54 lines
1.4 KiB
C
54 lines
1.4 KiB
C
// 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);
|
|
}
|
|
}
|