Refactor kernel command line parsing.

build-aux/iso-grub-cfg.sh

@@ -218,9 +218,9 @@ menuentry() {
   printf "}\n"
 }
 
-menuentry "live environment" ''
-menuentry "new installation" '--init="/sbin/init --target=sysinstall"'
-menuentry "upgrade existing installation" '--init="/sbin/init --target=sysupgrade"'
+menuentry "live environment" '-- /sbin/init'
+menuentry "new installation" '-- /sbin/init --target=sysinstall'
+menuentry "upgrade existing installation" '-- /sbin/init --target=sysupgrade'
 
 echo
 cat << EOF

init/init.8

@@ -7,6 +7,8 @@
 .Sh SYNOPSIS
 .Nm init
 .Op Fl \-target Ns "=" Ns Ar init-target
+.Op Fl \-
+.Op Ar chain-init ...
 .Sh DESCRIPTION
 .Nm
 is the first program run after system startup and is responsible for
@@ -93,7 +95,8 @@ The
 target mounts the root filesystem as in
 .Pa /etc/fstab
 (see
-.Xr fstab 5) and runs the next
+.Xr fstab 5 )
+and runs the next
 .Nm
 program.
 This is used by
@@ -113,7 +116,9 @@ filesystem directory is bound at
 .Pp
 Finally the
 .Pa /sbin/init
-program of the target root filesystem is run inside a chroot.
+program (or
+.Ar chain-init
+if specified) of the target root filesystem is run inside a chroot.
 .Ss Configuration
 Once the
 .Nm

init/init.c

@@ -813,8 +813,10 @@ static void niht(void)
 	}
 }
 
-static int init(const char* target)
+static int init(int argc, char** argv, const char* target)
 {
+	if ( 1 < argc )
+		fatal("unexpected extra operand: %s", argv[1]);
 	init_early();
 	set_hostname();
 	set_kblayout();
@@ -938,8 +940,10 @@ static int init(const char* target)
 	return result;
 }
 
-static int init_chain(const char* target)
+static int init_chain(int argc, char** argv, const char* target)
 {
+	int next_argc = argc - 1;
+	char** next_argv = argv + 1;
 	init_early();
 	prepare_block_devices();
 	load_fstab();
@@ -986,17 +990,27 @@ static int init_chain(const char* target)
 			if ( chdir("/") < 0 )
 				fatal("chdir: %s: %m", chain_location);
 			unsetenv("INIT_PID");
+			const char* program = next_argv[0];
 			if ( !strcmp(target, "chain-merge") )
 			{
-				const char* argv[] = { "init", "--target=merge", NULL };
-				execv("/sysmerge/sbin/init", (char* const*) argv);
-				fatal("Failed to load automatic update chain init: %s: %m", argv[0]);
+				if ( next_argc < 1 )
+				{
+					program = "/sysmerge/sbin/init";
+					next_argv = (char*[]) { "init", "--target=merge", NULL };
+				}
+				execvp(program, (char* const*) next_argv);
+				fatal("Failed to load automatic update chain init: %s: %m",
+				      next_argv[0]);
 			}
 			else
 			{
-				const char* argv[] = { "init", NULL };
-				execv("/sbin/init", (char* const*) argv);
-				fatal("Failed to load chain init: %s: %m", argv[0]);
+				if ( next_argc < 1 )
+				{
+					program = "/sbin/init";
+					next_argv = (char*[]) { "init", NULL };
+				}
+				execvp(program, (char* const*) next_argv);
+				fatal("Failed to load chain init: %s: %m", next_argv[0]);
 			}
 		}
 		int status;
@@ -1102,11 +1116,11 @@ int main(int argc, char* argv[])
 	     !strcmp(target, "sysinstall") ||
 	     !strcmp(target, "sysupgrade") ||
 	     !strcmp(target, "merge") )
-		return init(target);
+		return init(argc, argv, target);
 
 	if ( !strcmp(target, "chain") ||
 	     !strcmp(target, "chain-merge") )
-		return init_chain(target);
+		return init_chain(argc, argv, target);
 
 	fatal("Unknown initialization target `%s'", target);
 }

kernel/kernel.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012, 2013, 2014, 2015, 2016 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2011-2017 Jonas 'Sortie' Termansen.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -108,8 +108,9 @@ static void BootThread(void* user);
 static void InitThread(void* user);
 static void SystemIdleThread(void* user);
 
+static int argc;
+static char** argv;
 static multiboot_info_t* bootinfo;
-static char* init_cmdline;
 
 static char* cmdline_tokenize(char** saved)
 {
@@ -156,6 +157,19 @@ static char* cmdline_tokenize(char** saved)
 	return data;
 }
 
+static void compact_arguments(int* argc, char*** argv)
+{
+	for ( int i = 0; i < *argc; i++ )
+	{
+		while ( i < *argc && !(*argv)[i] )
+		{
+			for ( int n = i; n < *argc; n++ )
+				(*argv)[n] = (*argv)[n+1];
+			(*argc)--;
+		}
+	}
+}
+
 extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo_p)
 {
 	(void) magic;
@@ -235,59 +249,65 @@ extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo_p)
 		FreeKernelAddress(&alloc);
 	}
 
