Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module update from Rusty Russell:
 "The sweeping change is to make add_taint() explicitly indicate whether
  to disable lockdep, but it's a mechanical change."

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  MODSIGN: Add option to not sign modules during modules_install
  MODSIGN: Add -s <signature> option to sign-file
  MODSIGN: Specify the hash algorithm on sign-file command line
  MODSIGN: Simplify Makefile with a Kconfig helper
  module: clean up load_module a little more.
  modpost: Ignore ARC specific non-alloc sections
  module: constify within_module_*
  taint: add explicit flag to show whether lock dep is still OK.
  module: printk message when module signature fail taints kernel.

5 files changed, 108 insertions, 92 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 6c072b6..eceac38 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -153,23 +153,7 @@ kernel/modsign_certificate.o: signing_key.x509 extra_certificates
 # fail and that the kernel may be used afterwards.
 #
 ###############################################################################
-sign_key_with_hash :=
-ifeq ($(CONFIG_MODULE_SIG_SHA1),y)
-sign_key_with_hash := -sha1
-endif
-ifeq ($(CONFIG_MODULE_SIG_SHA224),y)
-sign_key_with_hash := -sha224
-endif
-ifeq ($(CONFIG_MODULE_SIG_SHA256),y)
-sign_key_with_hash := -sha256
-endif
-ifeq ($(CONFIG_MODULE_SIG_SHA384),y)
-sign_key_with_hash := -sha384
-endif
-ifeq ($(CONFIG_MODULE_SIG_SHA512),y)
-sign_key_with_hash := -sha512
-endif
-ifeq ($(sign_key_with_hash),)
+ifndef CONFIG_MODULE_SIG_HASH
 $(error Could not determine digest type to use from kernel config)
 endif
 
@@ -182,8 +166,8 @@ signing_key.priv signing_key.x509: x509.genkey
 	@echo "### needs to be run as root, and uses a hardware random"
 	@echo "### number generator if one is available."
 	@echo "###"
-	openssl req -new -nodes -utf8 $(sign_key_with_hash) -days 36500 -batch \
-		-x509 -config x509.genkey \
+	openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
+		-batch -x509 -config x509.genkey \
 		-outform DER -out signing_key.x509 \
 		-keyout signing_key.priv
 	@echo "###"
diff --git a/kernel/module.c b/kernel/module.c
index eab0827..921bed4 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -197,9 +197,10 @@ static inline int strong_try_module_get(struct module *mod)
 		return -ENOENT;
 }
 
-static inline void add_taint_module(struct module *mod, unsigned flag)
+static inline void add_taint_module(struct module *mod, unsigned flag,
+				    enum lockdep_ok lockdep_ok)
 {
-	add_taint(flag);
+	add_taint(flag, lockdep_ok);
 	mod->taints |= (1U << flag);
 }
 
@@ -727,7 +728,7 @@ static inline int try_force_unload(unsigned int flags)
 {
 	int ret = (flags & O_TRUNC);
 	if (ret)
-		add_taint(TAINT_FORCED_RMMOD);
+		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
 	return ret;
 }
 #else
@@ -1138,7 +1139,7 @@ static int try_to_force_load(struct module *mod, const char *reason)
 	if (!test_taint(TAINT_FORCED_MODULE))
 		printk(KERN_WARNING "%s: %s: kernel tainted.\n",
 		       mod->name, reason);
-	add_taint_module(mod, TAINT_FORCED_MODULE);
+	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
 	return 0;
 #else
 	return -ENOEXEC;
@@ -2147,7 +2148,8 @@ static void set_license(struct module *mod, const char *license)
 		if (!test_taint(TAINT_PROPRIETARY_MODULE))
 			printk(KERN_WARNING "%s: module license '%s' taints "
 				"kernel.\n", mod->name, license);
-		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+				 LOCKDEP_NOW_UNRELIABLE);
 	}
 }
 
