Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/lib/livepatch/Makefile b/lib/livepatch/Makefile
index 26900dd..dcc912b 100644
--- a/lib/livepatch/Makefile
+++ b/lib/livepatch/Makefile
@@ -8,8 +8,7 @@
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)
+ test_klp_shadow_vars.o \
+ test_klp_state.o \
+ test_klp_state2.o \
+ test_klp_state3.o
diff --git a/lib/livepatch/test_klp_callbacks_busy.c b/lib/livepatch/test_klp_callbacks_busy.c
index 40beddf..7ac845f 100644
--- a/lib/livepatch/test_klp_callbacks_busy.c
+++ b/lib/livepatch/test_klp_callbacks_busy.c
@@ -5,34 +5,53 @@
#include <linux/module.h>
#include <linux/kernel.h>
+#include <linux/sched.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)");
+/* load/run-time control from sysfs writer */
+static bool block_transition;
+module_param(block_transition, bool, 0644);
+MODULE_PARM_DESC(block_transition, "block_transition (default=false)");
static void busymod_work_func(struct work_struct *work);
-static DECLARE_DELAYED_WORK(work, busymod_work_func);
+static DECLARE_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 enter\n", __func__);
+
+ while (READ_ONCE(block_transition)) {
+ /*
+ * Busy-wait until the sysfs writer has acknowledged a
+ * blocked transition and clears the flag.
+ */
+ msleep(20);
+ }
+
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));
+ schedule_work(&work);
+
+ if (!block_transition) {
+ /*
+ * Serialize output: print all messages from the work
+ * function before returning from init().
+ */
+ flush_work(&work);
+ }
+
return 0;
}
static void test_klp_callbacks_busy_exit(void)
{
- cancel_delayed_work_sync(&work);
+ WRITE_ONCE(block_transition, false);
+ flush_work(&work);
pr_info("%s\n", __func__);
}
diff --git a/lib/livepatch/test_klp_shadow_vars.c b/lib/livepatch/test_klp_shadow_vars.c
index fe5c413..b991164 100644
--- a/lib/livepatch/test_klp_shadow_vars.c
+++ b/lib/livepatch/test_klp_shadow_vars.c
@@ -60,36 +60,43 @@
*/
static void *shadow_get(void *obj, unsigned long id)
{
- void *ret = klp_shadow_get(obj, id);
+ int **sv;
+ sv = 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));
+ __func__, ptr_id(obj), id, ptr_id(sv));
- return ret;
+ return sv;
}
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);
+ int **var = ctor_data;
+ int **sv;
+
+ sv = klp_shadow_alloc(obj, id, size, gfp_flags, ctor, var);
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;
+ ptr_id(*var), ptr_id(sv));
+
+ return sv;
}
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);
+ int **var = ctor_data;
+ int **sv;
+
+ sv = klp_shadow_get_or_alloc(obj, id, size, gfp_flags, ctor, var);
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;
+ ptr_id(*var), ptr_id(sv));
+
+ return sv;
}
static void shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor)
@@ -102,149 +109,185 @@
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));
+ 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));
+ int **sv = shadow_data;
+ int **var = ctor_data;
+
+ if (!var)
+ return -EINVAL;
+
+ *sv = *var;
+ pr_info("%s: PTR%d -> PTR%d\n", __func__, ptr_id(sv), ptr_id(*var));
return 0;
}
+/*
+ * With more than one item to free in the list, order is not determined and
+ * shadow_dtor will not be passed to shadow_free_all() which would make the
+ * test fail. (see pass 6)
+ */
static void shadow_dtor(void *obj, void *shadow_data)
{
+ int **sv = shadow_data;
+
pr_info("%s(obj=PTR%d, shadow_data=PTR%d)\n",
- __func__, ptr_id(obj), ptr_id(shadow_data));
+ __func__, ptr_id(obj), ptr_id(sv));
}
+/* number of objects we simulate that need shadow vars */
+#define NUM_OBJS 3
+
+/* dynamically created obj fields have the following shadow var id values */
+#define SV_ID1 0x1234
+#define SV_ID2 0x1235
+
+/*
+ * The main test case adds/removes new fields (shadow var) to each of these
+ * test structure instances. The last group of fields in the struct represent
+ * the idea that shadow variables may be added and removed to and from the
+ * struct during execution.
