Eric Lee / smarc-fsl-linux-kernel

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lib/livepatch/test_klp_callbacks_demo2.c 2.32 KB
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a2818ee4d   Joe Lawrence   selftests/livepat... 
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  // 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
  ", callback, obj->mod->name,
  			module_state[obj->mod->state]);
  	else
  		pr_info("%s: vmlinux
  ", 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");