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selftests/livepatch: introduce tests

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Add a few livepatch modules and simple target modules that the included
regression suite can run tests against:

  - basic livepatching (multiple patches, atomic replace)
  - pre/post (un)patch callbacks
  - shadow variable API

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Tested-by: Miroslav Benes <mbenes@suse.cz>
Tested-by: Alice Ferrazzi <alice.ferrazzi@gmail.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Joe Lawrence 2019-01-09 13:43:29 +01:00 committed by Jiri Kosina
parent d67a537209
commit a2818ee4dc
20 changed files with 1740 additions and 485 deletions
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489
Documentation/livepatch/callbacks.txt
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@ -118,488 +118,9 @@ similar change to their hw_features value. (Client functions of the
value may need to be updated accordingly.)
Test cases
==========
Other Examples
==============
What follows is not an exhaustive test suite of every possible livepatch
pre/post-(un)patch combination, but a selection that demonstrates a few
important concepts. Each test case uses the kernel modules located in
the samples/livepatch/ and assumes that no livepatches are loaded at the
beginning of the test.
Test 1
------
Test a combination of loading a kernel module and a livepatch that
patches a function in the first module. (Un)load the target module
before the livepatch module:
- load target module
- load livepatch
- disable livepatch
- unload target module
- unload livepatch
First load a target module:
% insmod samples/livepatch/livepatch-callbacks-mod.ko
[ 34.475708] livepatch_callbacks_mod: livepatch_callbacks_mod_init
On livepatch enable, before the livepatch transition starts, pre-patch
callbacks are executed for vmlinux and livepatch_callbacks_mod (those
klp_objects currently loaded). After klp_objects are patched according
to the klp_patch, their post-patch callbacks run and the transition
completes:
% insmod samples/livepatch/livepatch-callbacks-demo.ko
[ 36.503719] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 36.504213] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 36.504238] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 36.504721] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_LIVE] Normal state
[ 36.505849] livepatch: 'livepatch_callbacks_demo': starting patching transition
[ 37.727133] livepatch: 'livepatch_callbacks_demo': completing patching transition
[ 37.727232] livepatch_callbacks_demo: post_patch_callback: vmlinux
[ 37.727860] livepatch_callbacks_demo: post_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_LIVE] Normal state
[ 37.728792] livepatch: 'livepatch_callbacks_demo': patching complete
Similarly, on livepatch disable, pre-patch callbacks run before the
unpatching transition starts. klp_objects are reverted, post-patch
callbacks execute and the transition completes:
% echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo/enabled
[ 38.510209] livepatch: 'livepatch_callbacks_demo': initializing unpatching transition
[ 38.510234] livepatch_callbacks_demo: pre_unpatch_callback: vmlinux
[ 38.510982] livepatch_callbacks_demo: pre_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_LIVE] Normal state
[ 38.512209] livepatch: 'livepatch_callbacks_demo': starting unpatching transition
[ 39.711132] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 39.711210] livepatch_callbacks_demo: post_unpatch_callback: vmlinux
[ 39.711779] livepatch_callbacks_demo: post_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_LIVE] Normal state
[ 39.712735] livepatch: 'livepatch_callbacks_demo': unpatching complete
% rmmod samples/livepatch/livepatch-callbacks-demo.ko
% rmmod samples/livepatch/livepatch-callbacks-mod.ko
[ 42.534183] livepatch_callbacks_mod: livepatch_callbacks_mod_exit
Test 2
------
This test is similar to the previous test, but (un)load the livepatch
module before the target kernel module. This tests the livepatch core's
module_coming handler:
- load livepatch
- load target module
- disable livepatch
- unload livepatch
- unload target module
On livepatch enable, only pre/post-patch callbacks are executed for
currently loaded klp_objects, in this case, vmlinux:
% insmod samples/livepatch/livepatch-callbacks-demo.ko
[ 44.553328] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 44.553997] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 44.554049] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 44.554845] livepatch: 'livepatch_callbacks_demo': starting patching transition
[ 45.727128] livepatch: 'livepatch_callbacks_demo': completing patching transition
[ 45.727212] livepatch_callbacks_demo: post_patch_callback: vmlinux
[ 45.727961] livepatch: 'livepatch_callbacks_demo': patching complete
When a targeted module is subsequently loaded, only its pre/post-patch
callbacks are executed:
% insmod samples/livepatch/livepatch-callbacks-mod.ko
[ 46.560845] livepatch: applying patch 'livepatch_callbacks_demo' to loading module 'livepatch_callbacks_mod'
[ 46.561988] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
[ 46.563452] livepatch_callbacks_demo: post_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
[ 46.565495] livepatch_callbacks_mod: livepatch_callbacks_mod_init
On livepatch disable, all currently loaded klp_objects' (vmlinux and
livepatch_callbacks_mod) pre/post-unpatch callbacks are executed:
% echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo/enabled
[ 48.568885] livepatch: 'livepatch_callbacks_demo': initializing unpatching transition
[ 48.568910] livepatch_callbacks_demo: pre_unpatch_callback: vmlinux
[ 48.569441] livepatch_callbacks_demo: pre_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_LIVE] Normal state
[ 48.570502] livepatch: 'livepatch_callbacks_demo': starting unpatching transition
[ 49.759091] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 49.759171] livepatch_callbacks_demo: post_unpatch_callback: vmlinux
[ 49.759742] livepatch_callbacks_demo: post_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_LIVE] Normal state
[ 49.760690] livepatch: 'livepatch_callbacks_demo': unpatching complete
% rmmod samples/livepatch/livepatch-callbacks-demo.ko
% rmmod samples/livepatch/livepatch-callbacks-mod.ko
[ 52.592283] livepatch_callbacks_mod: livepatch_callbacks_mod_exit
Test 3
------
Test loading the livepatch after a targeted kernel module, then unload
the kernel module before disabling the livepatch. This tests the
livepatch core's module_going handler:
- load target module
- load livepatch
- unload target module
- disable livepatch
- unload livepatch
First load a target module, then the livepatch:
% insmod samples/livepatch/livepatch-callbacks-mod.ko
[ 54.607948] livepatch_callbacks_mod: livepatch_callbacks_mod_init
% insmod samples/livepatch/livepatch-callbacks-demo.ko
[ 56.613919] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 56.614411] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 56.614436] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 56.614818] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_LIVE] Normal state
[ 56.615656] livepatch: 'livepatch_callbacks_demo': starting patching transition
[ 57.759070] livepatch: 'livepatch_callbacks_demo': completing patching transition
[ 57.759147] livepatch_callbacks_demo: post_patch_callback: vmlinux
[ 57.759621] livepatch_callbacks_demo: post_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_LIVE] Normal state
[ 57.760307] livepatch: 'livepatch_callbacks_demo': patching complete
When a target module is unloaded, the livepatch is only reverted from
that klp_object (livepatch_callbacks_mod). As such, only its pre and
post-unpatch callbacks are executed when this occurs:
% rmmod samples/livepatch/livepatch-callbacks-mod.ko
[ 58.623409] livepatch_callbacks_mod: livepatch_callbacks_mod_exit
[ 58.623903] livepatch_callbacks_demo: pre_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_GOING] Going away
[ 58.624658] livepatch: reverting patch 'livepatch_callbacks_demo' on unloading module 'livepatch_callbacks_mod'
[ 58.625305] livepatch_callbacks_demo: post_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_GOING] Going away
When the livepatch is disabled, pre and post-unpatch callbacks are run
for the remaining klp_object, vmlinux:
% echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo/enabled
[ 60.638420] livepatch: 'livepatch_callbacks_demo': initializing unpatching transition
[ 60.638444] livepatch_callbacks_demo: pre_unpatch_callback: vmlinux
[ 60.638996] livepatch: 'livepatch_callbacks_demo': starting unpatching transition
[ 61.727088] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 61.727165] livepatch_callbacks_demo: post_unpatch_callback: vmlinux
[ 61.727985] livepatch: 'livepatch_callbacks_demo': unpatching complete
% rmmod samples/livepatch/livepatch-callbacks-demo.ko
Test 4
------
This test is similar to the previous test, however the livepatch is
loaded first. This tests the livepatch core's module_coming and
module_going handlers:
- load livepatch
- load target module
- unload target module
- disable livepatch
- unload livepatch
First load the livepatch:
% insmod samples/livepatch/livepatch-callbacks-demo.ko
[ 64.661552] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 64.662147] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 64.662175] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 64.662850] livepatch: 'livepatch_callbacks_demo': starting patching transition
[ 65.695056] livepatch: 'livepatch_callbacks_demo': completing patching transition
[ 65.695147] livepatch_callbacks_demo: post_patch_callback: vmlinux
[ 65.695561] livepatch: 'livepatch_callbacks_demo': patching complete
When a targeted kernel module is subsequently loaded, only its
pre/post-patch callbacks are executed:
% insmod samples/livepatch/livepatch-callbacks-mod.ko
[ 66.669196] livepatch: applying patch 'livepatch_callbacks_demo' to loading module 'livepatch_callbacks_mod'
[ 66.669882] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
[ 66.670744] livepatch_callbacks_demo: post_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
[ 66.672873] livepatch_callbacks_mod: livepatch_callbacks_mod_init
When the target module is unloaded, the livepatch is only reverted from
the livepatch_callbacks_mod klp_object. As such, only pre and
post-unpatch callbacks are executed when this occurs:
% rmmod samples/livepatch/livepatch-callbacks-mod.ko
[ 68.680065] livepatch_callbacks_mod: livepatch_callbacks_mod_exit
[ 68.680688] livepatch_callbacks_demo: pre_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_GOING] Going away
[ 68.681452] livepatch: reverting patch 'livepatch_callbacks_demo' on unloading module 'livepatch_callbacks_mod'
[ 68.682094] livepatch_callbacks_demo: post_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_GOING] Going away
% echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo/enabled
[ 70.689225] livepatch: 'livepatch_callbacks_demo': initializing unpatching transition
[ 70.689256] livepatch_callbacks_demo: pre_unpatch_callback: vmlinux
[ 70.689882] livepatch: 'livepatch_callbacks_demo': starting unpatching transition
[ 71.711080] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 71.711481] livepatch_callbacks_demo: post_unpatch_callback: vmlinux
[ 71.711988] livepatch: 'livepatch_callbacks_demo': unpatching complete
% rmmod samples/livepatch/livepatch-callbacks-demo.ko
Test 5
------
A simple test of loading a livepatch without one of its patch target
klp_objects ever loaded (livepatch_callbacks_mod):
- load livepatch
- disable livepatch
- unload livepatch
Load the livepatch:
% insmod samples/livepatch/livepatch-callbacks-demo.ko
[ 74.711081] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 74.711595] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 74.711639] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 74.712272] livepatch: 'livepatch_callbacks_demo': starting patching transition
