[patch 26/69] sysctl: share unsigned long const values

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Subject: sysctl: share unsigned long const values

Provide a way to share unsigned long values.  This will allow others to
not have to re-invent these values.

Link: https://lkml.kernel.org/r/20211124231435.1445213-9-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: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Iurii Zaikin <yzaikin@xxxxxxxxxx>
Cc: James E.J. Bottomley <jejb@xxxxxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: John Ogness <john.ogness@xxxxxxxxxxxxx>
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: Martin K. Petersen <martin.petersen@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: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Cc: Sebastian Reichel <sre@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Stephen Kitt <steve@xxxxxxx>
Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 fs/proc/proc_sysctl.c  |    3 +++
 include/linux/sysctl.h |    6 ++++++
 kernel/sysctl.c        |    9 +++------
 3 files changed, 12 insertions(+), 6 deletions(-)

--- a/fs/proc/proc_sysctl.c~sysctl-share-unsigned-long-const-values
+++ a/fs/proc/proc_sysctl.c
@@ -29,6 +29,9 @@ static const struct inode_operations pro
 const int sysctl_vals[] = { -1, 0, 1, 2, 4, 100, 200, 1000, 3000, INT_MAX };
 EXPORT_SYMBOL(sysctl_vals);
 
+const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX };
+EXPORT_SYMBOL_GPL(sysctl_long_vals);
+
 /* Support for permanently empty directories */
 
 struct ctl_table sysctl_mount_point[] = {
--- a/include/linux/sysctl.h~sysctl-share-unsigned-long-const-values
+++ a/include/linux/sysctl.h
@@ -51,6 +51,12 @@ struct ctl_dir;
 
 extern const int sysctl_vals[];
 
+#define SYSCTL_LONG_ZERO	((void *)&sysctl_long_vals[0])
+#define SYSCTL_LONG_ONE		((void *)&sysctl_long_vals[1])
+#define SYSCTL_LONG_MAX		((void *)&sysctl_long_vals[2])
+
+extern const unsigned long sysctl_long_vals[];
+
 typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer,
 		size_t *lenp, loff_t *ppos);
 
--- a/kernel/sysctl.c~sysctl-share-unsigned-long-const-values
+++ a/kernel/sysctl.c
@@ -100,9 +100,6 @@
 
 /* Constants used for minimum and  maximum */
 
-static const unsigned long zero_ul;
-static const unsigned long one_ul = 1;
-static const unsigned long long_max = LONG_MAX;
 #ifdef CONFIG_PRINTK
 static const int ten_thousand = 10000;
 #endif
@@ -2513,7 +2510,7 @@ static struct ctl_table vm_table[] = {
 		.maxlen		= sizeof(dirty_background_bytes),
 		.mode		= 0644,
 		.proc_handler	= dirty_background_bytes_handler,
-		.extra1		= (void *)&one_ul,
+		.extra1		= SYSCTL_LONG_ONE,
 	},
 	{
 		.procname	= "dirty_ratio",
@@ -2931,8 +2928,8 @@ static struct ctl_table fs_table[] = {
 		.maxlen		= sizeof(files_stat.max_files),
 		.mode		= 0644,
 		.proc_handler	= proc_doulongvec_minmax,
-		.extra1		= (void *)&zero_ul,
-		.extra2		= (void *)&long_max,
+		.extra1		= SYSCTL_LONG_ZERO,
+		.extra2		= SYSCTL_LONG_MAX,
 	},
 	{
 		.procname	= "nr_open",
_



[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux