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1275 |
phoenix |
#ifndef _ASM_IA64_UACCESS_H
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#define _ASM_IA64_UACCESS_H
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/*
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* This file defines various macros to transfer memory areas across
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* the user/kernel boundary. This needs to be done carefully because
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* this code is executed in kernel mode and uses user-specified
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* addresses. Thus, we need to be careful not to let the user to
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* trick us into accessing kernel memory that would normally be
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* inaccessible. This code is also fairly performance sensitive,
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* so we want to spend as little time doing safety checks as
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* possible.
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*
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* To make matters a bit more interesting, these macros sometimes also
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* called from within the kernel itself, in which case the address
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* validity check must be skipped. The get_fs() macro tells us what
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* to do: if get_fs()==USER_DS, checking is performed, if
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* get_fs()==KERNEL_DS, checking is bypassed.
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*
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* Note that even if the memory area specified by the user is in a
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* valid address range, it is still possible that we'll get a page
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* fault while accessing it. This is handled by filling out an
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* exception handler fixup entry for each instruction that has the
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* potential to fault. When such a fault occurs, the page fault
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* handler checks to see whether the faulting instruction has a fixup
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* associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and
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* then resumes execution at the continuation point.
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*
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* Based on <asm-alpha/uaccess.h>.
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*
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* Copyright (C) 1998, 1999, 2001, 2003 Hewlett-Packard Co
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* David Mosberger-Tang <davidm@hpl.hp.com>
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*/
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <asm/pgtable.h>
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/*
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* For historical reasons, the following macros are grossly misnamed:
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*/
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#define KERNEL_DS ((mm_segment_t) { ~0UL }) /* cf. access_ok() */
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#define USER_DS ((mm_segment_t) { TASK_SIZE-1 }) /* cf. access_ok() */
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#define VERIFY_READ 0
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#define VERIFY_WRITE 1
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#define get_ds() (KERNEL_DS)
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#define get_fs() (current->addr_limit)
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#define set_fs(x) (current->addr_limit = (x))
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#define segment_eq(a,b) ((a).seg == (b).seg)
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/*
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* When accessing user memory, we need to make sure the entire area really is in
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* user-level space. In order to do this efficiently, we make sure that the page at
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* address TASK_SIZE is never valid. We also need to make sure that the address doesn't
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* point inside the virtually mapped linear page table.
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*/
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#define __access_ok(addr,size,segment) \
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likely(((unsigned long) (addr)) <= (segment).seg \
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&& ((segment).seg == KERNEL_DS.seg \
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|| REGION_OFFSET((unsigned long) (addr)) < RGN_MAP_LIMIT))
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#define access_ok(type,addr,size) __access_ok((addr),(size),get_fs())
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static inline int
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verify_area (int type, const void *addr, unsigned long size)
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{
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return access_ok(type,addr,size) ? 0 : -EFAULT;
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}
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/*
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* These are the main single-value transfer routines. They automatically
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* use the right size if we just have the right pointer type.
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*
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* Careful to not
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* (a) re-use the arguments for side effects (sizeof/typeof is ok)
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* (b) require any knowledge of processes at this stage
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*/
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#define put_user(x,ptr) __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)),get_fs())
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#define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr)),get_fs())
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/*
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* The "__xxx" versions do not do address space checking, useful when
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* doing multiple accesses to the same area (the programmer has to do the
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* checks by hand with "access_ok()")
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*/
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#define __put_user(x,ptr) __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
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#define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
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extern void __get_user_unknown (void);
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#define __get_user_nocheck(x,ptr,size) \
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({ \
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register long __gu_err asm ("r8") = 0; \
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register long __gu_val asm ("r9") = 0; \
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switch (size) { \
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case 1: __get_user_8(ptr); break; \
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case 2: __get_user_16(ptr); break; \
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case 4: __get_user_32(ptr); break; \
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case 8: __get_user_64(ptr); break; \
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default: __get_user_unknown(); break; \
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} \
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(x) = (__typeof__(*(ptr))) __gu_val; \
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__gu_err; \
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})
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#define __get_user_check(x,ptr,size,segment) \
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({ \
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register long __gu_err asm ("r8") = -EFAULT; \
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register long __gu_val asm ("r9") = 0; \
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const __typeof__(*(ptr)) *__gu_addr = (ptr); \
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if (__access_ok((long)__gu_addr,size,segment)) { \
