[patch 15/69] test_sysctl: simplify subdirectory registration with register_sysctl()

[Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>]

From: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Subject: test_sysctl: simplify subdirectory registration with register_sysctl()

There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under.  Simplify this by using
register_sysctl() and specifying the directory path directly.

// pycocci sysctl-subdir-register-sysctl-simplify.cocci lib/test_sysctl.c

@c1@
expression E1;
identifier subdir, sysctls;
@@

static struct ctl_table subdir[] = {
	{
		.procname = E1,
		.maxlen = 0,
		.mode = 0555,
		.child = sysctls,
	},
	{ }
};

@c2@
identifier c1.subdir;

expression E2;
identifier base;
@@

static struct ctl_table base[] = {
	{
		.procname = E2,
		.maxlen = 0,
		.mode = 0555,
		.child = subdir,
	},
	{ }
};

@c3@
identifier c2.base;
identifier header;
@@

header = register_sysctl_table(base);

@r1 depends on c1 && c2 && c3@
expression c1.E1;
identifier c1.subdir, c1.sysctls;
@@

-static struct ctl_table subdir[] = {
-	{
-		.procname = E1,
-		.maxlen = 0,
-		.mode = 0555,
-		.child = sysctls,
-	},
-	{ }
-};

@r2 depends on c1 && c2 && c3@
identifier c1.subdir;

expression c2.E2;
identifier c2.base;
@@
-static struct ctl_table base[] = {
-	{
-		.procname = E2,
-		.maxlen = 0,
-		.mode = 0555,
-		.child = subdir,
-	},
-	{ }
-};

@initialize:python@
@@

def make_my_fresh_expression(s1, s2):
  return '"' + s1.strip('"') + "/" + s2.strip('"') + '"'

@r3 depends on c1 && c2 && c3@
expression c1.E1;
identifier c1.sysctls;
expression c2.E2;
identifier c2.base;
identifier c3.header;
fresh identifier E3 = script:python(E2, E1) { make_my_fresh_expression(E2, E1) };
@@

header =
-register_sysctl_table(base);
+register_sysctl(E3, sysctls);

Generated-by: Coccinelle SmPL
Link: https://lkml.kernel.org/r/20211123202422.819032-6-mcgrof@xxxxxxxxxx
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Amir Goldstein <amir73il@xxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Antti Palosaari <crope@xxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: Clemens Ladisch <clemens@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Iurii Zaikin <yzaikin@xxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Julia Lawall <julia.lawall@xxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Lukas Middendorf <kernel@xxxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Paul Turner <pjt@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Phillip Potter <phil@xxxxxxxxxxxxxxxx>
Cc: Qing Wang <wangqing@xxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Cc: Sebastian Reichel <sre@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Stephen Kitt <steve@xxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
Cc: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
Cc: James E.J. Bottomley <jejb@xxxxxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: John Ogness <john.ogness@xxxxxxxxxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 lib/test_sysctl.c |   22 +---------------------
 1 file changed, 1 insertion(+), 21 deletions(-)

--- a/lib/test_sysctl.c~test_sysctl-simplify-subdirectory-registration-with-register_sysctl
+++ a/lib/test_sysctl.c
@@ -128,26 +128,6 @@ static struct ctl_table test_table[] = {
 	{ }
 };
 
-static struct ctl_table test_sysctl_table[] = {
-	{
-		.procname	= "test_sysctl",
-		.maxlen		= 0,
-		.mode		= 0555,
-		.child		= test_table,
-	},
-	{ }
-};
-
-static struct ctl_table test_sysctl_root_table[] = {
-	{
-		.procname	= "debug",
-		.maxlen		= 0,
-		.mode		= 0555,
-		.child		= test_sysctl_table,
-	},
-	{ }
-};
-
 static struct ctl_table_header *test_sysctl_header;
 
 static int __init test_sysctl_init(void)
@@ -155,7 +135,7 @@ static int __init test_sysctl_init(void)
 	test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL);
 	if (!test_data.bitmap_0001)
 		return -ENOMEM;
-	test_sysctl_header = register_sysctl_table(test_sysctl_root_table);
+	test_sysctl_header = register_sysctl("debug/test_sysctl", test_table);
 	if (!test_sysctl_header) {
 		kfree(test_data.bitmap_0001);
 		return -ENOMEM;
_