1 files changed, 78 insertions, 61 deletions

diff --git a/kernel/module.c b/kernel/module.c
index be5413903d20..aa183c9ac0a2 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1510,8 +1510,7 @@ static inline bool sect_empty(const Elf_Shdr *sect)
 }
 
 struct module_sect_attr {
-	struct module_attribute mattr;
-	char *name;
+	struct bin_attribute battr;
 	unsigned long address;
 };
 
@@ -1521,13 +1520,18 @@ struct module_sect_attrs {
 	struct module_sect_attr attrs[];
 };
 
-static ssize_t module_sect_show(struct module_attribute *mattr,
-				struct module_kobject *mk, char *buf)
+static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
+				struct bin_attribute *battr,
+				char *buf, loff_t pos, size_t count)
 {
 	struct module_sect_attr *sattr =
-		container_of(mattr, struct module_sect_attr, mattr);
-	return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
-		       (void *)sattr->address : NULL);
+		container_of(battr, struct module_sect_attr, battr);
+
+	if (pos != 0)
+		return -EINVAL;
+
+	return sprintf(buf, "0x%px\n",
+		       kallsyms_show_value(file->f_cred) ? (void *)sattr->address : NULL);
 }
 
 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
@@ -1535,7 +1539,7 @@ static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
 	unsigned int section;
 
 	for (section = 0; section < sect_attrs->nsections; section++)
-		kfree(sect_attrs->attrs[section].name);
+		kfree(sect_attrs->attrs[section].battr.attr.name);
 	kfree(sect_attrs);
 }
 
@@ -1544,42 +1548,41 @@ static void add_sect_attrs(struct module *mod, const struct load_info *info)
 	unsigned int nloaded = 0, i, size[2];
 	struct module_sect_attrs *sect_attrs;
 	struct module_sect_attr *sattr;
-	struct attribute **gattr;
+	struct bin_attribute **gattr;
 
 	/* Count loaded sections and allocate structures */
 	for (i = 0; i < info->hdr->e_shnum; i++)
 		if (!sect_empty(&info->sechdrs[i]))
 			nloaded++;
 	size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
-			sizeof(sect_attrs->grp.attrs[0]));
-	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
+			sizeof(sect_attrs->grp.bin_attrs[0]));
+	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
 	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
 	if (sect_attrs == NULL)
 		return;
 
 	/* Setup section attributes. */
 	sect_attrs->grp.name = "sections";
-	sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
+	sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
 
 	sect_attrs->nsections = 0;
 	sattr = &sect_attrs->attrs[0];
-	gattr = &sect_attrs->grp.attrs[0];
+	gattr = &sect_attrs->grp.bin_attrs[0];
 	for (i = 0; i < info->hdr->e_shnum; i++) {
 		Elf_Shdr *sec = &info->sechdrs[i];
 		if (sect_empty(sec))
 			continue;
+		sysfs_bin_attr_init(&sattr->battr);
 		sattr->address = sec->sh_addr;
-		sattr->name = kstrdup(info->secstrings + sec->sh_name,
-					GFP_KERNEL);
-		if (sattr->name == NULL)
+		sattr->battr.attr.name =
+			kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
+		if (sattr->battr.attr.name == NULL)
 			goto out;
 		sect_attrs->nsections++;
-		sysfs_attr_init(&sattr->mattr.attr);
-		sattr->mattr.show = module_sect_show;
-		sattr->mattr.store = NULL;
-		sattr->mattr.attr.name = sattr->name;
-		sattr->mattr.attr.mode = S_IRUSR;
-		*(gattr++) = &(sattr++)->mattr.attr;
+		sattr->battr.read = module_sect_read;
+		sattr->battr.size = 3 /* "0x", "\n" */ + (BITS_PER_LONG / 4);
+		sattr->battr.attr.mode = 0400;
+		*(gattr++) = &(sattr++)->battr;
 	}
 	*gattr = NULL;
 
@@ -1669,7 +1672,7 @@ static void add_notes_attrs(struct module *mod, const struct load_info *info)
 			continue;
 		if (info->sechdrs[i].sh_type == SHT_NOTE) {
 			sysfs_bin_attr_init(nattr);
-			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
+			nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
 			nattr->attr.mode = S_IRUGO;
 			nattr->size = info->sechdrs[i].sh_size;
 			nattr->private = (void *) info->sechdrs[i].sh_addr;
@@ -1946,7 +1949,6 @@ static void mod_sysfs_teardown(struct module *mod)
 	mod_sysfs_fini(mod);
 }
 
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
 /*
  * LKM RO/NX protection: protect module's text/ro-data
  * from modification and any data from execution.
@@ -1960,6 +1962,14 @@ static void mod_sysfs_teardown(struct module *mod)
  *
  * These values are always page-aligned (as is base)
  */
+
+/*
+ * Since some arches are moving towards PAGE_KERNEL module allocations instead
+ * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
+ * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
+ * whether we are strict.
+ */
+#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
 static void frob_text(const struct module_layout *layout,
 		      int (*set_memory)(unsigned long start, int num_pages))
 {
@@ -1969,6 +1979,15 @@ static void frob_text(const struct module_layout *layout,
 		   layout->text_size >> PAGE_SHIFT);
 }
 