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__gu_err = 0; \
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switch (size) { \
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case 1: __get_user_8(__gu_addr); break; \
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case 2: __get_user_16(__gu_addr); break; \
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case 4: __get_user_32(__gu_addr); break; \
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case 8: __get_user_64(__gu_addr); break; \
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default: __get_user_unknown(); break; \
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} \
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} \
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(x) = (__typeof__(*(ptr))) __gu_val; \
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__gu_err; \
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})
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struct __large_struct { unsigned long buf[100]; };
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#define __m(x) (*(struct __large_struct *)(x))
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/* We need to declare the __ex_table section before we can use it in .xdata. */
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asm (".section \"__ex_table\", \"a\"\n\t.previous");
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#if __GNUC__ >= 3
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# define GAS_HAS_LOCAL_TAGS /* define if gas supports local tags a la [1:] */
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#endif
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#ifdef GAS_HAS_LOCAL_TAGS
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# define _LL "[1:]"
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#else
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# define _LL "1:"
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#endif
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#define __get_user_64(addr) \
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asm ("\n"_LL"\tld8 %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \
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"\t.xdata4 \"__ex_table\", @gprel(1b), @gprel(1f)+4\n" \
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_LL \
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: "=r"(__gu_val), "=r"(__gu_err) : "m"(__m(addr)), "1"(__gu_err));
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#define __get_user_32(addr) \
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asm ("\n"_LL"\tld4 %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \
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"\t.xdata4 \"__ex_table\", @gprel(1b), @gprel(1f)+4\n" \
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_LL \
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: "=r"(__gu_val), "=r"(__gu_err) : "m"(__m(addr)), "1"(__gu_err));
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#define __get_user_16(addr) \
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asm ("\n"_LL"\tld2 %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \
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"\t.xdata4 \"__ex_table\", @gprel(1b), @gprel(1f)+4\n" \
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_LL \
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: "=r"(__gu_val), "=r"(__gu_err) : "m"(__m(addr)), "1"(__gu_err));
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#define __get_user_8(addr) \
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asm ("\n"_LL"\tld1 %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \
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"\t.xdata4 \"__ex_table\", @gprel(1b), @gprel(1f)+4\n" \
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_LL \
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: "=r"(__gu_val), "=r"(__gu_err) : "m"(__m(addr)), "1"(__gu_err));
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extern void __put_user_unknown (void);
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#define __put_user_nocheck(x,ptr,size) \
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({ \
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register long __pu_err asm ("r8") = 0; \
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switch (size) { \
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case 1: __put_user_8(x,ptr); break; \
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case 2: __put_user_16(x,ptr); break; \
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case 4: __put_user_32(x,ptr); break; \
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case 8: __put_user_64(x,ptr); break; \
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default: __put_user_unknown(); break; \
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} \
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__pu_err; \
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})
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#define __put_user_check(x,ptr,size,segment) \
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({ \
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register long __pu_err asm ("r8") = -EFAULT; \
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__typeof__(*(ptr)) *__pu_addr = (ptr); \
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if (__access_ok((long)__pu_addr,size,segment)) { \
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__pu_err = 0; \
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switch (size) { \
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case 1: __put_user_8(x,__pu_addr); break; \
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case 2: __put_user_16(x,__pu_addr); break; \
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case 4: __put_user_32(x,__pu_addr); break; \
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case 8: __put_user_64(x,__pu_addr); break; \
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default: __put_user_unknown(); break; \
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} \
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} \
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__pu_err; \
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})
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/*
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* The "__put_user_xx()" macros tell gcc they read from memory
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* instead of writing: this is because they do not write to
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* any memory gcc knows about, so there are no aliasing issues
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*/
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#define __put_user_64(x,addr) \
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asm volatile ( \
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"\n"_LL"\tst8 %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
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"\t.xdata4 \"__ex_table\", @gprel(1b), @gprel(1f)\n" \
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_LL \
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: "=r"(__pu_err) : "m"(__m(addr)), "rO"(x), "0"(__pu_err))
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#define __put_user_32(x,addr) \
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asm volatile ( \
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"\n"_LL"\tst4 %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
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"\t.xdata4 \"__ex_table\", @gprel(1b), @gprel(1f)\n" \
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_LL \
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: "=r"(__pu_err) : "m"(__m(addr)), "rO"(x), "0"(__pu_err))
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#define __put_user_16(x,addr) \
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asm volatile ( \
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"\n"_LL"\tst2 %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
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"\t.xdata4 \"__ex_table\", @gprel(1b), @gprel(1f)\n" \
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_LL \
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: "=r"(__pu_err) : "m"(__m(addr)), "rO"(x), "0"(__pu_err))
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#define __put_user_8(x,addr) \
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asm volatile ( \
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"\n"_LL"\tst1 %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
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"\t.xdata4 \"__ex_table\", @gprel(1b), @gprel(1f)\n" \
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_LL \
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: "=r"(__pu_err) : "m"(__m(addr)), "rO"(x), "0"(__pu_err))
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/*
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* Complex access routines
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*/
