X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fmodule.c;h=c968d3606dca8cbf9d4e3ba04bcb0a48091024e9;hb=5cacdb4add1b1e50fe75edc50ebbb7bddd9cf5e7;hp=64787cddeb5ee34c0ffb891e711e89d4f5b71b79;hpb=23fb064bb96f001ecb8682129f7ee1bc1ca691bc;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/module.c b/kernel/module.c
index 64787cd..c968d36 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -474,9 +474,10 @@ static void module_unload_init(struct module *mod)
 
 	INIT_LIST_HEAD(&mod->modules_which_use_me);
 	for_each_possible_cpu(cpu)
-		local_set(__module_ref_addr(mod, cpu), 0);
+		per_cpu_ptr(mod->refptr, cpu)->count = 0;
+
 	/* Hold reference count during initialization. */
-	local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
+	__this_cpu_write(mod->refptr->count, 1);
 	/* Backwards compatibility macros put refcount during init. */
 	mod->waiter = current;
 }
@@ -619,7 +620,7 @@ unsigned int module_refcount(struct module *mod)
 	int cpu;
 
 	for_each_possible_cpu(cpu)
-		total += local_read(__module_ref_addr(mod, cpu));
+		total += per_cpu_ptr(mod->refptr, cpu)->count;
 	return total;
 }
 EXPORT_SYMBOL(module_refcount);
@@ -796,14 +797,15 @@ static struct module_attribute refcnt = {
 void module_put(struct module *module)
 {
 	if (module) {
-		unsigned int cpu = get_cpu();
-		local_dec(__module_ref_addr(module, cpu));
+		preempt_disable();
+		__this_cpu_dec(module->refptr->count);
+
 		trace_module_put(module, _RET_IP_,
-				 local_read(__module_ref_addr(module, cpu)));
+				 __this_cpu_read(module->refptr->count));
 		/* Maybe they're waiting for us to drop reference? */
 		if (unlikely(!module_is_live(module)))
 			wake_up_process(module->waiter);
-		put_cpu();
+		preempt_enable();
 	}
 }
 EXPORT_SYMBOL(module_put);
@@ -880,11 +882,23 @@ static int try_to_force_load(struct module *mod, const char *reason)
 }
 
 #ifdef CONFIG_MODVERSIONS
+/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
+static unsigned long maybe_relocated(unsigned long crc,
+				     const struct module *crc_owner)
+{
+#ifdef ARCH_RELOCATES_KCRCTAB
+	if (crc_owner == NULL)
+		return crc - (unsigned long)reloc_start;
+#endif
+	return crc;
+}
+
 static int check_version(Elf_Shdr *sechdrs,
 			 unsigned int versindex,
 			 const char *symname,
 			 struct module *mod, 
-			 const unsigned long *crc)
+			 const unsigned long *crc,
+			 const struct module *crc_owner)
 {
 	unsigned int i, num_versions;
 	struct modversion_info *versions;
@@ -905,10 +919,10 @@ static int check_version(Elf_Shdr *sechdrs,
 		if (strcmp(versions[i].name, symname) != 0)
 			continue;
 
-		if (versions[i].crc == *crc)
+		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
 			return 1;
 		DEBUGP("Found checksum %lX vs module %lX\n",
-		       *crc, versions[i].crc);
+		       maybe_relocated(*crc, crc_owner), versions[i].crc);
 		goto bad_version;
 	}
 
@@ -931,7 +945,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
 	if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
 			 &crc, true, false))
 		BUG();
-	return check_version(sechdrs, versindex, "module_layout", mod, crc);
+	return check_version(sechdrs, versindex, "module_layout", mod, crc,
+			     NULL);
 }
 
 /* First part is kernel version, which we ignore if module has crcs. */
@@ -949,7 +964,8 @@ static inline int check_version(Elf_Shdr *sechdrs,
 				unsigned int versindex,
 				const char *symname,
 				struct module *mod, 
-				const unsigned long *crc)
+				const unsigned long *crc,
+				const struct module *crc_owner)
 {
 	return 1;
 }
@@ -984,8 +1000,8 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
 	/* use_module can fail due to OOM,
 	   or module initialization or unloading */
 	if (sym) {
-		if (!check_version(sechdrs, versindex, name, mod, crc) ||
-		    !use_module(mod, owner))
+		if (!check_version(sechdrs, versindex, name, mod, crc, owner)
+		    || !use_module(mod, owner))
 			sym = NULL;
 	}
 	return sym;
@@ -996,6 +1012,12 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
  * J. Corbet <corbet@lwn.net>
  */
 #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
+
+static inline bool sect_empty(const Elf_Shdr *sect)
+{
+	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+
 struct module_sect_attr
 {
 	struct module_attribute mattr;
@@ -1037,7 +1059,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect,
 
 	/* Count loaded sections and allocate structures */
 	for (i = 0; i < nsect; i++)
-		if (sechdrs[i].sh_flags & SHF_ALLOC)
+		if (!sect_empty(&sechdrs[i]))
 			nloaded++;
 	size[0] = ALIGN(sizeof(*sect_attrs)
 			+ nloaded * sizeof(sect_attrs->attrs[0]),
@@ -1055,7 +1077,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect,
 	sattr = &sect_attrs->attrs[0];
 	gattr = &sect_attrs->grp.attrs[0];
 	for (i = 0; i < nsect; i++) {
-		if (! (sechdrs[i].sh_flags & SHF_ALLOC))
+		if (sect_empty(&sechdrs[i]))
 			continue;
 		sattr->address = sechdrs[i].sh_addr;
 		sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
@@ -1063,6 +1085,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect,
 		if (sattr->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;
@@ -1139,7 +1162,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect,
 	/* Count notes sections and allocate structures.  */
 	notes = 0;
 	for (i = 0; i < nsect; i++)
-		if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
+		if (!sect_empty(&sechdrs[i]) &&
 		    (sechdrs[i].sh_type == SHT_NOTE))
 			++notes;
 
@@ -1155,9 +1178,10 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect,
 	notes_attrs->notes = notes;
 	nattr = &notes_attrs->attrs[0];
 	for (loaded = i = 0; i < nsect; ++i) {
-		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+		if (sect_empty(&sechdrs[i]))
 			continue;
 		if (sechdrs[i].sh_type == SHT_NOTE) {
+			sysfs_bin_attr_init(nattr);
 			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
 			nattr->attr.mode = S_IRUGO;
 			nattr->size = sechdrs[i].sh_size;
@@ -1230,6 +1254,7 @@ int module_add_modinfo_attrs(struct module *mod)
 		if (!attr->test ||
 		    (attr->test && attr->test(mod))) {
 			memcpy(temp_attr, attr, sizeof(*temp_attr));
+			sysfs_attr_init(&temp_attr->attr);
 			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
 			++temp_attr;
 		}
@@ -1377,9 +1402,9 @@ static void free_module(struct module *mod)
 	kfree(mod->args);
 	if (mod->percpu)
 		percpu_modfree(mod->percpu);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+#if defined(CONFIG_MODULE_UNLOAD)
 	if (mod->refptr)
-		percpu_modfree(mod->refptr);
+		free_percpu(mod->refptr);
 #endif
 	/* Free lock-classes: */
 	lockdep_free_key_range(mod->module_core, mod->core_size);
@@ -1893,9 +1918,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
 	unsigned int i;
 
 	/* only scan the sections containing data */
-	kmemleak_scan_area(mod->module_core, (unsigned long)mod -
-			   (unsigned long)mod->module_core,
-			   sizeof(struct module), GFP_KERNEL);
+	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
 
 	for (i = 1; i < hdr->e_shnum; i++) {
 		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
@@ -1904,8 +1927,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
 		    && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
 			continue;
 
-		kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr -
-				   (unsigned long)mod->module_core,
+		kmemleak_scan_area((void *)sechdrs[i].sh_addr,
 				   sechdrs[i].sh_size, GFP_KERNEL);
 	}
 }
@@ -2145,9 +2167,8 @@ static noinline struct module *load_module(void __user *umod,
 	mod = (void *)sechdrs[modindex].sh_addr;
 	kmemleak_load_module(mod, hdr, sechdrs, secstrings);
 
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
-	mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
-				      mod->name);
+#if defined(CONFIG_MODULE_UNLOAD)
+	mod->refptr = alloc_percpu(struct module_ref);
 	if (!mod->refptr) {
 		err = -ENOMEM;
 		goto free_init;
@@ -2233,6 +2254,12 @@ static noinline struct module *load_module(void __user *umod,
 					 "_ftrace_events",
 					 sizeof(*mod->trace_events),
 					 &mod->num_trace_events);
+	/*
+	 * This section contains pointers to allocated objects in the trace
+	 * code and not scanning it leads to false positives.
+	 */
+	kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
+			   mod->num_trace_events, GFP_KERNEL);
 #endif
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 	/* sechdrs[0].sh_size is always zero */
@@ -2373,8 +2400,8 @@ static noinline struct module *load_module(void __user *umod,
 	kobject_put(&mod->mkobj.kobj);
  free_unload:
 	module_unload_free(mod);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
-	percpu_modfree(mod->refptr);
+#if defined(CONFIG_MODULE_UNLOAD)
+	free_percpu(mod->refptr);
  free_init:
 #endif
 	module_free(mod, mod->module_init);