[ 75.743137] livepatch: 'livepatch_callbacks_demo': completing patching transition
[ 75.743219] livepatch_callbacks_demo: post_patch_callback: vmlinux
[ 75.743867] livepatch: 'livepatch_callbacks_demo': patching complete
As expected, only pre/post-(un)patch handlers are executed for vmlinux:
% echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo/enabled
[ 76.716254] livepatch: 'livepatch_callbacks_demo': initializing unpatching transition
[ 76.716278] livepatch_callbacks_demo: pre_unpatch_callback: vmlinux
[ 76.716666] livepatch: 'livepatch_callbacks_demo': starting unpatching transition
[ 77.727089] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 77.727194] livepatch_callbacks_demo: post_unpatch_callback: vmlinux
[ 77.727907] livepatch: 'livepatch_callbacks_demo': unpatching complete
% rmmod samples/livepatch/livepatch-callbacks-demo.ko
Test 6
------
Test a scenario where a vmlinux pre-patch callback returns a non-zero
status (ie, failure):
- load target module
- load livepatch -ENODEV
- unload target module
First load a target module:
% insmod samples/livepatch/livepatch-callbacks-mod.ko
[ 80.740520] livepatch_callbacks_mod: livepatch_callbacks_mod_init
Load the livepatch module, setting its 'pre_patch_ret' value to -19
(-ENODEV). When its vmlinux pre-patch callback executed, this status
code will propagate back to the module-loading subsystem. The result is
that the insmod command refuses to load the livepatch module:
% insmod samples/livepatch/livepatch-callbacks-demo.ko pre_patch_ret=-19
[ 82.747326] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 82.747743] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 82.747767] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 82.748237] livepatch: pre-patch callback failed for object 'vmlinux'
[ 82.748637] livepatch: failed to enable patch 'livepatch_callbacks_demo'
[ 82.749059] livepatch: 'livepatch_callbacks_demo': canceling transition, going to unpatch
[ 82.749060] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 82.749868] livepatch: 'livepatch_callbacks_demo': unpatching complete
[ 82.765809] insmod: ERROR: could not insert module samples/livepatch/livepatch-callbacks-demo.ko: No such device
% rmmod samples/livepatch/livepatch-callbacks-mod.ko
[ 84.774238] livepatch_callbacks_mod: livepatch_callbacks_mod_exit
Test 7
------
Similar to the previous test, setup a livepatch such that its vmlinux
pre-patch callback returns success. However, when a targeted kernel
module is later loaded, have the livepatch return a failing status code:
- load livepatch
- setup -ENODEV
- load target module
- disable livepatch
- unload livepatch
Load the livepatch, notice vmlinux pre-patch callback succeeds:
% insmod samples/livepatch/livepatch-callbacks-demo.ko
[ 86.787845] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 86.788325] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 86.788427] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 86.788821] livepatch: 'livepatch_callbacks_demo': starting patching transition
[ 87.711069] livepatch: 'livepatch_callbacks_demo': completing patching transition
[ 87.711143] livepatch_callbacks_demo: post_patch_callback: vmlinux
[ 87.711886] livepatch: 'livepatch_callbacks_demo': patching complete
Set a trap so subsequent pre-patch callbacks to this livepatch will
return -ENODEV:
% echo -19 > /sys/module/livepatch_callbacks_demo/parameters/pre_patch_ret
The livepatch pre-patch callback for subsequently loaded target modules
will return failure, so the module loader refuses to load the kernel
module. Notice that no post-patch or pre/post-unpatch callbacks are
executed for this klp_object:
% insmod samples/livepatch/livepatch-callbacks-mod.ko
[ 90.796976] livepatch: applying patch 'livepatch_callbacks_demo' to loading module 'livepatch_callbacks_mod'
[ 90.797834] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
[ 90.798900] livepatch: pre-patch callback failed for object 'livepatch_callbacks_mod'
[ 90.799652] livepatch: patch 'livepatch_callbacks_demo' failed for module 'livepatch_callbacks_mod', refusing to load module 'livepatch_callbacks_mod'
[ 90.819737] insmod: ERROR: could not insert module samples/livepatch/livepatch-callbacks-mod.ko: No such device
However, pre/post-unpatch callbacks run for the vmlinux klp_object:
% echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo/enabled
[ 92.823547] livepatch: 'livepatch_callbacks_demo': initializing unpatching transition
[ 92.823573] livepatch_callbacks_demo: pre_unpatch_callback: vmlinux
[ 92.824331] livepatch: 'livepatch_callbacks_demo': starting unpatching transition
[ 93.727128] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 93.727327] livepatch_callbacks_demo: post_unpatch_callback: vmlinux
[ 93.727861] livepatch: 'livepatch_callbacks_demo': unpatching complete
% rmmod samples/livepatch/livepatch-callbacks-demo.ko
Test 8
------
Test loading multiple targeted kernel modules. This test-case is
mainly for comparing with the next test-case.
- load busy target module (0s sleep),
- load livepatch
- load target module
- unload target module
- disable livepatch
- unload livepatch
- unload busy target module
Load a target "busy" kernel module which kicks off a worker function
that immediately exits:
% insmod samples/livepatch/livepatch-callbacks-busymod.ko sleep_secs=0
[ 96.910107] livepatch_callbacks_busymod: livepatch_callbacks_mod_init
[ 96.910600] livepatch_callbacks_busymod: busymod_work_func, sleeping 0 seconds ...
[ 96.913024] livepatch_callbacks_busymod: busymod_work_func exit
Proceed with loading the livepatch and another ordinary target module,
notice that the post-patch callbacks are executed and the transition
completes quickly:
% insmod samples/livepatch/livepatch-callbacks-demo.ko
[ 98.917892] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 98.918426] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 98.918453] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 98.918955] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_busymod -> [MODULE_STATE_LIVE] Normal state
[ 98.923835] livepatch: 'livepatch_callbacks_demo': starting patching transition
[ 99.743104] livepatch: 'livepatch_callbacks_demo': completing patching transition
[ 99.743156] livepatch_callbacks_demo: post_patch_callback: vmlinux
[ 99.743679] livepatch_callbacks_demo: post_patch_callback: livepatch_callbacks_busymod -> [MODULE_STATE_LIVE] Normal state
[ 99.744616] livepatch: 'livepatch_callbacks_demo': patching complete
% insmod samples/livepatch/livepatch-callbacks-mod.ko
[ 100.930955] livepatch: applying patch 'livepatch_callbacks_demo' to loading module 'livepatch_callbacks_mod'
[ 100.931668] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
[ 100.932645] livepatch_callbacks_demo: post_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
[ 100.934125] livepatch_callbacks_mod: livepatch_callbacks_mod_init
% rmmod samples/livepatch/livepatch-callbacks-mod.ko
[ 102.942805] livepatch_callbacks_mod: livepatch_callbacks_mod_exit
[ 102.943640] livepatch_callbacks_demo: pre_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_GOING] Going away
[ 102.944585] livepatch: reverting patch 'livepatch_callbacks_demo' on unloading module 'livepatch_callbacks_mod'
[ 102.945455] livepatch_callbacks_demo: post_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_GOING] Going away
% echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo/enabled
[ 104.953815] livepatch: 'livepatch_callbacks_demo': initializing unpatching transition
[ 104.953838] livepatch_callbacks_demo: pre_unpatch_callback: vmlinux
[ 104.954431] livepatch_callbacks_demo: pre_unpatch_callback: livepatch_callbacks_busymod -> [MODULE_STATE_LIVE] Normal state
[ 104.955426] livepatch: 'livepatch_callbacks_demo': starting unpatching transition
[ 106.719073] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 106.722633] livepatch_callbacks_demo: post_unpatch_callback: vmlinux
[ 106.723282] livepatch_callbacks_demo: post_unpatch_callback: livepatch_callbacks_busymod -> [MODULE_STATE_LIVE] Normal state
[ 106.724279] livepatch: 'livepatch_callbacks_demo': unpatching complete
% rmmod samples/livepatch/livepatch-callbacks-demo.ko
% rmmod samples/livepatch/livepatch-callbacks-busymod.ko
[ 108.975660] livepatch_callbacks_busymod: livepatch_callbacks_mod_exit
Test 9
------
A similar test as the previous one, but force the "busy" kernel module
to do longer work.
The livepatching core will refuse to patch a task that is currently
executing a to-be-patched function -- the consistency model stalls the
current patch transition until this safety-check is met. Test a
scenario where one of a livepatch's target klp_objects sits on such a
function for a long time. Meanwhile, load and unload other target
kernel modules while the livepatch transition is in progress.
- load busy target module (30s sleep)
- load livepatch
- load target module
- unload target module
- disable livepatch
- unload livepatch
- unload busy target module
Load the "busy" kernel module, this time make it do 30 seconds worth of
work:
% insmod samples/livepatch/livepatch-callbacks-busymod.ko sleep_secs=30
[ 110.993362] livepatch_callbacks_busymod: livepatch_callbacks_mod_init
[ 110.994059] livepatch_callbacks_busymod: busymod_work_func, sleeping 30 seconds ...
Meanwhile, the livepatch is loaded. Notice that the patch transition
does not complete as the targeted "busy" module is sitting on a
to-be-patched function:
% insmod samples/livepatch/livepatch-callbacks-demo.ko
[ 113.000309] livepatch: enabling patch 'livepatch_callbacks_demo'
[ 113.000764] livepatch: 'livepatch_callbacks_demo': initializing patching transition
[ 113.000791] livepatch_callbacks_demo: pre_patch_callback: vmlinux
[ 113.001289] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_busymod -> [MODULE_STATE_LIVE] Normal state
[ 113.005208] livepatch: 'livepatch_callbacks_demo': starting patching transition
Load a second target module (this one is an ordinary idle kernel
module). Note that *no* post-patch callbacks will be executed while the
livepatch is still in transition:
% insmod samples/livepatch/livepatch-callbacks-mod.ko
[ 115.012740] livepatch: applying patch 'livepatch_callbacks_demo' to loading module 'livepatch_callbacks_mod'
[ 115.013406] livepatch_callbacks_demo: pre_patch_callback: livepatch_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init
[ 115.015315] livepatch_callbacks_mod: livepatch_callbacks_mod_init
Request an unload of the simple kernel module. The patch is still
transitioning, so its pre-unpatch callbacks are skipped:
% rmmod samples/livepatch/livepatch-callbacks-mod.ko
[ 117.022626] livepatch_callbacks_mod: livepatch_callbacks_mod_exit
[ 117.023376] livepatch: reverting patch 'livepatch_callbacks_demo' on unloading module 'livepatch_callbacks_mod'
[ 117.024533] livepatch_callbacks_demo: post_unpatch_callback: livepatch_callbacks_mod -> [MODULE_STATE_GOING] Going away
Finally the livepatch is disabled. Since none of the patch's
klp_object's post-patch callbacks executed, the remaining klp_object's
pre-unpatch callbacks are skipped:
% echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo/enabled
[ 119.035408] livepatch: 'livepatch_callbacks_demo': reversing transition from patching to unpatching
[ 119.035485] livepatch: 'livepatch_callbacks_demo': starting unpatching transition
[ 119.711166] livepatch: 'livepatch_callbacks_demo': completing unpatching transition
[ 119.714179] livepatch_callbacks_demo: post_unpatch_callback: vmlinux
[ 119.714653] livepatch_callbacks_demo: post_unpatch_callback: livepatch_callbacks_busymod -> [MODULE_STATE_LIVE] Normal state
[ 119.715437] livepatch: 'livepatch_callbacks_demo': unpatching complete
% rmmod samples/livepatch/livepatch-callbacks-demo.ko
% rmmod samples/livepatch/livepatch-callbacks-busymod.ko
[ 141.279111] livepatch_callbacks_busymod: busymod_work_func exit
[ 141.279760] livepatch_callbacks_busymod: livepatch_callbacks_mod_exit
Sample livepatch modules demonstrating the callback API can be found in
samples/livepatch/ directory. These samples were modified for use in
kselftests and can be found in the lib/livepatch directory.

1
MAINTAINERS
View File

@ -8832,6 +8832,7 @@ F: arch/x86/kernel/livepatch.c
F: Documentation/livepatch/
F: Documentation/ABI/testing/sysfs-kernel-livepatch
F: samples/livepatch/
F: tools/testing/selftests/livepatch/
L: live-patching@vger.kernel.org
T: git git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching.git

22
lib/Kconfig.debug
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@ -1991,6 +1991,27 @@ config TEST_MEMCAT_P
If unsure, say N.
config TEST_LIVEPATCH
tristate "Test livepatching"
default n
depends on LIVEPATCH
depends on m
help
Test kernel livepatching features for correctness. The tests will
load test modules that will be livepatched in various scenarios.
To run all the livepatching tests:
make -C tools/testing/selftests TARGETS=livepatch run_tests
Alternatively, individual tests may be invoked:
tools/testing/selftests/livepatch/test-callbacks.sh
tools/testing/selftests/livepatch/test-livepatch.sh
tools/testing/selftests/livepatch/test-shadow-vars.sh
If unsure, say N.
config TEST_OBJAGG
tristate "Perform selftest on object aggreration manager"
default n
@ -1999,7 +2020,6 @@ config TEST_OBJAGG
Enable this option to test object aggregation manager on boot
(or module load).
If unsure, say N.
endif # RUNTIME_TESTING_MENU

2
lib/Makefile
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@ -77,6 +77,8 @@ obj-$(CONFIG_TEST_DEBUG_VIRTUAL) += test_debug_virtual.o
obj-$(CONFIG_TEST_MEMCAT_P) += test_memcat_p.o
obj-$(CONFIG_TEST_OBJAGG) += test_objagg.o
obj-$(CONFIG_TEST_LIVEPATCH) += livepatch/
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
CFLAGS_kobject_uevent.o += -DDEBUG

15
lib/livepatch/Makefile Normal file
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@ -0,0 +1,15 @@
# SPDX-License-Identifier: GPL-2.0
#
# Makefile for livepatch test code.
obj-$(CONFIG_TEST_LIVEPATCH) += test_klp_atomic_replace.o \
test_klp_callbacks_demo.o \
test_klp_callbacks_demo2.o \
test_klp_callbacks_busy.o \
test_klp_callbacks_mod.o \
test_klp_livepatch.o \
test_klp_shadow_vars.o
# Target modules to be livepatched require CC_FLAGS_FTRACE
CFLAGS_test_klp_callbacks_busy.o += $(CC_FLAGS_FTRACE)
CFLAGS_test_klp_callbacks_mod.o += $(CC_FLAGS_FTRACE)

57
lib/livepatch/test_klp_atomic_replace.c Normal file
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@ -0,0 +1,57 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/livepatch.h>
static int replace;
module_param(replace, int, 0644);
MODULE_PARM_DESC(replace, "replace (default=0)");
#include <linux/seq_file.h>
static int livepatch_meminfo_proc_show(struct seq_file *m, void *v)
{
seq_printf(m, "%s: %s\n", THIS_MODULE->name,
"this has been live patched");
return 0;
}
static struct klp_func funcs[] = {
{
.old_name = "meminfo_proc_show",
.new_func = livepatch_meminfo_proc_show,
}, {}
};
static struct klp_object objs[] = {
{
/* name being NULL means vmlinux */
.funcs = funcs,
}, {}
};
static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
/* set .replace in the init function below for demo purposes */
};
static int test_klp_atomic_replace_init(void)
{
patch.replace = replace;
return klp_enable_patch(&patch);
}
static void test_klp_atomic_replace_exit(void)
{
}
module_init(test_klp_atomic_replace_init);
module_exit(test_klp_atomic_replace_exit);
MODULE_LICENSE("GPL");
MODULE_INFO(livepatch, "Y");
MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
MODULE_DESCRIPTION("Livepatch test: atomic replace");