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extern unsigned long __copy_user (void *to, const void *from, unsigned long count);
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#define __copy_to_user(to,from,n) __copy_user((to), (from), (n))
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#define __copy_from_user(to,from,n) __copy_user((to), (from), (n))
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| 241 |
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#define copy_to_user(to,from,n) __copy_tofrom_user((to), (from), (n), 1)
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#define copy_from_user(to,from,n) __copy_tofrom_user((to), (from), (n), 0)
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#define __copy_tofrom_user(to,from,n,check_to) \
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({ \
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void *__cu_to = (to); \
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const void *__cu_from = (from); \
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| 248 |
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long __cu_len = (n); \
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\
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| 250 |
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if (__access_ok((long) ((check_to) ? __cu_to : __cu_from), __cu_len, get_fs())) { \
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__cu_len = __copy_user(__cu_to, __cu_from, __cu_len); \
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} \
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| 253 |
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__cu_len; \
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| 254 |
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})
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| 256 |
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extern unsigned long __do_clear_user (void *, unsigned long);
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| 257 |
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| 258 |
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#define __clear_user(to,n) \
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({ \
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| 260 |
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__do_clear_user(to,n); \
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})
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| 262 |
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| 263 |
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#define clear_user(to,n) \
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| 264 |
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({ \
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| 265 |
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unsigned long __cu_len = (n); \
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| 266 |
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if (__access_ok((long) to, __cu_len, get_fs())) { \
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| 267 |
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__cu_len = __do_clear_user(to, __cu_len); \
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| 268 |
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} \
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| 269 |
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__cu_len; \
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| 270 |
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})
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| 271 |
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| 272 |
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| 273 |
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/* Returns: -EFAULT if exception before terminator, N if the entire
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| 274 |
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buffer filled, else strlen. */
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| 275 |
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| 276 |
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extern long __strncpy_from_user (char *to, const char *from, long to_len);
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| 277 |
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| 278 |
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#define strncpy_from_user(to,from,n) \
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| 279 |
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({ \
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| 280 |
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const char * __sfu_from = (from); \
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| 281 |
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long __sfu_ret = -EFAULT; \
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| 282 |
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if (__access_ok((long) __sfu_from, 0, get_fs())) \
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| 283 |
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__sfu_ret = __strncpy_from_user((to), __sfu_from, (n)); \
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| 284 |
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__sfu_ret; \
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| 285 |
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})
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| 286 |
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| 287 |
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/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
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| 288 |
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extern unsigned long __strlen_user (const char *);
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| 289 |
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| 290 |
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#define strlen_user(str) \
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| 291 |
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({ \
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| 292 |
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const char *__su_str = (str); \
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| 293 |
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unsigned long __su_ret = 0; \
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| 294 |
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if (__access_ok((long) __su_str, 0, get_fs())) \
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| 295 |
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__su_ret = __strlen_user(__su_str); \
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| 296 |
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__su_ret; \
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| 297 |
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})
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| 298 |
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| 299 |
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/*
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| 300 |
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* Returns: 0 if exception before NUL or reaching the supplied limit
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| 301 |
|
|
* (N), a value greater than N if the limit would be exceeded, else
|
| 302 |
|
|
* strlen.
|
| 303 |
|
|
*/
|
| 304 |
|
|
extern unsigned long __strnlen_user (const char *, long);
|
| 305 |
|
|
|
| 306 |
|
|
#define strnlen_user(str, len) \
|
| 307 |
|
|
({ \
|
| 308 |
|
|
const char *__su_str = (str); \
|
| 309 |
|
|
unsigned long __su_ret = 0; \
|
| 310 |
|
|
if (__access_ok((long) __su_str, 0, get_fs())) \
|
| 311 |
|
|
__su_ret = __strnlen_user(__su_str, len); \
|
| 312 |
|
|
__su_ret; \
|
| 313 |
|
|
})
|
| 314 |
|
|
|
| 315 |
|
|
struct exception_table_entry {
|
| 316 |
|
|
int addr; /* gp-relative address of insn this fixup is for */
|
| 317 |
|
|
int cont; /* gp-relative continuation address; if bit 2 is set, r9 is set to 0 */
|
| 318 |
|
|
};
|
| 319 |
|
|
|
| 320 |
|
|
struct exception_fixup {
|
| 321 |
|
|
unsigned long cont; /* continuation point (bit 2: clear r9 if set) */
|
| 322 |
|
|
};
|
| 323 |
|
|
|
| 324 |
|
|
extern struct exception_fixup search_exception_table (unsigned long addr);
|
| 325 |
|
|
extern void handle_exception (struct pt_regs *regs, struct exception_fixup fixup);
|
| 326 |
|
|
|
| 327 |
|
|
#ifdef GAS_HAS_LOCAL_TAGS
|
| 328 |
|
|
#define SEARCH_EXCEPTION_TABLE(regs) search_exception_table(regs->cr_iip + ia64_psr(regs)->ri);
|
| 329 |
|
|
#else
|
| 330 |
|
|
#define SEARCH_EXCEPTION_TABLE(regs) search_exception_table(regs->cr_iip);
|
| 331 |
|
|
#endif
|
| 332 |
|
|
|
| 333 |
|
|
static inline int
|
| 334 |
|
|
done_with_exception (struct pt_regs *regs)
|
| 335 |
|
|
{
|
| 336 |
|
|
struct exception_fixup fix;
|
| 337 |
|
|
fix = SEARCH_EXCEPTION_TABLE(regs);
|
| 338 |
|
|
if (fix.cont) {
|
| 339 |
|
|
handle_exception(regs, fix);
|
| 340 |
|
|
return 1;
|
| 341 |
|
|
}
|
| 342 |
|
|
return 0;
|
| 343 |
|
|
}
|
| 344 |
|
|
|
| 345 |
|
|
#endif /* _ASM_IA64_UACCESS_H */
|
