user(to, from, n); return n; } extern unsigned long __do_clear_user (void __user *, unsigned long); #define __clear_user(to, n) __do_clear_user(to, n) #define clear_user(to, n) \ ({ \ unsigned long __cu_len = (n); \ if (__access_ok(to, __cu_len, get_fs())) \ __cu_len = __do_clear_user(to, __cu_len); \ __cu_len; \ }) /* * Returns: -EFAULT if exception before terminator, N if the entire buffer filled, else * strlen. */ extern long __must_check __strncpy_from_user (char *to, const char __user *from, long to_len); #define strncpy_from_user(to, from, n) \ ({ \ const char __user * __sfu_from = (from); \ long __sfu_ret = -EFAULT; \ if (__access_ok(__sfu_from, 0, get_fs())) \ __sfu_ret = __strncpy_from_user((to), __sfu_from, (n)); \ __sfu_ret; \ }) /* Returns: 0 if bad, string length+1 (memory size) of string if ok */ extern unsigned long __strlen_user (const char __user *); #define strlen_user(str) \ ({ \ const char __user *__su_str = (str); \ unsigned long __su_ret = 0; \ if (__access_ok(__su_str, 0, get_fs())) \ __su_ret = __strlen_user(__su_str); \ __su_ret; \ }) /* * Returns: 0 if exception before NUL or reaching the supplied limit * (N), a value greater than N if the limit would be exceeded, else * strlen. */ extern unsigned long __strnlen_user (const char __user *, long); #define strnlen_user(str, len) \ ({ \ const char __user *__su_str = (str); \ unsigned long __su_ret = 0; \ if (__access_ok(__su_str, 0, get_fs())) \ __su_ret = __strnlen_user(__su_str, len); \ __su_ret; \ }) /* Generic code can't deal with the location-relative format that we use for compactness. */ #define ARCH_HAS_SORT_EXTABLE #define ARCH_HAS_SEARCH_EXTABLE struct exception_table_entry { int addr; /* location-relative address of insn this fixup is for */ int cont; /* location-relative continuation addr.; if bit 2 is set, r9 is set to 0 */ }; extern void ia64_handle_exception (struct pt_regs *regs, const struct exception_table_entry *e); extern const struct exception_table_entry *search_exception_tables (unsigned long addr); static inline int ia64_done_with_exception (struct pt_regs *regs) { const struct exception_table_entry *e; e = search_exception_tables(regs->cr_iip + ia64_psr(regs)->ri); if (e) { ia64_handle_exception(regs, e); return 1; } return 0; } #define ARCH_HAS_TRANSLATE_MEM_PTR 1 static __inline__ char * xlate_dev_mem_ptr (unsigned long p) { struct page *page; char * ptr; page = pfn_to_page(p >> PAGE_SHIFT); if (PageUncached(page)) ptr = (char *)p + __IA64_UNCACHED_OFFSET; else ptr = __va(p); return ptr; } /* * Convert a virtual cached kernel memory pointer to an uncached pointer */ static __inline__ char * xlate_dev_kmem_ptr (char * p) { struct page *page; char * ptr; page = virt_to_page((unsigned long)p >> PAGE_SHIFT); if (PageUncached(page)) ptr = (char *)__pa(p) + __IA64_UNCACHED_OFFSET; else ptr = p; return ptr; } #endif /* _ASM_IA64_UACCESS_H */