43
lib/livepatch/test_klp_callbacks_busy.c Normal file
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@ -0,0 +1,43 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
static int sleep_secs;
module_param(sleep_secs, int, 0644);
MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)");
static void busymod_work_func(struct work_struct *work);
static DECLARE_DELAYED_WORK(work, busymod_work_func);
static void busymod_work_func(struct work_struct *work)
{
pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs);
msleep(sleep_secs * 1000);
pr_info("%s exit\n", __func__);
}
static int test_klp_callbacks_busy_init(void)
{
pr_info("%s\n", __func__);
schedule_delayed_work(&work,
msecs_to_jiffies(1000 * 0));
return 0;
}
static void test_klp_callbacks_busy_exit(void)
{
cancel_delayed_work_sync(&work);
pr_info("%s\n", __func__);
}
module_init(test_klp_callbacks_busy_init);
module_exit(test_klp_callbacks_busy_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
MODULE_DESCRIPTION("Livepatch test: busy target module");

121
lib/livepatch/test_klp_callbacks_demo.c Normal file
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@ -0,0 +1,121 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/livepatch.h>
static int pre_patch_ret;
module_param(pre_patch_ret, int, 0644);
MODULE_PARM_DESC(pre_patch_ret, "pre_patch_ret (default=0)");
static const char *const module_state[] = {
[MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",
[MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init",
[MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away",
[MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",
};
static void callback_info(const char *callback, struct klp_object *obj)
{
if (obj->mod)
pr_info("%s: %s -> %s\n", callback, obj->mod->name,
module_state[obj->mod->state]);
else
pr_info("%s: vmlinux\n", callback);
}
/* Executed on object patching (ie, patch enablement) */
static int pre_patch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
return pre_patch_ret;
}
/* Executed on object unpatching (ie, patch disablement) */
static void post_patch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
/* Executed on object unpatching (ie, patch disablement) */
static void pre_unpatch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
/* Executed on object unpatching (ie, patch disablement) */
static void post_unpatch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
static void patched_work_func(struct work_struct *work)
{
pr_info("%s\n", __func__);
}
static struct klp_func no_funcs[] = {
{}
};
static struct klp_func busymod_funcs[] = {
{
.old_name = "busymod_work_func",
.new_func = patched_work_func,
}, {}
};
static struct klp_object objs[] = {
{
.name = NULL, /* vmlinux */
.funcs = no_funcs,
.callbacks = {
.pre_patch = pre_patch_callback,
.post_patch = post_patch_callback,
.pre_unpatch = pre_unpatch_callback,
.post_unpatch = post_unpatch_callback,
},
}, {
.name = "test_klp_callbacks_mod",
.funcs = no_funcs,
.callbacks = {
.pre_patch = pre_patch_callback,
.post_patch = post_patch_callback,
.pre_unpatch = pre_unpatch_callback,
.post_unpatch = post_unpatch_callback,
},
}, {
.name = "test_klp_callbacks_busy",
.funcs = busymod_funcs,
.callbacks = {
.pre_patch = pre_patch_callback,
.post_patch = post_patch_callback,
.pre_unpatch = pre_unpatch_callback,
.post_unpatch = post_unpatch_callback,
},
}, { }
};
static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
};
static int test_klp_callbacks_demo_init(void)
{
return klp_enable_patch(&patch);
}
static void test_klp_callbacks_demo_exit(void)
{
}
module_init(test_klp_callbacks_demo_init);
module_exit(test_klp_callbacks_demo_exit);
MODULE_LICENSE("GPL");
MODULE_INFO(livepatch, "Y");
MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
MODULE_DESCRIPTION("Livepatch test: livepatch demo");

93
lib/livepatch/test_klp_callbacks_demo2.c Normal file
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@ -0,0 +1,93 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/livepatch.h>
static int replace;
module_param(replace, int, 0644);
MODULE_PARM_DESC(replace, "replace (default=0)");
static const char *const module_state[] = {
[MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",
[MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init",
[MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away",
[MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",
};
static void callback_info(const char *callback, struct klp_object *obj)
{
if (obj->mod)
pr_info("%s: %s -> %s\n", callback, obj->mod->name,
module_state[obj->mod->state]);
else
pr_info("%s: vmlinux\n", callback);
}
/* Executed on object patching (ie, patch enablement) */
static int pre_patch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
return 0;
}
/* Executed on object unpatching (ie, patch disablement) */
static void post_patch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
/* Executed on object unpatching (ie, patch disablement) */
static void pre_unpatch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
/* Executed on object unpatching (ie, patch disablement) */
static void post_unpatch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
static struct klp_func no_funcs[] = {
{ }
};
static struct klp_object objs[] = {
{
.name = NULL, /* vmlinux */
.funcs = no_funcs,
.callbacks = {
.pre_patch = pre_patch_callback,
.post_patch = post_patch_callback,
.pre_unpatch = pre_unpatch_callback,
.post_unpatch = post_unpatch_callback,
},
}, { }
};
static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
/* set .replace in the init function below for demo purposes */
};
static int test_klp_callbacks_demo2_init(void)
{
patch.replace = replace;
return klp_enable_patch(&patch);
}
static void test_klp_callbacks_demo2_exit(void)
{
}
module_init(test_klp_callbacks_demo2_init);
module_exit(test_klp_callbacks_demo2_exit);
MODULE_LICENSE("GPL");
MODULE_INFO(livepatch, "Y");
MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
MODULE_DESCRIPTION("Livepatch test: livepatch demo2");

24
lib/livepatch/test_klp_callbacks_mod.c Normal file
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@ -0,0 +1,24 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
static int test_klp_callbacks_mod_init(void)
{
pr_info("%s\n", __func__);
return 0;
}
static void test_klp_callbacks_mod_exit(void)
{
pr_info("%s\n", __func__);
}
module_init(test_klp_callbacks_mod_init);
module_exit(test_klp_callbacks_mod_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
MODULE_DESCRIPTION("Livepatch test: target module");

51
lib/livepatch/test_klp_livepatch.c Normal file
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@ -0,0 +1,51 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/livepatch.h>
#include <linux/seq_file.h>
static int livepatch_cmdline_proc_show(struct seq_file *m, void *v)
{
seq_printf(m, "%s: %s\n", THIS_MODULE->name,
"this has been live patched");
return 0;
}
static struct klp_func funcs[] = {
{
.old_name = "cmdline_proc_show",
.new_func = livepatch_cmdline_proc_show,
}, { }
};
static struct klp_object objs[] = {
{
/* name being NULL means vmlinux */
.funcs = funcs,
}, { }
};
static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
};
static int test_klp_livepatch_init(void)
{
return klp_enable_patch(&patch);
}
static void test_klp_livepatch_exit(void)
{
}
module_init(test_klp_livepatch_init);
module_exit(test_klp_livepatch_exit);
MODULE_LICENSE("GPL");
MODULE_INFO(livepatch, "Y");
MODULE_AUTHOR("Seth Jennings <sjenning@redhat.com>");
MODULE_DESCRIPTION("Livepatch test: livepatch module");

