1 files changed, 118 insertions, 106 deletions

diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index b1abf663417c..0ffbae902e2f 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>
@@ -36,56 +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_int() % 1024 + 1) * 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_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,
@@ -128,22 +79,27 @@ 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 +117,67 @@ 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 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 +186,12 @@ 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;
@@ -234,37 +202,54 @@ 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,
 		    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))
@@ -273,26 +258,51 @@ 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);
+	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;
@@ -300,14 +310,15 @@ int module_finalize(const Elf_Ehdr *hdr,
 	}
 	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)
@@ -320,4 +331,5 @@ int module_finalize(const Elf_Ehdr *hdr,
 void module_arch_cleanup(struct module *mod)
 {
 	alternatives_smp_module_del(mod);
+	its_free_mod(mod);
 }