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Date:   Wed, 9 Oct 2019 10:27:18 -0400
From:   Joe Lawrence <joe.lawrence@redhat.com>
To:     Petr Mladek <pmladek@suse.com>
Cc:     Jiri Kosina <jikos@kernel.org>,
        Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Miroslav Benes <mbenes@suse.cz>,
        Nicolai Stange <nstange@suse.de>, linux-kernel@vger.kernel.org,
        live-patching@vger.kernel.org
Subject: Re: [PATCH v3 5/5] livepatch: Selftests of the API for tracking
 system state changes
Message-ID: <20191009142718.GB3333@redhat.com>
References: <20191003090137.6874-1-pmladek@suse.com>
 <20191003090137.6874-6-pmladek@suse.com>
 <20191004144742.GB3768@redhat.com>
 <20191009141859.ndyv7jznjasxcpsw@pathway.suse.cz>
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On Wed, Oct 09, 2019 at 04:18:59PM +0200, Petr Mladek wrote:
> On Fri 2019-10-04 10:47:42, Joe Lawrence wrote:
> > On Thu, Oct 03, 2019 at 11:01:37AM +0200, Petr Mladek wrote:
> > > Four selftests for the new API.
> > > 
> > > --- /dev/null
> > > +++ b/tools/testing/selftests/livepatch/test-state.sh
> > > @@ -0,0 +1,180 @@
> > > +#!/bin/bash
> > > +# SPDX-License-Identifier: GPL-2.0
> > > +# Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
> > > +
> > 
> > nit: this should probably read as:
> > # Copyright (C) 2019 Petr Mladek <pmladek@suse.com>
> > 
> > > +
> > > +load_lp $MOD_LIVEPATCH
> > > +disable_lp $MOD_LIVEPATCH
> > > +unload_lp $MOD_LIVEPATCH
> > > +
> > > +check_result "% modprobe test_klp_state
> > > +livepatch: enabling patch 'test_klp_state'
> > > +livepatch: 'test_klp_state': initializing patching transition
> > > +test_klp_state: pre_patch_callback: vmlinux
> > > +test_klp_state: allocate_loglevel_state: allocating space to store console_loglevel
> > > +livepatch: 'test_klp_state': starting patching transition
> > > +livepatch: 'test_klp_state': completing patching transition
> > > +test_klp_state: post_patch_callback: vmlinux
> > > +test_klp_state: fix_console_loglevel: fixing console_loglevel
> > > +livepatch: 'test_klp_state': patching complete
> > > +% echo 0 > /sys/kernel/livepatch/test_klp_state/enabled
> > > +livepatch: 'test_klp_state': initializing unpatching transition
> > > +test_klp_state: pre_unpatch_callback: vmlinux
> > > +test_klp_state: restore_console_loglevel: restoring console_loglevel
> > > +livepatch: 'test_klp_state': starting unpatching transition
> > > +livepatch: 'test_klp_state': completing unpatching transition
> > > +test_klp_state: post_unpatch_callback: vmlinux
> > > +test_klp_state: free_loglevel_state: freeing space for the stored console_loglevel
> > > +livepatch: 'test_klp_state': unpatching complete
> > > +% rmmod test_klp_state"
> > > +
> > 
> > nit: a matter of style, and I don't mind either, but the other test
> > scripts used $MOD_LIVEPATCH{2,3} variable replacement in the
> > check_result string.  I think I originally did that when we were
> > reviewing the first self-test patchset and the filenames may or may not
> > have changed.  Those names are stable now, so I don't have a strong
> > opinion either way.
> 
> Please, find below and updated version of the patch that fixes
> the two above problems and also the kbuild robot failure.
> 
> The build failure was fixed by #include <linux/slab.h>
> 
> Here we go:
> 
> From 206e0a53de25ddb042e5947c2a736e33ca4a2b4c Mon Sep 17 00:00:00 2001
> From: Petr Mladek <pmladek@suse.com>
> Date: Mon, 10 Jun 2019 14:02:42 +0200
> Subject: [PATCH v3.1 5/5] livepatch: Selftests of the API for tracking system state
>  changes
> 
> Four selftests for the new API.