236
lib/livepatch/test_klp_shadow_vars.c Normal file
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@ -0,0 +1,236 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/livepatch.h>
#include <linux/slab.h>
/*
* Keep a small list of pointers so that we can print address-agnostic
* pointer values. Use a rolling integer count to differentiate the values.
* Ironically we could have used the shadow variable API to do this, but
* let's not lean too heavily on the very code we're testing.
*/
static LIST_HEAD(ptr_list);
struct shadow_ptr {
void *ptr;
int id;
struct list_head list;
};
static void free_ptr_list(void)
{
struct shadow_ptr *sp, *tmp_sp;
list_for_each_entry_safe(sp, tmp_sp, &ptr_list, list) {
list_del(&sp->list);
kfree(sp);
}
}
static int ptr_id(void *ptr)
{
struct shadow_ptr *sp;
static int count;
list_for_each_entry(sp, &ptr_list, list) {
if (sp->ptr == ptr)
return sp->id;
}
sp = kmalloc(sizeof(*sp), GFP_ATOMIC);
if (!sp)
return -1;
sp->ptr = ptr;
sp->id = count++;
list_add(&sp->list, &ptr_list);
return sp->id;
}
/*
* Shadow variable wrapper functions that echo the function and arguments
* to the kernel log for testing verification. Don't display raw pointers,
* but use the ptr_id() value instead.
*/
static void *shadow_get(void *obj, unsigned long id)
{
void *ret = klp_shadow_get(obj, id);
pr_info("klp_%s(obj=PTR%d, id=0x%lx) = PTR%d\n",
__func__, ptr_id(obj), id, ptr_id(ret));
return ret;
}
static void *shadow_alloc(void *obj, unsigned long id, size_t size,
gfp_t gfp_flags, klp_shadow_ctor_t ctor,
void *ctor_data)
{
void *ret = klp_shadow_alloc(obj, id, size, gfp_flags, ctor,
ctor_data);
pr_info("klp_%s(obj=PTR%d, id=0x%lx, size=%zx, gfp_flags=%pGg), ctor=PTR%d, ctor_data=PTR%d = PTR%d\n",
__func__, ptr_id(obj), id, size, &gfp_flags, ptr_id(ctor),
ptr_id(ctor_data), ptr_id(ret));
return ret;
}
static void *shadow_get_or_alloc(void *obj, unsigned long id, size_t size,
gfp_t gfp_flags, klp_shadow_ctor_t ctor,
void *ctor_data)
{
void *ret = klp_shadow_get_or_alloc(obj, id, size, gfp_flags, ctor,
ctor_data);
pr_info("klp_%s(obj=PTR%d, id=0x%lx, size=%zx, gfp_flags=%pGg), ctor=PTR%d, ctor_data=PTR%d = PTR%d\n",
__func__, ptr_id(obj), id, size, &gfp_flags, ptr_id(ctor),
ptr_id(ctor_data), ptr_id(ret));
return ret;
}
static void shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor)
{
klp_shadow_free(obj, id, dtor);
pr_info("klp_%s(obj=PTR%d, id=0x%lx, dtor=PTR%d)\n",
__func__, ptr_id(obj), id, ptr_id(dtor));
}
static void shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor)
{
klp_shadow_free_all(id, dtor);
pr_info("klp_%s(id=0x%lx, dtor=PTR%d)\n",
__func__, id, ptr_id(dtor));
}
/* Shadow variable constructor - remember simple pointer data */
static int shadow_ctor(void *obj, void *shadow_data, void *ctor_data)
{
int **shadow_int = shadow_data;
*shadow_int = ctor_data;
pr_info("%s: PTR%d -> PTR%d\n",
__func__, ptr_id(shadow_int), ptr_id(ctor_data));
return 0;
}
static void shadow_dtor(void *obj, void *shadow_data)
{
pr_info("%s(obj=PTR%d, shadow_data=PTR%d)\n",
__func__, ptr_id(obj), ptr_id(shadow_data));
}
static int test_klp_shadow_vars_init(void)
{
void *obj = THIS_MODULE;
int id = 0x1234;
size_t size = sizeof(int *);
gfp_t gfp_flags = GFP_KERNEL;
int var1, var2, var3, var4;
int **sv1, **sv2, **sv3, **sv4;
void *ret;
ptr_id(NULL);
ptr_id(&var1);
ptr_id(&var2);
ptr_id(&var3);
ptr_id(&var4);
/*
* With an empty shadow variable hash table, expect not to find
* any matches.
*/
ret = shadow_get(obj, id);
if (!ret)
pr_info(" got expected NULL result\n");
/*
* Allocate a few shadow variables with different <obj> and <id>.
*/
sv1 = shadow_alloc(obj, id, size, gfp_flags, shadow_ctor, &var1);
sv2 = shadow_alloc(obj + 1, id, size, gfp_flags, shadow_ctor, &var2);
sv3 = shadow_alloc(obj, id + 1, size, gfp_flags, shadow_ctor, &var3);
/*
* Verify we can find our new shadow variables and that they point
* to expected data.
*/
ret = shadow_get(obj, id);
if (ret == sv1 && *sv1 == &var1)
pr_info(" got expected PTR%d -> PTR%d result\n",
ptr_id(sv1), ptr_id(*sv1));
ret = shadow_get(obj + 1, id);
if (ret == sv2 && *sv2 == &var2)
pr_info(" got expected PTR%d -> PTR%d result\n",
ptr_id(sv2), ptr_id(*sv2));
ret = shadow_get(obj, id + 1);
if (ret == sv3 && *sv3 == &var3)
pr_info(" got expected PTR%d -> PTR%d result\n",
ptr_id(sv3), ptr_id(*sv3));
/*
* Allocate or get a few more, this time with the same <obj>, <id>.
* The second invocation should return the same shadow var.
*/
sv4 = shadow_get_or_alloc(obj + 2, id, size, gfp_flags, shadow_ctor, &var4);
ret = shadow_get_or_alloc(obj + 2, id, size, gfp_flags, shadow_ctor, &var4);
if (ret == sv4 && *sv4 == &var4)
pr_info(" got expected PTR%d -> PTR%d result\n",
ptr_id(sv4), ptr_id(*sv4));
/*
* Free the <obj=*, id> shadow variables and check that we can no
* longer find them.
*/
shadow_free(obj, id, shadow_dtor); /* sv1 */
ret = shadow_get(obj, id);
if (!ret)
pr_info(" got expected NULL result\n");
shadow_free(obj + 1, id, shadow_dtor); /* sv2 */
ret = shadow_get(obj + 1, id);
if (!ret)
pr_info(" got expected NULL result\n");
shadow_free(obj + 2, id, shadow_dtor); /* sv4 */
ret = shadow_get(obj + 2, id);
if (!ret)
pr_info(" got expected NULL result\n");
/*
* We should still find an <id+1> variable.
*/
ret = shadow_get(obj, id + 1);
if (ret == sv3 && *sv3 == &var3)
pr_info(" got expected PTR%d -> PTR%d result\n",
ptr_id(sv3), ptr_id(*sv3));
/*
* Free all the <id+1> variables, too.
*/
shadow_free_all(id + 1, shadow_dtor); /* sv3 */
ret = shadow_get(obj, id);
if (!ret)
pr_info(" shadow_get() got expected NULL result\n");
free_ptr_list();
return 0;
}
static void test_klp_shadow_vars_exit(void)
{
}
module_init(test_klp_shadow_vars_init);
module_exit(test_klp_shadow_vars_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
MODULE_DESCRIPTION("Livepatch test: shadow variables");

1
tools/testing/selftests/Makefile
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@ -21,6 +21,7 @@ TARGETS += ir
TARGETS += kcmp
TARGETS += kvm
TARGETS += lib
TARGETS += livepatch
TARGETS += membarrier
TARGETS += memfd
TARGETS += memory-hotplug

8
tools/testing/selftests/livepatch/Makefile Normal file
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@ -0,0 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
TEST_GEN_PROGS := \
test-livepatch.sh \
test-callbacks.sh \
test-shadow-vars.sh
include ../lib.mk

43
tools/testing/selftests/livepatch/README Normal file
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@ -0,0 +1,43 @@
====================
Livepatch Self Tests
====================
This is a small set of sanity tests for the kernel livepatching.
The test suite loads and unloads several test kernel modules to verify
livepatch behavior. Debug information is logged to the kernel's message
buffer and parsed for expected messages. (Note: the tests will clear
the message buffer between individual tests.)
Config
------
Set these config options and their prerequisites:
CONFIG_LIVEPATCH=y
CONFIG_TEST_LIVEPATCH=m
Running the tests
-----------------
Test kernel modules are built as part of lib/ (make modules) and need to
be installed (make modules_install) as the test scripts will modprobe
them.
To run the livepatch selftests, from the top of the kernel source tree:
% make -C tools/testing/selftests TARGETS=livepatch run_tests
Adding tests
------------
See the common functions.sh file for the existing collection of utility
functions, most importantly set_dynamic_debug() and check_result(). The
latter function greps the kernel's ring buffer for "livepatch:" and
"test_klp" strings, so tests be sure to include one of those strings for
result comparison. Other utility functions include general module
loading and livepatch loading helpers (waiting for patch transitions,
sysfs entries, etc.)

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@ -0,0 +1 @@
CONFIG_TEST_LIVEPATCH=m

