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-rw-r--r--arch/x86/kernel/module.c91
1 files changed, 70 insertions, 21 deletions
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index d5c72cb877b3..c032edcd3d95 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -18,10 +18,10 @@
#include <linux/gfp.h>
#include <linux/jump_label.h>
#include <linux/random.h>
+#include <linux/memory.h>
#include <asm/text-patching.h>
#include <asm/page.h>
-#include <asm/pgtable.h>
#include <asm/setup.h>
#include <asm/unwind.h>
@@ -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;
+ (prandom_u32_max(1024) + 1) * PAGE_SIZE;
mutex_unlock(&module_kaslr_mutex);
}
return module_load_offset;
@@ -67,6 +67,7 @@ static unsigned long int get_module_load_offset(void)
void *module_alloc(unsigned long size)
{
+ gfp_t gfp_mask = GFP_KERNEL;
void *p;
if (PAGE_ALIGN(size) > MODULES_LEN)
@@ -74,10 +75,10 @@ void *module_alloc(unsigned long size)
p = __vmalloc_node_range(size, MODULE_ALIGN,
MODULES_VADDR + get_module_load_offset(),
- MODULES_END, GFP_KERNEL,
- PAGE_KERNEL, 0, NUMA_NO_NODE,
+ MODULES_END, gfp_mask,
+ PAGE_KERNEL, VM_DEFER_KMEMLEAK, NUMA_NO_NODE,
__builtin_return_address(0));
- if (p && (kasan_module_alloc(p, size) < 0)) {
+ if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
vfree(p);
return NULL;
}
@@ -114,6 +115,7 @@ 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;
@@ -126,11 +128,12 @@ int apply_relocate(Elf32_Shdr *sechdrs,
return 0;
}
#else /*X86_64*/
-int apply_relocate_add(Elf64_Shdr *sechdrs,
+static int __apply_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))
{
unsigned int i;
Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
@@ -162,19 +165,19 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
case R_X86_64_64:
if (*(u64 *)loc != 0)
goto invalid_relocation;
- *(u64 *)loc = val;
+ write(loc, &val, 8);
break;
case R_X86_64_32:
if (*(u32 *)loc != 0)
goto invalid_relocation;
- *(u32 *)loc = val;
+ write(loc, &val, 4);
if (val != *(u32 *)loc)
goto overflow;
break;
case R_X86_64_32S:
if (*(s32 *)loc != 0)
goto invalid_relocation;
- *(s32 *)loc = val;
+ write(loc, &val, 4);
if ((s64)val != *(s32 *)loc)
goto overflow;
break;
@@ -183,7 +186,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
if (*(u32 *)loc != 0)
goto invalid_relocation;
val -= (u64)loc;
- *(u32 *)loc = val;
+ write(loc, &val, 4);
#if 0
if ((s64)val != *(s32 *)loc)
goto overflow;
@@ -193,7 +196,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
if (*(u64 *)loc != 0)
goto invalid_relocation;
val -= (u64)loc;
- *(u64 *)loc = val;
+ write(loc, &val, 8);
break;
default:
pr_err("%s: Unknown rela relocation: %llu\n",
@@ -215,6 +218,33 @@ overflow:
me->name);
return -ENOEXEC;
}
+
+int apply_relocate_add(Elf64_Shdr *sechdrs,
+ const char *strtab,
+ unsigned int symindex,
+ unsigned int relsec,
+ struct module *me)
+{
+ 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 = __apply_relocate_add(sechdrs, strtab, symindex, relsec, me,
+ write);
+
+ if (!early) {
+ text_poke_sync();
+ mutex_unlock(&text_mutex);
+ }
+
+ return ret;
+}
+
#endif
int module_finalize(const Elf_Ehdr *hdr,
@@ -222,7 +252,8 @@ int module_finalize(const Elf_Ehdr *hdr,
struct module *me)
{
const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
- *para = NULL, *orc = NULL, *orc_ip = NULL;
+ *para = NULL, *orc = NULL, *orc_ip = NULL,
+ *retpolines = NULL, *returns = NULL, *ibt_endbr = NULL;
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
@@ -238,13 +269,39 @@ int module_finalize(const Elf_Ehdr *hdr,
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(".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) {
+ void *rseg = (void *)retpolines->sh_addr;
+ apply_retpolines(rseg, rseg + retpolines->sh_size);
+ }
+ 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 (ibt_endbr) {
+ void *iseg = (void *)ibt_endbr->sh_addr;
+ apply_ibt_endbr(iseg, iseg + ibt_endbr->sh_size);
+ }
if (locks && text) {
void *lseg = (void *)locks->sh_addr;
void *tseg = (void *)text->sh_addr;
@@ -253,14 +310,6 @@ int module_finalize(const Elf_Ehdr *hdr,
tseg, tseg + text->sh_size);
}
- if (para) {
- void *pseg = (void *)para->sh_addr;
- apply_paravirt(pseg, pseg + para->sh_size);
- }
-
- /* 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);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.