> 
> Signed-off-by: Petr Mladek <pmladek@suse.com>
> Acked-by: Miroslav Benes <mbenes@suse.cz>
> ---
>  lib/livepatch/Makefile                          |   5 +-
>  lib/livepatch/test_klp_state.c                  | 162 ++++++++++++++++++++
>  lib/livepatch/test_klp_state2.c                 | 191 ++++++++++++++++++++++++
>  lib/livepatch/test_klp_state3.c                 |   5 +
>  tools/testing/selftests/livepatch/Makefile      |   3 +-
>  tools/testing/selftests/livepatch/test-state.sh | 180 ++++++++++++++++++++++
>  6 files changed, 544 insertions(+), 2 deletions(-)
>  create mode 100644 lib/livepatch/test_klp_state.c
>  create mode 100644 lib/livepatch/test_klp_state2.c
>  create mode 100644 lib/livepatch/test_klp_state3.c
>  create mode 100755 tools/testing/selftests/livepatch/test-state.sh
> 
> diff --git a/lib/livepatch/Makefile b/lib/livepatch/Makefile
> index 26900ddaef82..295b94bff370 100644
> --- a/lib/livepatch/Makefile
> +++ b/lib/livepatch/Makefile
> @@ -8,7 +8,10 @@ obj-$(CONFIG_TEST_LIVEPATCH) += test_klp_atomic_replace.o \
>  				test_klp_callbacks_busy.o \
>  				test_klp_callbacks_mod.o \
>  				test_klp_livepatch.o \
> -				test_klp_shadow_vars.o
> +				test_klp_shadow_vars.o \
> +				test_klp_state.o \
> +				test_klp_state2.o \
> +				test_klp_state3.o
>  
>  # Target modules to be livepatched require CC_FLAGS_FTRACE
>  CFLAGS_test_klp_callbacks_busy.o	+= $(CC_FLAGS_FTRACE)
> diff --git a/lib/livepatch/test_klp_state.c b/lib/livepatch/test_klp_state.c
> new file mode 100644
> index 000000000000..57a4253acb01
> --- /dev/null
> +++ b/lib/livepatch/test_klp_state.c
> @@ -0,0 +1,162 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2019 SUSE
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/printk.h>
> +#include <linux/livepatch.h>
> +
> +#define CONSOLE_LOGLEVEL_STATE 1
> +/* Version 1 does not support migration. */
> +#define CONSOLE_LOGLEVEL_STATE_VERSION 1
> +
> +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);
> +}
> +
> +static struct klp_patch patch;
> +
> +static int allocate_loglevel_state(void)
> +{
> +	struct klp_state *loglevel_state;
> +
> +	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
> +	if (!loglevel_state)
> +		return -EINVAL;
> +
> +	loglevel_state->data = kzalloc(sizeof(console_loglevel), GFP_KERNEL);
> +	if (!loglevel_state->data)
> +		return -ENOMEM;
> +
> +	pr_info("%s: allocating space to store console_loglevel\n",
> +		__func__);
> +	return 0;
> +}
> +
> +static void fix_console_loglevel(void)
> +{
> +	struct klp_state *loglevel_state;
> +
> +	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
> +	if (!loglevel_state)
> +		return;
> +
> +	pr_info("%s: fixing console_loglevel\n", __func__);
> +	*(int *)loglevel_state->data = console_loglevel;
> +	console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
> +}
> +
> +static void restore_console_loglevel(void)
> +{
> +	struct klp_state *loglevel_state;
> +
> +	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
> +	if (!loglevel_state)
> +		return;
> +
> +	pr_info("%s: restoring console_loglevel\n", __func__);
> +	console_loglevel = *(int *)loglevel_state->data;
> +}
> +
> +static void free_loglevel_state(void)
> +{
> +	struct klp_state *loglevel_state;
> +
> +	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
> +	if (!loglevel_state)
> +		return;
> +
> +	pr_info("%s: freeing space for the stored console_loglevel\n",
> +		__func__);
> +	kfree(loglevel_state->data);
> +}
> +
> +/* Executed on object patching (ie, patch enablement) */
> +static int pre_patch_callback(struct klp_object *obj)
> +{
> +	callback_info(__func__, obj);
> +	return allocate_loglevel_state();
> +}
> +
> +/* Executed on object unpatching (ie, patch disablement) */
> +static void post_patch_callback(struct klp_object *obj)
> +{
> +	callback_info(__func__, obj);
> +	fix_console_loglevel();
> +}
> +
> +/* Executed on object unpatching (ie, patch disablement) */
> +static void pre_unpatch_callback(struct klp_object *obj)
> +{
> +	callback_info(__func__, obj);
> +	restore_console_loglevel();
> +}
> +
> +/* Executed on object unpatching (ie, patch disablement) */
> +static void post_unpatch_callback(struct klp_object *obj)
> +{
> +	callback_info(__func__, obj);
> +	free_loglevel_state();
> +}
> +
> +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_state states[] = {
> +	{
> +		.id = CONSOLE_LOGLEVEL_STATE,
> +		.version = CONSOLE_LOGLEVEL_STATE_VERSION,
> +	}, { }
> +};
> +
> +static struct klp_patch patch = {
> +	.mod = THIS_MODULE,
> +	.objs = objs,
> +	.states = states,
> +	.replace = true,
> +};
> +
> +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("Petr Mladek <pmladek@suse.com>");
> +MODULE_DESCRIPTION("Livepatch test: system state modification");
> diff --git a/lib/livepatch/test_klp_state2.c b/lib/livepatch/test_klp_state2.c
> new file mode 100644
> index 000000000000..c978ea4d5e67
> --- /dev/null
> +++ b/lib/livepatch/test_klp_state2.c
> @@ -0,0 +1,191 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2019 SUSE
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/printk.h>
> +#include <linux/livepatch.h>
> +
> +#define CONSOLE_LOGLEVEL_STATE 1
> +/* Version 2 supports migration. */
> +#define CONSOLE_LOGLEVEL_STATE_VERSION 2
> +
> +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);
> +}
> +
> +static struct klp_patch patch;
> +
> +static int allocate_loglevel_state(void)
> +{
> +	struct klp_state *loglevel_state, *prev_loglevel_state;
> +
> +	prev_loglevel_state = klp_get_prev_state(CONSOLE_LOGLEVEL_STATE);
> +	if (prev_loglevel_state) {
> +		pr_info("%s: space to store console_loglevel already allocated\n",
> +		__func__);
> +		return 0;
> +	}
> +
> +	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
> +	if (!loglevel_state)
> +		return -EINVAL;
> +
> +	loglevel_state->data = kzalloc(sizeof(console_loglevel), GFP_KERNEL);
> +	if (!loglevel_state->data)
> +		return -ENOMEM;
> +
> +	pr_info("%s: allocating space to store console_loglevel\n",
> +		__func__);
> +	return 0;
> +}
> +
> +static void fix_console_loglevel(void)
> +{
> +	struct klp_state *loglevel_state, *prev_loglevel_state;
> +
> +	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
> +	if (!loglevel_state)
> +		return;
> +
> +	prev_loglevel_state = klp_get_prev_state(CONSOLE_LOGLEVEL_STATE);
> +	if (prev_loglevel_state) {
> +		pr_info("%s: taking over the console_loglevel change\n",
> +		__func__);
> +		loglevel_state->data = prev_loglevel_state->data;
> +		return;
> +	}
> +
> +	pr_info("%s: fixing console_loglevel\n", __func__);
> +	*(int *)loglevel_state->data = console_loglevel;
> +	console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
> +}
> +
> +static void restore_console_loglevel(void)
> +{
> +	struct klp_state *loglevel_state, *prev_loglevel_state;
> +
> +	prev_loglevel_state = klp_get_prev_state(CONSOLE_LOGLEVEL_STATE);
> +	if (prev_loglevel_state) {
> +		pr_info("%s: passing the console_loglevel change back to the old livepatch\n",
> +		__func__);
> +		return;
> +	}
> +
> +	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
> +	if (!loglevel_state)
> +		return;
> +
> +	pr_info("%s: restoring console_loglevel\n", __func__);
> +	console_loglevel = *(int *)loglevel_state->data;
> +}
> +
> +static void free_loglevel_state(void)
