kernel-ark/arch/ia64/include/asm/uaccess.h
Tony Luck 7f30491ccd [IA64] Move include/asm-ia64 to arch/ia64/include/asm
After moving the the include files there were a few clean-ups:

1) Some files used #include <asm-ia64/xyz.h>, changed to <asm/xyz.h>

2) Some comments alerted maintainers to look at various header files to
make matching updates if certain code were to be changed. Updated these
comments to use the new include paths.

3) Some header files mentioned their own names in initial comments. Just
deleted these self references.

Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-08-01 10:21:21 -07:00

402 lines
14 KiB
C

#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())
/*
* 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; \
unsigned long __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, (__force void __user *) from, count);
}
static inline unsigned long
__copy_from_user (void *to, const void __user *from, unsigned long count)
{
return __copy_user((__force 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, (__force 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((__force 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);
if (PageUncached(page))
ptr = (char *)__pa(p) + __IA64_UNCACHED_OFFSET;
else
ptr = p;
return ptr;
}
#endif /* _ASM_IA64_UACCESS_H */