[patch 01/26] Dynamic kernel command-line - common

Bernhard Walle
2007-01-18T13:04:55Z

[-- Attachment #1: dynamic-kernel-command-line-common.diff --]
[-- Type: text/plain, Size: 4166 bytes --]

1. Rename saved_command_line into boot_command_line, mark
as init disposable.
2. Add dynamic allocated saved_command_line.
3. Add dynamic allocated static_command_line.
4. During startup copy:
boot_command_line into saved_command_line.
arch command_line into static_command_line.
5. Parse static_command_line and not
arch command_line, so arch command_line may
be freed.

Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>

---
include/linux/init.h | 5 +++--
init/main.c | 29 ++++++++++++++++++++++++-----
2 files changed, 27 insertions(+), 7 deletions(-)

Index: linux-2.6.20-rc4-mm1/include/linux/init.h
===================================================================
--- linux-2.6.20-rc4-mm1.orig/include/linux/init.h
+++ linux-2.6.20-rc4-mm1/include/linux/init.h
@@ -67,7 +67,8 @@ extern initcall_t __con_initcall_start[]
extern initcall_t __security_initcall_start[], __security_initcall_end[];

/* Defined in init/main.c */
-extern char saved_command_line[];
+extern char __initdata boot_command_line[];
+extern char *saved_command_line;
extern unsigned int reset_devices;

/* used by init/main.c */
@@ -164,7 +165,7 @@ struct obs_kernel_param {
#define early_param(str, fn) \
__setup_param(str, fn, fn, 1)

-/* Relies on saved_command_line being set */
+/* Relies on boot_command_line being set */
void __init parse_early_param(void);
#endif /* __ASSEMBLY__ */

Index: linux-2.6.20-rc4-mm1/init/main.c
===================================================================
--- linux-2.6.20-rc4-mm1.orig/init/main.c
+++ linux-2.6.20-rc4-mm1/init/main.c
@@ -122,8 +122,12 @@ extern void time_init(void);
void (*late_time_init)(void);
extern void softirq_init(void);

-/* Untouched command line (eg. for /proc) saved by arch-specific code. */
-char saved_command_line[COMMAND_LINE_SIZE];
+/* Untouched command line saved by arch-specific code. */
+char __initdata boot_command_line[COMMAND_LINE_SIZE];
+/* Untouched saved command line (eg. for /proc) */
+char *saved_command_line;
+/* Command line for parameter parsing */
+static char *static_command_line;

static char *execute_command;
static char *ramdisk_execute_command;
@@ -406,6 +410,20 @@ static void __init smp_init(void)
#endif

/*
+ * We need to store the untouched command line for future reference.
+ * We also need to store the touched command line since the parameter
+ * parsing is performed in place, and we should allow a component to
+ * store reference of name/value for future reference.
+ */
+static void __init setup_command_line(char *command_line)
+{
+ saved_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);
+}
+
+/*
* We need to finalize in a non-__init function or else race conditions
* between the root thread and the init thread may cause start_kernel to
* be reaped by free_initmem before the root thread has proceeded to
@@ -459,7 +477,7 @@ void __init parse_early_param(void)
return;

/* All fall through to do_early_param. */
- strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE);
+ strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
done = 1;
}
@@ -509,6 +527,7 @@ asmlinkage void __init start_kernel(void
printk(KERN_NOTICE);
printk(linux_banner);
setup_arch(&command_line);
+ setup_command_line(command_line);
unwind_setup();
setup_per_cpu_areas();
smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
@@ -526,9 +545,9 @@ asmlinkage void __init start_kernel(void
preempt_disable();
build_all_zonelists();
page_alloc_init();
- printk(KERN_NOTICE "Kernel command line: %s\n", saved_command_line);
+ printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
parse_early_param();
- parse_args("Booting kernel", command_line, __start___param,
+ parse_args("Booting kernel", static_command_line, __start___param,
__stop___param - __start___param,
&unknown_bootoption);
if (!irqs_disabled()) {

--