203
tools/testing/selftests/livepatch/functions.sh Normal file
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@ -0,0 +1,203 @@
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
# Shell functions for the rest of the scripts.
MAX_RETRIES=600
RETRY_INTERVAL=".1" # seconds
# log(msg) - write message to kernel log
# msg - insightful words
function log() {
echo "$1" > /dev/kmsg
}
# die(msg) - game over, man
# msg - dying words
function die() {
log "ERROR: $1"
echo "ERROR: $1" >&2
exit 1
}
# set_dynamic_debug() - setup kernel dynamic debug
# TODO - push and pop this config?
function set_dynamic_debug() {
cat << EOF > /sys/kernel/debug/dynamic_debug/control
file kernel/livepatch/* +p
func klp_try_switch_task -p
EOF
}
# loop_until(cmd) - loop a command until it is successful or $MAX_RETRIES,
# sleep $RETRY_INTERVAL between attempts
# cmd - command and its arguments to run
function loop_until() {
local cmd="$*"
local i=0
while true; do
eval "$cmd" && return 0
[[ $((i++)) -eq $MAX_RETRIES ]] && return 1
sleep $RETRY_INTERVAL
done
}
function is_livepatch_mod() {
local mod="$1"
if [[ $(modinfo "$mod" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then
return 0
fi
return 1
}
function __load_mod() {
local mod="$1"; shift
local args="$*"
local msg="% modprobe $mod $args"
log "${msg%% }"
ret=$(modprobe "$mod" "$args" 2>&1)
if [[ "$ret" != "" ]]; then
die "$ret"
fi
# Wait for module in sysfs ...
loop_until '[[ -e "/sys/module/$mod" ]]' ||
die "failed to load module $mod"
}
# load_mod(modname, params) - load a kernel module
# modname - module name to load
# params - module parameters to pass to modprobe
function load_mod() {
local mod="$1"; shift
local args="$*"
is_livepatch_mod "$mod" &&
die "use load_lp() to load the livepatch module $mod"
__load_mod "$mod" "$args"
}
# load_lp_nowait(modname, params) - load a kernel module with a livepatch
# but do not wait on until the transition finishes
# modname - module name to load
# params - module parameters to pass to modprobe
function load_lp_nowait() {
local mod="$1"; shift
local args="$*"
is_livepatch_mod "$mod" ||
die "module $mod is not a livepatch"
__load_mod "$mod" "$args"
# Wait for livepatch in sysfs ...
loop_until '[[ -e "/sys/kernel/livepatch/$mod" ]]' ||
die "failed to load module $mod (sysfs)"
}
# load_lp(modname, params) - load a kernel module with a livepatch
# modname - module name to load
# params - module parameters to pass to modprobe
function load_lp() {
local mod="$1"; shift
local args="$*"
load_lp_nowait "$mod" "$args"
# Wait until the transition finishes ...
loop_until 'grep -q '^0$' /sys/kernel/livepatch/$mod/transition' ||
die "failed to complete transition"
}
# load_failing_mod(modname, params) - load a kernel module, expect to fail
# modname - module name to load
# params - module parameters to pass to modprobe
function load_failing_mod() {
local mod="$1"; shift
local args="$*"
local msg="% modprobe $mod $args"
log "${msg%% }"
ret=$(modprobe "$mod" "$args" 2>&1)
if [[ "$ret" == "" ]]; then
die "$mod unexpectedly loaded"
fi
log "$ret"
}
# unload_mod(modname) - unload a kernel module
# modname - module name to unload
function unload_mod() {
local mod="$1"
# Wait for module reference count to clear ...
loop_until '[[ $(cat "/sys/module/$mod/refcnt") == "0" ]]' ||
die "failed to unload module $mod (refcnt)"
log "% rmmod $mod"
ret=$(rmmod "$mod" 2>&1)
if [[ "$ret" != "" ]]; then
die "$ret"
fi
# Wait for module in sysfs ...
loop_until '[[ ! -e "/sys/module/$mod" ]]' ||
die "failed to unload module $mod (/sys/module)"
}
# unload_lp(modname) - unload a kernel module with a livepatch
# modname - module name to unload
function unload_lp() {
unload_mod "$1"
}
# disable_lp(modname) - disable a livepatch
# modname - module name to unload
function disable_lp() {
local mod="$1"
log "% echo 0 > /sys/kernel/livepatch/$mod/enabled"
echo 0 > /sys/kernel/livepatch/"$mod"/enabled
# Wait until the transition finishes and the livepatch gets
# removed from sysfs...
loop_until '[[ ! -e "/sys/kernel/livepatch/$mod" ]]' ||
die "failed to disable livepatch $mod"
}
# set_pre_patch_ret(modname, pre_patch_ret)
# modname - module name to set
# pre_patch_ret - new pre_patch_ret value
function set_pre_patch_ret {
local mod="$1"; shift
local ret="$1"
log "% echo $ret > /sys/module/$mod/parameters/pre_patch_ret"
echo "$ret" > /sys/module/"$mod"/parameters/pre_patch_ret
# Wait for sysfs value to hold ...
loop_until '[[ $(cat "/sys/module/$mod/parameters/pre_patch_ret") == "$ret" ]]' ||
die "failed to set pre_patch_ret parameter for $mod module"
}
# check_result() - verify dmesg output
# TODO - better filter, out of order msgs, etc?
function check_result {
local expect="$*"
local result
result=$(dmesg | grep -v 'tainting' | grep -e 'livepatch:' -e 'test_klp' | sed 's/^\[[ 0-9.]*\] //')
if [[ "$expect" == "$result" ]] ; then
echo "ok"
else
echo -e "not ok\n\n$(diff -upr --label expected --label result <(echo "$expect") <(echo "$result"))\n"
die "livepatch kselftest(s) failed"
fi
}

