Commit 51e158c1 authored by Rusty Russell's avatar Rusty Russell
Browse files

param: hand arguments after -- straight to init 



The kernel passes any args it doesn't need through to init, except it
assumes anything containing '.' belongs to the kernel (for a module).
This change means all users can clearly distinguish which arguments
are for init.

For example, the kernel uses debug ("dee-bug") to mean log everything to
the console, where systemd uses the debug from the Scandinavian "day-boog"
meaning "fail to boot".  If a future versions uses argv[] instead of
reading /proc/cmdline, this confusion will be avoided.

eg: test 'FOO="this is --foo"' -- 'systemd.debug="true true true"'

Gives:
argv[0] = '/debug-init'
argv[1] = 'test'
argv[2] = 'systemd.debug=true true true'
envp[0] = 'HOME=/'
envp[1] = 'TERM=linux'
envp[2] = 'FOO=this is --foo'

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 2ee41e62

include/linux/moduleparam.h

+1 −1
Original line number Diff line number Diff line
@@ -321,7 +321,7 @@ extern bool parameq(const char *name1, const char *name2); 
extern bool parameqn(const char *name1, const char *name2, size_t n);



/* Called on module insert or kernel boot */

extern int parse_args(const char *name,

extern char *parse_args(const char *name,

		      char *args,

		      const struct kernel_param *params,

		      unsigned num,

init/main.c

+29 −4
Original line number Diff line number Diff line
@@ -252,6 +252,27 @@ static int __init repair_env_string(char *param, char *val, const char *unused) 
	return 0;

}



/* Anything after -- gets handed straight to init. */

static int __init set_init_arg(char *param, char *val, const char *unused)

{

	unsigned int i;



	if (panic_later)

		return 0;



	repair_env_string(param, val, unused);



	for (i = 0; argv_init[i]; i++) {

		if (i == MAX_INIT_ARGS) {

			panic_later = "init";

			panic_param = param;

			return 0;

		}

	}

	argv_init[i] = param;

	return 0;

}



/*

 * Unknown boot options get handed to init, unless they look like

 * unused parameters (modprobe will find them in /proc/cmdline).
@@ -478,7 +499,7 @@ static void __init mm_init(void) 


asmlinkage void __init start_kernel(void)

{

	char * command_line;

	char * command_line, *after_dashes;

	extern const struct kernel_param __start___param[], __stop___param[];



	/*
@@ -519,9 +540,13 @@ asmlinkage void __init start_kernel(void) 


	pr_notice("Kernel command line: %s\n", boot_command_line);

	parse_early_param();

	parse_args("Booting kernel", static_command_line, __start___param,

	after_dashes = parse_args("Booting kernel",

				  static_command_line, __start___param,

				  __stop___param - __start___param,

				  -1, -1, &unknown_bootoption);

	if (after_dashes)

		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,

			   set_init_arg);



	jump_label_init();

kernel/module.c

+9 −3
Original line number Diff line number Diff line
@@ -3193,6 +3193,7 @@ static int load_module(struct load_info *info, const char __user *uargs, 
{

	struct module *mod;

	long err;

	char *after_dashes;



	err = module_sig_check(info);

	if (err)
@@ -3277,10 +3278,15 @@ static int load_module(struct load_info *info, const char __user *uargs, 
		goto ddebug_cleanup;



	/* Module is ready to execute: parsing args may do that. */

	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,

	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,

				  -32768, 32767, unknown_module_param_cb);

	if (err < 0)

	if (IS_ERR(after_dashes)) {

		err = PTR_ERR(after_dashes);

		goto bug_cleanup;

	} else if (after_dashes) {

		pr_warn("%s: parameters '%s' after `--' ignored\n",

		       mod->name, after_dashes);

	}



	/* Link in to syfs. */

	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);

kernel/params.c

+14 −11
Original line number Diff line number Diff line
@@ -177,7 +177,7 @@ static char *next_arg(char *args, char **param, char **val) 
}



/* Args looks like "foo=bar,bar2 baz=fuz wiz". */

int parse_args(const char *doing,

char *parse_args(const char *doing,

		 char *args,

		 const struct kernel_param *params,

		 unsigned num,
@@ -198,6 +198,9 @@ int parse_args(const char *doing, 
		int irq_was_disabled;



		args = next_arg(args, &param, &val);

		/* Stop at -- */

		if (!val && strcmp(param, "--") == 0)

			return args;

		irq_was_disabled = irqs_disabled();

		ret = parse_one(param, val, doing, params, num,

				min_level, max_level, unknown);
@@ -208,22 +211,22 @@ int parse_args(const char *doing, 
		switch (ret) {

		case -ENOENT:

			pr_err("%s: Unknown parameter `%s'\n", doing, param);

			return ret;

			return ERR_PTR(ret);

		case -ENOSPC:

			pr_err("%s: `%s' too large for parameter `%s'\n",

			       doing, val ?: "", param);

			return ret;

			return ERR_PTR(ret);

		case 0:

			break;

		default:

			pr_err("%s: `%s' invalid for parameter `%s'\n",

			       doing, val ?: "", param);

			return ret;

			return ERR_PTR(ret);

		}

	}



	/* All parsed OK. */

	return 0;

	return NULL;

}



/* Lazy bastard, eh? */

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