xref: /freebsd/lib/libsys/kldsym.2 (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
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25.Dd October 17, 2016
26.Dt KLDSYM 2
27.Os
28.Sh NAME
29.Nm kldsym
30.Nd look up address by symbol name in a KLD
31.Sh LIBRARY
32.Lb libc
33.Sh SYNOPSIS
34.In sys/param.h
35.In sys/linker.h
36.Ft int
37.Fn kldsym "int fileid" "int cmd" "void *data"
38.Sh DESCRIPTION
39The
40.Fn kldsym
41system call returns the address of the symbol specified in
42.Fa data
43in the module specified by
44.Fa fileid .
45If
46.Fa fileid
47is 0, all loaded modules are searched.
48Currently, the only
49.Fa cmd
50implemented is
51.Dv KLDSYM_LOOKUP .
52.Pp
53The
54.Fa data
55argument is of the following structure:
56.Bd -literal -offset indent
57struct kld_sym_lookup {
58    int         version;        /* sizeof(struct kld_sym_lookup) */
59    char        *symname;       /* Symbol name we are looking up */
60    u_long      symvalue;
61    size_t      symsize;
62};
63.Ed
64.Pp
65The
66.Va version
67member is to be set
68by the code calling
69.Fn kldsym
70to
71.Fn sizeof "struct kld_sym_lookup" .
72The next two members,
73.Va version
74and
75.Va symname ,
76are specified by the user.
77The last two,
78.Va symvalue
79and
80.Va symsize ,
81are filled in by
82.Fn kldsym
83and contain the address associated with
84.Va symname
85and the size of the data it points to, respectively.
86.Sh RETURN VALUES
87.Rv -std kldsym
88.Sh ERRORS
89The
90.Fn kldsym
91system call will fail if:
92.Bl -tag -width Er
93.It Bq Er EINVAL
94Invalid value in
95.Fa data->version
96or
97.Fa cmd .
98.It Bq Er ENOENT
99The
100.Fa fileid
101argument
102is invalid,
103or the specified symbol could not be found.
104.El
105.Sh SEE ALSO
106.Xr kldfind 2 ,
107.Xr kldfirstmod 2 ,
108.Xr kldload 2 ,
109.Xr kldnext 2 ,
110.Xr kldunload 2 ,
111.Xr modfind 2 ,
112.Xr modnext 2 ,
113.Xr modstat 2 ,
114.Xr kld 4
115.Sh HISTORY
116The
117.Fn kldsym
118system call first appeared in
119.Fx 3.0 .
120