336 lines
9.5 KiB
C
336 lines
9.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ALPHA_UACCESS_H
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#define __ALPHA_UACCESS_H
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/*
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* The fs value determines whether argument validity checking should be
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* performed or not. If get_fs() == USER_DS, checking is performed, with
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* get_fs() == KERNEL_DS, checking is bypassed.
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*
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* Or at least it did once upon a time. Nowadays it is a mask that
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* defines which bits of the address space are off limits. This is a
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* wee bit faster than the above.
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*
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* For historical reasons, these macros are grossly misnamed.
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*/
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#define KERNEL_DS ((mm_segment_t) { 0UL })
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#define USER_DS ((mm_segment_t) { -0x40000000000UL })
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#define get_fs() (current_thread_info()->addr_limit)
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#define set_fs(x) (current_thread_info()->addr_limit = (x))
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#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
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/*
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* Is a address valid? This does a straightforward calculation rather
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* than tests.
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*
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* Address valid if:
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* - "addr" doesn't have any high-bits set
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* - AND "size" doesn't have any high-bits set
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* - AND "addr+size-(size != 0)" doesn't have any high-bits set
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* - OR we are in kernel mode.
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*/
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#define __access_ok(addr, size) ({ \
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unsigned long __ao_a = (addr), __ao_b = (size); \
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unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b; \
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(get_fs().seg & (__ao_a | __ao_b | __ao_end)) == 0; })
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#define access_ok(addr, size) \
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({ \
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__chk_user_ptr(addr); \
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__access_ok(((unsigned long)(addr)), (size)); \
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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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* As the alpha uses the same address space for kernel and user
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* data, we can just do these as direct assignments. (Of course, the
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* exception handling means that it's no longer "just"...)
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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) \
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__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
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#define get_user(x, ptr) \
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__get_user_check((x), (ptr), sizeof(*(ptr)))
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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) \
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__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
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#define __get_user(x, ptr) \
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__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
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/*
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* The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to
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* encode the bits we need for resolving the exception. See the
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* more extensive comments with fixup_inline_exception below for
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* more information.
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*/
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#define EXC(label,cont,res,err) \
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".section __ex_table,\"a\"\n" \
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" .long "#label"-.\n" \
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" lda "#res","#cont"-"#label"("#err")\n" \
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".previous\n"
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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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long __gu_err = 0; \
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unsigned long __gu_val; \
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__chk_user_ptr(ptr); \
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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) = (__force __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) \
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({ \
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long __gu_err = -EFAULT; \
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unsigned long __gu_val = 0; \
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const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
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if (__access_ok((unsigned long)__gu_addr, size)) { \
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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) = (__force __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 __user *)(x))
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#define __get_user_64(addr) \
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__asm__("1: ldq %0,%2\n" \
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"2:\n" \
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EXC(1b,2b,%0,%1) \
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: "=r"(__gu_val), "=r"(__gu_err) \
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: "m"(__m(addr)), "1"(__gu_err))
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#define __get_user_32(addr) \
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__asm__("1: ldl %0,%2\n" \
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"2:\n" \
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EXC(1b,2b,%0,%1) \
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: "=r"(__gu_val), "=r"(__gu_err) \
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: "m"(__m(addr)), "1"(__gu_err))
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#ifdef __alpha_bwx__
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/* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */
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#define __get_user_16(addr) \
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__asm__("1: ldwu %0,%2\n" \
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"2:\n" \
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EXC(1b,2b,%0,%1) \
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: "=r"(__gu_val), "=r"(__gu_err) \
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: "m"(__m(addr)), "1"(__gu_err))
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#define __get_user_8(addr) \
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__asm__("1: ldbu %0,%2\n" \
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"2:\n" \
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EXC(1b,2b,%0,%1) \
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: "=r"(__gu_val), "=r"(__gu_err) \
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: "m"(__m(addr)), "1"(__gu_err))
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#else
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/* Unfortunately, we can't get an unaligned access trap for the sub-word
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load, so we have to do a general unaligned operation. */
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#define __get_user_16(addr) \
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{ \
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long __gu_tmp; \
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__asm__("1: ldq_u %0,0(%3)\n" \
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"2: ldq_u %1,1(%3)\n" \
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" extwl %0,%3,%0\n" \
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" extwh %1,%3,%1\n" \
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" or %0,%1,%0\n" \
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"3:\n" \
