init: fix in-place parameter modification regression

Before commit 026cee0086
("params: <level>_initcall-like kernel parameters") the __setup
parameter parsing code could modify parameter in the
static_command_line buffer and such modifications were kept. After
that commit such modifications are destroyed during per-initcall level
parameter parsing because the same static_command_line buffer is used
and only parameters for appropriate initcall level are parsed.

That change broke at least parsing "ubd" parameter in the ubd driver
when the COW file is used.

Now the separate buffer is used for per-initcall parameter parsing.

Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

init/main.c

@@ -131,6 +131,8 @@ char __initdata boot_command_line[COMMAND_LINE_SIZE];
 char *saved_command_line;
 /* Command line for parameter parsing */
 static char *static_command_line;
+/* Command line for per-initcall parameter parsing */
+static char *initcall_command_line;
 
 static char *execute_command;
 static char *ramdisk_execute_command;
@@ -347,6 +349,7 @@ static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 static void __init setup_command_line(char *command_line)
 {
 	saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
+	initcall_command_line = alloc_bootmem(strlen (boot_command_line)+1);
 	static_command_line = alloc_bootmem(strlen (command_line)+1);
 	strcpy (saved_command_line, boot_command_line);
 	strcpy (static_command_line, command_line);
@@ -744,9 +747,9 @@ static void __init do_initcall_level(int level)
 	extern const struct kernel_param __start___param[], __stop___param[];
 	initcall_t *fn;
 
-	strcpy(static_command_line, saved_command_line);
+	strcpy(initcall_command_line, saved_command_line);
 	parse_args(initcall_level_names[level],
-		   static_command_line, __start___param,
+		   initcall_command_line, __start___param,
 		   __stop___param - __start___param,
 		   level, level,
 		   &repair_env_string);