module: add extra argument for parse_params() callback

Author: 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 
Cc: Arjan van de Ven 
Cc: Greg Kroah-Hartman 
Cc: Rusty Russell 
Cc: Christoph Hellwig 
Cc: Felipe Contreras 
Cc: Ewan Milne 
Cc: Jean Delvare 
Cc: Hannes Reinecke 
Cc: Jani Nikula 
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Tejun Heo 
Acked-by: Rusty Russell 
Signed-off-by: Luis R. Rodriguez 
Signed-off-by: Greg Kroah-Hartman

---
 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 0ce968b..d230158 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 2115055..edcb134 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))
@@ -410,7 +413,8 @@ 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;
 
@@ -429,7 +433,8 @@ 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. */
@@ -535,10 +540,10 @@ 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();
 
@@ -847,7 +852,7 @@ 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 42a1d2a..24d1f31 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3237,7 +3237,8 @@ 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);
@@ -3342,7 +3343,8 @@ 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 a22d6a7..30288c1 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;

--- 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 0ce968b..d230158 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 2115055..edcb134 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)) @@ -410,7 +413,8 @@ 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; @@ -429,7 +433,8 @@ 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. */ @@ -535,10 +540,10 @@ 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(); @@ -847,7 +852,7 @@ 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 42a1d2a..24d1f31 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3237,7 +3237,8 @@ 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); @@ -3342,7 +3343,8 @@ 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 a22d6a7..30288c1 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;

module: add extra argument for parse_params() callback

qlambert

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