Annotation of src/usr.bin/ktrace/ltrace.1, Revision 1.10
1.10 ! guenther 1: .\" $OpenBSD: ltrace.1,v 1.9 2016/03/06 20:25:27 guenther Exp $
1.1 miod 2: .\"
3: .\" Copyright (c) 2013 Miodrag Vallat.
4: .\"
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44: .\" from: @(#)ktrace.1 8.1 (Berkeley) 6/6/93
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1.10 ! guenther 46: .Dd $Mdocdate: March 6 2016 $
1.1 miod 47: .Dt LTRACE 1
48: .Os
49: .Sh NAME
50: .Nm ltrace
51: .Nd shared library function call tracer
52: .Sh SYNOPSIS
53: .Nm ltrace
54: .Op Fl ai
55: .Op Fl f Ar trfile
1.5 miod 56: .Op Fl t Ar trstr
1.1 miod 57: .Op Fl u Ar trspec
58: .Ar command
59: .Sh DESCRIPTION
60: .Nm ltrace
61: enables shared library function calls issued by the specified processes
62: to be traced using the
63: .Xr utrace 2
64: user tracing facility.
65: By default, call trace data is logged to the file
66: .Pa ktrace.out ,
67: unless overridden by the
68: .Fl f
69: option.
70: Each function call is traced as a pair of
71: .Dv KTRFAC_USER
72: entries;
73: the first entry contains the shared library containing the symbol being
74: called, and the second entry contains the symbol name.
75: .Pp
76: Once tracing is enabled on a process, trace data will be logged until
77: either the process exits or the trace point is cleared with
78: .Xr ktrace 1 .
79: A traced process can generate enormous amounts of log data quickly;
80: it is strongly suggested that users memorize how to disable tracing before
81: attempting to trace a process.
82: The following command is sufficient to disable tracing on all user owned
1.6 jmc 83: processes and, if executed by root, all processes:
1.1 miod 84: .Pp
85: .Dl $ ktrace -C
86: .Pp
87: The trace file is not human-readable; use
88: .Xr kdump 1
89: to decode it.
90: .Pp
91: The options are as follows:
92: .Bl -tag -width 9n
93: .It Fl a
94: Append to the trace file instead of recreating it.
95: .It Fl f Ar trfile
96: Log trace records to
97: .Ar trfile
98: instead of
99: .Pa ktrace.out .
100: .It Fl i
101: Inherit; pass the trace flags to all future children of the designated
102: processes.
1.5 miod 103: .It Fl t Ar trstr
104: The string argument represents the kernel trace points, one per letter.
1.10 ! guenther 105: The default is just
! 106: .Cm u .
! 107: The following table equates the letters with the trace points:
1.5 miod 108: .Pp
109: .Bl -tag -width flag -offset indent -compact
110: .It Cm c
111: trace system calls
112: .It Cm i
113: trace I/O
114: .It Cm n
115: trace namei translations
1.10 ! guenther 116: .It Cm p
! 117: trace violation of
! 118: .Xr pledge 2
! 119: restrictions
1.5 miod 120: .It Cm s
121: trace signal processing
122: .It Cm t
123: trace various structures
124: .It Cm u
125: trace user data coming from
126: .Xr utrace 2
1.9 guenther 127: .It Cm x
128: trace argument vector in
129: .Xr execve 2
130: .It Cm X
131: trace environment in
132: .Xr execve 2
1.5 miod 133: .It Cm +
134: trace the default points
1.9 guenther 135: .El
1.1 miod 136: .It Fl u Ar trspec
137: Restrict the trace to a list of shared objects and/or function names, as
138: specified by the
139: .Ar trspec
140: argument.
141: The trace specification is a comma-separated list of library names,
142: followed by a colon
1.2 jmc 143: .Pq :\& ,
144: and a comma-separated list of function names.
1.1 miod 145: Each list can be empty.
1.2 jmc 146: Each list member may end with a star
1.1 miod 147: .Pq *
148: to only match the beginning of a name.
1.4 jmc 149: An exclamation mark at the beginning of a list turns it into a rejection list,
1.1 miod 150: causing all unmatched names to be traced.
151: Library names are compared without their version number and
152: .Sq .so
153: suffix.
1.2 jmc 154: .It Ar command
155: Execute
156: .Ar command
157: with the specified trace flags.
1.1 miod 158: .El
159: .Sh FILES
1.2 jmc 160: .Bl -tag -width ktrace.outXXX -compact
1.1 miod 161: .It Pa ktrace.out
1.2 jmc 162: Default
163: .Nm
164: dump file.
1.1 miod 165: .El
166: .Sh EXAMPLES
167: Trace all shared library function calls from
168: .Xr wc 1
169: reading the message of the day:
170: .Dl $ ltrace wc -lh /etc/motd
171: .Pp
172: Trace only the shared library function calls in
173: .Pa libutil.so :
174: .Dl $ ltrace -u libutil wc -lh /etc/motd
175: .Pp
176: Trace all the shared library function calls but those in
177: .Pa libc.so :
178: .Dl $ ltrace -u \(dq!libc\(dq wc -lh /etc/motd
179: .Pp
1.2 jmc 180: Trace all the shared library function calls with names starting
1.3 jmc 181: .Qq fmt :
1.1 miod 182: .Dl $ ltrace -u \(dq:fmt*\(dq wc -lh /etc/motd
1.5 miod 183: .Pp
184: Trace all shared library function calls, as well as all system calls:
185: .Dl $ ltrace -t cu wc -lh /etc/motd
1.1 miod 186: .Sh SEE ALSO
187: .Xr kdump 1 ,
188: .Xr ktrace 1 ,
189: .Xr ktrace 2 ,
190: .Xr utrace 2
1.5 miod 191: .Sh HISTORY
192: The
193: .Nm ltrace
194: command appeared in
195: .Ox 5.4 .