> +{
> +	struct klp_state *loglevel_state, *prev_loglevel_state;
> +
> +	prev_loglevel_state = klp_get_prev_state(CONSOLE_LOGLEVEL_STATE);
> +	if (prev_loglevel_state) {
> +		pr_info("%s: keeping space to store console_loglevel\n",
> +		__func__);
> +		return;
> +	}
> +
> +	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
> +	if (!loglevel_state)
> +		return;
> +
> +	pr_info("%s: freeing space for the stored console_loglevel\n",
> +		__func__);
> +	kfree(loglevel_state->data);
> +}
> +
> +/* Executed on object patching (ie, patch enablement) */
> +static int pre_patch_callback(struct klp_object *obj)
> +{
> +	callback_info(__func__, obj);
> +	return allocate_loglevel_state();
> +}
> +
> +/* Executed on object unpatching (ie, patch disablement) */
> +static void post_patch_callback(struct klp_object *obj)
> +{
> +	callback_info(__func__, obj);
> +	fix_console_loglevel();
> +}
> +
> +/* Executed on object unpatching (ie, patch disablement) */
> +static void pre_unpatch_callback(struct klp_object *obj)
> +{
> +	callback_info(__func__, obj);
> +	restore_console_loglevel();
> +}
> +
> +/* Executed on object unpatching (ie, patch disablement) */
> +static void post_unpatch_callback(struct klp_object *obj)
> +{
> +	callback_info(__func__, obj);
> +	free_loglevel_state();
> +}
> +
> +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_state states[] = {
> +	{
> +		.id = CONSOLE_LOGLEVEL_STATE,
> +		.version = CONSOLE_LOGLEVEL_STATE_VERSION,
> +	}, { }
> +};
> +
> +static struct klp_patch patch = {
> +	.mod = THIS_MODULE,
> +	.objs = objs,
> +	.states = states,
> +	.replace = true,
> +};
> +
> +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("Petr Mladek <pmladek@suse.com>");
> +MODULE_DESCRIPTION("Livepatch test: system state modification");
> diff --git a/lib/livepatch/test_klp_state3.c b/lib/livepatch/test_klp_state3.c
> new file mode 100644
> index 000000000000..9226579d10c5
> --- /dev/null
> +++ b/lib/livepatch/test_klp_state3.c
> @@ -0,0 +1,5 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2019 SUSE
> +
> +/* The console loglevel fix is the same in the next cumulative patch. */
> +#include "test_klp_state2.c"
> diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile
> index fd405402c3ff..1cf40a9e7185 100644
> --- a/tools/testing/selftests/livepatch/Makefile
> +++ b/tools/testing/selftests/livepatch/Makefile
> @@ -4,6 +4,7 @@ TEST_PROGS_EXTENDED := functions.sh
>  TEST_PROGS := \
>  	test-livepatch.sh \
>  	test-callbacks.sh \
> -	test-shadow-vars.sh
> +	test-shadow-vars.sh \
> +	test-state.sh
>  
>  include ../lib.mk
> diff --git a/tools/testing/selftests/livepatch/test-state.sh b/tools/testing/selftests/livepatch/test-state.sh
> new file mode 100755
> index 000000000000..dc2908c22c26
> --- /dev/null
> +++ b/tools/testing/selftests/livepatch/test-state.sh
> @@ -0,0 +1,180 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2019 SUSE
> +
> +. $(dirname $0)/functions.sh
> +
> +MOD_LIVEPATCH=test_klp_state
> +MOD_LIVEPATCH2=test_klp_state2
> +MOD_LIVEPATCH3=test_klp_state3
> +
> +set_dynamic_debug
> +
> +
> +# TEST: Loading and removing a module that modifies the system state
> +
> +echo -n "TEST: system state modification ... "
> +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
> +$MOD_LIVEPATCH: allocate_loglevel_state: allocating space to store console_loglevel
> +livepatch: '$MOD_LIVEPATCH': starting patching transition
> +livepatch: '$MOD_LIVEPATCH': completing patching transition
> +$MOD_LIVEPATCH: post_patch_callback: vmlinux
> +$MOD_LIVEPATCH: fix_console_loglevel: fixing console_loglevel