@@ -2700,10 +2702,10 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 	}
 
 	if (!get_modinfo(info, "intree"))
-		add_taint_module(mod, TAINT_OOT_MODULE);
+		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
 
 	if (get_modinfo(info, "staging")) {
-		add_taint_module(mod, TAINT_CRAP);
+		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
 		printk(KERN_WARNING "%s: module is from the staging directory,"
 		       " the quality is unknown, you have been warned.\n",
 		       mod->name);
@@ -2869,15 +2871,17 @@ static int check_module_license_and_versions(struct module *mod)
 	 * using GPL-only symbols it needs.
 	 */
 	if (strcmp(mod->name, "ndiswrapper") == 0)
-		add_taint(TAINT_PROPRIETARY_MODULE);
+		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
 
 	/* driverloader was caught wrongly pretending to be under GPL */
 	if (strcmp(mod->name, "driverloader") == 0)
-		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+				 LOCKDEP_NOW_UNRELIABLE);
 
 	/* lve claims to be GPL but upstream won't provide source */
 	if (strcmp(mod->name, "lve") == 0)
-		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+				 LOCKDEP_NOW_UNRELIABLE);
 
 #ifdef CONFIG_MODVERSIONS
 	if ((mod->num_syms && !mod->crcs)
@@ -3141,12 +3145,72 @@ static int may_init_module(void)
 	return 0;
 }
 
+/*
+ * We try to place it in the list now to make sure it's unique before
+ * we dedicate too many resources.  In particular, temporary percpu
+ * memory exhaustion.
+ */
+static int add_unformed_module(struct module *mod)
+{
+	int err;
+	struct module *old;
+
+	mod->state = MODULE_STATE_UNFORMED;
+
+again:
+	mutex_lock(&module_mutex);
+	if ((old = find_module_all(mod->name, true)) != NULL) {
+		if (old->state == MODULE_STATE_COMING
+		    || old->state == MODULE_STATE_UNFORMED) {
+			/* Wait in case it fails to load. */
+			mutex_unlock(&module_mutex);
+			err = wait_event_interruptible(module_wq,
+					       finished_loading(mod->name));
+			if (err)
+				goto out_unlocked;
+			goto again;
+		}
+		err = -EEXIST;
+		goto out;
+	}
+	list_add_rcu(&mod->list, &modules);
+	err = 0;
+
+out:
+	mutex_unlock(&module_mutex);
+out_unlocked:
+	return err;
+}
+
+static int complete_formation(struct module *mod, struct load_info *info)
+{
+	int err;
+
+	mutex_lock(&module_mutex);
+
+	/* Find duplicate symbols (must be called under lock). */
+	err = verify_export_symbols(mod);
+	if (err < 0)
+		goto out;
+
+	/* This relies on module_mutex for list integrity. */
+	module_bug_finalize(info->hdr, info->sechdrs, mod);
+
+	/* Mark state as coming so strong_try_module_get() ignores us,
+	 * but kallsyms etc. can see us. */
+	mod->state = MODULE_STATE_COMING;
+
+out:
+	mutex_unlock(&module_mutex);
+	return err;
+}
+
 /* Allocate and load the module: note that size of section 0 is always
    zero, and we rely on this for optional sections. */
 static int load_module(struct load_info *info, const char __user *uargs,
 		       int flags)
 {
-	struct module *mod, *old;
+	struct module *mod;
 	long err;
 
 	err = module_sig_check(info);
@@ -3164,36 +3228,20 @@ static int load_module(struct load_info *info, const char __user *uargs,
 		goto free_copy;
 	}
 
-	/*
-	 * We try to place it in the list now to make sure it's unique
-	 * before we dedicate too many resources.  In particular,
-	 * temporary percpu memory exhaustion.
-	 */
-	mod->state = MODULE_STATE_UNFORMED;
-again:
-	mutex_lock(&module_mutex);
-	if ((old = find_module_all(mod->name, true)) != NULL) {
-		if (old->state == MODULE_STATE_COMING
-		    || old->state == MODULE_STATE_UNFORMED) {
-			/* Wait in case it fails to load. */
-			mutex_unlock(&module_mutex);
-			err = wait_event_interruptible(module_wq,
-					       finished_loading(mod->name));
-			if (err)
-				goto free_module;
-			goto again;
-		}
-		err = -EEXIST;
-		mutex_unlock(&module_mutex);
+	/* Reserve our place in the list. */
+	err = add_unformed_module(mod);
+	if (err)
 		goto free_module;
-	}
-	list_add_rcu(&mod->list, &modules);
-	mutex_unlock(&module_mutex);
 
