aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/module.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/module.c')
-rw-r--r--arch/x86/kernel/module.c120
1 files changed, 61 insertions, 59 deletions
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index 8f295609173..e69f9882bf9 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -15,6 +15,9 @@
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
+
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
@@ -24,49 +27,70 @@
#include <linux/bug.h>
#include <linux/mm.h>
#include <linux/gfp.h>
+#include <linux/jump_label.h>
+#include <linux/random.h>
-#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#if 0
-#define DEBUGP printk
+#define DEBUGP(fmt, ...) \
+ printk(KERN_DEBUG fmt, ##__VA_ARGS__)
#else
-#define DEBUGP(fmt...)
+#define DEBUGP(fmt, ...) \
+do { \
+ if (0) \
+ printk(KERN_DEBUG fmt, ##__VA_ARGS__); \
+} while (0)
#endif
-void *module_alloc(unsigned long size)
-{
- struct vm_struct *area;
-
- if (!size)
- return NULL;
- size = PAGE_ALIGN(size);
- if (size > MODULES_LEN)
- return NULL;
+#ifdef CONFIG_RANDOMIZE_BASE
+static unsigned long module_load_offset;
+static int randomize_modules = 1;
- area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
- if (!area)
- return NULL;
+/* Mutex protects the module_load_offset. */
+static DEFINE_MUTEX(module_kaslr_mutex);
- return __vmalloc_area(area, GFP_KERNEL | __GFP_HIGHMEM,
- PAGE_KERNEL_EXEC);
+static int __init parse_nokaslr(char *p)
+{
+ randomize_modules = 0;
+ return 0;
}
+early_param("nokaslr", parse_nokaslr);
-/* Free memory returned from module_alloc */
-void module_free(struct module *mod, void *module_region)
+static unsigned long int get_module_load_offset(void)
{
- vfree(module_region);
+ if (randomize_modules) {
+ 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_int() % 1024 + 1) * PAGE_SIZE;
+ mutex_unlock(&module_kaslr_mutex);
+ }
+ return module_load_offset;
}
-
-/* We don't need anything special. */
-int module_frob_arch_sections(Elf_Ehdr *hdr,
- Elf_Shdr *sechdrs,
- char *secstrings,
- struct module *mod)
+#else
+static unsigned long int get_module_load_offset(void)
{
return 0;
}
+#endif
+
+void *module_alloc(unsigned long size)
+{
+ if (PAGE_ALIGN(size) > MODULES_LEN)
+ return NULL;
+ return __vmalloc_node_range(size, 1,
+ MODULES_VADDR + get_module_load_offset(),
+ MODULES_END, GFP_KERNEL | __GFP_HIGHMEM,
+ PAGE_KERNEL_EXEC, NUMA_NO_NODE,
+ __builtin_return_address(0));
+}
#ifdef CONFIG_X86_32
int apply_relocate(Elf32_Shdr *sechdrs,
@@ -80,8 +104,8 @@ int apply_relocate(Elf32_Shdr *sechdrs,
Elf32_Sym *sym;
uint32_t *location;
- DEBUGP("Applying relocate section %u to %u\n", relsec,
- sechdrs[relsec].sh_info);
+ DEBUGP("Applying relocate section %u to %u\n",
+ relsec, sechdrs[relsec].sh_info);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
@@ -97,28 +121,17 @@ int apply_relocate(Elf32_Shdr *sechdrs,
*location += sym->st_value;
break;
case R_386_PC32:
- /* Add the value, subtract its postition */
+ /* Add the value, subtract its position */
*location += sym->st_value - (uint32_t)location;
break;
default:
- printk(KERN_ERR "module %s: Unknown relocation: %u\n",
+ pr_err("%s: Unknown relocation: %u\n",
me->name, ELF32_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
}
return 0;
}
-
-int apply_relocate_add(Elf32_Shdr *sechdrs,
- const char *strtab,
- unsigned int symindex,
- unsigned int relsec,
- struct module *me)
-{
- printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
- me->name);
- return -ENOEXEC;
-}
#else /*X86_64*/
int apply_relocate_add(Elf64_Shdr *sechdrs,
const char *strtab,
@@ -132,8 +145,8 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
void *loc;
u64 val;
- DEBUGP("Applying relocate section %u to %u\n", relsec,
- sechdrs[relsec].sh_info);
+ DEBUGP("Applying relocate section %u to %u\n",
+ relsec, sechdrs[relsec].sh_info);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
@@ -145,8 +158,8 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
+ ELF64_R_SYM(rel[i].r_info);
DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
- (int)ELF64_R_TYPE(rel[i].r_info),
- sym->st_value, rel[i].r_addend, (u64)loc);
+ (int)ELF64_R_TYPE(rel[i].r_info),
+ sym->st_value, rel[i].r_addend, (u64)loc);
val = sym->st_value + rel[i].r_addend;
@@ -175,7 +188,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
#endif
break;
default:
- printk(KERN_ERR "module %s: Unknown rela relocation: %llu\n",
+ pr_err("%s: Unknown rela relocation: %llu\n",
me->name, ELF64_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
@@ -183,23 +196,12 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
return 0;
overflow:
- printk(KERN_ERR "overflow in relocation type %d val %Lx\n",
+ pr_err("overflow in relocation type %d val %Lx\n",
(int)ELF64_R_TYPE(rel[i].r_info), val);
- printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
+ pr_err("`%s' likely not compiled with -mcmodel=kernel\n",
me->name);
return -ENOEXEC;
}
-
-int apply_relocate(Elf_Shdr *sechdrs,
- const char *strtab,
- unsigned int symindex,
- unsigned int relsec,
- struct module *me)
-{
- printk(KERN_ERR "non add relocation not supported\n");
- return -ENOSYS;
-}
-
#endif
int module_finalize(const Elf_Ehdr *hdr,
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 12:55:41 +0000