1 .\" $NetBSD: fetch.9,v 1.2 1996/01/09 21:59:24 perry Exp $
3 .\" Copyright (c) 1996 Jason R. Thorpe.
4 .\" All rights reserved.
6 .\" This code is derived from software contributed by Kenneth Stailey.
8 .\" Redistribution and use in source and binary forms, with or without
9 .\" modification, are permitted provided that the following conditions
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13 .\" 2. Redistributions in binary form must reproduce the above copyright
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18 .\" This product includes software developed for the NetBSD Project
19 .\" by Jason R. Thorpe.
20 .\" 4. The name of the author may not be used to endorse or promote products
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51 .Nd fetch data from user-space
56 .Fn fubyte "volatile const void *base"
58 .Fn fuword "volatile const void *base"
60 .Fn fuword16 "volatile const void *base"
62 .Fn fuword32 "volatile const void *base"
64 .Fn fuword64 "volatile const void *base"
66 .Fn fueword "volatile const void *base" "long *val"
68 .Fn fueword32 "volatile const void *base" "int32_t *val"
70 .Fn fueword64 "volatile const void *base" "int64_t *val"
73 .Fn fuswintr "void *base"
77 functions are designed to copy small amounts of data from user-space
78 of the current process.
79 If read is successful, it is performed atomically.
80 The data read must be naturally aligned.
84 routines provide the following functionality:
85 .Bl -tag -width "fueword32()"
87 Fetches a byte of data from the user-space address
89 The byte read is zero-extended into the results variable.
91 Fetches a word of data (long) from the user-space address
94 Fetches 16 bits of data from the user-space address
96 The half-word read is zero-extended into the results variable.
98 Fetches 32 bits of data from the user-space address
101 Fetches 64 bits of data from the user-space address
104 Fetches a short word of data from the user-space address
106 This function is safe to call during an interrupt context.
108 Fetches a word of data (long) from the user-space address
110 and stores the result in the variable pointed by
113 Fetches 32 bits of data from the user-space address
115 and stores the result in the variable pointed by
118 Fetches 64 bits of data from the user-space address
120 and stores the result in the variable pointed by
129 functions cannot distinguish between -1 read from
130 userspace and function failure.
140 functions return the data fetched or -1 on failure.
146 functions return 0 on success and -1 on failure.