[PATCH v3 2/4] sysctl: Move some boundary constants form sysctl.c to sysctl_vals
From: Xiaoming Ni
Date: Mon May 18 2020 - 00:00:21 EST
Some boundary (.extra1 .extra2) constants (E.g: neg_one two) in
sysctl.c are used in multiple features. Move these variables to
sysctl_vals to avoid adding duplicate variables when cleaning up
sysctls table.
Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
fs/proc/proc_sysctl.c | 2 +-
include/linux/sysctl.h | 11 ++++++++---
kernel/sysctl.c | 37 ++++++++++++++++---------------------
3 files changed, 25 insertions(+), 25 deletions(-)
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index b6f5d45..3f77e64 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -23,7 +23,7 @@
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, 1000, INT_MAX };
EXPORT_SYMBOL(sysctl_vals);
/* Support for permanently empty directories */
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 43f8ef9..bf97c30 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -38,9 +38,14 @@
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_ONE_THOUSAND ((void *)&sysctl_vals[6])
+#define SYSCTL_INT_MAX ((void *)&sysctl_vals[7])
extern const int sysctl_vals[];
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c96122f..76c3237 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -124,14 +124,9 @@
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 one_thousand = 1000;
#ifdef CONFIG_PRINTK
static int ten_thousand = 10000;
#endif
@@ -547,7 +542,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &neg_one,
+ .extra1 = SYSCTL_NEG_ONE,
.extra2 = SYSCTL_ONE,
},
#endif
@@ -878,7 +873,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = proc_dointvec_minmax_sysadmin,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
#endif
{
@@ -1187,7 +1182,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.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",
@@ -1205,7 +1200,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = perf_event_max_stack_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_thousand,
+ .extra2 = SYSCTL_ONE_THOUSAND,
},
#endif
{
@@ -1280,7 +1275,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "panic_on_oom",
@@ -1289,7 +1284,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "oom_kill_allocating_task",
@@ -1334,7 +1329,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = dirty_background_ratio_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "dirty_background_bytes",
@@ -1351,7 +1346,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = dirty_ratio_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "dirty_bytes",
@@ -1391,7 +1386,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
#ifdef CONFIG_HUGETLB_PAGE
{
@@ -1448,7 +1443,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0200,
.proc_handler = drop_caches_sysctl_handler,
.extra1 = SYSCTL_ONE,
- .extra2 = &four,
+ .extra2 = SYSCTL_FOUR,
},
#ifdef CONFIG_COMPACTION
{
@@ -1501,7 +1496,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = watermark_scale_factor_sysctl_handler,
.extra1 = SYSCTL_ONE,
- .extra2 = &one_thousand,
+ .extra2 = SYSCTL_ONE_THOUSAND,
},
{
.procname = "percpu_pagelist_fraction",
@@ -1580,7 +1575,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "min_slab_ratio",
@@ -1589,7 +1584,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0644,
.proc_handler = sysctl_min_slab_ratio_sysctl_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &one_hundred,
+ .extra2 = SYSCTL_ONE_HUNDRED,
},
#endif
#ifdef CONFIG_SMP
@@ -1872,7 +1867,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0600,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "protected_regular",
@@ -1881,7 +1876,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.mode = 0600,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &two,
+ .extra2 = SYSCTL_TWO,
},
{
.procname = "suid_dumpable",
@@ -1890,7 +1885,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.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)
{
--
1.8.5.6