xref: /freebsd/lib/libkvm/kvm_nlist.3 (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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32.Dd November 27, 2015
33.Dt KVM_NLIST 3
34.Os
35.Sh NAME
36.Nm kvm_nlist ,
37.Nm kvm_nlist2
38.Nd retrieve symbol table names from a kernel image
39.Sh LIBRARY
40.Lb libkvm
41.Sh SYNOPSIS
42.In kvm.h
43.In nlist.h
44.Ft int
45.Fn kvm_nlist "kvm_t *kd" "struct nlist *nl"
46.Ft int
47.Fn kvm_nlist2 "kvm_t *kd" "struct kvm_nlist *nl"
48.Sh DESCRIPTION
49The
50.Fn kvm_nlist
51function retrieves the symbol table entries indicated by the name list argument
52.Fa \&nl .
53This argument points to an array of nlist structures, terminated by
54an entry whose
55.Fa n_name
56field is
57.Dv NULL
58(see
59.Xr nlist 3 ) .
60Each symbol is looked up using the
61.Fa n_name
62field, and if found, the
63corresponding
64.Fa n_type
65and
66.Fa n_value
67fields are filled in.
68These fields are set
69to 0 if the symbol is not found.
70.Pp
71The
72.Xr kldsym 2
73system call is used to locate symbols in live kernels.
74This is a less than perfect
75emulation of the nlist values but has the advantage of being aware of kernel
76modules and is reasonably fast.
77.Pp
78The
79.Fn kvm_nlist2
80function retrieves the symbol table entries indicated by the name list argument
81.Fa nl .
82This argument points to an array of
83.Vt "struct kvm_nlist"
84structures,
85terminated by an entry whose
86.Fa n_name
87field is
88.Dv NULL
89These structures are similar to the nlist structures used by
90.Fn kvm_nlist
91except that the
92.Fa n_value
93field uses a different type
94.Pq Vt kvaddr_t
95to avoid truncation when examining non-native kernel images.
96.Sh RETURN VALUES
97The
98.Fn kvm_nlist
99and
100.Fn kvm_nlist2
101functions return the number of invalid entries found.
102If the kernel symbol table was unreadable, -1 is returned.
103.Sh SEE ALSO
104.Xr kldsym 2 ,
105.Xr kvm 3 ,
106.Xr kvm_close 3 ,
107.Xr kvm_getargv 3 ,
108.Xr kvm_getenvv 3 ,
109.Xr kvm_geterr 3 ,
110.Xr kvm_getprocs 3 ,
111.Xr kvm_native 3 ,
112.Xr kvm_open 3 ,
113.Xr kvm_openfiles 3 ,
114.Xr kvm_read 3 ,
115.Xr kvm_write 3
116.Sh HISTORY
117The
118.Fn kvm_nlist2
119function first appeared in
120.Fx 11.0 .
121