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EXC(1b,3b,%0,%2) \
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EXC(2b,3b,%0,%2) \
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: "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \
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: "r"(addr), "2"(__gu_err)); \
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}
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#define __get_user_8(addr) \
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__asm__("1: ldq_u %0,0(%2)\n" \
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" extbl %0,%2,%0\n" \
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"2:\n" \
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EXC(1b,2b,%0,%1) \
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: "=&r"(__gu_val), "=r"(__gu_err) \
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: "r"(addr), "1"(__gu_err))
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#endif
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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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long __pu_err = 0; \
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__chk_user_ptr(ptr); \
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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) \
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({ \
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long __pu_err = -EFAULT; \
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__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
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if (__access_ok((unsigned long)__pu_addr, size)) { \
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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__("1: stq %r2,%1\n" \
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"2:\n" \
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EXC(1b,2b,$31,%0) \
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: "=r"(__pu_err) \
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: "m" (__m(addr)), "rJ" (x), "0"(__pu_err))
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#define __put_user_32(x, addr) \
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__asm__ __volatile__("1: stl %r2,%1\n" \
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"2:\n" \
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EXC(1b,2b,$31,%0) \
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: "=r"(__pu_err) \
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: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
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#ifdef __alpha_bwx__
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/* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */
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#define __put_user_16(x, addr) \
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__asm__ __volatile__("1: stw %r2,%1\n" \
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"2:\n" \
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EXC(1b,2b,$31,%0) \
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: "=r"(__pu_err) \
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: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
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#define __put_user_8(x, addr) \
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__asm__ __volatile__("1: stb %r2,%1\n" \
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"2:\n" \
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EXC(1b,2b,$31,%0) \
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: "=r"(__pu_err) \
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: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
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#else
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/* Unfortunately, we can't get an unaligned access trap for the sub-word
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write, so we have to do a general unaligned operation. */
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#define __put_user_16(x, addr) \
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{ \
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long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \
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__asm__ __volatile__( \
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"1: ldq_u %2,1(%5)\n" \
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"2: ldq_u %1,0(%5)\n" \
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" inswh %6,%5,%4\n" \
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" inswl %6,%5,%3\n" \
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" mskwh %2,%5,%2\n" \
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" mskwl %1,%5,%1\n" \
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" or %2,%4,%2\n" \
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" or %1,%3,%1\n" \
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"3: stq_u %2,1(%5)\n" \
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"4: stq_u %1,0(%5)\n" \
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"5:\n" \
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EXC(1b,5b,$31,%0) \
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EXC(2b,5b,$31,%0) \
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EXC(3b,5b,$31,%0) \
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EXC(4b,5b,$31,%0) \
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: "=r"(__pu_err), "=&r"(__pu_tmp1), \
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"=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \
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"=&r"(__pu_tmp4) \
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: "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \
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}
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#define __put_user_8(x, addr) \
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{ \
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long __pu_tmp1, __pu_tmp2; \
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__asm__ __volatile__( \
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"1: ldq_u %1,0(%4)\n" \
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" insbl %3,%4,%2\n" \
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" mskbl %1,%4,%1\n" \
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" or %1,%2,%1\n" \
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"2: stq_u %1,0(%4)\n" \
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"3:\n" \
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EXC(1b,3b,$31,%0) \
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EXC(2b,3b,$31,%0) \
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: "=r"(__pu_err), \
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"=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \
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: "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \
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}
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#endif
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/*
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* Complex access routines
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*/
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extern long __copy_user(void *to, const void *from, long len);
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static inline unsigned long
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raw_copy_from_user(void *to, const void __user *from, unsigned long len)
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{
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return __copy_user(to, (__force const void *)from, len);
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}
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static inline unsigned long
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raw_copy_to_user(void __user *to, const void *from, unsigned long len)
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{
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return __copy_user((__force void *)to, from, len);
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}
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extern long __clear_user(void __user *to, long len);
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extern inline long
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clear_user(void __user *to, long len)
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{
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if (__access_ok((unsigned long)to, len))
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len = __clear_user(to, len);
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return len;
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}
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#define user_addr_max() \
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(uaccess_kernel() ? ~0UL : TASK_SIZE)
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extern long strncpy_from_user(char *dest, const char __user *src, long count);
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extern __must_check long strnlen_user(const char __user *str, long n);
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#include <asm/extable.h>
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#endif /* __ALPHA_UACCESS_H */
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