UBUNTU: SAUCE: add option to hand off all kernel parameters to init

BugLink: http://bugs.launchpad.net/bugs/586386

Some init packages such as upstart find having all of the kernel parameters
passed in useful.  Currently they have to open up /proc/cmdline and
reparse that to obtain this information.  Add a kernel configuration
option to enable passing of all options.

Note, enabling this option will reduce the chances that a fallback from
/sbin/init to /bin/bash or /bin/sh will succeed.  Though it should be
noted that there are commonly unknown options present which would already
break this fallback.  init=/bin/foo provides explicit control over options
which is unaffected by this change.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>

6 files changed, 59 insertions, 21 deletions

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index c18257b0fa7..75949f6b6ab 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -45,7 +45,7 @@ extern __printf(2, 3)
 int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
 
 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
-					const char *modname);
+					const char *modname, int all);
 
 struct device;
 
@@ -106,7 +106,7 @@ static inline int ddebug_remove_module(const char *mod)
 }
 
 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
-						const char *modname)
+						const char *modname, int all)
 {
 	if (strstr(param, "dyndbg")) {
 		/* avoid pr_warn(), which wants pr_fmt() fully defined */
@@ -114,7 +114,11 @@ static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
 			"CONFIG_DYNAMIC_DEBUG builds\n");
 		return 0; /* allow and ignore */
 	}
-	return -EINVAL;
+
+	if (!all)
+		return -EINVAL;
+
+	return 0;
 }
 
 #define dynamic_pr_debug(fmt, ...)					\
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index d6a58065c09..827f76fdbd8 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -320,8 +320,8 @@ extern int parse_args(const char *name,
 		      unsigned num,
 		      s16 level_min,
 		      s16 level_max,
-		      int (*unknown)(char *param, char *val,
-			      const char *doing));
+		      int (*handle_arg)(char *param, char *val,
+			      const char *doing, int known));
 
 /* Called by module remove. */
 #ifdef CONFIG_SYSFS
diff --git a/init/Kconfig b/init/Kconfig
index 8f46d1aae7d..2ad6a994c1b 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -79,6 +79,13 @@ config INIT_ENV_ARG_LIMIT
 	  Maximum of each of the number of arguments and environment
 	  variables passed to init from the kernel command line.
 
+config INIT_PASS_ALL_PARAMS
+	bool "Pass all (known and unknown) kernel parameters to init"
+	default n
+	help
+	  Pass all kernel command line parameters to init, this includes
+	  those consumed by kernel modules.  This is useful for upstart
+	  based systems.  If in doubt say N.
 
 config CROSS_COMPILE
 	string "Cross-compiler tool prefix"
diff --git a/init/main.c b/init/main.c
index b0751f0bfe0..1118f3a159f 100644
--- a/init/main.c
+++ b/init/main.c
@@ -112,6 +112,11 @@ EXPORT_SYMBOL(system_state);
  */
 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
+#ifdef CONFIG_INIT_PASS_ALL_PARAMS
+#define INIT_PASS_FUNCTION pass_all_bootoptions
+#else
+#define INIT_PASS_FUNCTION pass_unknown_bootoptions
+#endif
 
 extern void time_init(void);
 /* Default late time init is NULL. archs can override this later. */
@@ -226,7 +231,7 @@ static int __init loglevel(char *str)
 early_param("loglevel", loglevel);
 
 /* Change NUL term back to "=", to make "param" the whole string. */
-static int __init repair_env_string(char *param, char *val, const char *unused)
+static int __init repair_env_string(char *param, char *val, const char *unused, int known)
 {
 	if (val) {
 		/* param=val or param="val"? */
@@ -243,19 +248,20 @@ static int __init repair_env_string(char *param, char *val, const char *unused)
 }
 
 /*
- * Unknown boot options get handed to init, unless they look like
- * unused parameters (modprobe will find them in /proc/cmdline).
+ * Select boot options to hand to init.  If all is set hand off them all
+ * otherwise only hand off unused ones which do not apply to modules
+ * (modprobe will find them in /proc/cmdline).
  */
-static int __init unknown_bootoption(char *param, char *val, const char *unused)
+static int __init pass_bootoption(char *param, char *val, const char *unused, int all)
 {
-	repair_env_string(param, val, unused);
+	repair_env_string(param, val, unused, all);
 