587
tools/testing/selftests/livepatch/test-callbacks.sh Executable file
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@ -0,0 +1,587 @@
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
. $(dirname $0)/functions.sh
MOD_LIVEPATCH=test_klp_callbacks_demo
MOD_LIVEPATCH2=test_klp_callbacks_demo2
MOD_TARGET=test_klp_callbacks_mod
MOD_TARGET_BUSY=test_klp_callbacks_busy
set_dynamic_debug
# TEST: target module before livepatch
#
# Test a combination of loading a kernel module and a livepatch that
# patches a function in the first module. Load the target module
# before the livepatch module. Unload them in the same order.
#
# - On livepatch enable, before the livepatch transition starts,
# pre-patch callbacks are executed for vmlinux and $MOD_TARGET (those
# klp_objects currently loaded). After klp_objects are patched
# according to the klp_patch, their post-patch callbacks run and the
# transition completes.
#
# - Similarly, on livepatch disable, pre-patch callbacks run before the
# unpatching transition starts. klp_objects are reverted, post-patch
# callbacks execute and the transition completes.
echo -n "TEST: target module before livepatch ... "
dmesg -C
load_mod $MOD_TARGET
load_lp $MOD_LIVEPATCH
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
unload_mod $MOD_TARGET
check_result "% modprobe $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_init
% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
$MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': patching complete
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
$MOD_LIVEPATCH: pre_unpatch_callback: vmlinux
$MOD_LIVEPATCH: pre_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
$MOD_LIVEPATCH: post_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH
% rmmod $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_exit"
# TEST: module_coming notifier
#
# This test is similar to the previous test, but (un)load the livepatch
# module before the target kernel module. This tests the livepatch
# core's module_coming handler.
#
# - On livepatch enable, only pre/post-patch callbacks are executed for
# currently loaded klp_objects, in this case, vmlinux.
#
# - When a targeted module is subsequently loaded, only its
# pre/post-patch callbacks are executed.
#
# - On livepatch disable, all currently loaded klp_objects' (vmlinux and
# $MOD_TARGET) pre/post-unpatch callbacks are executed.
echo -n "TEST: module_coming notifier ... "
dmesg -C
load_lp $MOD_LIVEPATCH
load_mod $MOD_TARGET
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
unload_mod $MOD_TARGET
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': patching complete
% modprobe $MOD_TARGET
livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET'
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init
$MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init
$MOD_TARGET: ${MOD_TARGET}_init
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
$MOD_LIVEPATCH: pre_unpatch_callback: vmlinux
$MOD_LIVEPATCH: pre_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
$MOD_LIVEPATCH: post_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH
% rmmod $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_exit"
# TEST: module_going notifier
#
# Test loading the livepatch after a targeted kernel module, then unload
# the kernel module before disabling the livepatch. This tests the
# livepatch core's module_going handler.
#
# - First load a target module, then the livepatch.
#
# - When a target module is unloaded, the livepatch is only reverted
# from that klp_object ($MOD_TARGET). As such, only its pre and
# post-unpatch callbacks are executed when this occurs.
#
# - When the livepatch is disabled, pre and post-unpatch callbacks are
# run for the remaining klp_object, vmlinux.
echo -n "TEST: module_going notifier ... "
dmesg -C
load_mod $MOD_TARGET
load_lp $MOD_LIVEPATCH
unload_mod $MOD_TARGET
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
check_result "% modprobe $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_init
% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
$MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': patching complete
% rmmod $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_exit
$MOD_LIVEPATCH: pre_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_GOING] Going away
livepatch: reverting patch '$MOD_LIVEPATCH' on unloading module '$MOD_TARGET'
$MOD_LIVEPATCH: post_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_GOING] Going away
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
$MOD_LIVEPATCH: pre_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH"
# TEST: module_coming and module_going notifiers
#
# This test is similar to the previous test, however the livepatch is
# loaded first. This tests the livepatch core's module_coming and
# module_going handlers.
#
# - First load the livepatch.
#
# - When a targeted kernel module is subsequently loaded, only its
# pre/post-patch callbacks are executed.
#
# - When the target module is unloaded, the livepatch is only reverted
# from the $MOD_TARGET klp_object. As such, only pre and
# post-unpatch callbacks are executed when this occurs.
echo -n "TEST: module_coming and module_going notifiers ... "
dmesg -C
load_lp $MOD_LIVEPATCH
load_mod $MOD_TARGET
unload_mod $MOD_TARGET
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': patching complete
% modprobe $MOD_TARGET
livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET'
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init
$MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init
$MOD_TARGET: ${MOD_TARGET}_init
% rmmod $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_exit
$MOD_LIVEPATCH: pre_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_GOING] Going away
livepatch: reverting patch '$MOD_LIVEPATCH' on unloading module '$MOD_TARGET'
$MOD_LIVEPATCH: post_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_GOING] Going away
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
$MOD_LIVEPATCH: pre_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH"
# TEST: target module not present
#
# A simple test of loading a livepatch without one of its patch target
# klp_objects ever loaded ($MOD_TARGET).
#
# - Load the livepatch.
#
# - As expected, only pre/post-(un)patch handlers are executed for
# vmlinux.
echo -n "TEST: target module not present ... "
dmesg -C
load_lp $MOD_LIVEPATCH
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': patching complete
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
$MOD_LIVEPATCH: pre_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH"
# TEST: pre-patch callback -ENODEV
#
# Test a scenario where a vmlinux pre-patch callback returns a non-zero
# status (ie, failure).
#
# - First load a target module.
#
# - Load the livepatch module, setting its 'pre_patch_ret' value to -19
# (-ENODEV). When its vmlinux pre-patch callback executes, this
# status code will propagate back to the module-loading subsystem.
# The result is that the insmod command refuses to load the livepatch
# module.
echo -n "TEST: pre-patch callback -ENODEV ... "
dmesg -C
load_mod $MOD_TARGET
load_failing_mod $MOD_LIVEPATCH pre_patch_ret=-19
unload_mod $MOD_TARGET
check_result "% modprobe $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_init
% modprobe $MOD_LIVEPATCH pre_patch_ret=-19
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
test_klp_callbacks_demo: pre_patch_callback: vmlinux
livepatch: pre-patch callback failed for object 'vmlinux'
livepatch: failed to enable patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': canceling patching transition, going to unpatch
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
livepatch: '$MOD_LIVEPATCH': unpatching complete
modprobe: ERROR: could not insert '$MOD_LIVEPATCH': No such device
% rmmod $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_exit"
# TEST: module_coming + pre-patch callback -ENODEV
#
# Similar to the previous test, setup a livepatch such that its vmlinux
# pre-patch callback returns success. However, when a targeted kernel
# module is later loaded, have the livepatch return a failing status
# code.
#
# - Load the livepatch, vmlinux pre-patch callback succeeds.
#
# - Set a trap so subsequent pre-patch callbacks to this livepatch will
# return -ENODEV.
#
# - The livepatch pre-patch callback for subsequently loaded target
# modules will return failure, so the module loader refuses to load
# the kernel module. No post-patch or pre/post-unpatch callbacks are
# executed for this klp_object.
#
# - Pre/post-unpatch callbacks are run for the vmlinux klp_object.
echo -n "TEST: module_coming + pre-patch callback -ENODEV ... "
dmesg -C
load_lp $MOD_LIVEPATCH
set_pre_patch_ret $MOD_LIVEPATCH -19
load_failing_mod $MOD_TARGET
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': patching complete
% echo -19 > /sys/module/$MOD_LIVEPATCH/parameters/pre_patch_ret
% modprobe $MOD_TARGET
livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET'
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init
livepatch: pre-patch callback failed for object '$MOD_TARGET'
livepatch: patch '$MOD_LIVEPATCH' failed for module '$MOD_TARGET', refusing to load module '$MOD_TARGET'
modprobe: ERROR: could not insert '$MOD_TARGET': No such device
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
$MOD_LIVEPATCH: pre_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH"
# TEST: multiple target modules
#
# Test loading multiple targeted kernel modules. This test-case is
# mainly for comparing with the next test-case.
#
# - Load a target "busy" kernel module which kicks off a worker function
# that immediately exits.
#
# - Proceed with loading the livepatch and another ordinary target
# module. Post-patch callbacks are executed and the transition
# completes quickly.
echo -n "TEST: multiple target modules ... "
dmesg -C
load_mod $MOD_TARGET_BUSY sleep_secs=0
# give $MOD_TARGET_BUSY::busymod_work_func() a chance to run
sleep 5
load_lp $MOD_LIVEPATCH
load_mod $MOD_TARGET
unload_mod $MOD_TARGET
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
unload_mod $MOD_TARGET_BUSY
check_result "% modprobe $MOD_TARGET_BUSY sleep_secs=0
$MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_init
$MOD_TARGET_BUSY: busymod_work_func, sleeping 0 seconds ...
$MOD_TARGET_BUSY: busymod_work_func exit
% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET_BUSY -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
$MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET_BUSY -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': patching complete
% modprobe $MOD_TARGET
livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET'
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init
$MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init
$MOD_TARGET: ${MOD_TARGET}_init
% rmmod $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_exit
$MOD_LIVEPATCH: pre_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_GOING] Going away
livepatch: reverting patch '$MOD_LIVEPATCH' on unloading module '$MOD_TARGET'
$MOD_LIVEPATCH: post_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_GOING] Going away
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
$MOD_LIVEPATCH: pre_unpatch_callback: vmlinux
$MOD_LIVEPATCH: pre_unpatch_callback: $MOD_TARGET_BUSY -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
$MOD_LIVEPATCH: post_unpatch_callback: $MOD_TARGET_BUSY -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH
% rmmod $MOD_TARGET_BUSY
$MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_exit"
# TEST: busy target module
#
# A similar test as the previous one, but force the "busy" kernel module
# to do longer work.
#
# The livepatching core will refuse to patch a task that is currently
# executing a to-be-patched function -- the consistency model stalls the
# current patch transition until this safety-check is met. Test a
# scenario where one of a livepatch's target klp_objects sits on such a
# function for a long time. Meanwhile, load and unload other target
# kernel modules while the livepatch transition is in progress.
#
# - Load the "busy" kernel module, this time make it do 10 seconds worth
# of work.
#
# - Meanwhile, the livepatch is loaded. Notice that the patch
# transition does not complete as the targeted "busy" module is
# sitting on a to-be-patched function.
#
# - Load a second target module (this one is an ordinary idle kernel
# module). Note that *no* post-patch callbacks will be executed while
# the livepatch is still in transition.
#
# - Request an unload of the simple kernel module. The patch is still
# transitioning, so its pre-unpatch callbacks are skipped.
#
# - Finally the livepatch is disabled. Since none of the patch's
# klp_object's post-patch callbacks executed, the remaining
# klp_object's pre-unpatch callbacks are skipped.
echo -n "TEST: busy target module ... "
dmesg -C
load_mod $MOD_TARGET_BUSY sleep_secs=10
load_lp_nowait $MOD_LIVEPATCH
# Don't wait for transition, load $MOD_TARGET while the transition
# is still stalled in $MOD_TARGET_BUSY::busymod_work_func()
sleep 5
load_mod $MOD_TARGET
unload_mod $MOD_TARGET
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
unload_mod $MOD_TARGET_BUSY
check_result "% modprobe $MOD_TARGET_BUSY sleep_secs=10
$MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_init
$MOD_TARGET_BUSY: busymod_work_func, sleeping 10 seconds ...
% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET_BUSY -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': starting patching transition
% modprobe $MOD_TARGET
livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET'
$MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init
$MOD_TARGET: ${MOD_TARGET}_init
% rmmod $MOD_TARGET
$MOD_TARGET: ${MOD_TARGET}_exit
livepatch: reverting patch '$MOD_LIVEPATCH' on unloading module '$MOD_TARGET'
$MOD_LIVEPATCH: post_unpatch_callback: $MOD_TARGET -> [MODULE_STATE_GOING] Going away
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': reversing transition from patching to unpatching
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
$MOD_LIVEPATCH: post_unpatch_callback: $MOD_TARGET_BUSY -> [MODULE_STATE_LIVE] Normal state
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH
% rmmod $MOD_TARGET_BUSY
$MOD_TARGET_BUSY: busymod_work_func exit
$MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_exit"
# TEST: multiple livepatches
#
# Test loading multiple livepatches. This test-case is mainly for comparing
# with the next test-case.
#
# - Load and unload two livepatches, pre and post (un)patch callbacks
# execute as each patch progresses through its (un)patching
# transition.
echo -n "TEST: multiple livepatches ... "
dmesg -C
load_lp $MOD_LIVEPATCH
load_lp $MOD_LIVEPATCH2
disable_lp $MOD_LIVEPATCH2
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH2
unload_lp $MOD_LIVEPATCH
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': patching complete
% modprobe $MOD_LIVEPATCH2
livepatch: enabling patch '$MOD_LIVEPATCH2'
livepatch: '$MOD_LIVEPATCH2': initializing patching transition
$MOD_LIVEPATCH2: pre_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': starting patching transition
livepatch: '$MOD_LIVEPATCH2': completing patching transition
$MOD_LIVEPATCH2: post_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': patching complete
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH2/enabled
livepatch: '$MOD_LIVEPATCH2': initializing unpatching transition
$MOD_LIVEPATCH2: pre_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': starting unpatching transition
livepatch: '$MOD_LIVEPATCH2': completing unpatching transition
$MOD_LIVEPATCH2: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': unpatching complete
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
$MOD_LIVEPATCH: pre_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH2
% rmmod $MOD_LIVEPATCH"
# TEST: atomic replace
#
# Load multiple livepatches, but the second as an 'atomic-replace'
# patch. When the latter loads, the original livepatch should be
# disabled and *none* of its pre/post-unpatch callbacks executed. On
# the other hand, when the atomic-replace livepatch is disabled, its
# pre/post-unpatch callbacks *should* be executed.
#
# - Load and unload two livepatches, the second of which has its
# .replace flag set true.
#
# - Pre and post patch callbacks are executed for both livepatches.
#
# - Once the atomic replace module is loaded, only its pre and post
# unpatch callbacks are executed.
echo -n "TEST: atomic replace ... "
dmesg -C
load_lp $MOD_LIVEPATCH
load_lp $MOD_LIVEPATCH2 replace=1
disable_lp $MOD_LIVEPATCH2
unload_lp $MOD_LIVEPATCH2
unload_lp $MOD_LIVEPATCH
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
$MOD_LIVEPATCH: pre_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
$MOD_LIVEPATCH: post_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': patching complete
% modprobe $MOD_LIVEPATCH2 replace=1
livepatch: enabling patch '$MOD_LIVEPATCH2'
livepatch: '$MOD_LIVEPATCH2': initializing patching transition
$MOD_LIVEPATCH2: pre_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': starting patching transition
livepatch: '$MOD_LIVEPATCH2': completing patching transition
$MOD_LIVEPATCH2: post_patch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': patching complete
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH2/enabled
livepatch: '$MOD_LIVEPATCH2': initializing unpatching transition
$MOD_LIVEPATCH2: pre_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': starting unpatching transition
livepatch: '$MOD_LIVEPATCH2': completing unpatching transition
$MOD_LIVEPATCH2: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': unpatching complete
% rmmod $MOD_LIVEPATCH2
% rmmod $MOD_LIVEPATCH"
exit 0

