[PATCH 1/8] module: add extra argument for parse_params() callback

Dmitry Torokhov
2015-03-30T23:20:28Z

From: "Luis R. Rodriguez" <mcgrof@suse.com>

This adds an extra argument onto parse_params() to be used
as a way to make the unused callback a bit more useful and
generic by allowing the caller to pass on a data structure
of its choice. An example use case is to allow us to easily
make module parameters for every module which we will do
next.

@ parse @
identifier name, args, params, num, level_min, level_max;
identifier unknown, param, val, doing;
type s16;
@@
extern char *parse_args(const char *name,
char *args,
const struct kernel_param *params,
unsigned num,
s16 level_min,
s16 level_max,
+ void *arg,
int (*unknown)(char *param, char *val,
const char *doing
+ , void *arg
));

@ parse_mod @
identifier name, args, params, num, level_min, level_max;
identifier unknown, param, val, doing;
type s16;
@@
char *parse_args(const char *name,
char *args,
const struct kernel_param *params,
unsigned num,
s16 level_min,
s16 level_max,
+ void *arg,
int (*unknown)(char *param, char *val,
const char *doing
+ , void *arg
))
{
...
}

@ parse_args_found @
expression R, E1, E2, E3, E4, E5, E6;
identifier func;
@@

(
R =
parse_args(E1, E2, E3, E4, E5, E6,
+ NULL,
func);
|
R =
parse_args(E1, E2, E3, E4, E5, E6,
+ NULL,
&func);
|
R =
parse_args(E1, E2, E3, E4, E5, E6,
+ NULL,
NULL);
|
parse_args(E1, E2, E3, E4, E5, E6,
+ NULL,
func);
|
parse_args(E1, E2, E3, E4, E5, E6,
+ NULL,
&func);
|
parse_args(E1, E2, E3, E4, E5, E6,
+ NULL,
NULL);
)

@ parse_args_unused depends on parse_args_found @
identifier parse_args_found.func;
@@

int func(char *param, char *val, const char *unused
+ , void *arg
)
{
...
}

@ mod_unused depends on parse_args_found @
identifier parse_args_found.func;
expression A1, A2, A3;
@@

- func(A1, A2, A3);
+ func(A1, A2, A3, NULL);

Generated-by: Coccinelle SmPL
Cc: cocci@systeme.lip6.fr
Cc: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Ewan Milne <emilne@redhat.com>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
---
arch/powerpc/mm/hugetlbpage.c | 4 ++--
include/linux/moduleparam.h | 3 ++-
init/main.c | 25 +++++++++++++++----------
kernel/module.c | 6 ++++--
kernel/params.c | 11 +++++++----
lib/dynamic_debug.c | 4 ++--
6 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 7e408bf..a444c23 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -336,7 +336,7 @@ int alloc_bootmem_huge_page(struct hstate *hstate)
unsigned long gpage_npages[MMU_PAGE_COUNT];

static int __init do_gpage_early_setup(char *param, char *val,
- const char *unused)
+ const char *unused, void *arg)
{
static phys_addr_t size;
unsigned long npages;
@@ -385,7 +385,7 @@ void __init reserve_hugetlb_gpages(void)

strlcpy(cmdline, boot_command_line, COMMAND_LINE_SIZE);
parse_args("hugetlb gpages", cmdline, NULL, 0, 0, 0,
- &do_gpage_early_setup);
+ NULL, &do_gpage_early_setup);

/*
* Walk gpage list in reverse, allocating larger page sizes first.
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 1c9effa..1392370 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -357,8 +357,9 @@ extern char *parse_args(const char *name,
unsigned num,
s16 level_min,
s16 level_max,
+ void *arg,
int (*unknown)(char *param, char *val,
- const char *doing));
+ const char *doing, void *arg));

/* Called by module remove. */
#ifdef CONFIG_SYSFS
diff --git a/init/main.c b/init/main.c
index 739a677..b36373a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -235,7 +235,8 @@ static int __init loglevel(char *str)
early_param("loglevel", loglevel);

/* Change NUL term back to "=", to make "param" the whole string. */
-static int __init repair_env_string(char *param, char *val, const char *unused)
+static int __init repair_env_string(char *param, char *val,
+ const char *unused, void *arg)
{
if (val) {
/* param=val or param="val"? */
@@ -252,14 +253,15 @@ static int __init repair_env_string(char *param, char *val, const char *unused)
}

/* Anything after -- gets handed straight to init. */
-static int __init set_init_arg(char *param, char *val, const char *unused)
+static int __init set_init_arg(char *param, char *val,
+ const char *unused, void *arg)
{
unsigned int i;

if (panic_later)
return 0;