+static void module_enable_x(const struct module *mod)
+{
+	frob_text(&mod->core_layout, set_memory_x);
+	frob_text(&mod->init_layout, set_memory_x);
+}
+#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+static void module_enable_x(const struct module *mod) { }
+#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+
 #ifdef CONFIG_STRICT_MODULE_RWX
 static void frob_rodata(const struct module_layout *layout,
 			int (*set_memory)(unsigned long start, int num_pages))
@@ -2000,20 +2019,7 @@ static void frob_writable_data(const struct module_layout *layout,
 		   (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
 }
 
-/* livepatching wants to disable read-only so it can frob module. */
-void module_disable_ro(const struct module *mod)
-{
-	if (!rodata_enabled)
-		return;
-
-	frob_text(&mod->core_layout, set_memory_rw);
-	frob_rodata(&mod->core_layout, set_memory_rw);
-	frob_ro_after_init(&mod->core_layout, set_memory_rw);
-	frob_text(&mod->init_layout, set_memory_rw);
-	frob_rodata(&mod->init_layout, set_memory_rw);
-}
-
-void module_enable_ro(const struct module *mod, bool after_init)
+static void module_enable_ro(const struct module *mod, bool after_init)
 {
 	if (!rodata_enabled)
 		return;
@@ -2039,19 +2045,29 @@ static void module_enable_nx(const struct module *mod)
 	frob_writable_data(&mod->init_layout, set_memory_nx);
 }
 
+static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+				       char *secstrings, struct module *mod)
+{
+	const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
+	int i;
+
+	for (i = 0; i < hdr->e_shnum; i++) {
+		if ((sechdrs[i].sh_flags & shf_wx) == shf_wx)
+			return -ENOEXEC;
+	}
+
+	return 0;
+}
+
 #else /* !CONFIG_STRICT_MODULE_RWX */
 static void module_enable_nx(const struct module *mod) { }
-#endif /*  CONFIG_STRICT_MODULE_RWX */
-static void module_enable_x(const struct module *mod)
+static void module_enable_ro(const struct module *mod, bool after_init) {}
+static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+				       char *secstrings, struct module *mod)
 {
-	frob_text(&mod->core_layout, set_memory_x);
-	frob_text(&mod->init_layout, set_memory_x);
+	return 0;
 }
-#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-static void module_enable_nx(const struct module *mod) { }
-static void module_enable_x(const struct module *mod) { }
-#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-
+#endif /*  CONFIG_STRICT_MODULE_RWX */
 
 #ifdef CONFIG_LIVEPATCH
 /*
@@ -2337,11 +2353,13 @@ static int apply_relocations(struct module *mod, const struct load_info *info)
 		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
 			continue;
 
-		/* Livepatch relocation sections are applied by livepatch */
 		if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
-			continue;
-
-		if (info->sechdrs[i].sh_type == SHT_REL)
+			err = klp_apply_section_relocs(mod, info->sechdrs,
+						       info->secstrings,
+						       info->strtab,
+						       info->index.sym, i,
+						       NULL);
+		else if (info->sechdrs[i].sh_type == SHT_REL)
 			err = apply_relocate(info->sechdrs, info->strtab,
 					     info->index.sym, i, mod);
 		else if (info->sechdrs[i].sh_type == SHT_RELA)
@@ -2768,7 +2786,9 @@ static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
 
 void * __weak module_alloc(unsigned long size)
 {
-	return vmalloc_exec(size);
+	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
+			GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
+			NUMA_NO_NODE, __builtin_return_address(0));
 }
 
 bool __weak module_init_section(const char *name)
@@ -3329,12 +3349,6 @@ static int check_module_license_and_versions(struct module *mod)
 
 static void flush_module_icache(const struct module *mod)
 {
-	mm_segment_t old_fs;
-
-	/* flush the icache in correct context */
-	old_fs = get_fs();
-	set_fs(KERNEL_DS);
-
 	/*
 	 * Flush the instruction cache, since we've played with text.
 	 * Do it before processing of module parameters, so the module
@@ -3346,8 +3360,6 @@ static void flush_module_icache(const struct module *mod)
 				   + mod->init_layout.size);
 	flush_icache_range((unsigned long)mod->core_layout.base,
 			   (unsigned long)mod->core_layout.base + mod->core_layout.size);
-
-	set_fs(old_fs);
 }
 
 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
@@ -3395,6 +3407,11 @@ static struct module *layout_and_allocate(struct load_info *info, int flags)
 	if (err < 0)
 		return ERR_PTR(err);
 
+	err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
+					  info->secstrings, info->mod);
+	if (err < 0)
+		return ERR_PTR(err);
+
 	/* We will do a special allocation for per-cpu sections later. */
 	info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
 
@@ -4365,7 +4382,7 @@ static int modules_open(struct inode *inode, struct file *file)
 
 	if (!err) {
 		struct seq_file *m = file->private_data;
-		m->private = kallsyms_show_value() ? NULL : (void *)8ul;
+		m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
 	}
 
 	return err;