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authorLinus Torvalds <torvalds@linux-foundation.org>2008-05-01 08:26:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-05-01 08:26:56 -0700
commit03fc922f4085a0139f313831fe2dc6fed467cd2d (patch)
tree1404c800acaf02eab054eb3448803db9d9b89262 /kernel
parenta0be7522b25f17ac2c3964a24b88b5fe7c9404b8 (diff)
parentdf4b565e1fbc777bb6e274378a41fa8ff7485680 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: module: add MODULE_STATE_GOING notifier call module: Enhance verify_export_symbols module: set unused_gpl_crcs instead of overwriting unused_crcs module: neaten __find_symbol, rename to find_symbol module: reduce module image and resident size module: make module_sect_attrs private to kernel/module.c
Diffstat (limited to 'kernel')
-rw-r--r--kernel/module.c319
1 files changed, 171 insertions, 148 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 8d6cccc6c3c..8674a390a2e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -164,131 +164,140 @@ static const struct kernel_symbol *lookup_symbol(const char *name,
return NULL;
}
-static void printk_unused_warning(const char *name)
+static bool always_ok(bool gplok, bool warn, const char *name)
{
- printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
- "however this module is using it.\n", name);
- printk(KERN_WARNING "This symbol will go away in the future.\n");
- printk(KERN_WARNING "Please evalute if this is the right api to use, "
- "and if it really is, submit a report the linux kernel "
- "mailinglist together with submitting your code for "
- "inclusion.\n");
+ return true;
}
-/* Find a symbol, return value, crc and module which owns it */
-static unsigned long __find_symbol(const char *name,
- struct module **owner,
- const unsigned long **crc,
- int gplok)
+static bool printk_unused_warning(bool gplok, bool warn, const char *name)
{
- struct module *mod;
- const struct kernel_symbol *ks;
-
- /* Core kernel first. */
- *owner = NULL;
- ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
- if (ks) {
- *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
- return ks->value;
+ if (warn) {
+ printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
+ "however this module is using it.\n", name);
+ printk(KERN_WARNING
+ "This symbol will go away in the future.\n");
+ printk(KERN_WARNING
+ "Please evalute if this is the right api to use and if "
+ "it really is, submit a report the linux kernel "
+ "mailinglist together with submitting your code for "
+ "inclusion.\n");
}
- if (gplok) {
- ks = lookup_symbol(name, __start___ksymtab_gpl,
- __stop___ksymtab_gpl);
- if (ks) {
- *crc = symversion(__start___kcrctab_gpl,
- (ks - __start___ksymtab_gpl));
- return ks->value;
- }
- }
- ks = lookup_symbol(name, __start___ksymtab_gpl_future,
- __stop___ksymtab_gpl_future);
- if (ks) {
- if (!gplok) {
- printk(KERN_WARNING "Symbol %s is being used "
- "by a non-GPL module, which will not "
- "be allowed in the future\n", name);
- printk(KERN_WARNING "Please see the file "
- "Documentation/feature-removal-schedule.txt "
- "in the kernel source tree for more "
- "details.\n");
- }
- *crc = symversion(__start___kcrctab_gpl_future,
- (ks - __start___ksymtab_gpl_future));
- return ks->value;
+ return true;
+}
+
+static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name)
+{
+ if (!gplok)
+ return false;
+ return printk_unused_warning(gplok, warn, name);
+}
+
+static bool gpl_only(bool gplok, bool warn, const char *name)
+{
+ return gplok;
+}
+
+static bool warn_if_not_gpl(bool gplok, bool warn, const char *name)
+{
+ if (!gplok && warn) {
+ printk(KERN_WARNING "Symbol %s is being used "
+ "by a non-GPL module, which will not "
+ "be allowed in the future\n", name);
+ printk(KERN_WARNING "Please see the file "
+ "Documentation/feature-removal-schedule.txt "
+ "in the kernel source tree for more details.\n");
}
+ return true;
+}
- ks = lookup_symbol(name, __start___ksymtab_unused,
- __stop___ksymtab_unused);
- if (ks) {
- printk_unused_warning(name);
- *crc = symversion(__start___kcrctab_unused,
- (ks - __start___ksymtab_unused));
- return ks->value;
+struct symsearch {
+ const struct kernel_symbol *start, *stop;
+ const unsigned long *crcs;
+ bool (*check)(bool gplok, bool warn, const char *name);
+};
+
+/* Look through this array of symbol tables for a symbol match which
+ * passes the check function. */
+static const struct kernel_symbol *search_symarrays(const struct symsearch *arr,
+ unsigned int num,
+ const char *name,
+ bool gplok,
+ bool warn,
+ const unsigned long **crc)
