[PATCH 1/2] UBUNTU: SAUCE: add option to hand off all kernel parameters to init
Andy Whitcroft
apw at canonical.com
Thu Jun 17 09:46:47 UTC 2010
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 at canonical.com>
---
include/linux/moduleparam.h | 2 +-
init/Kconfig | 7 +++++++
init/main.c | 33 ++++++++++++++++++++++++++-------
kernel/params.c | 20 ++++++++++++++------
4 files changed, 48 insertions(+), 14 deletions(-)
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 82a9124..c425126 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -144,7 +144,7 @@ extern int parse_args(const char *name,
char *args,
struct kernel_param *params,
unsigned num,
- int (*unknown)(char *param, char *val));
+ int (*handle)(char *param, char *val, int known));
/* Called by module remove. */
#ifdef CONFIG_SYSFS
diff --git a/init/Kconfig b/init/Kconfig
index ce68380..fc438f8 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -75,6 +75,13 @@ 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 de016bc..1b1d50e 100644
--- a/init/main.c
+++ b/init/main.c
@@ -107,6 +107,11 @@ 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. */
@@ -265,10 +270,11 @@ static int __init loglevel(char *str)
early_param("loglevel", loglevel);
/*
- * 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)
+static int __init pass_bootoption(char *param, char *val, int all)
{
/* Change NUL term back to "=", to make "param" the whole string. */
if (val) {
@@ -284,11 +290,11 @@ static int __init unknown_bootoption(char *param, char *val)
}
/* 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)
@@ -319,6 +325,16 @@ static int __init unknown_bootoption(char *param, char *val)
}
return 0;
}
+static int __init pass_unknown_bootoptions(char *param, char *val, int known)
+{
+ if (known)
+ return 0;
+ return pass_bootoption(param, val, 0);
+}
+static int __init pass_all_bootoptions(char *param, char *val, int known)
+{
+ return pass_bootoption(param, val, 1);
+}
#ifdef CONFIG_DEBUG_PAGEALLOC
int __read_mostly debug_pagealloc_enabled = 0;
@@ -450,10 +466,13 @@ static noinline void __init_refok rest_init(void)
}
/* Check for early params. */
-static int __init do_early_param(char *param, char *val)
+static int __init do_early_param(char *param, char *val, int known)
{
struct obs_kernel_param *p;
+ if (known)
+ return 0;
+
for (p = __setup_start; p < __setup_end; p++) {
if ((p->early && strcmp(param, p->str) == 0) ||
(strcmp(param, "console") == 0 &&
@@ -574,7 +593,7 @@ asmlinkage void __init start_kernel(void)
parse_early_param();
parse_args("Booting kernel", static_command_line, __start___param,
__stop___param - __start___param,
- &unknown_bootoption);
+ &INIT_PASS_FUNCTION);
/*
* These use large bootmem allocations and must precede
* kmem_cache_init()
diff --git a/kernel/params.c b/kernel/params.c
index 0b30ecd..0267fd1 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -51,22 +51,30 @@ static int parse_one(char *param,
char *val,
struct kernel_param *params,
unsigned num_params,
- int (*handle_unknown)(char *param, char *val))
+ int (*handle_arg)(char *param, char *val, int known))
{
unsigned int i;
/* Find parameter */
for (i = 0; i < num_params; i++) {
if (parameq(param, params[i].name)) {
+ if (handle_arg) {
+ int ret;
+ DEBUGP("Valid argument: calling %p\n",
+ handle_arg);
+ ret = handle_arg(param, val, 1);
+ if (ret)
+ return ret;
+ }
DEBUGP("They are equal! Calling %p\n",
params[i].set);
return params[i].set(val, ¶ms[i]);
}
}
- if (handle_unknown) {
- DEBUGP("Unknown argument: calling %p\n", handle_unknown);
- return handle_unknown(param, val);
+ if (handle_arg) {
+ DEBUGP("Unknown argument: calling %p\n", handle_arg);
+ return handle_arg(param, val, 0);
}
DEBUGP("Unknown argument `%s'\n", param);
@@ -130,7 +138,7 @@ int parse_args(const char *name,
char *args,
struct kernel_param *params,
unsigned num,
- int (*unknown)(char *param, char *val))
+ int (*handle_arg)(char *param, char *val, int arg))
{
char *param, *val;
@@ -145,7 +153,7 @@ int parse_args(const char *name,
args = next_arg(args, ¶m, &val);
irq_was_disabled = irqs_disabled();
- ret = parse_one(param, val, params, num, unknown);
+ ret = parse_one(param, val, params, num, handle_arg);
if (irq_was_disabled && !irqs_disabled()) {
printk(KERN_WARNING "parse_args(): option '%s' enabled "
"irq's!\n", param);
--
1.7.0.4
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