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-rw-r--r--arch/x86/kernel/module.c235
1 files changed, 180 insertions, 55 deletions
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index 216a4d754b0c..11c45ce42694 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -1,19 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* Kernel module help for x86.
Copyright (C) 2001 Rusty Russell.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -24,13 +12,19 @@
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
+#include <linux/kasan.h>
#include <linux/bug.h>
#include <linux/mm.h>
#include <linux/gfp.h>
#include <linux/jump_label.h>
+#include <linux/random.h>
+#include <linux/memory.h>
+#include <linux/stackprotector.h>
+#include <asm/text-patching.h>
#include <asm/page.h>
-#include <asm/pgtable.h>
+#include <asm/setup.h>
+#include <asm/unwind.h>
#if 0
#define DEBUGP(fmt, ...) \
@@ -43,15 +37,6 @@ do { \
} while (0)
#endif
-void *module_alloc(unsigned long size)
-{
- if (PAGE_ALIGN(size) > MODULES_LEN)
- return NULL;
- return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
- GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
- -1, __builtin_return_address(0));
-}
-
#ifdef CONFIG_X86_32
int apply_relocate(Elf32_Shdr *sechdrs,
const char *strtab,
@@ -81,6 +66,7 @@ int apply_relocate(Elf32_Shdr *sechdrs,
*location += sym->st_value;
break;
case R_386_PC32:
+ case R_386_PLT32:
/* Add the value, subtract its position */
*location += sym->st_value - (uint32_t)location;
break;
@@ -93,21 +79,28 @@ int apply_relocate(Elf32_Shdr *sechdrs,
return 0;
}
#else /*X86_64*/
-int apply_relocate_add(Elf64_Shdr *sechdrs,
+static int __write_relocate_add(Elf64_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
- struct module *me)
+ struct module *me,
+ void *(*write)(void *dest, const void *src, size_t len),
+ bool apply)
{
unsigned int i;
Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
Elf64_Sym *sym;
void *loc;
u64 val;
+ u64 zero = 0ULL;
- DEBUGP("Applying relocate section %u to %u\n",
+ DEBUGP("%s relocate section %u to %u\n",
+ apply ? "Applying" : "Clearing",
relsec, sechdrs[relsec].sh_info);
+
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+ size_t size;
+
/* This is where to make the change */
loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rel[i].r_offset;
@@ -125,84 +118,215 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
switch (ELF64_R_TYPE(rel[i].r_info)) {
case R_X86_64_NONE:
- break;
+ continue; /* nothing to write */
case R_X86_64_64:
- *(u64 *)loc = val;
+ size = 8;
break;
case R_X86_64_32:
- *(u32 *)loc = val;
- if (val != *(u32 *)loc)
+ if (val != *(u32 *)&val)
goto overflow;
+ size = 4;
break;
case R_X86_64_32S:
- *(s32 *)loc = val;
- if ((s64)val != *(s32 *)loc)
+ if ((s64)val != *(s32 *)&val)
goto overflow;
+ size = 4;
break;
+#if defined(CONFIG_STACKPROTECTOR) && \
+ defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 170000
+ case R_X86_64_REX_GOTPCRELX: {
+ static unsigned long __percpu *const addr = &__stack_chk_guard;
+
+ if (sym->st_value != (u64)addr) {
+ pr_err("%s: Unsupported GOTPCREL relocation\n", me->name);
+ return -ENOEXEC;
+ }
+
+ val = (u64)&addr + rel[i].r_addend;
+ fallthrough;
+ }
+#endif
case R_X86_64_PC32:
+ case R_X86_64_PLT32:
val -= (u64)loc;
- *(u32 *)loc = val;
-#if 0
- if ((s64)val != *(s32 *)loc)
- goto overflow;
-#endif
+ size = 4;
+ break;
+ case R_X86_64_PC64:
+ val -= (u64)loc;
+ size = 8;
break;
default:
pr_err("%s: Unknown rela relocation: %llu\n",
me->name, ELF64_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
+
+ if (apply) {
+ if (memcmp(loc, &zero, size)) {
+ pr_err("x86/modules: Invalid relocation target, existing value is nonzero for sec %u, idx %u, type %d, loc %lx, val %llx\n",
+ relsec, i, (int)ELF64_R_TYPE(rel[i].r_info),
+ (unsigned long)loc, val);
+ return -ENOEXEC;
+ }
+ write(loc, &val, size);
+ } else {
+ if (memcmp(loc, &val, size)) {
+ pr_warn("x86/modules: Invalid relocation target, existing value does not match expected value for sec %u, idx %u, type %d, loc %lx, val %llx\n",
+ relsec, i, (int)ELF64_R_TYPE(rel[i].r_info),
+ (unsigned long)loc, val);
+ return -ENOEXEC;
+ }
+ write(loc, &zero, size);
+ }
}
return 0;
overflow:
- pr_err("overflow in relocation type %d val %Lx\n",