+{
+ unsigned int i;
+ const struct kernel_symbol *ks;
+
+ for (i = 0; i < num; i++) {
+ ks = lookup_symbol(name, arr[i].start, arr[i].stop);
+ if (!ks || !arr[i].check(gplok, warn, name))
+ continue;
+
+ if (crc)
+ *crc = symversion(arr[i].crcs, ks - arr[i].start);
+ return ks;
}
+ return NULL;
+}
+
+/* Find a symbol, return value, (optional) crc and (optional) module
+ * which owns it */
+static unsigned long find_symbol(const char *name,
+ struct module **owner,
+ const unsigned long **crc,
+ bool gplok,
+ bool warn)
+{
+ struct module *mod;
+ const struct kernel_symbol *ks;
+ const struct symsearch arr[] = {
+ { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
+ always_ok },
+ { __start___ksymtab_gpl, __stop___ksymtab_gpl,
+ __start___kcrctab_gpl, gpl_only },
+ { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
+ __start___kcrctab_gpl_future, warn_if_not_gpl },
+ { __start___ksymtab_unused, __stop___ksymtab_unused,
+ __start___kcrctab_unused, printk_unused_warning },
+ { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
+ __start___kcrctab_unused_gpl, gpl_only_unused_warning },
+ };
- if (gplok)
- ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
- __stop___ksymtab_unused_gpl);
+ /* Core kernel first. */
+ ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc);
if (ks) {
- printk_unused_warning(name);
- *crc = symversion(__start___kcrctab_unused_gpl,
- (ks - __start___ksymtab_unused_gpl));
+ if (owner)
+ *owner = NULL;
return ks->value;
}
/* Now try modules. */
list_for_each_entry(mod, &modules, list) {
- *owner = mod;
- ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
- if (ks) {
- *crc = symversion(mod->crcs, (ks - mod->syms));
- return ks->value;
- }
-
- if (gplok) {
- ks = lookup_symbol(name, mod->gpl_syms,
- mod->gpl_syms + mod->num_gpl_syms);
- if (ks) {
- *crc = symversion(mod->gpl_crcs,
- (ks - mod->gpl_syms));
- return ks->value;
- }
- }
- ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
+ struct symsearch arr[] = {
+ { mod->syms, mod->syms + mod->num_syms, mod->crcs,
+ always_ok },
+ { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
+ mod->gpl_crcs, gpl_only },
+ { mod->gpl_future_syms,
+ mod->gpl_future_syms + mod->num_gpl_future_syms,
+ mod->gpl_future_crcs, warn_if_not_gpl },
+ { mod->unused_syms,
+ mod->unused_syms + mod->num_unused_syms,
+ mod->unused_crcs, printk_unused_warning },
+ { mod->unused_gpl_syms,
+ mod->unused_gpl_syms + mod->num_unused_gpl_syms,
+ mod->unused_gpl_crcs, gpl_only_unused_warning },
+ };
+
+ ks = search_symarrays(arr, ARRAY_SIZE(arr),
+ name, gplok, warn, crc);
if (ks) {
- printk_unused_warning(name);
- *crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
- return ks->value;
- }
-
- if (gplok) {
- ks = lookup_symbol(name, mod->unused_gpl_syms,
- mod->unused_gpl_syms + mod->num_unused_gpl_syms);
- if (ks) {
- printk_unused_warning(name);
- *crc = symversion(mod->unused_gpl_crcs,
- (ks - mod->unused_gpl_syms));
- return ks->value;
- }
- }
- ks = lookup_symbol(name, mod->gpl_future_syms,
- (mod->gpl_future_syms +
- mod->num_gpl_future_syms));
- if (ks) {
- if (!gplok) {
- printk(KERN_WARNING "Symbol %s is being used "
- "by a non-GPL module, which will not "
- "be allowed in the future\n", name);
- printk(KERN_WARNING "Please see the file "
- "Documentation/feature-removal-schedule.txt "
- "in the kernel source tree for more "
- "details.\n");
- }
- *crc = symversion(mod->gpl_future_crcs,
- (ks - mod->gpl_future_syms));
+ if (owner)
+ *owner = mod;
return ks->value;
}
}
+
DEBUGP("Failed to find symbol %s\n", name);
return -ENOENT;
}
@@ -736,12 +745,13 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
if (!forced && module_refcount(mod) != 0)
wait_for_zero_refcount(mod);
+ mutex_unlock(&module_mutex);
/* Final destruction now noone is using it. */
- if (mod->exit != NULL) {
- mutex_unlock(&module_mutex);
+ if (mod->exit != NULL)
mod->exit();
- mutex_lock(&module_mutex);
- }
+ blocking_notifier_call_chain(&module_notify_list,
+ MODULE_STATE_GOING, mod);
+ mutex_lock(&module_mutex);
/* Store the name of the last unloaded module for diagnostic purposes */
strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
free_module(mod);
@@ -777,10 +787,9 @@ static void print_unload_info(struct seq_file *m, struct module *mod)
void __symbol_put(const char *symbol)
{
struct module *owner;
- const unsigned long *crc;
preempt_disable();
- if (IS_ERR_VALUE(__find_symbol(symbol, &owner, &crc, 1)))
+ if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
BUG();
module_put(owner);
preempt_enable();
