mirror of https://github.com/torvalds/linux.git
109 lines
2.2 KiB
C
109 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Init code for a livepatch kernel module
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/livepatch.h>
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extern struct klp_object_ext __start_klp_objects[];
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extern struct klp_object_ext __stop_klp_objects[];
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static struct klp_patch *patch;
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static int __init livepatch_mod_init(void)
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{
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struct klp_object *objs;
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unsigned int nr_objs;
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int ret;
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nr_objs = __stop_klp_objects - __start_klp_objects;
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if (!nr_objs) {
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pr_err("nothing to patch!\n");
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ret = -EINVAL;
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goto err;
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}
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patch = kzalloc(sizeof(*patch), GFP_KERNEL);
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if (!patch) {
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ret = -ENOMEM;
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goto err;
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}
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objs = kzalloc(sizeof(struct klp_object) * (nr_objs + 1), GFP_KERNEL);
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if (!objs) {
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ret = -ENOMEM;
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goto err_free_patch;
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}
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for (int i = 0; i < nr_objs; i++) {
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struct klp_object_ext *obj_ext = __start_klp_objects + i;
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struct klp_func_ext *funcs_ext = obj_ext->funcs;
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unsigned int nr_funcs = obj_ext->nr_funcs;
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struct klp_func *funcs = objs[i].funcs;
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struct klp_object *obj = objs + i;
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funcs = kzalloc(sizeof(struct klp_func) * (nr_funcs + 1), GFP_KERNEL);
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if (!funcs) {
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ret = -ENOMEM;
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for (int j = 0; j < i; j++)
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kfree(objs[i].funcs);
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goto err_free_objs;
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}
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for (int j = 0; j < nr_funcs; j++) {
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funcs[j].old_name = funcs_ext[j].old_name;
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funcs[j].new_func = funcs_ext[j].new_func;
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funcs[j].old_sympos = funcs_ext[j].sympos;
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}
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obj->name = obj_ext->name;
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obj->funcs = funcs;
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memcpy(&obj->callbacks, &obj_ext->callbacks, sizeof(struct klp_callbacks));
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}
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patch->mod = THIS_MODULE;
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patch->objs = objs;
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/* TODO patch->states */
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#ifdef KLP_NO_REPLACE
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patch->replace = false;
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#else
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patch->replace = true;
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#endif
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return klp_enable_patch(patch);
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err_free_objs:
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kfree(objs);
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err_free_patch:
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kfree(patch);
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err:
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return ret;
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}
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static void __exit livepatch_mod_exit(void)
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{
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unsigned int nr_objs;
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nr_objs = __stop_klp_objects - __start_klp_objects;
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for (int i = 0; i < nr_objs; i++)
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kfree(patch->objs[i].funcs);
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kfree(patch->objs);
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kfree(patch);
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}
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module_init(livepatch_mod_init);
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module_exit(livepatch_mod_exit);
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MODULE_LICENSE("GPL");
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MODULE_INFO(livepatch, "Y");
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MODULE_DESCRIPTION("Livepatch module");
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