 	/* Handle obsolete-style parameters */
-	if (obsolete_checksetup(param))
+	if (obsolete_checksetup(param) && !all)
 		return 0;
 
 	/* Unused module parameter. */
-	if (strchr(param, '.') && (!val || strchr(param, '.') < val))
+	if (!all && strchr(param, '.') && (!val || strchr(param, '.') < val))
 		return 0;
 
 	if (panic_later)
@@ -286,6 +292,16 @@ static int __init unknown_bootoption(char *param, char *val, const char *unused)
 	}
 	return 0;
 }
+static int __init pass_unknown_bootoptions(char *param, char *val, const char *unused, int known)
+{
+	if (known)
+		return 0;
+	return pass_bootoption(param, val, unused, 0);
+}
+static int __init pass_all_bootoptions(char *param, char *val, const char *unused, int known)
+{
+	return pass_bootoption(param, val, unused, 1);
+}
 
 static int __init init_setup(char *str)
 {
@@ -385,10 +401,13 @@ static noinline void __init_refok rest_init(void)
 }
 
 /* Check for early params. */
-static int __init do_early_param(char *param, char *val, const char *unused)
+static int __init do_early_param(char *param, char *val, const char *unused, int known)
 {
 	const struct obs_kernel_param *p;
 
+	if (known)
+		return 0;
+
 	for (p = __setup_start; p < __setup_end; p++) {
 		if ((p->early && parameq(param, p->str)) ||
 		    (strcmp(param, "console") == 0 &&
@@ -508,7 +527,7 @@ asmlinkage void __init start_kernel(void)
 	parse_early_param();
 	parse_args("Booting kernel", static_command_line, __start___param,
 		   __stop___param - __start___param,
-		   -1, -1, &unknown_bootoption);
+		   -1, -1, &INIT_PASS_FUNCTION);
 
 	jump_label_init();
 
diff --git a/kernel/params.c b/kernel/params.c
index ed35345be53..8b8b3144793 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -90,8 +90,8 @@ static int parse_one(char *param,
 		     unsigned num_params,
 		     s16 min_level,
 		     s16 max_level,
-		     int (*handle_unknown)(char *param, char *val,
-				     const char *doing))
+		     int (*handle_arg)(char *param, char *val,
+				     const char *doing, int known))
 {
 	unsigned int i;
 	int err;
@@ -106,6 +106,14 @@ static int parse_one(char *param,
 			if (!val && params[i].ops->set != param_set_bool
 			    && params[i].ops->set != param_set_bint)
 				return -EINVAL;
+			if (handle_arg) {
+				int ret;
+				pr_debug("Valid argument: calling %p\n",
+				       handle_arg);
+				ret = handle_arg(param, val, doing, 1);
+				if (ret)
+					return ret;
+			}
 			pr_debug("handling %s with %p\n", param,
 				params[i].ops->set);
 			mutex_lock(&param_lock);
@@ -115,9 +123,9 @@ static int parse_one(char *param,
 		}
 	}
 
-	if (handle_unknown) {
+	if (handle_arg) {
 		pr_debug("doing %s: %s='%s'\n", doing, param, val);
-		return handle_unknown(param, val, doing);
+		return handle_arg(param, val, doing, 0);
 	}
 
 	pr_debug("Unknown argument '%s'\n", param);
@@ -183,7 +191,7 @@ int parse_args(const char *doing,
 	       unsigned num,
 	       s16 min_level,
 	       s16 max_level,
-	       int (*unknown)(char *param, char *val, const char *doing))
+	       int (*handle_arg)(char *param, char *val, const char *doing, int arg))
 {
 	char *param, *val;
 
@@ -200,7 +208,7 @@ int parse_args(const char *doing,
 		args = next_arg(args, &param, &val);
 		irq_was_disabled = irqs_disabled();
 		ret = parse_one(param, val, doing, params, num,
-				min_level, max_level, unknown);
+				min_level, max_level, handle_arg);
 		if (irq_was_disabled && !irqs_disabled())
 			pr_warn("%s: option '%s' enabled irq's!\n",
 				doing, param);
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 7ca29a0a301..fa196a00bf5 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -900,7 +900,7 @@ static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
  * passes them to load_module().  This callback gets unknown params,
  * processes dyndbg params, rejects others.
  */
-int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
+int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module, int all)
 {
 	vpr_info("module: %s %s=\"%s\"\n", module, param, val);
 	return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);