- repair_env_string(param, val, unused);
+ repair_env_string(param, val, unused, NULL);

for (i = 0; argv_init[i]; i++) {
if (i == MAX_INIT_ARGS) {
@@ -276,9 +278,10 @@ static int __init set_init_arg(char *param, char *val, const char *unused)
* Unknown boot options get handed to init, unless they look like
* unused parameters (modprobe will find them in /proc/cmdline).
*/
-static int __init unknown_bootoption(char *param, char *val, const char *unused)
+static int __init unknown_bootoption(char *param, char *val,
+ const char *unused, void *arg)
{
- repair_env_string(param, val, unused);
+ repair_env_string(param, val, unused, NULL);

/* Handle obsolete-style parameters */
if (obsolete_checksetup(param))
@@ -409,7 +412,8 @@ static noinline void __init_refok rest_init(void)
}

/* Check for early params. */
-static int __init do_early_param(char *param, char *val, const char *unused)
+static int __init do_early_param(char *param, char *val,
+ const char *unused, void *arg)
{
const struct obs_kernel_param *p;

@@ -428,7 +432,8 @@ static int __init do_early_param(char *param, char *val, const char *unused)

void __init parse_early_options(char *cmdline)
{
- parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
+ parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
+ do_early_param);
}

/* Arch code calls this early on, or if not, just before other parsing. */
@@ -534,10 +539,10 @@ asmlinkage __visible void __init start_kernel(void)
after_dashes = parse_args("Booting kernel",
static_command_line, __start___param,
__stop___param - __start___param,
- -1, -1, &unknown_bootoption);
+ -1, -1, NULL, &unknown_bootoption);
if (!IS_ERR_OR_NULL(after_dashes))
parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
- set_init_arg);
+ NULL, set_init_arg);

jump_label_init();

@@ -846,7 +851,7 @@ static void __init do_initcall_level(int level)
initcall_command_line, __start___param,
__stop___param - __start___param,
level, level,
- &repair_env_string);
+ NULL, &repair_env_string);

for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
do_one_initcall(*fn);
diff --git a/kernel/module.c b/kernel/module.c
index 58bee45..05f6931 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3217,7 +3217,8 @@ out:
return err;
}

-static int unknown_module_param_cb(char *param, char *val, const char *modname)
+static int unknown_module_param_cb(char *param, char *val, const char *modname,
+ void *arg)
{
/* Check for magic 'dyndbg' arg */
int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
@@ -3322,7 +3323,8 @@ static int load_module(struct load_info *info, const char __user *uargs,

/* Module is ready to execute: parsing args may do that. */
after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
- -32768, 32767, unknown_module_param_cb);
+ -32768, 32767, NULL,
+ unknown_module_param_cb);
if (IS_ERR(after_dashes)) {
err = PTR_ERR(after_dashes);
goto bug_cleanup;
diff --git a/kernel/params.c b/kernel/params.c
index 728e05b..91b76d2 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -100,8 +100,9 @@ static int parse_one(char *param,
unsigned num_params,
s16 min_level,
s16 max_level,
+ void *arg,
int (*handle_unknown)(char *param, char *val,
- const char *doing))
+ const char *doing, void *arg))
{
unsigned int i;
int err;
@@ -128,7 +129,7 @@ static int parse_one(char *param,

if (handle_unknown) {
pr_debug("doing %s: %s='%s'\n", doing, param, val);
- return handle_unknown(param, val, doing);
+ return handle_unknown(param, val, doing, arg);
}

pr_debug("Unknown argument '%s'\n", param);
@@ -194,7 +195,9 @@ char *parse_args(const char *doing,
unsigned num,
s16 min_level,
s16 max_level,
- int (*unknown)(char *param, char *val, const char *doing))
+ void *arg,
+ int (*unknown)(char *param, char *val,
+ const char *doing, void *arg))
{
char *param, *val;

@@ -214,7 +217,7 @@ char *parse_args(const char *doing,
return args;
irq_was_disabled = irqs_disabled();
ret = parse_one(param, val, doing, params, num,
- min_level, max_level, unknown);
+ min_level, max_level, arg, unknown);
if (irq_was_disabled && !irqs_disabled())
pr_warn("%s: option '%s' enabled irq's!\n",
doing, param);
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index d8f3d31..e491e02 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -887,7 +887,7 @@ static int ddebug_dyndbg_param_cb(char *param, char *val,

/* handle both dyndbg and $module.dyndbg params at boot */
static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
- const char *unused)
+ const char *unused, void *arg)
{
vpr_info("%s=\"%s\"\n", param, val);
return ddebug_dyndbg_param_cb(param, val, NULL, 0);
@@ -1028,7 +1028,7 @@ static int __init dynamic_debug_init(void)
*/
cmdline = kstrdup(saved_command_line, GFP_KERNEL);
parse_args("dyndbg params", cmdline, NULL,
- 0, 0, 0, &ddebug_dyndbg_boot_param_cb);
+ 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
kfree(cmdline);
return 0;

--
2.2.0.rc0.207.ga3a616c