> +livepatch: '$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: restore_console_loglevel: restoring console_loglevel
> +livepatch: '$MOD_LIVEPATCH': starting unpatching transition
> +livepatch: '$MOD_LIVEPATCH': completing unpatching transition
> +$MOD_LIVEPATCH: post_unpatch_callback: vmlinux
> +$MOD_LIVEPATCH: free_loglevel_state: freeing space for the stored console_loglevel
> +livepatch: '$MOD_LIVEPATCH': unpatching complete
> +% rmmod $MOD_LIVEPATCH"
> +
> +
> +# TEST: Take over system state change by a cumulative patch
> +
> +echo -n "TEST: taking over system state modification ... "
> +dmesg -C
> +
> +load_lp $MOD_LIVEPATCH
> +load_lp $MOD_LIVEPATCH2
> +unload_lp $MOD_LIVEPATCH
> +disable_lp $MOD_LIVEPATCH2
> +unload_lp $MOD_LIVEPATCH2
> +
> +check_result "% modprobe $MOD_LIVEPATCH
> +livepatch: enabling patch '$MOD_LIVEPATCH'
> +livepatch: '$MOD_LIVEPATCH': initializing patching transition
> +$MOD_LIVEPATCH: pre_patch_callback: vmlinux
> +$MOD_LIVEPATCH: allocate_loglevel_state: allocating space to store console_loglevel
> +livepatch: '$MOD_LIVEPATCH': starting patching transition
> +livepatch: '$MOD_LIVEPATCH': completing patching transition
> +$MOD_LIVEPATCH: post_patch_callback: vmlinux
> +$MOD_LIVEPATCH: fix_console_loglevel: fixing console_loglevel
> +livepatch: '$MOD_LIVEPATCH': patching complete
> +% modprobe $MOD_LIVEPATCH2
> +livepatch: enabling patch '$MOD_LIVEPATCH2'
> +livepatch: '$MOD_LIVEPATCH2': initializing patching transition
> +$MOD_LIVEPATCH2: pre_patch_callback: vmlinux
> +$MOD_LIVEPATCH2: allocate_loglevel_state: space to store console_loglevel already allocated
> +livepatch: '$MOD_LIVEPATCH2': starting patching transition
> +livepatch: '$MOD_LIVEPATCH2': completing patching transition
> +$MOD_LIVEPATCH2: post_patch_callback: vmlinux
> +$MOD_LIVEPATCH2: fix_console_loglevel: taking over the console_loglevel change
> +livepatch: '$MOD_LIVEPATCH2': patching complete
> +% rmmod $MOD_LIVEPATCH
> +% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH2/enabled
> +livepatch: '$MOD_LIVEPATCH2': initializing unpatching transition
> +$MOD_LIVEPATCH2: pre_unpatch_callback: vmlinux
> +$MOD_LIVEPATCH2: restore_console_loglevel: restoring console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': starting unpatching transition
> +livepatch: '$MOD_LIVEPATCH2': completing unpatching transition
> +$MOD_LIVEPATCH2: post_unpatch_callback: vmlinux
> +$MOD_LIVEPATCH2: free_loglevel_state: freeing space for the stored console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': unpatching complete
> +% rmmod $MOD_LIVEPATCH2"
> +
> +
> +# TEST: Take over system state change by a cumulative patch
> +
> +echo -n "TEST: compatible cumulative livepatches ... "
> +dmesg -C
> +
> +load_lp $MOD_LIVEPATCH2
> +load_lp $MOD_LIVEPATCH3
> +unload_lp $MOD_LIVEPATCH2
> +load_lp $MOD_LIVEPATCH2
> +disable_lp $MOD_LIVEPATCH2
> +unload_lp $MOD_LIVEPATCH2
> +unload_lp $MOD_LIVEPATCH3
> +
> +check_result "% modprobe $MOD_LIVEPATCH2
> +livepatch: enabling patch '$MOD_LIVEPATCH2'
> +livepatch: '$MOD_LIVEPATCH2': initializing patching transition
> +$MOD_LIVEPATCH2: pre_patch_callback: vmlinux
> +$MOD_LIVEPATCH2: allocate_loglevel_state: allocating space to store console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': starting patching transition
> +livepatch: '$MOD_LIVEPATCH2': completing patching transition
> +$MOD_LIVEPATCH2: post_patch_callback: vmlinux
> +$MOD_LIVEPATCH2: fix_console_loglevel: fixing console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': patching complete
> +% modprobe $MOD_LIVEPATCH3
> +livepatch: enabling patch '$MOD_LIVEPATCH3'
