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Diffstat (limited to 'arch/x86/kernel/module.c')
-rw-r--r--arch/x86/kernel/module.c219
1 files changed, 99 insertions, 120 deletions
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index 705fb2a41d7d..11c45ce42694 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -19,6 +19,7 @@
#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>
@@ -36,57 +37,6 @@ do { \
} while (0)
#endif
-#ifdef CONFIG_RANDOMIZE_BASE
-static unsigned long module_load_offset;
-
-/* Mutex protects the module_load_offset. */
-static DEFINE_MUTEX(module_kaslr_mutex);
-
-static unsigned long int get_module_load_offset(void)
-{
- if (kaslr_enabled()) {
- mutex_lock(&module_kaslr_mutex);
- /*
- * Calculate the module_load_offset the first time this
- * code is called. Once calculated it stays the same until
- * reboot.
- */
- if (module_load_offset == 0)
- module_load_offset =
- get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
- mutex_unlock(&module_kaslr_mutex);
- }
- return module_load_offset;
-}
-#else
-static unsigned long int get_module_load_offset(void)
-{
- return 0;
-}
-#endif
-
-void *module_alloc(unsigned long size)
-{
- gfp_t gfp_mask = GFP_KERNEL;
- void *p;
-
- if (PAGE_ALIGN(size) > MODULES_LEN)
- return NULL;
-
- p = __vmalloc_node_range(size, MODULE_ALIGN,
- MODULES_VADDR + get_module_load_offset(),
- MODULES_END, gfp_mask, PAGE_KERNEL,
- VM_FLUSH_RESET_PERMS | VM_DEFER_KMEMLEAK,
- NUMA_NO_NODE, __builtin_return_address(0));
-
- if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
- vfree(p);
- return NULL;
- }
-
- return p;
-}
-
#ifdef CONFIG_X86_32
int apply_relocate(Elf32_Shdr *sechdrs,
const char *strtab,
@@ -129,22 +79,28 @@ int apply_relocate(Elf32_Shdr *sechdrs,
return 0;
}
#else /*X86_64*/
-static 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,
- void *(*write)(void *dest, const void *src, size_t len))
+ 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;
@@ -162,69 +118,83 @@ static 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:
- if (*(u64 *)loc != 0)
- goto invalid_relocation;
- write(loc, &val, 8);
+ size = 8;
break;
case R_X86_64_32:
- if (*(u32 *)loc != 0)
- goto invalid_relocation;
- write(loc, &val, 4);
- if (val != *(u32 *)loc)
+ if (val != *(u32 *)&val)
goto overflow;
+ size = 4;
break;
case R_X86_64_32S:
- if (*(s32 *)loc != 0)
- goto invalid_relocation;
- write(loc, &val, 4);
- 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:
- if (*(u32 *)loc != 0)
- goto invalid_relocation;
val -= (u64)loc;
- write(loc, &val, 4);
-#if 0
- if ((s64)val != *(s32 *)loc)
- goto overflow;
-#endif
+ size = 4;
break;
case R_X86_64_PC64:
- if (*(u64 *)loc != 0)
- goto invalid_relocation;
val -= (u64)loc;
- write(loc, &val, 8);
+ 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;
-invalid_relocation:
- pr_err("x86/modules: Skipping invalid relocation target, existing value is nonzero for type %d, loc %p, val %Lx\n",
- (int)ELF64_R_TYPE(rel[i].r_info), loc, val);
- return -ENOEXEC;
-
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;
}
-int apply_relocate_add(Elf64_Shdr *sechdrs,
- const char *strtab,
- unsigned int symindex,
- unsigned int relsec,
- struct module *me)
+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;
@@ -235,17 +205,37 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
mutex_lock(&text_mutex);
}
- ret = __apply_relocate_add(sechdrs, strtab, symindex, relsec, me,
- write);
+ ret = __write_relocate_add(sechdrs, strtab, symindex, relsec, me,
+ write, apply);
if (!early) {
- text_poke_sync();
+ 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,
@@ -253,7 +243,7 @@ int module_finalize(const Elf_Ehdr *hdr,
struct module *me)
{
const Elf_Shdr *s, *alt = NULL, *locks = NULL,
- *para = NULL, *orc = NULL, *orc_ip = 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;
@@ -263,8 +253,6 @@ int module_finalize(const Elf_Ehdr *hdr,
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))
@@ -281,14 +269,8 @@ int module_finalize(const Elf_Ehdr *hdr,
ibt_endbr = s;
}
- /*
- * See alternative_instructions() for the ordering rules between the
- * various patching types.
- */
- if (para) {
- void *pseg = (void *)para->sh_addr;
- apply_paravirt(pseg, pseg + para->sh_size);
- }
+ its_init_mod(me);
+
if (retpolines || cfi) {
void *rseg = NULL, *cseg = NULL;
unsigned int rsize = 0, csize = 0;
@@ -309,38 +291,34 @@ int module_finalize(const Elf_Ehdr *hdr,
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 (alt) {
- /* patch .altinstructions */
- void *aseg = (void *)alt->sh_addr;
- apply_alternatives(aseg, aseg + alt->sh_size);
- }
- if (calls || para) {
+ if (calls) {
struct callthunk_sites cs = {};
- if (calls) {
- cs.call_start = (void *)calls->sh_addr;
- cs.call_end = (void *)calls->sh_addr + calls->sh_size;
- }
-
- if (para) {
- cs.pv_start = (void *)para->sh_addr;
- cs.pv_end = (void *)para->sh_addr + para->sh_size;
- }
+ 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 (ibt_endbr) {
void *iseg = (void *)ibt_endbr->sh_addr;
- apply_ibt_endbr(iseg, iseg + ibt_endbr->sh_size);
+ apply_seal_endbr(iseg, iseg + ibt_endbr->sh_size);
}
if (locks) {
void *lseg = (void *)locks->sh_addr;
- void *text = me->core_layout.base;
- void *text_end = text + me->core_layout.text_size;
+ 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,
text, text_end);
@@ -356,4 +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);
}
generated by cgit (git 2.34.1) at 2025-12-21 18:29:14 +0000