- (int)ELF64_R_TYPE(rel[i].r_info), val);
+ pr_err("overflow in relocation type %d val %llx sec %u idx %d\n",
+ (int)ELF64_R_TYPE(rel[i].r_info), val, relsec, i);
pr_err("`%s' likely not compiled with -mcmodel=kernel\n",
me->name);
return -ENOEXEC;
}
+
+static int write_relocate_add(Elf64_Shdr *sechdrs,
+ const char *strtab,
+ unsigned int symindex,
+ unsigned int relsec,
+ struct module *me,
+ bool apply)
+{
+ int ret;
+ bool early = me->state == MODULE_STATE_UNFORMED;
+ void *(*write)(void *, const void *, size_t) = memcpy;
+
+ if (!early) {
+ write = text_poke;
+ mutex_lock(&text_mutex);
+ }
+
+ ret = __write_relocate_add(sechdrs, strtab, symindex, relsec, me,
+ write, apply);
+
+ if (!early) {
+ smp_text_poke_sync_each_cpu();
+ mutex_unlock(&text_mutex);
+ }
+
+ return ret;
+}
+
+int apply_relocate_add(Elf64_Shdr *sechdrs,
+ const char *strtab,
+ unsigned int symindex,
+ unsigned int relsec,
+ struct module *me)
+{
+ return write_relocate_add(sechdrs, strtab, symindex, relsec, me, true);
+}
+
+#ifdef CONFIG_LIVEPATCH
+void clear_relocate_add(Elf64_Shdr *sechdrs,
+ const char *strtab,
+ unsigned int symindex,
+ unsigned int relsec,
+ struct module *me)
+{
+ write_relocate_add(sechdrs, strtab, symindex, relsec, me, false);
+}
+#endif
+
#endif
int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
- const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
- *para = NULL;
+ const Elf_Shdr *s, *alt = NULL, *locks = NULL,
+ *orc = NULL, *orc_ip = NULL,
+ *retpolines = NULL, *returns = NULL, *ibt_endbr = NULL,
+ *calls = NULL, *cfi = NULL;
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
- if (!strcmp(".text", secstrings + s->sh_name))
- text = s;
if (!strcmp(".altinstructions", secstrings + s->sh_name))
alt = s;
if (!strcmp(".smp_locks", secstrings + s->sh_name))
locks = s;
- if (!strcmp(".parainstructions", secstrings + s->sh_name))
- para = s;
+ if (!strcmp(".orc_unwind", secstrings + s->sh_name))
+ orc = s;
+ if (!strcmp(".orc_unwind_ip", secstrings + s->sh_name))
+ orc_ip = s;
+ if (!strcmp(".retpoline_sites", secstrings + s->sh_name))
+ retpolines = s;
+ if (!strcmp(".return_sites", secstrings + s->sh_name))
+ returns = s;
+ if (!strcmp(".call_sites", secstrings + s->sh_name))
+ calls = s;
+ if (!strcmp(".cfi_sites", secstrings + s->sh_name))
+ cfi = s;
+ if (!strcmp(".ibt_endbr_seal", secstrings + s->sh_name))
+ ibt_endbr = s;
+ }
+
+ its_init_mod(me);
+
+ if (retpolines || cfi) {
+ void *rseg = NULL, *cseg = NULL;
+ unsigned int rsize = 0, csize = 0;
+
+ if (retpolines) {
+ rseg = (void *)retpolines->sh_addr;
+ rsize = retpolines->sh_size;
+ }
+
+ if (cfi) {
+ cseg = (void *)cfi->sh_addr;
+ csize = cfi->sh_size;
+ }
+
+ apply_fineibt(rseg, rseg + rsize, cseg, cseg + csize);
}
+ if (retpolines) {
+ void *rseg = (void *)retpolines->sh_addr;
+ apply_retpolines(rseg, rseg + retpolines->sh_size);
+ }
+
+ its_fini_mod(me);
+ if (returns) {
+ void *rseg = (void *)returns->sh_addr;
+ apply_returns(rseg, rseg + returns->sh_size);
+ }
+ if (calls) {
+ struct callthunk_sites cs = {};
+
+ cs.call_start = (void *)calls->sh_addr;
+ cs.call_end = (void *)calls->sh_addr + calls->sh_size;
+
+ callthunks_patch_module_calls(&cs, me);
+ }
if (alt) {
/* patch .altinstructions */
void *aseg = (void *)alt->sh_addr;
apply_alternatives(aseg, aseg + alt->sh_size);
}
- if (locks && text) {
+ if (ibt_endbr) {
+ void *iseg = (void *)ibt_endbr->sh_addr;
+ apply_seal_endbr(iseg, iseg + ibt_endbr->sh_size);
+ }
+ if (locks) {
void *lseg = (void *)locks->sh_addr;
- void *tseg = (void *)text->sh_addr;
+ void *text = me->mem[MOD_TEXT].base;
+ void *text_end = text + me->mem[MOD_TEXT].size;
alternatives_smp_module_add(me, me->name,
lseg, lseg + locks->sh_size,
- tseg, tseg + text->sh_size);
- }
-
- if (para) {
- void *pseg = (void *)para->sh_addr;
- apply_paravirt(pseg, pseg + para->sh_size);
+ text, text_end);
}
- /* make jump label nops */
- jump_label_apply_nops(me);
+ if (orc && orc_ip)
+ unwind_module_init(me, (void *)orc_ip->sh_addr, orc_ip->sh_size,
+ (void *)orc->sh_addr, orc->sh_size);
return 0;
}
@@ -210,4 +334,5 @@ int module_finalize(const Elf_Ehdr *hdr,
void module_arch_cleanup(struct module *mod)
{
alternatives_smp_module_del(mod);
+ its_free_mod(mod);
}
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