freebsd-skq/lib/libc/sys/kldsym.2

.\" Copyright (c) 2001 Chris Costello <chris@FreeBSD.org>
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.Dd July 26, 2001
.Dt KLDSYM 2
.Os
.Sh NAME
.Nm kldsym
.Nd look up address by symbol name in a KLD
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/param.h
.In sys/linker.h
.Ft int
.Fn kldsym "int fileid" "int command" "void *data"
.Sh DESCRIPTION
The
.Fn kldsym
function returns the address of the symbol specified in
.Fa data
in the module specified by
.Fa fileid .
If
.Fa fileid
is 0, all loaded modules are searched.
Currently, the only
.Fa command
implemented is
.Dv KLDSYM_LOOKUP .
.Pp
The
.Fa data
argument is of the following structure:
.Pp
.Bd -literal -offset indent
struct kld_sym_lookup {
    int         version;        /* sizeof(struct kld_sym_lookup) */
    char        *symname;       /* Symbol name we are looking up */
    u_long      symvalue;
    size_t      symsize;
};
.Ed
.Pp
The
.Va version
member is to be set
by the code calling
.Fn kldsym
to
.Fn sizeof "struct kld_sym_lookup" .
The next two members,
.Va version
and
.Va symname ,
are specified by the user.
The last two,
.Va symvalue
and
.Va symsize
are filled in by
.Fn kldsym
and contain the address associated with
.Va symname
and the size of the data it points to, respectively.
.Sh RETURN VALUES
.Rv -std kldsym
.Sh ERRORS
The
.Fn kldsym
function will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
Invalid value in
.Fa data->version
or
.Fa command .
.It Bq Er ENOENT
.Fa fileid
is invalid,
or the specified symbol could not be found.
.El
.Sh SEE ALSO
.Xr kldfind 2 ,
.Xr kldfirstmod 2 ,
.Xr kldload 2 ,
.Xr kldnext 2 ,
.Xr kldunload 2 ,
.Xr modfind 2 ,
.Xr modnext 2 ,
.Xr modstat 2 ,
.Xr kld 4
.Sh HISTORY
The
.Fn kldsym
function first appeared in
.Fx 3.0 .