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authorLinus Torvalds <torvalds@linux-foundation.org>2019-11-25 19:43:48 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-11-25 19:43:48 -0800
commitf838767555d40f29bc4771c5c8cc63193094b7cc (patch)
tree50d126b8fd20a8f50e13263529805e8eaea73db3 /lib
parent436b2a8039ac00f8dc6ae8f3bd2be83748f72312 (diff)
parent0e672adc87e5ae1758b6e0571b42d743a8324327 (diff)
Merge tag 'livepatching-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching
Pull livepatching updates from Petr Mladek: - New API to track system state changes done be livepatch callbacks. It helps to maintain compatibility between livepatches. - Update Kconfig help text. ORC is another reliable unwinder. - Disable generic selftest timeout. Livepatch selftests have their own per-operation fine-grained timeouts. * tag 'livepatching-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: x86/stacktrace: update kconfig help text for reliable unwinders livepatch: Selftests of the API for tracking system state changes livepatch: Documentation of the new API for tracking system state changes livepatch: Allow to distinguish different version of system state changes livepatch: Basic API to track system state changes livepatch: Keep replaced patches until post_patch callback is called selftests/livepatch: Disable the timeout
Diffstat (limited to 'lib')
-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"