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authorPetr Mladek <pmladek@suse.com>2019-10-30 16:43:13 +0100
committerPetr Mladek <pmladek@suse.com>2019-11-01 13:08:29 +0100
commitecd25094c5f5d5af12dffd3a4f2f4a42e486cdd8 (patch)
tree41cb3130ac1daccc5ec5fa4a4095bfa24a77a2fe /lib/livepatch
parente553d2a53d47853b3f1780fd65f8259672daabed (diff)
downloadlinux-ecd25094c5f5d5af12dffd3a4f2f4a42e486cdd8.tar.bz2
livepatch: Selftests of the API for tracking system state changes
Four selftests for the new API. Link: http://lkml.kernel.org/r/20191030154313.13263-6-pmladek@suse.com To: Jiri Kosina <jikos@kernel.org> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Nicolai Stange <nstange@suse.de> Cc: live-patching@vger.kernel.org Cc: linux-kernel@vger.kernel.org Acked-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'lib/livepatch')
-rw-r--r--lib/livepatch/Makefile5
-rw-r--r--lib/livepatch/test_klp_state.c162
-rw-r--r--lib/livepatch/test_klp_state2.c191
-rw-r--r--lib/livepatch/test_klp_state3.c5
4 files changed, 362 insertions, 1 deletions
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"