Differential D15102 Diff 41584 head/share/man/man9/fetch.9

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head/share/man/man9/fetch.9

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	.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED			.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
	.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,			.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY			.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF			.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	.\" SUCH DAMAGE.			.\" SUCH DAMAGE.
	.\"			.\"
	.\" $FreeBSD$			.\" $FreeBSD$
	.\"			.\"
	.Dd October 29, 2014			.Dd April 17, 2018
	.Dt FETCH 9			.Dt FETCH 9
	.Os			.Os
	.Sh NAME			.Sh NAME
	.Nm fetch ,			.Nm fetch ,
	.Nm fubyte ,			.Nm fubyte ,
	.Nm fuswintr ,
	.Nm fuword ,			.Nm fuword ,
	.Nm fuword16 ,			.Nm fuword16 ,
	.Nm fuword32 ,			.Nm fuword32 ,
	.Nm fuword64 ,			.Nm fuword64 ,
	.Nm fueword ,			.Nm fueword ,
	.Nm fueword32 ,			.Nm fueword32 ,
	.Nm fueword64			.Nm fueword64
	.Nd fetch data from user-space			.Nd fetch data from user-space
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	.Fn fuword64 "volatile const void *base"			.Fn fuword64 "volatile const void *base"
	.Ft long			.Ft long
	.Fn fueword "volatile const void base" "long val"			.Fn fueword "volatile const void base" "long val"
	.Ft int32_t			.Ft int32_t
	.Fn fueword32 "volatile const void base" "int32_t val"			.Fn fueword32 "volatile const void base" "int32_t val"
	.Ft int64_t			.Ft int64_t
	.Fn fueword64 "volatile const void base" "int64_t val"			.Fn fueword64 "volatile const void base" "int64_t val"
	.In sys/resourcevar.h			.In sys/resourcevar.h
	.Ft int
	.Fn fuswintr "void *base"
	.Sh DESCRIPTION			.Sh DESCRIPTION
	The			The
	.Nm			.Nm
	functions are designed to copy small amounts of data from user-space			functions are designed to copy small amounts of data from user-space
	of the current process.			of the current process.
	If read is successful, it is performed atomically.			If read is successful, it is performed atomically.
	The data read must be naturally aligned.			The data read must be naturally aligned.
	.Pp			.Pp
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	.Pa base .			.Pa base .
	The half-word read is zero-extended into the results variable.			The half-word read is zero-extended into the results variable.
	.It Fn fuword32			.It Fn fuword32
	Fetches 32 bits of data from the user-space address			Fetches 32 bits of data from the user-space address
	.Pa base .			.Pa base .
	.It Fn fuword64			.It Fn fuword64
	Fetches 64 bits of data from the user-space address			Fetches 64 bits of data from the user-space address
	.Pa base .			.Pa base .
	.It Fn fuswintr
	Fetches a short word of data from the user-space address
	.Pa base .
	This function is safe to call during an interrupt context.
	.It Fn fueword			.It Fn fueword
	Fetches a word of data (long) from the user-space address			Fetches a word of data (long) from the user-space address
	.Pa base			.Pa base
	and stores the result in the variable pointed by			and stores the result in the variable pointed by
	.Pa val .			.Pa val .
	.It Fn fueword32			.It Fn fueword32
	Fetches 32 bits of data from the user-space address			Fetches 32 bits of data from the user-space address
	.Pa base			.Pa base
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	functions cannot distinguish between -1 read from			functions cannot distinguish between -1 read from
	userspace and function failure.			userspace and function failure.
	.Sh RETURN VALUES			.Sh RETURN VALUES
	The			The
	.Fn fubyte ,			.Fn fubyte ,
	.Fn fuword ,			.Fn fuword ,
	.Fn fuword16 ,			.Fn fuword16 ,
	.Fn fuword32 ,			.Fn fuword32 ,
	.Fn fuword64 ,
	and			and
	.Fn fuswintr			.Fn fuword64
	functions return the data fetched or -1 on failure.			functions return the data fetched or -1 on failure.
	The			The
	.Fn fueword ,			.Fn fueword ,
	.Fn fueword32			.Fn fueword32
	and			and
	.Fn fueword64			.Fn fueword64
	functions return 0 on success and -1 on failure.			functions return 0 on success and -1 on failure.
	.Sh SEE ALSO			.Sh SEE ALSO
	.Xr copy 9 ,			.Xr copy 9 ,
	.Xr store 9			.Xr store 9