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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 20:12:43 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 20:12:43 -0800
commit4d98ead183a2be77bfea425d5243e32629eaaeb1 (patch)
treeabd2282b8fed47a972a0334fb5b466d640fe385e /kernel/module.c
parenta57cb1c1d7974c62a5c80f7869e35b492ace12cd (diff)
parent4d217a5adccf5e806790c37c61cc374a08bd7381 (diff)
Merge tag 'modules-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull modules updates from Jessica Yu: "Summary of modules changes for the 4.10 merge window: - The rodata= cmdline parameter has been extended to additionally apply to module mappings - Fix a hard to hit race between module loader error/clean up handling and ftrace registration - Some code cleanups, notably panic.c and modules code use a unified taint_flags table now. This is much cleaner than duplicating the taint flag code in modules.c" * tag 'modules-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: fix DEBUG_SET_MODULE_RONX typo module: extend 'rodata=off' boot cmdline parameter to module mappings module: Fix a comment above strong_try_module_get() module: When modifying a module's text ignore modules which are going away too module: Ensure a module's state is set accordingly during module coming cleanup code module: remove trailing whitespace taint/module: Clean up global and module taint flags handling modpost: free allocated memory
Diffstat (limited to 'kernel/module.c')
-rw-r--r--kernel/module.c69
1 files changed, 43 insertions, 26 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 0e54d5bf0097..f7482db0f843 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -313,8 +313,11 @@ struct load_info {
} index;
};
-/* We require a truly strong try_module_get(): 0 means failure due to
- ongoing or failed initialization etc. */
+/*
+ * We require a truly strong try_module_get(): 0 means success.
+ * Otherwise an error is returned due to ongoing or failed
+ * initialization etc.
+ */
static inline int strong_try_module_get(struct module *mod)
{
BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
@@ -330,7 +333,7 @@ static inline void add_taint_module(struct module *mod, unsigned flag,
enum lockdep_ok lockdep_ok)
{
add_taint(flag, lockdep_ok);
- mod->taints |= (1U << flag);
+ set_bit(flag, &mod->taints);
}
/*
@@ -1138,24 +1141,13 @@ static inline int module_unload_init(struct module *mod)
static size_t module_flags_taint(struct module *mod, char *buf)
{
size_t l = 0;
+ int i;
+
+ for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
+ if (taint_flags[i].module && test_bit(i, &mod->taints))
+ buf[l++] = taint_flags[i].true;
+ }
- if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
- buf[l++] = 'P';
- if (mod->taints & (1 << TAINT_OOT_MODULE))
- buf[l++] = 'O';
- if (mod->taints & (1 << TAINT_FORCED_MODULE))
- buf[l++] = 'F';
- if (mod->taints & (1 << TAINT_CRAP))
- buf[l++] = 'C';
- if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
- buf[l++] = 'E';
- if (mod->taints & (1 << TAINT_LIVEPATCH))
- buf[l++] = 'K';
- /*
- * TAINT_FORCED_RMMOD: could be added.
- * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
- * apply to modules.
- */
return l;
}
@@ -1911,6 +1903,9 @@ static void frob_writable_data(const struct module_layout *layout,
/* 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);
@@ -1920,6 +1915,9 @@ void module_disable_ro(const struct module *mod)
void module_enable_ro(const struct module *mod, bool after_init)
{
+ if (!rodata_enabled)
+ return;
+
frob_text(&mod->core_layout, set_memory_ro);
frob_rodata(&mod->core_layout, set_memory_ro);
frob_text(&mod->init_layout, set_memory_ro);
@@ -1952,6 +1950,9 @@ void set_all_modules_text_rw(void)
{
struct module *mod;
+ if (!rodata_enabled)
+ return;
+
mutex_lock(&module_mutex);
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
@@ -1968,9 +1969,18 @@ void set_all_modules_text_ro(void)
{
struct module *mod;
+ if (!rodata_enabled)
+ return;
+
mutex_lock(&module_mutex);
list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
+ /*
+ * Ignore going modules since it's possible that ro
+ * protection has already been disabled, otherwise we'll
+ * run into protection faults at module deallocation.
+ */
+ if (mod->state == MODULE_STATE_UNFORMED ||
+ mod->state == MODULE_STATE_GOING)
continue;
frob_text(&mod->core_layout, set_memory_ro);
@@ -1981,10 +1991,12 @@ void set_all_modules_text_ro(void)
static void disable_ro_nx(const struct module_layout *layout)
{
- frob_text(layout, set_memory_rw);
- frob_rodata(layout, set_memory_rw);
+ if (rodata_enabled) {
+ frob_text(layout, set_memory_rw);
+ frob_rodata(layout, set_memory_rw);
+ frob_ro_after_init(layout, set_memory_rw);
+ }
frob_rodata(layout, set_memory_x);
- frob_ro_after_init(layout, set_memory_rw);
frob_ro_after_init(layout, set_memory_x);
frob_writable_data(layout, set_memory_x);
}
@@ -3709,6 +3721,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
sysfs_cleanup:
mod_sysfs_teardown(mod);
coming_cleanup:
+ mod->state = MODULE_STATE_GOING;
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
klp_module_going(mod);
@@ -4042,6 +4055,10 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
}
#endif /* CONFIG_KALLSYMS */
+/* Maximum number of characters written by module_flags() */
+#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
+
+/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
static char *module_flags(struct module *mod, char *buf)
{
int bx = 0;
@@ -4086,7 +4103,7 @@ static void m_stop(struct seq_file *m, void *p)
static int m_show(struct seq_file *m, void *p)
{
struct module *mod = list_entry(p, struct module, list);
- char buf[8];
+ char buf[MODULE_FLAGS_BUF_SIZE];
/* We always ignore unformed modules. */
if (mod->state == MODULE_STATE_UNFORMED)
@@ -4257,7 +4274,7 @@ EXPORT_SYMBOL_GPL(__module_text_address);
void print_modules(void)
{
struct module *mod;
- char buf[8];
+ char buf[MODULE_FLAGS_BUF_SIZE];
printk(KERN_DEFAULT "Modules linked in:");
/* Most callers should already have preempt disabled, but make sure */