@@ -924,13 +933,10 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
struct module *mod)
{
const unsigned long *crc;
- struct module *owner;
- if (IS_ERR_VALUE(__find_symbol("struct_module",
- &owner, &crc, 1)))
+ if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
BUG();
- return check_version(sechdrs, versindex, "struct_module", mod,
- crc);
+ return check_version(sechdrs, versindex, "struct_module", mod, crc);
}
/* First part is kernel version, which we ignore. */
@@ -974,8 +980,8 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
unsigned long ret;
const unsigned long *crc;
- ret = __find_symbol(name, &owner, &crc,
- !(mod->taints & TAINT_PROPRIETARY_MODULE));
+ ret = find_symbol(name, &owner, &crc,
+ !(mod->taints & TAINT_PROPRIETARY_MODULE), true);
if (!IS_ERR_VALUE(ret)) {
/* use_module can fail due to OOM,
or module initialization or unloading */
@@ -991,6 +997,20 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
* J. Corbet <corbet@lwn.net>
*/
#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
+struct module_sect_attr
+{
+ struct module_attribute mattr;
+ char *name;
+ unsigned long address;
+};
+
+struct module_sect_attrs
+{
+ struct attribute_group grp;
+ unsigned int nsections;
+ struct module_sect_attr attrs[0];
+};
+
static ssize_t module_sect_show(struct module_attribute *mattr,
struct module *mod, char *buf)
{
@@ -1001,7 +1021,7 @@ static ssize_t module_sect_show(struct module_attribute *mattr,
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
- int section;
+ unsigned int section;
for (section = 0; section < sect_attrs->nsections; section++)
kfree(sect_attrs->attrs[section].name);
@@ -1362,10 +1382,9 @@ void *__symbol_get(const char *symbol)
{
struct module *owner;
unsigned long value;
- const unsigned long *crc;
preempt_disable();
- value = __find_symbol(symbol, &owner, &crc, 1);
+ value = find_symbol(symbol, &owner, NULL, true, true);
if (IS_ERR_VALUE(value))
value = 0;
else if (strong_try_module_get(owner))
@@ -1382,33 +1401,33 @@ EXPORT_SYMBOL_GPL(__symbol_get);
*/
static int verify_export_symbols(struct module *mod)
{
- const char *name = NULL;
- unsigned long i, ret = 0;
+ unsigned int i;
struct module *owner;
- const unsigned long *crc;
-
- for (i = 0; i < mod->num_syms; i++)
- if (!IS_ERR_VALUE(__find_symbol(mod->syms[i].name,
- &owner, &crc, 1))) {
- name = mod->syms[i].name;
- ret = -ENOEXEC;
- goto dup;
- }
+ const struct kernel_symbol *s;
+ struct {
+ const struct kernel_symbol *sym;
+ unsigned int num;
+ } arr[] = {
+ { mod->syms, mod->num_syms },
+ { mod->gpl_syms, mod->num_gpl_syms },
+ { mod->gpl_future_syms, mod->num_gpl_future_syms },
+ { mod->unused_syms, mod->num_unused_syms },
+ { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
+ };
- for (i = 0; i < mod->num_gpl_syms; i++)
- if (!IS_ERR_VALUE(__find_symbol(mod->gpl_syms[i].name,
- &owner, &crc, 1))) {
- name = mod->gpl_syms[i].name;
- ret = -ENOEXEC;
- goto dup;
+ for (i = 0; i < ARRAY_SIZE(arr); i++) {
+ for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
+ if (!IS_ERR_VALUE(find_symbol(s->name, &owner,
+ NULL, true, false))) {
+ printk(KERN_ERR
+ "%s: exports duplicate symbol %s"
+ " (owned by %s)\n",
+ mod->name, s->name, module_name(owner));
+ return -ENOEXEC;
+ }
}
-
-dup:
- if (ret)
- printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
- mod->name, name, module_name(owner));
-
- return ret;
+ }
+ return 0;
}
/* Change all symbols so that st_value encodes the pointer directly. */
@@ -1814,8 +1833,9 @@ static struct module *load_module(void __user *umod,
unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
#endif
- /* Don't keep modinfo section */
+ /* Don't keep modinfo and version sections. */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
+ sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
#ifdef CONFIG_KALLSYMS
/* Keep symbol and string tables for decoding later. */
sechdrs[symindex].sh_flags |= SHF_ALLOC;
@@ -1977,7 +1997,8 @@ static struct module *load_module(void __user *umod,
mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
if (unusedgplcrcindex)
- mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
+ mod->unused_gpl_crcs
+ = (void *)sechdrs[unusedgplcrcindex].sh_addr;
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !crcindex) ||
@@ -2171,6 +2192,8 @@ sys_init_module(void __user *umod,
mod->state = MODULE_STATE_GOING;
synchronize_sched();
module_put(mod);
+ blocking_notifier_call_chain(&module_notify_list,
+ MODULE_STATE_GOING, mod);
mutex_lock(&module_mutex);
free_module(mod);
mutex_unlock(&module_mutex);