-	bool no_random_seed = false;
+	int argmax = 1;
+	argv = new char*[argmax + 1];
+	if ( !argv )
+		Panic("Failed to allocate kernel command line");
+
 	char* arg_saved = cmdline;
 	char* arg;
-	struct kernel_option
-	{
-		const char* name;
-		bool has_parameter;
-	} options[] =
-	{
-		{ "--init", true },
-		{ "--no-random-seed", false },
-	};
-	size_t options_count = sizeof(options) / sizeof(options[0]);
 	while ( (arg = cmdline_tokenize(&arg_saved)) )
 	{
-		struct kernel_option* option = NULL;
-		char* parameter = NULL;
-		for ( size_t i = 0; i < options_count; i++ )
+		if ( argc == argmax )
 		{
-			struct kernel_option* candidate = &options[i];
-			if ( candidate->has_parameter )
+			argmax = argmax ? 2 * argmax : 8;
+			char** new_argv = new char*[argmax + 1];
+			if ( !new_argv )
+				Panic("Failed to allocate kernel command line");
+			for ( int i = 0; i < argc; i++ )
+				new_argv[i] = argv[i];
+			argv = new_argv;
+		}
+		argv[argc++] = arg;
+	}
+	argv[argc] = NULL;
+
+	bool no_random_seed = false;
+	for ( int i = 0; i < argc; i++ )
 	{
-				size_t name_length = strlen(candidate->name);
-				if ( strncmp(arg, candidate->name, name_length) != 0 )
+		const char* arg = argv[i];
+		if ( arg[0] != '-' || !arg[1] )
 			continue;
-				if ( arg[name_length] == '=' )
-					parameter = arg + name_length + 1;
-				else if ( !arg[name_length] )
+		argv[i] = NULL;
+		if ( !strcmp(arg, "--") )
+			break;
+		if ( arg[1] != '-' )
 		{
-					if ( !(parameter = cmdline_tokenize(&arg_saved)) )
+			char c;
+			while ( (c = *++arg) ) switch ( c )
 			{
+			default:
 				Log::PrintF("\r\e[J");
-						Log::PrintF("kernel: fatal: option '%s' requires an argument\n", arg);
+				Log::PrintF("kernel: fatal: unknown option -- '%c'\n", c);
 				HaltKernel();
 			}
 		}
+		else if ( !strcmp(arg, "--no-random-seed") )
+			no_random_seed = true;
 		else
-					continue;
-			}
-			else if ( strcmp(arg, candidate->name) != 0 )
-				continue;
-			option = candidate;
-		}
-		if ( !option )
 		{
 			Log::PrintF("\r\e[J");
 			Log::PrintF("kernel: fatal: unrecognized option '%s'\n", arg);
 			HaltKernel();
 		}
-		if ( !strcmp(option->name, "--init") )
-			init_cmdline = parameter;
-		else if ( !strcmp(option->name, "--no-random-seed") )
-			no_random_seed = true;
+	}
+
+	compact_arguments(&argc, &argv);
+
+	if ( argc == 0 )
+	{
+		argv[argc++] = (char*) "/sbin/init";
+		argv[argc] = NULL;
 	}
 
 	// Initialize the interrupt handler table and enable interrupts.
@@ -684,33 +704,6 @@ static void InitThread(void* /*user*/)
 
 	dtable.Reset();
 
-	static char default_init_cmdline[] = "/sbin/init";
-	if ( !init_cmdline )
-		init_cmdline = default_init_cmdline;
-
-	char* init_cmdline_dup = strdup(init_cmdline);
-	if ( !init_cmdline_dup )
-		PanicF("strdup: %m");
-	size_t init_cmdline_tokens = 0;
-	char* saved = init_cmdline_dup;
-	char* arg;
-	while ( (arg = cmdline_tokenize(&saved)) )
-		init_cmdline_tokens++;
-	free(init_cmdline_dup);
-
-	if ( INT_MAX - 1 < init_cmdline_tokens )
-		Panic("Too many tokens in init command line");
-
-	int argc = init_cmdline_tokens;
-	char** argv = new char*[argc + 1];
-	if ( !argv )
-		PanicF("operator new: %m");
-	saved = init_cmdline;
-	for ( int i = 0; i <= argc; i++ )
-		argv[i] = cmdline_tokenize(&saved);
-
-	if ( argc == 0 )
-		Panic("No init specified");
 	const char* initpath = argv[0];
 	Ref<Descriptor> init = root->open(&ctx, initpath, O_EXEC | O_READ);
 	if ( !init )

share/man/man7/kernel.7

@@ -6,7 +6,9 @@
 .Nd operating system kernel
 .Sh SYNOPSIS
 .Pa /boot/sortix.bin
-.Op Fl \-init Ns "=" Ns Ar init-command-line
+.Op Fl \-no-random-seed
+.Op Fl \-
+.Op Ar init ...
 .Sh DESCRIPTION
 .Pa /boot/sortix.bin
 is the operating system
@@ -19,22 +21,28 @@ compatible executable loaded by the bootloader along with a companion
 .Xr initrd 7
 that contains a userland.
 .Pp
-The kernel extracts the initrd into the initial kernel memory root filesystem
-and executes
+The kernel extracts the initrd into the initial kernel memory root filesystem.
+The specified
+.Ar init
+program is invoked with the given arguments, defaulting to the
 .Xr init 8
-as
-.Pa /sbin/init .
-The computer is powered off if this process exits 0, rebooted if it exits 1,
+at
+.Pa /sbin/init
+if
+.Ar init
+is not specified.
+If the
+.Nm init
+is to receive any argument starting with a dash, first pass the
+.Fl \-
+delimiter to stop kernel option parsing.
+The computer is powered off if the
+.Nm init
+process exits 0, rebooted if it exits 1,
 halted if it exits 2, and paniced otherwise.
 .Pp
 The options are as follows:
 .Bl -tag -width "12345678"
-.It Fl \-init Ns "=" Ns Ar init-command-line
-The
-.Ar init-command-line
-argument is split into tokens and used as the command line to invoke the
-specified
-.Xr init 8 .
 .It Fl \-no-random-seed
 Don't warn if no random seed file was loaded by the bootloader (usually from
 .Pa /boot/random.seed ) .