> +livepatch: '$MOD_LIVEPATCH3': initializing patching transition
> +$MOD_LIVEPATCH3: pre_patch_callback: vmlinux
> +$MOD_LIVEPATCH3: allocate_loglevel_state: space to store console_loglevel already allocated
> +livepatch: '$MOD_LIVEPATCH3': starting patching transition
> +livepatch: '$MOD_LIVEPATCH3': completing patching transition
> +$MOD_LIVEPATCH3: post_patch_callback: vmlinux
> +$MOD_LIVEPATCH3: fix_console_loglevel: taking over the console_loglevel change
> +livepatch: '$MOD_LIVEPATCH3': patching complete
> +% rmmod $MOD_LIVEPATCH2
> +% modprobe $MOD_LIVEPATCH2
> +livepatch: enabling patch '$MOD_LIVEPATCH2'
> +livepatch: '$MOD_LIVEPATCH2': initializing patching transition
> +$MOD_LIVEPATCH2: pre_patch_callback: vmlinux
> +$MOD_LIVEPATCH2: allocate_loglevel_state: space to store console_loglevel already allocated
> +livepatch: '$MOD_LIVEPATCH2': starting patching transition
> +livepatch: '$MOD_LIVEPATCH2': completing patching transition
> +$MOD_LIVEPATCH2: post_patch_callback: vmlinux
> +$MOD_LIVEPATCH2: fix_console_loglevel: taking over the console_loglevel change
> +livepatch: '$MOD_LIVEPATCH2': patching complete
> +% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH2/enabled
> +livepatch: '$MOD_LIVEPATCH2': initializing unpatching transition
> +$MOD_LIVEPATCH2: pre_unpatch_callback: vmlinux
> +$MOD_LIVEPATCH2: restore_console_loglevel: restoring console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': starting unpatching transition
> +livepatch: '$MOD_LIVEPATCH2': completing unpatching transition
> +$MOD_LIVEPATCH2: post_unpatch_callback: vmlinux
> +$MOD_LIVEPATCH2: free_loglevel_state: freeing space for the stored console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': unpatching complete
> +% rmmod $MOD_LIVEPATCH2
> +% rmmod $MOD_LIVEPATCH3"
> +
> +
> +# TEST: Failure caused by incompatible cumulative livepatches
> +
> +echo -n "TEST: incompatible cumulative livepatches ... "
> +dmesg -C
> +
> +load_lp $MOD_LIVEPATCH2
> +load_failing_mod $MOD_LIVEPATCH
> +disable_lp $MOD_LIVEPATCH2
> +unload_lp $MOD_LIVEPATCH2
> +
> +check_result "% modprobe $MOD_LIVEPATCH2
> +livepatch: enabling patch '$MOD_LIVEPATCH2'
> +livepatch: '$MOD_LIVEPATCH2': initializing patching transition
> +$MOD_LIVEPATCH2: pre_patch_callback: vmlinux
> +$MOD_LIVEPATCH2: allocate_loglevel_state: allocating space to store console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': starting patching transition
> +livepatch: '$MOD_LIVEPATCH2': completing patching transition
> +$MOD_LIVEPATCH2: post_patch_callback: vmlinux
> +$MOD_LIVEPATCH2: fix_console_loglevel: fixing console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': patching complete
> +% modprobe $MOD_LIVEPATCH
> +livepatch: Livepatch patch ($MOD_LIVEPATCH) is not compatible with the already installed livepatches.
> +modprobe: ERROR: could not insert '$MOD_LIVEPATCH': Invalid argument
> +% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH2/enabled
> +livepatch: '$MOD_LIVEPATCH2': initializing unpatching transition
> +$MOD_LIVEPATCH2: pre_unpatch_callback: vmlinux
> +$MOD_LIVEPATCH2: restore_console_loglevel: restoring console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': starting unpatching transition
> +livepatch: '$MOD_LIVEPATCH2': completing unpatching transition
> +$MOD_LIVEPATCH2: post_unpatch_callback: vmlinux
> +$MOD_LIVEPATCH2: free_loglevel_state: freeing space for the stored console_loglevel
> +livepatch: '$MOD_LIVEPATCH2': unpatching complete
> +% rmmod $MOD_LIVEPATCH2"
> +
> +exit 0
> -- 
> 2.16.4
> 
> 

Looks good to me...

Acked-by: Joe Lawrence <joe.lawrence@redhat.com>

-- Joe