diff options
| -rw-r--r-- | Documentation/livepatch/module-elf-format.rst | 15 | ||||
| -rw-r--r-- | arch/x86/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/livepatch.c | 53 | ||||
| -rw-r--r-- | include/linux/livepatch.h | 3 | ||||
| -rw-r--r-- | kernel/livepatch/core.c | 27 |
5 files changed, 11 insertions, 88 deletions
diff --git a/Documentation/livepatch/module-elf-format.rst b/Documentation/livepatch/module-elf-format.rst index 2a591e6f8e6c..8c6b894c4661 100644 --- a/Documentation/livepatch/module-elf-format.rst +++ b/Documentation/livepatch/module-elf-format.rst @@ -14,8 +14,7 @@ This document outlines the Elf format requirements that livepatch modules must f 4. Livepatch symbols 4.1 A livepatch module's symbol table 4.2 Livepatch symbol format - 5. Architecture-specific sections - 6. Symbol table and Elf section access + 5. Symbol table and Elf section access 1. Background and motivation ============================ @@ -298,17 +297,7 @@ Examples: Note that the 'Ndx' (Section index) for these symbols is SHN_LIVEPATCH (0xff20). "OS" means OS-specific. -5. Architecture-specific sections -================================= -Architectures may override arch_klp_init_object_loaded() to perform -additional arch-specific tasks when a target module loads, such as applying -arch-specific sections. On x86 for example, we must apply per-object -.altinstructions and .parainstructions sections when a target module loads. -These sections must be prefixed with ".klp.arch.$objname." so that they can -be easily identified when iterating through a patch module's Elf sections -(See arch/x86/kernel/livepatch.c for a complete example). - -6. Symbol table and Elf section access +5. Symbol table and Elf section access ====================================== A livepatch module's symbol table is accessible through module->symtab. diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index ba89cabe5fcf..bae9f9033734 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -90,7 +90,6 @@ obj-$(CONFIG_X86_MPPARSE) += mpparse.o obj-y += apic/ obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups_32.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o -obj-$(CONFIG_LIVEPATCH) += livepatch.o obj-$(CONFIG_FUNCTION_TRACER) += ftrace_$(BITS).o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o diff --git a/arch/x86/kernel/livepatch.c b/arch/x86/kernel/livepatch.c deleted file mode 100644 index 6a68e41206e7..000000000000 --- a/arch/x86/kernel/livepatch.c +++ /dev/null @@ -1,53 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * livepatch.c - x86-specific Kernel Live Patching Core - */ - -#include <linux/module.h> -#include <linux/kallsyms.h> -#include <linux/livepatch.h> -#include <asm/text-patching.h> - -/* Apply per-object alternatives. Based on x86 module_finalize() */ -void arch_klp_init_object_loaded(struct klp_patch *patch, - struct klp_object *obj) -{ - int cnt; - struct klp_modinfo *info; - Elf_Shdr *s, *alt = NULL, *para = NULL; - void *aseg, *pseg; - const char *objname; - char sec_objname[MODULE_NAME_LEN]; - char secname[KSYM_NAME_LEN]; - - info = patch->mod->klp_info; - objname = obj->name ? obj->name : "vmlinux"; - - /* See livepatch core code for BUILD_BUG_ON() explanation */ - BUILD_BUG_ON(MODULE_NAME_LEN < 56 || KSYM_NAME_LEN != 128); - - for (s = info->sechdrs; s < info->sechdrs + info->hdr.e_shnum; s++) { - /* Apply per-object .klp.arch sections */ - cnt = sscanf(info->secstrings + s->sh_name, - ".klp.arch.%55[^.].%127s", - sec_objname, secname); - if (cnt != 2) - continue; - if (strcmp(sec_objname, objname)) - continue; - if (!strcmp(".altinstructions", secname)) - alt = s; - if (!strcmp(".parainstructions", secname)) - para = s; - } - - if (alt) { - aseg = (void *) alt->sh_addr; - apply_alternatives(aseg, aseg + alt->sh_size); - } - - if (para) { - pseg = (void *) para->sh_addr; - apply_paravirt(pseg, pseg + para->sh_size); - } -} diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index c4302e9a5905..2614247a9781 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -195,9 +195,6 @@ struct klp_patch { int klp_enable_patch(struct klp_patch *); -void arch_klp_init_object_loaded(struct klp_patch *patch, - struct klp_object *obj); - /* Called from the module loader during module coming/going states */ int klp_module_coming(struct module *mod); void klp_module_going(struct module *mod); diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index c02791e5c75b..16632e75112a 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -729,12 +729,6 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func) func->old_sympos ? func->old_sympos : 1); } -/* Arches may override this to finish any remaining arch-specific tasks */ -void __weak arch_klp_init_object_loaded(struct klp_patch *patch, - struct klp_object *obj) -{ -} - int klp_apply_object_relocs(struct klp_patch *patch, struct klp_object *obj) { int i, ret; @@ -764,10 +758,11 @@ static int klp_init_object_loaded(struct klp_patch *patch, struct klp_func *func; int ret; - mutex_lock(&text_mutex); - module_disable_ro(patch->mod); - if (klp_is_module(obj)) { + + mutex_lock(&text_mutex); + module_disable_ro(patch->mod); + /* * Only write module-specific relocations here * (.klp.rela.{module}.*). vmlinux-specific relocations were @@ -775,17 +770,13 @@ static int klp_init_object_loaded(struct klp_patch *patch, * itself. */ ret = klp_apply_object_relocs(patch, obj); - if (ret) { - module_enable_ro(patch->mod, true); - mutex_unlock(&text_mutex); - return ret; - } - } - arch_klp_init_object_loaded(patch, obj); + module_enable_ro(patch->mod, true); + mutex_unlock(&text_mutex); - module_enable_ro(patch->mod, true); - mutex_unlock(&text_mutex); + if (ret) + return ret; + } klp_for_each_func(obj, func) { ret = klp_find_object_symbol(obj->name, func->old_name, |