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Diffstat (limited to 'arch/x86/kernel/module.c')
-rw-r--r--arch/x86/kernel/module.c169
1 files changed, 109 insertions, 60 deletions
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index b1abf663417c..e18914c0e38a 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -53,7 +53,7 @@ static unsigned long int get_module_load_offset(void)
*/
if (module_load_offset == 0)
module_load_offset =
- (get_random_int() % 1024 + 1) * PAGE_SIZE;
+ get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
mutex_unlock(&module_kaslr_mutex);
}
return module_load_offset;
@@ -74,10 +74,11 @@ void *module_alloc(unsigned long size)
return NULL;
p = __vmalloc_node_range(size, MODULE_ALIGN,
- MODULES_VADDR + get_module_load_offset(),
- MODULES_END, gfp_mask,
- PAGE_KERNEL, VM_DEFER_KMEMLEAK, NUMA_NO_NODE,
- __builtin_return_address(0));
+ 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;
@@ -128,22 +129,27 @@ 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;
@@ -161,56 +167,53 @@ 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;
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 type %d, loc %p, val %Lx\n",
+ (int)ELF64_R_TYPE(rel[i].r_info), 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 type %d, loc %p, val %Lx\n",
+ (int)ELF64_R_TYPE(rel[i].r_info), 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);
@@ -219,11 +222,12 @@ overflow:
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;
@@ -234,8 +238,8 @@ 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();
@@ -245,26 +249,43 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
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, *orc = NULL, *orc_ip = NULL,
- *retpolines = NULL, *returns = NULL, *ibt_endbr = 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))
@@ -273,17 +294,29 @@ int module_finalize(const Elf_Ehdr *hdr,
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;
}
- /*
- * 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);
+ 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;
@@ -298,16 +331,32 @@ int module_finalize(const Elf_Ehdr *hdr,
void *aseg = (void *)alt->sh_addr;
apply_alternatives(aseg, aseg + alt->sh_size);
}
+ if (calls || alt) {
+ struct callthunk_sites cs = {};
+
+ if (calls) {
+ cs.call_start = (void *)calls->sh_addr;
+ cs.call_end = (void *)calls->sh_addr + calls->sh_size;
+ }
+
+ if (alt) {
+ cs.alt_start = (void *)alt->sh_addr;
+ cs.alt_end = (void *)alt->sh_addr + alt->sh_size;
+ }
+
+ callthunks_patch_module_calls(&cs, me);
+ }
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 && text) {
+ 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);
+ text, text_end);
}
if (orc && orc_ip)
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