 #ifdef CONFIG_MODULE_SIG
 	mod->sig_ok = info->sig_ok;
-	if (!mod->sig_ok)
-		add_taint_module(mod, TAINT_FORCED_MODULE);
+	if (!mod->sig_ok) {
+		printk_once(KERN_NOTICE
+			    "%s: module verification failed: signature and/or"
+			    " required key missing - tainting kernel\n",
+			    mod->name);
+		add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK);
+	}
 #endif
 
 	/* Now module is in final location, initialize linked lists, etc. */
@@ -3236,21 +3284,11 @@ again:
 
 	dynamic_debug_setup(info->debug, info->num_debug);
 
-	mutex_lock(&module_mutex);
-	/* Find duplicate symbols (must be called under lock). */
-	err = verify_export_symbols(mod);
-	if (err < 0)
+	/* Finally it's fully formed, ready to start executing. */
+	err = complete_formation(mod, info);
+	if (err)
 		goto ddebug_cleanup;
 
-	/* This relies on module_mutex for list integrity. */
-	module_bug_finalize(info->hdr, info->sechdrs, mod);
-
-	/* Mark state as coming so strong_try_module_get() ignores us,
-	 * but kallsyms etc. can see us. */
-	mod->state = MODULE_STATE_COMING;
-
-	mutex_unlock(&module_mutex);
-
 	/* Module is ready to execute: parsing args may do that. */
 	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
 			 -32768, 32767, &ddebug_dyndbg_module_param_cb);
@@ -3274,8 +3312,8 @@ again:
 	/* module_bug_cleanup needs module_mutex protection */
 	mutex_lock(&module_mutex);
 	module_bug_cleanup(mod);
- ddebug_cleanup:
 	mutex_unlock(&module_mutex);
+ ddebug_cleanup:
 	dynamic_debug_remove(info->debug);
 	synchronize_sched();
 	kfree(mod->args);
diff --git a/kernel/panic.c b/kernel/panic.c
index e1b2822..7c57cc9 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -259,26 +259,19 @@ unsigned long get_taint(void)
 	return tainted_mask;
 }
 
-void add_taint(unsigned flag)
+/**
+ * add_taint: add a taint flag if not already set.
+ * @flag: one of the TAINT_* constants.
+ * @lockdep_ok: whether lock debugging is still OK.
+ *
+ * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
+ * some notewortht-but-not-corrupting cases, it can be set to true.
+ */
+void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
 {
-	/*
-	 * Can't trust the integrity of the kernel anymore.
-	 * We don't call directly debug_locks_off() because the issue
-	 * is not necessarily serious enough to set oops_in_progress to 1
-	 * Also we want to keep up lockdep for staging/out-of-tree
-	 * development and post-warning case.
-	 */
-	switch (flag) {
-	case TAINT_CRAP:
-	case TAINT_OOT_MODULE:
-	case TAINT_WARN:
-	case TAINT_FIRMWARE_WORKAROUND:
-		break;
-
-	default:
-		if (__debug_locks_off())
-			printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
-	}
+	if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
+		printk(KERN_WARNING
+		       "Disabling lock debugging due to kernel taint\n");
 
 	set_bit(flag, &tainted_mask);
 }
@@ -421,7 +414,8 @@ static void warn_slowpath_common(const char *file, int line, void *caller,
 	print_modules();
 	dump_stack();
 	print_oops_end_marker();
-	add_taint(taint);
+	/* Just a warning, don't kill lockdep. */
+	add_taint(taint, LOCKDEP_STILL_OK);
 }
 
 void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f1bdecf..fc9103e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2796,7 +2796,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
 	if (irqs_disabled())
 		print_irqtrace_events(prev);
 	dump_stack();
-	add_taint(TAINT_WARN);
+	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
 }
 
 /*
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 95e9e55..d8df00e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2018,7 +2018,7 @@ static int proc_taint(struct ctl_table *table, int write,
 		int i;
 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
 			if ((tmptaint >> i) & 1)
-				add_taint(i);
+				add_taint(i, LOCKDEP_STILL_OK);
 		}
 	}