168
tools/testing/selftests/livepatch/test-livepatch.sh Executable file
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#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
. $(dirname $0)/functions.sh
MOD_LIVEPATCH=test_klp_livepatch
MOD_REPLACE=test_klp_atomic_replace
set_dynamic_debug
# TEST: basic function patching
# - load a livepatch that modifies the output from /proc/cmdline and
# verify correct behavior
# - unload the livepatch and make sure the patch was removed
echo -n "TEST: basic function patching ... "
dmesg -C
load_lp $MOD_LIVEPATCH
if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then
echo -e "FAIL\n\n"
die "livepatch kselftest(s) failed"
fi
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
if [[ "$(cat /proc/cmdline)" == "$MOD_LIVEPATCH: this has been live patched" ]] ; then
echo -e "FAIL\n\n"
die "livepatch kselftest(s) failed"
fi
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
livepatch: '$MOD_LIVEPATCH': patching complete
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH"
# TEST: multiple livepatches
# - load a livepatch that modifies the output from /proc/cmdline and
# verify correct behavior
# - load another livepatch and verify that both livepatches are active
# - unload the second livepatch and verify that the first is still active
# - unload the first livepatch and verify none are active
echo -n "TEST: multiple livepatches ... "
dmesg -C
load_lp $MOD_LIVEPATCH
grep 'live patched' /proc/cmdline > /dev/kmsg
grep 'live patched' /proc/meminfo > /dev/kmsg
load_lp $MOD_REPLACE replace=0
grep 'live patched' /proc/cmdline > /dev/kmsg
grep 'live patched' /proc/meminfo > /dev/kmsg
disable_lp $MOD_REPLACE
unload_lp $MOD_REPLACE
grep 'live patched' /proc/cmdline > /dev/kmsg
grep 'live patched' /proc/meminfo > /dev/kmsg
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
grep 'live patched' /proc/cmdline > /dev/kmsg
grep 'live patched' /proc/meminfo > /dev/kmsg
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
livepatch: '$MOD_LIVEPATCH': patching complete
$MOD_LIVEPATCH: this has been live patched
% modprobe $MOD_REPLACE replace=0
livepatch: enabling patch '$MOD_REPLACE'
livepatch: '$MOD_REPLACE': initializing patching transition
livepatch: '$MOD_REPLACE': starting patching transition
livepatch: '$MOD_REPLACE': completing patching transition
livepatch: '$MOD_REPLACE': patching complete
$MOD_LIVEPATCH: this has been live patched
$MOD_REPLACE: this has been live patched
% echo 0 > /sys/kernel/livepatch/$MOD_REPLACE/enabled
livepatch: '$MOD_REPLACE': initializing unpatching transition
livepatch: '$MOD_REPLACE': starting unpatching transition
livepatch: '$MOD_REPLACE': completing unpatching transition
livepatch: '$MOD_REPLACE': unpatching complete
% rmmod $MOD_REPLACE
$MOD_LIVEPATCH: this has been live patched
% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH"
# TEST: atomic replace livepatch
# - load a livepatch that modifies the output from /proc/cmdline and
# verify correct behavior
# - load an atomic replace livepatch and verify that only the second is active
# - remove the first livepatch and verify that the atomic replace livepatch
# is still active
# - remove the atomic replace livepatch and verify that none are active
echo -n "TEST: atomic replace livepatch ... "
dmesg -C
load_lp $MOD_LIVEPATCH
grep 'live patched' /proc/cmdline > /dev/kmsg
grep 'live patched' /proc/meminfo > /dev/kmsg
load_lp $MOD_REPLACE replace=1
grep 'live patched' /proc/cmdline > /dev/kmsg
grep 'live patched' /proc/meminfo > /dev/kmsg
unload_lp $MOD_LIVEPATCH
grep 'live patched' /proc/cmdline > /dev/kmsg
grep 'live patched' /proc/meminfo > /dev/kmsg
disable_lp $MOD_REPLACE
unload_lp $MOD_REPLACE
grep 'live patched' /proc/cmdline > /dev/kmsg
grep 'live patched' /proc/meminfo > /dev/kmsg
check_result "% modprobe $MOD_LIVEPATCH
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
livepatch: '$MOD_LIVEPATCH': patching complete
$MOD_LIVEPATCH: this has been live patched
% modprobe $MOD_REPLACE replace=1
livepatch: enabling patch '$MOD_REPLACE'
livepatch: '$MOD_REPLACE': initializing patching transition
livepatch: '$MOD_REPLACE': starting patching transition
livepatch: '$MOD_REPLACE': completing patching transition
livepatch: '$MOD_REPLACE': patching complete
$MOD_REPLACE: this has been live patched
% rmmod $MOD_LIVEPATCH
$MOD_REPLACE: this has been live patched
% echo 0 > /sys/kernel/livepatch/$MOD_REPLACE/enabled
livepatch: '$MOD_REPLACE': initializing unpatching transition
livepatch: '$MOD_REPLACE': starting unpatching transition
livepatch: '$MOD_REPLACE': completing unpatching transition
livepatch: '$MOD_REPLACE': unpatching complete
% rmmod $MOD_REPLACE"
exit 0

60
tools/testing/selftests/livepatch/test-shadow-vars.sh Executable file
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#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
. $(dirname $0)/functions.sh
MOD_TEST=test_klp_shadow_vars
set_dynamic_debug
# TEST: basic shadow variable API
# - load a module that exercises the shadow variable API
echo -n "TEST: basic shadow variable API ... "
dmesg -C
load_mod $MOD_TEST
unload_mod $MOD_TEST
check_result "% modprobe $MOD_TEST
$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1234) = PTR0
$MOD_TEST: got expected NULL result
$MOD_TEST: shadow_ctor: PTR6 -> PTR1
$MOD_TEST: klp_shadow_alloc(obj=PTR5, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR1 = PTR6
$MOD_TEST: shadow_ctor: PTR8 -> PTR2
$MOD_TEST: klp_shadow_alloc(obj=PTR9, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR2 = PTR8
$MOD_TEST: shadow_ctor: PTR10 -> PTR3
$MOD_TEST: klp_shadow_alloc(obj=PTR5, id=0x1235, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR3 = PTR10
$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1234) = PTR6
$MOD_TEST: got expected PTR6 -> PTR1 result
$MOD_TEST: klp_shadow_get(obj=PTR9, id=0x1234) = PTR8
$MOD_TEST: got expected PTR8 -> PTR2 result
$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1235) = PTR10
$MOD_TEST: got expected PTR10 -> PTR3 result
$MOD_TEST: shadow_ctor: PTR11 -> PTR4
$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR12, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR4 = PTR11
$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR12, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR4 = PTR11
$MOD_TEST: got expected PTR11 -> PTR4 result
$MOD_TEST: shadow_dtor(obj=PTR5, shadow_data=PTR6)
$MOD_TEST: klp_shadow_free(obj=PTR5, id=0x1234, dtor=PTR13)
$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1234) = PTR0
$MOD_TEST: got expected NULL result
$MOD_TEST: shadow_dtor(obj=PTR9, shadow_data=PTR8)
$MOD_TEST: klp_shadow_free(obj=PTR9, id=0x1234, dtor=PTR13)
$MOD_TEST: klp_shadow_get(obj=PTR9, id=0x1234) = PTR0
$MOD_TEST: got expected NULL result
$MOD_TEST: shadow_dtor(obj=PTR12, shadow_data=PTR11)
$MOD_TEST: klp_shadow_free(obj=PTR12, id=0x1234, dtor=PTR13)
$MOD_TEST: klp_shadow_get(obj=PTR12, id=0x1234) = PTR0
$MOD_TEST: got expected NULL result
$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1235) = PTR10
$MOD_TEST: got expected PTR10 -> PTR3 result
$MOD_TEST: shadow_dtor(obj=PTR5, shadow_data=PTR10)
$MOD_TEST: klp_shadow_free_all(id=0x1235, dtor=PTR13)
$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1234) = PTR0
$MOD_TEST: shadow_get() got expected NULL result
% rmmod test_klp_shadow_vars"
exit 0