3 # Copyright (C) 2007-2009 Ksplice, Inc.
4 # Authors: Jeff Arnold, Anders Kaseorg, Tim Abbott
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License, version 2.
9 # This program is distributed in the hope that it will be useful,
10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 # GNU General Public License for more details.
14 # You should have received a copy of the GNU General Public License
15 # along with this program; if not, write to the Free Software
16 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
21 use lib
'KSPLICE_DATA_DIR';
23 my $have_usleep = eval { require Time
::HiRes
};
27 GetOptions
(@common_options,
29 "debugfile=s" => \
$debug) or pod2usage
(1);
31 pod2usage
(1) if($help || scalar(@ARGV) != 1);
32 $debugon = 1 if (defined($debug));
33 $debug = abs_path
($debug) if (defined $debug);
36 $kid =~ s/^ksplice[-_]//;
38 my $update = "ksplice_$kid";
39 my $nounload = runstr
("lsmod") =~ m/- $/m;
41 if (!update_loaded
($kid)) {
42 print "Ksplice id $kid is not present in the kernel\n";
46 chdir("/sys/module/");
47 set_debug_level
($kid, $debugon);
48 my $stage = get_stage
($kid);
49 if ($stage ne 'applied') {
50 print "Ksplice id $kid is not applied\n";
53 set_stage
($kid, "reversed");
56 $stage = get_stage
($kid);
58 $failed = 1 if ($stage ne 'reversed');
59 foreach my $module (glob("${update}_*")) {
60 if (!$nounload && runval_raw
('rmmod', $module) != 0) {
66 set_stage
($kid, "cleanup");
69 while (update_loaded
($kid) && $count < 5) {
70 Time
::HiRes
::usleep
(100000);
74 sleep(1) if (!update_loaded
($kid));
77 if ($failed == 0 && -e
"/sys/module/$update") {
78 if (!$nounload && runval_raw
('rmmod', $update) != 0) {
83 unless($failed == 0) {
84 my $debugfile = get_debug_output
($kid, $debug);
85 print STDERR
"Error undoing Ksplice update $kid:\n";
86 my $abort_cause = get_abort_cause
($kid);
87 my $conflicts = get_conflicts
($kid);
88 print_error
($abort_cause);
89 if ($abort_cause eq 'code_busy') {
92 if($debugon && defined $debugfile) {
93 print("Debugging output saved to $debugfile\n");
97 rmtree
("/var/run/ksplice/updates/$kid");
103 "code_busy" => <<'END',
104 Ksplice has aborted the undo operation because it appears that the code that
105 you are trying to change is continuously in use by the system. More
106 specifically, Ksplice has been unable to find a moment when one or more of the
107 to-be-changed functions is not on a thread's kernel stack.
109 "module_busy" => <<'END',
110 Ksplice has aborted the undo operation because it appears that the Ksplice
111 update that you are trying to unload is in use by another module. You can find
112 out what module is using the Ksplice update using the lsmod command.
114 "unexpected_running_task" => <<'END',
115 Ksplice has aborted the undo operation because of an unexpected failure during
116 the kernel stack check. Please consider reporting a bug to PACKAGE_BUGREPORT.
118 "out_of_memory" => <<'END',
119 Ksplice has aborted the undo operation because the kernel ran out of memory.
121 "call_failed" => <<'END',
122 Ksplice has aborted the undo operation at the request of a one of the
123 pre-application hooks that were included as part of this Ksplice
124 update. This is likely the result of a bug in the patch used to
125 generate this update.
127 "cold_update_loaded" => <<'END',
128 Ksplice has aborted the undo operation because the update was applied using the
129 --partial option, and one of the modules that was changed by the update was loaded
130 since the update was applied. You must first unload that (cold patched) module
131 before you can undo this update.
133 "unexpected" => <<'END',
134 Ksplice has aborted because of an unexpected error.
135 Please consider reporting a bug to PACKAGE_BUGREPORT.
137 "UNKNOWN" => <<'END',
138 The Ksplice kernel component has returned an error code that this version of
139 ksplice-undo does not understand.
142 Ksplice has aborted the undo operation for unknown reasons.
143 Please consider reporting a bug to PACKAGE_BUGREPORT.
146 $error = "UNKNOWN" if (!exists $errors{$error});
147 print STDERR
"\n$errors{$error}\n";
152 ksplice-undo - Undo a Ksplice update that has been applied to the running kernel
156 B<ksplice-undo> [I<OPTIONS>] I<KSPLICE_ID>
160 B<ksplice-undo> takes as input a Ksplice identification tag, as reported by
161 L<ksplice-view(8)>, and it reverses that update within the running binary kernel.
169 Reverses the update with debugging output enabled. Recommended only for
172 =item B<--debugfile=>I<filename>
174 Sets the location where debugging output should be saved. Implies --debug.
180 L<ksplice-create(8)>, L<ksplice-apply(8)>, L<ksplice-view(8)>
184 Please report bugs to <PACKAGE_BUGREPORT>.
188 Jeff Arnold, Anders Kaseorg, and Tim Abbott
192 Copyright (C) 2007-2009 Ksplice, Inc.
194 This is free software and documentation. You can redistribute and/or modify it
195 under the terms of the GNU General Public License, version 2.