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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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d2ad824f4b
Allow accessing 64-bit values in userspace from a 32-bit kernel. The access is not atomic. Signed-off-by: Helge Deller <deller@gmx.de>
238 lines
7.6 KiB
C
238 lines
7.6 KiB
C
#ifndef __PARISC_UACCESS_H
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#define __PARISC_UACCESS_H
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/*
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* User space memory access functions
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*/
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#include <asm/page.h>
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#include <asm/cache.h>
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#include <asm/errno.h>
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#include <asm-generic/uaccess-unaligned.h>
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#include <linux/bug.h>
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#define VERIFY_READ 0
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#define VERIFY_WRITE 1
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#define KERNEL_DS ((mm_segment_t){0})
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#define USER_DS ((mm_segment_t){1})
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#define segment_eq(a, b) ((a).seg == (b).seg)
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#define get_ds() (KERNEL_DS)
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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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/*
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* Note that since kernel addresses are in a separate address space on
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* parisc, we don't need to do anything for access_ok().
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* We just let the page fault handler do the right thing. This also means
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* that put_user is the same as __put_user, etc.
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*/
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static inline long access_ok(int type, const void __user * addr,
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unsigned long size)
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{
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return 1;
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}
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#define put_user __put_user
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#define get_user __get_user
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#if !defined(CONFIG_64BIT)
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#define LDD_USER(ptr) __get_user_asm64(ptr)
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#define STD_USER(x, ptr) __put_user_asm64(x, ptr)
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#else
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#define LDD_USER(ptr) __get_user_asm("ldd", ptr)
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#define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
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#endif
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/*
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* The exception table contains two values: the first is the relative offset to
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* the address of the instruction that is allowed to fault, and the second is
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* the relative offset to the address of the fixup routine. Since relative
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* addresses are used, 32bit values are sufficient even on 64bit kernel.
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*/
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#define ARCH_HAS_RELATIVE_EXTABLE
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struct exception_table_entry {
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int insn; /* relative address of insn that is allowed to fault. */
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int fixup; /* relative address of fixup routine */
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};
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#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
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".section __ex_table,\"aw\"\n" \
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".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
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".previous\n"
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/*
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* The page fault handler stores, in a per-cpu area, the following information
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* if a fixup routine is available.
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*/
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struct exception_data {
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unsigned long fault_ip;
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unsigned long fault_gp;
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unsigned long fault_space;
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unsigned long fault_addr;
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};
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/*
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* load_sr2() preloads the space register %%sr2 - based on the value of
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* get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
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* is 0), or with the current value of %%sr3 to access user space (USER_DS)
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* memory. The following __get_user_asm() and __put_user_asm() functions have
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* %%sr2 hard-coded to access the requested memory.
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*/
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#define load_sr2() \
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__asm__(" or,= %0,%%r0,%%r0\n\t" \
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" mfsp %%sr3,%0\n\t" \
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" mtsp %0,%%sr2\n\t" \
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: : "r"(get_fs()) : )
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#define __get_user(x, ptr) \
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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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\
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load_sr2(); \
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switch (sizeof(*(ptr))) { \
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case 1: __get_user_asm("ldb", ptr); break; \
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case 2: __get_user_asm("ldh", ptr); break; \
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case 4: __get_user_asm("ldw", ptr); break; \
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case 8: LDD_USER(ptr); break; \
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default: BUILD_BUG(); 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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#define __get_user_asm(ldx, ptr) \
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__asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
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: "=r"(__gu_val), "=r"(__gu_err) \
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: "r"(ptr), "1"(__gu_err) \
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: "r1");
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#if !defined(CONFIG_64BIT)
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#define __get_user_asm64(ptr) \
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__asm__("\n1:\tldw 0(%%sr2,%2),%0" \
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"\n2:\tldw 4(%%sr2,%2),%R0\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_2)\
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ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_get_user_skip_1)\
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: "=r"(__gu_val), "=r"(__gu_err) \
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: "r"(ptr), "1"(__gu_err) \
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: "r1");
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#endif /* !defined(CONFIG_64BIT) */
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#define __put_user(x, ptr) \
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({ \
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register long __pu_err __asm__ ("r8") = 0; \
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__typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
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\
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load_sr2(); \
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switch (sizeof(*(ptr))) { \
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case 1: __put_user_asm("stb", __x, ptr); break; \
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case 2: __put_user_asm("sth", __x, ptr); break; \
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case 4: __put_user_asm("stw", __x, ptr); break; \
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case 8: STD_USER(__x, ptr); break; \
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default: BUILD_BUG(); 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/kernel_asm()" macros tell gcc they read from memory
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* instead of writing. This is because they do not write to any memory
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* gcc knows about, so there are no aliasing issues. These macros must
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* also be aware that "fixup_put_user_skip_[12]" are executed in the
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* context of the fault, and any registers used there must be listed
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* as clobbers. In this case only "r1" is used by the current routines.
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* r8/r9 are already listed as err/val.
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*/
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#define __put_user_asm(stx, x, ptr) \
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__asm__ __volatile__ ( \
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"\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
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: "=r"(__pu_err) \
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: "r"(ptr), "r"(x), "0"(__pu_err) \
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: "r1")
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#if !defined(CONFIG_64BIT)
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#define __put_user_asm64(__val, ptr) do { \
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__asm__ __volatile__ ( \
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"\n1:\tstw %2,0(%%sr2,%1)" \
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"\n2:\tstw %R2,4(%%sr2,%1)\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
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ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
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: "=r"(__pu_err) \
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: "r"(ptr), "r"(__val), "0"(__pu_err) \
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: "r1"); \
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} while (0)
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#endif /* !defined(CONFIG_64BIT) */
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/*
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* Complex access routines -- external declarations
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*/
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extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
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extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
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extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
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extern long strncpy_from_user(char *, const char __user *, long);
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extern unsigned lclear_user(void __user *, unsigned long);
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extern long lstrnlen_user(const char __user *, long);
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/*
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* Complex access routines -- macros
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*/
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#define user_addr_max() (~0UL)
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#define strnlen_user lstrnlen_user
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#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
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#define clear_user lclear_user
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#define __clear_user lclear_user
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unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
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#define __copy_to_user copy_to_user
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unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
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unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
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#define __copy_in_user copy_in_user
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#define __copy_to_user_inatomic __copy_to_user
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#define __copy_from_user_inatomic __copy_from_user
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extern void copy_from_user_overflow(void)
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#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
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__compiletime_error("copy_from_user() buffer size is not provably correct")
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#else
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__compiletime_warning("copy_from_user() buffer size is not provably correct")
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#endif
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;
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static inline unsigned long __must_check copy_from_user(void *to,
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const void __user *from,
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unsigned long n)
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{
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int sz = __compiletime_object_size(to);
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int ret = -EFAULT;
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if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
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ret = __copy_from_user(to, from, n);
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else
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copy_from_user_overflow();
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return ret;
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}
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struct pt_regs;
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int fixup_exception(struct pt_regs *regs);
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#endif /* __PARISC_UACCESS_H */
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