xref: /freebsd/lib/libkvm/kvm_nlist.3 (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
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32.\"     @(#)kvm_nlist.3	8.1 (Berkeley) 6/4/93
33.\" $FreeBSD$
34.\"
35.Dd November 27, 2015
36.Dt KVM_NLIST 3
37.Os
38.Sh NAME
39.Nm kvm_nlist ,
40.Nm kvm_nlist2
41.Nd retrieve symbol table names from a kernel image
42.Sh LIBRARY
43.Lb libkvm
44.Sh SYNOPSIS
45.In kvm.h
46.In nlist.h
47.Ft int
48.Fn kvm_nlist "kvm_t *kd" "struct nlist *nl"
49.Ft int
50.Fn kvm_nlist2 "kvm_t *kd" "struct kvm_nlist *nl"
51.Sh DESCRIPTION
52The
53.Fn kvm_nlist
54function retrieves the symbol table entries indicated by the name list argument
55.Fa \&nl .
56This argument points to an array of nlist structures, terminated by
57an entry whose
58.Fa n_name
59field is
60.Dv NULL
61(see
62.Xr nlist 3 ) .
63Each symbol is looked up using the
64.Fa n_name
65field, and if found, the
66corresponding
67.Fa n_type
68and
69.Fa n_value
70fields are filled in.
71These fields are set
72to 0 if the symbol is not found.
73.Pp
74The
75.Xr kldsym 2
76system call is used to locate symbols in live kernels.
77This is a less than perfect
78emulation of the nlist values but has the advantage of being aware of kernel
79modules and is reasonably fast.
80.Pp
81The
82.Fn kvm_nlist2
83function retrieves the symbol table entries indicated by the name list argument
84.Fa nl .
85This argument points to an array of
86.Vt "struct kvm_nlist"
87structures,
88terminated by an entry whose
89.Fa n_name
90field is
91.Dv NULL
92These structures are similar to the nlist structures used by
93.Fn kvm_nlist
94except that the
95.Fa n_value
96field uses a different type
97.Pq Vt kvaddr_t
98to avoid truncation when examining non-native kernel images.
99.Sh RETURN VALUES
100The
101.Fn kvm_nlist
102and
103.Fn kvm_nlist2
104functions return the number of invalid entries found.
105If the kernel symbol table was unreadable, -1 is returned.
106.Sh SEE ALSO
107.Xr kldsym 2 ,
108.Xr kvm 3 ,
109.Xr kvm_close 3 ,
110.Xr kvm_getargv 3 ,
111.Xr kvm_getenvv 3 ,
112.Xr kvm_geterr 3 ,
113.Xr kvm_getprocs 3 ,
114.Xr kvm_native 3 ,
115.Xr kvm_open 3 ,
116.Xr kvm_openfiles 3 ,
117.Xr kvm_read 3 ,
118.Xr kvm_write 3
119