[PATCH 5.15 040/201] sysctl: move some boundary constants from sysctl.c to sysctl_vals

From: Greg Kroah-Hartman
Date: Wed Jul 27 2022 - 13:07:40 EST


From: Xiaoming Ni <nixiaoming@xxxxxxxxxx>

[ Upstream commit 78e36f3b0dae586f623c4a37ec5eb5496f5abbe1 ]

sysctl has helpers which let us specify boundary values for a min or max
int value. Since these are used for a boundary check only they don't
change, so move these variables to sysctl_vals to avoid adding duplicate
variables. This will help with our cleanup of kernel/sysctl.c.

[akpm@xxxxxxxxxxxxxxxxxxxx: update it for "mm/pagealloc: sysctl: change watermark_scale_factor max limit to 30%"]
[mcgrof@xxxxxxxxxx: major rebase]

Link: https://lkml.kernel.org/r/20211123202347.818157-3-mcgrof@xxxxxxxxxx
Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Amir Goldstein <amir73il@xxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Iurii Zaikin <yzaikin@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Paul Turner <pjt@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Qing Wang <wangqing@xxxxxxxx>
Cc: Sebastian Reichel <sre@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Stephen Kitt <steve@xxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Antti Palosaari <crope@xxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Clemens Ladisch <clemens@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Julia Lawall <julia.lawall@xxxxxxxx>
Cc: Lukas Middendorf <kernel@xxxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Phillip Potter <phil@xxxxxxxxxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
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>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/proc/proc_sysctl.c | 2 +-
include/linux/sysctl.h | 13 +++++++++---
kernel/sysctl.c | 45 ++++++++++++++++++------------------------
3 files changed, 30 insertions(+), 30 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 5d66faecd4ef..013fc5931bc3 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -25,7 +25,7 @@ static const struct file_operations proc_sys_dir_file_operations;
static const struct inode_operations proc_sys_dir_operations;

/* shared constants to be used in various sysctls */
-const int sysctl_vals[] = { 0, 1, INT_MAX };
+const int sysctl_vals[] = { -1, 0, 1, 2, 4, 100, 200, 1000, 3000, INT_MAX };
EXPORT_SYMBOL(sysctl_vals);

/* Support for permanently empty directories */
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 1fa2b69c6fc3..fa372b4c2313 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -38,9 +38,16 @@ struct ctl_table_header;
struct ctl_dir;

/* Keep the same order as in fs/proc/proc_sysctl.c */
-#define SYSCTL_ZERO ((void *)&sysctl_vals[0])
-#define SYSCTL_ONE ((void *)&sysctl_vals[1])
-#define SYSCTL_INT_MAX ((void *)&sysctl_vals[2])
+#define SYSCTL_NEG_ONE ((void *)&sysctl_vals[0])
+#define SYSCTL_ZERO ((void *)&sysctl_vals[1])
+#define SYSCTL_ONE ((void *)&sysctl_vals[2])
+#define SYSCTL_TWO ((void *)&sysctl_vals[3])
+#define SYSCTL_FOUR ((void *)&sysctl_vals[4])
+#define SYSCTL_ONE_HUNDRED ((void *)&sysctl_vals[5])
+#define SYSCTL_TWO_HUNDRED ((void *)&sysctl_vals[6])
+#define SYSCTL_ONE_THOUSAND ((void *)&sysctl_vals[7])
+#define SYSCTL_THREE_THOUSAND ((void *)&sysctl_vals[8])
+#define SYSCTL_INT_MAX ((void *)&sysctl_vals[9])

extern const int sysctl_vals[];

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 347a90a878b3..23c08bf3db58 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -113,16 +113,9 @@
static int sixty = 60;
#endif

-static int __maybe_unused neg_one = -1;
-static int __maybe_unused two = 2;
-static int __maybe_unused four = 4;
static unsigned long zero_ul;
static unsigned long one_ul = 1;
static unsigned long long_max = LONG_MAX;
-static int one_hundred = 100;
-static int two_hundred = 200;
-static int one_thousand = 1000;
-static int three_thousand = 3000;
#ifdef CONFIG_PRINTK
static int ten_thousand = 10000;
#endif
@@ -1973,7 +1966,7 @@ static struct ctl_table kern_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &neg_one,
+ .extra1 = SYSCTL_NEG_ONE,
.extra2 = SYSCTL_ONE,
},
#endif
@@ -2315,7 +2308,7 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec_minmax_sysadmin,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
#endif
{
@@ -2575,7 +2568,7 @@ static struct ctl_table kern_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &neg_one,
+ .extra1 = SYSCTL_NEG_ONE,
},
#endif
#ifdef CONFIG_RT_MUTEXES
@@ -2637,7 +2630,7 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = perf_cpu_time_max_percent_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "perf_event_max_stack",
@@ -2655,7 +2648,7 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = perf_event_max_stack_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_thousand,
+ .extra2 = SYSCTL_ONE_THOUSAND,
},
#endif
{
@@ -2686,7 +2679,7 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = bpf_unpriv_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "bpf_stats_enabled",
@@ -2740,7 +2733,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = overcommit_policy_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "panic_on_oom",
@@ -2749,7 +2742,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "oom_kill_allocating_task",
@@ -2794,7 +2787,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = dirty_background_ratio_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "dirty_background_bytes",
@@ -2811,7 +2804,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = dirty_ratio_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "dirty_bytes",
@@ -2851,7 +2844,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two_hundred,
+ .extra2 = SYSCTL_TWO_HUNDRED,
},
#ifdef CONFIG_NUMA
{
@@ -2910,7 +2903,7 @@ static struct ctl_table vm_table[] = {
.mode = 0200,
.proc_handler = drop_caches_sysctl_handler,
.extra1 = SYSCTL_ONE,
- .extra2 = &four,
+ .extra2 = SYSCTL_FOUR,
},
#ifdef CONFIG_COMPACTION
{
@@ -2927,7 +2920,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = compaction_proactiveness_sysctl_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "extfrag_threshold",
@@ -2972,7 +2965,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = watermark_scale_factor_sysctl_handler,
.extra1 = SYSCTL_ONE,
- .extra2 = &three_thousand,
+ .extra2 = SYSCTL_THREE_THOUSAND,
},
{
.procname = "percpu_pagelist_high_fraction",
@@ -3051,7 +3044,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "min_slab_ratio",
@@ -3060,7 +3053,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = sysctl_min_slab_ratio_sysctl_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
#endif
#ifdef CONFIG_SMP
@@ -3350,7 +3343,7 @@ static struct ctl_table fs_table[] = {
.mode = 0600,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "protected_regular",
@@ -3359,7 +3352,7 @@ static struct ctl_table fs_table[] = {
.mode = 0600,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "suid_dumpable",
@@ -3368,7 +3361,7 @@ static struct ctl_table fs_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec_minmax_coredump,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
{
--
2.35.1