439 lines
11 KiB
C
439 lines
11 KiB
C
/*
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* S390 version
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* Copyright IBM Corp. 1999, 2000
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* Author(s): Hartmut Penner (hp@de.ibm.com),
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* Martin Schwidefsky (schwidefsky@de.ibm.com)
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*
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* Derived from "include/asm-i386/uaccess.h"
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*/
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#ifndef __S390_UACCESS_H
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#define __S390_UACCESS_H
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/*
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* User space memory access functions
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*/
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <asm/ctl_reg.h>
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#define VERIFY_READ 0
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#define VERIFY_WRITE 1
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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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* For historical reasons, these macros are grossly misnamed.
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*/
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#define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
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#define KERNEL_DS MAKE_MM_SEG(0)
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#define USER_DS MAKE_MM_SEG(1)
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#define get_ds() (KERNEL_DS)
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#define get_fs() (current->thread.mm_segment)
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#define set_fs(x) \
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({ \
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unsigned long __pto; \
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current->thread.mm_segment = (x); \
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__pto = current->thread.mm_segment.ar4 ? \
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S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
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__ctl_load(__pto, 7, 7); \
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})
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#define segment_eq(a,b) ((a).ar4 == (b).ar4)
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static inline int __range_ok(unsigned long addr, unsigned long size)
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{
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return 1;
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}
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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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__range_ok((unsigned long)(addr), (size)); \
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})
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#define access_ok(type, addr, size) __access_ok(addr, size)
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/*
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* The exception table consists of pairs of addresses: the first is the
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* address of an instruction that is allowed to fault, and the second is
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* the address at which the program should continue. No registers are
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* modified, so it is entirely up to the continuation code to figure out
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* what to do.
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*
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* All the routines below use bits of fixup code that are out of line
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* with the main instruction path. This means when everything is well,
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* we don't even have to jump over them. Further, they do not intrude
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* on our cache or tlb entries.
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*/
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struct exception_table_entry
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{
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int insn, fixup;
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};
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static inline unsigned long extable_fixup(const struct exception_table_entry *x)
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{
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return (unsigned long)&x->fixup + x->fixup;
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}
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#define ARCH_HAS_RELATIVE_EXTABLE
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/**
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* __copy_from_user: - Copy a block of data from user space, with less checking.
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* @to: Destination address, in kernel space.
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* @from: Source address, in user space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only. This function may sleep if pagefaults are
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* enabled.
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*
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* Copy data from user space to kernel space. Caller must check
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* the specified block with access_ok() before calling this function.
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*
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* Returns number of bytes that could not be copied.
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* On success, this will be zero.
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*
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* If some data could not be copied, this function will pad the copied
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* data to the requested size using zero bytes.
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*/
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unsigned long __must_check __copy_from_user(void *to, const void __user *from,
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unsigned long n);
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/**
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* __copy_to_user: - Copy a block of data into user space, with less checking.
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* @to: Destination address, in user space.
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* @from: Source address, in kernel space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only. This function may sleep if pagefaults are
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* enabled.
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*
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* Copy data from kernel space to user space. Caller must check
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* the specified block with access_ok() before calling this function.
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*
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* Returns number of bytes that could not be copied.
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* On success, this will be zero.
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*/
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unsigned long __must_check __copy_to_user(void __user *to, const void *from,
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unsigned long n);
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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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#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
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#define __put_get_user_asm(to, from, size, spec) \
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({ \
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register unsigned long __reg0 asm("0") = spec; \
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int __rc; \
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\
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asm volatile( \
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"0: mvcos %1,%3,%2\n" \
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"1: xr %0,%0\n" \
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"2:\n" \
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".pushsection .fixup, \"ax\"\n" \
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"3: lhi %0,%5\n" \
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" jg 2b\n" \
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".popsection\n" \
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EX_TABLE(0b,3b) EX_TABLE(1b,3b) \
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: "=d" (__rc), "+Q" (*(to)) \
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: "d" (size), "Q" (*(from)), \
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"d" (__reg0), "K" (-EFAULT) \
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: "cc"); \
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__rc; \
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})
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static __always_inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
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{
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unsigned long spec = 0x810000UL;
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int rc;
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switch (size) {
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case 1:
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rc = __put_get_user_asm((unsigned char __user *)ptr,
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(unsigned char *)x,
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size, spec);
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break;
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case 2:
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rc = __put_get_user_asm((unsigned short __user *)ptr,
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(unsigned short *)x,
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size, spec);
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break;
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case 4:
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rc = __put_get_user_asm((unsigned int __user *)ptr,
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(unsigned int *)x,
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size, spec);
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break;
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case 8:
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rc = __put_get_user_asm((unsigned long __user *)ptr,
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(unsigned long *)x,
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size, spec);
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break;
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};
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return rc;
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}
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static __always_inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
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{
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unsigned long spec = 0x81UL;
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int rc;
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switch (size) {
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case 1:
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rc = __put_get_user_asm((unsigned char *)x,
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(unsigned char __user *)ptr,
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size, spec);
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break;
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case 2:
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rc = __put_get_user_asm((unsigned short *)x,
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(unsigned short __user *)ptr,
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size, spec);
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break;
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case 4:
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rc = __put_get_user_asm((unsigned int *)x,
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(unsigned int __user *)ptr,
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size, spec);
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break;
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case 8:
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rc = __put_get_user_asm((unsigned long *)x,
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(unsigned long __user *)ptr,
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size, spec);
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break;
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};
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return rc;
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}
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#else /* CONFIG_HAVE_MARCH_Z10_FEATURES */
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static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
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{
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size = __copy_to_user(ptr, x, size);
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return size ? -EFAULT : 0;
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}
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static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
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{
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size = __copy_from_user(x, ptr, size);
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return size ? -EFAULT : 0;
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}
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#endif /* CONFIG_HAVE_MARCH_Z10_FEATURES */
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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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#define __put_user(x, ptr) \
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({ \
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__typeof__(*(ptr)) __x = (x); \
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int __pu_err = -EFAULT; \
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__chk_user_ptr(ptr); \
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switch (sizeof (*(ptr))) { \
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case 1: \
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case 2: \
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case 4: \
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case 8: \
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__pu_err = __put_user_fn(&__x, ptr, \
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sizeof(*(ptr))); \
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break; \
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default: \
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__put_user_bad(); \
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break; \
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} \
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__builtin_expect(__pu_err, 0); \
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})
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#define put_user(x, ptr) \
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({ \
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might_fault(); \
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__put_user(x, ptr); \
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})
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int __put_user_bad(void) __attribute__((noreturn));
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#define __get_user(x, ptr) \
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({ \
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int __gu_err = -EFAULT; \
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__chk_user_ptr(ptr); \
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switch (sizeof(*(ptr))) { \
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case 1: { \
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unsigned char __x = 0; \
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__gu_err = __get_user_fn(&__x, ptr, \
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sizeof(*(ptr))); \
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \
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break; \
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}; \
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case 2: { \
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unsigned short __x = 0; \
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__gu_err = __get_user_fn(&__x, ptr, \
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sizeof(*(ptr))); \
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \
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break; \
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}; \
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case 4: { \
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unsigned int __x = 0; \
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__gu_err = __get_user_fn(&__x, ptr, \
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sizeof(*(ptr))); \
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \
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break; \
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}; \
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case 8: { \
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unsigned long long __x = 0; \
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__gu_err = __get_user_fn(&__x, ptr, \
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sizeof(*(ptr))); \
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \
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break; \
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}; \
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default: \
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__get_user_bad(); \
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break; \
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} \
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__builtin_expect(__gu_err, 0); \
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})
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#define get_user(x, ptr) \
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({ \
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might_fault(); \
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__get_user(x, ptr); \
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})
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int __get_user_bad(void) __attribute__((noreturn));
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#define __put_user_unaligned __put_user
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#define __get_user_unaligned __get_user
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extern void __compiletime_error("usercopy buffer size is too small")
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__bad_copy_user(void);
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static inline void copy_user_overflow(int size, unsigned long count)
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{
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WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
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}
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/**
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* copy_to_user: - Copy a block of data into user space.
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* @to: Destination address, in user space.
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* @from: Source address, in kernel space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only. This function may sleep if pagefaults are
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* enabled.
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*
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* Copy data from kernel space to user space.
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*
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* Returns number of bytes that could not be copied.
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* On success, this will be zero.
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*/
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static inline unsigned long __must_check
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copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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might_fault();
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return __copy_to_user(to, from, n);
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}
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/**
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* copy_from_user: - Copy a block of data from user space.
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* @to: Destination address, in kernel space.
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* @from: Source address, in user space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only. This function may sleep if pagefaults are
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* enabled.
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*
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* Copy data from user space to kernel space.
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*
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* Returns number of bytes that could not be copied.
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* On success, this will be zero.
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*
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* If some data could not be copied, this function will pad the copied
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* data to the requested size using zero bytes.
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*/
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static inline unsigned long __must_check
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copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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unsigned int sz = __compiletime_object_size(to);
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might_fault();
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if (unlikely(sz != -1 && sz < n)) {
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if (!__builtin_constant_p(n))
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copy_user_overflow(sz, n);
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else
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__bad_copy_user();
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return n;
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}
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return __copy_from_user(to, from, n);
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}
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unsigned long __must_check
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__copy_in_user(void __user *to, const void __user *from, unsigned long n);
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static inline unsigned long __must_check
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copy_in_user(void __user *to, const void __user *from, unsigned long n)
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{
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might_fault();
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return __copy_in_user(to, from, n);
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}
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/*
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* Copy a null terminated string from userspace.
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*/
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long __strncpy_from_user(char *dst, const char __user *src, long count);
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static inline long __must_check
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strncpy_from_user(char *dst, const char __user *src, long count)
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{
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might_fault();
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return __strncpy_from_user(dst, src, count);
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}
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unsigned long __must_check __strnlen_user(const char __user *src, unsigned long count);
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static inline unsigned long strnlen_user(const char __user *src, unsigned long n)
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{
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might_fault();
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return __strnlen_user(src, n);
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}
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/**
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* strlen_user: - Get the size of a string in user space.
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* @str: The string to measure.
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*
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* Context: User context only. This function may sleep if pagefaults are
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* enabled.
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*
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* Get the size of a NUL-terminated string in user space.
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*
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* Returns the size of the string INCLUDING the terminating NUL.
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* On exception, returns 0.
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*
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* If there is a limit on the length of a valid string, you may wish to
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* consider using strnlen_user() instead.
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*/
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#define strlen_user(str) strnlen_user(str, ~0UL)
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/*
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* Zero Userspace
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*/
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unsigned long __must_check __clear_user(void __user *to, unsigned long size);
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static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
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{
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might_fault();
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return __clear_user(to, n);
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}
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int copy_to_user_real(void __user *dest, void *src, unsigned long count);
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void s390_kernel_write(void *dst, const void *src, size_t size);
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#endif /* __S390_UACCESS_H */
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