+ */
+struct test_object {
+ /* add anything here below and avoid to define an empty struct */
+ struct shadow_ptr sp;
+
+ /* these represent shadow vars added and removed with SV_ID{1,2} */
+ /* char nfield1; */
+ /* int nfield2; */
+};
+
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;
+ struct test_object objs[NUM_OBJS];
+ char nfields1[NUM_OBJS], *pnfields1[NUM_OBJS], **sv1[NUM_OBJS];
+ char *pndup[NUM_OBJS];
+ int nfields2[NUM_OBJS], *pnfields2[NUM_OBJS], **sv2[NUM_OBJS];
+ void **sv;
+ int ret;
+ int i;
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)
+ sv = shadow_get(&objs[0], SV_ID1);
+ if (!sv)
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);
- if (!sv1)
- return -ENOMEM;
+ /* pass 1: init & alloc a char+int pair of svars for each objs */
+ for (i = 0; i < NUM_OBJS; i++) {
+ pnfields1[i] = &nfields1[i];
+ ptr_id(pnfields1[i]);
- sv2 = shadow_alloc(obj + 1, id, size, gfp_flags, shadow_ctor, &var2);
- if (!sv2)
- return -ENOMEM;
+ if (i % 2) {
+ sv1[i] = shadow_alloc(&objs[i], SV_ID1,
+ sizeof(pnfields1[i]), GFP_KERNEL,
+ shadow_ctor, &pnfields1[i]);
+ } else {
+ sv1[i] = shadow_get_or_alloc(&objs[i], SV_ID1,
+ sizeof(pnfields1[i]), GFP_KERNEL,
+ shadow_ctor, &pnfields1[i]);
+ }
+ if (!sv1[i]) {
+ ret = -ENOMEM;
+ goto out;
+ }
- sv3 = shadow_alloc(obj, id + 1, size, gfp_flags, shadow_ctor, &var3);
- if (!sv3)
- return -ENOMEM;
+ pnfields2[i] = &nfields2[i];
+ ptr_id(pnfields2[i]);
+ sv2[i] = shadow_alloc(&objs[i], SV_ID2, sizeof(pnfields2[i]),
+ GFP_KERNEL, shadow_ctor, &pnfields2[i]);
+ if (!sv2[i]) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
- /*
- * Verify we can find our new shadow variables and that they point
- * to expected data.
- */
- ret = shadow_get(obj, id);
- if (!ret)
- return -EINVAL;
- if (ret == sv1 && *sv1 == &var1)
- pr_info(" got expected PTR%d -> PTR%d result\n",
- ptr_id(sv1), ptr_id(*sv1));
+ /* pass 2: verify we find allocated svars and where they point to */
+ for (i = 0; i < NUM_OBJS; i++) {
+ /* check the "char" svar for all objects */
+ sv = shadow_get(&objs[i], SV_ID1);
+ if (!sv) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i])
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv1[i]), ptr_id(*sv1[i]));
- ret = shadow_get(obj + 1, id);
- if (!ret)
- return -EINVAL;
- 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)
- return -EINVAL;
- if (ret == sv3 && *sv3 == &var3)
- pr_info(" got expected PTR%d -> PTR%d result\n",
- ptr_id(sv3), ptr_id(*sv3));
+ /* check the "int" svar for all objects */
+ sv = shadow_get(&objs[i], SV_ID2);
+ if (!sv) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i])
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv2[i]), ptr_id(*sv2[i]));
+ }
- /*
- * 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);
- if (!sv4)
- return -ENOMEM;
+ /* pass 3: verify that 'get_or_alloc' returns already allocated svars */
+ for (i = 0; i < NUM_OBJS; i++) {
+ pndup[i] = &nfields1[i];
+ ptr_id(pndup[i]);
- ret = shadow_get_or_alloc(obj + 2, id, size, gfp_flags, shadow_ctor, &var4);
- if (!ret)
- return -EINVAL;
- if (ret == sv4 && *sv4 == &var4)
- pr_info(" got expected PTR%d -> PTR%d result\n",
- ptr_id(sv4), ptr_id(*sv4));
+ sv = shadow_get_or_alloc(&objs[i], SV_ID1, sizeof(pndup[i]),
+ GFP_KERNEL, shadow_ctor, &pndup[i]);
+ if (!sv) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i])
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv1[i]), ptr_id(*sv1[i]));
+ }
- /*
- * 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");
+ /* pass 4: free <objs[*], SV_ID1> pairs of svars, verify removal */
+ for (i = 0; i < NUM_OBJS; i++) {
+ shadow_free(&objs[i], SV_ID1, shadow_dtor); /* 'char' pairs */
+ sv = shadow_get(&objs[i], SV_ID1);
+ if (!sv)
+ 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");
+ /* pass 5: check we still find <objs[*], SV_ID2> svar pairs */
+ for (i = 0; i < NUM_OBJS; i++) {
+ sv = shadow_get(&objs[i], SV_ID2); /* 'int' pairs */
+ if (!sv) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i])
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv2[i]), ptr_id(*sv2[i]));
+ }
- 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)
- return -EINVAL;
- 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");
-
+ /* pass 6: free all the <objs[*], SV_ID2> svar pairs too. */
+ shadow_free_all(SV_ID2, NULL); /* 'int' pairs */
+ for (i = 0; i < NUM_OBJS; i++) {
+ sv = shadow_get(&objs[i], SV_ID2);
+ if (!sv)
+ pr_info(" got expected NULL result\n");
+ }
free_ptr_list();
return 0;
+out:
+ shadow_free_all(SV_ID1, NULL); /* 'char' pairs */
+ shadow_free_all(SV_ID2, NULL); /* 'int' pairs */
+ free_ptr_list();
+
+ return ret;
}
static void test_klp_shadow_vars_exit(void)
diff --git a/lib/livepatch/test_klp_state.c b/lib/livepatch/test_klp_state.c
new file mode 100644
index 0000000..57a4253
--- /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 0000000..c978ea4
--- /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 0000000..9226579
--- /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"