The patch titled
Subject: sysctl: use const for typically used max/min proc sysctls
has been added to the -mm tree. Its filename is
sysctl-use-const-for-typically-used-max-min-proc-sysctls.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/sysctl-use-const-for-typically-used-max-min-proc-sysctls.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/sysctl-use-const-for-typically-used-max-min-proc-sysctls.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
Subject: sysctl: use const for typically used max/min proc sysctls
When proc_dointvec_minmax() or proc_doulongvec_minmax() are used we are
using the extra1 and extra2 parameters on the sysctl table only for a min
and max boundary, these extra1 and extra2 arguments are then used for
read-only operations. So make them const to reflect this.
[mcgrof@xxxxxxxxxx: commit log love]
Link: https://lkml.kernel.org/r/20211123202347.818157-7-mcgrof@xxxxxxxxxx
Signed-off-by: Xiaoming Ni <nixiaoming@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: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Hailong Liu <liu.hailong6@xxxxxxxxxx>
Cc: Iurii Zaikin <yzaikin@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
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: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: Phillip Potter <phil@xxxxxxxxxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/sysctl.c | 53 ++++++++++++++++++++++------------------------
1 file changed, 26 insertions(+), 27 deletions(-)
--- a/kernel/sysctl.c~sysctl-use-const-for-typically-used-max-min-proc-sysctls
+++ a/kernel/sysctl.c
@@ -107,27 +107,26 @@
/* Constants used for minimum and maximum */
-static unsigned long zero_ul;
-static unsigned long one_ul = 1;
-static unsigned long long_max = LONG_MAX;
+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 int ten_thousand = 10000;
+static const int ten_thousand = 10000;
#endif
#ifdef CONFIG_PERF_EVENTS
-static int six_hundred_forty_kb = 640 * 1024;
+static const int six_hundred_forty_kb = 640 * 1024;
#endif
/* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
-static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
+static const unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
-static int maxolduid = 65535;
-static int minolduid;
+static const int maxolduid = 65535;
+static const int minolduid;
static const int ngroups_max = NGROUPS_MAX;
static const int cap_last_cap = CAP_LAST_CAP;
-
#ifdef CONFIG_INOTIFY_USER
#include <linux/inotify.h>
#endif
@@ -171,8 +170,8 @@ int sysctl_legacy_va_layout;
#endif
#ifdef CONFIG_COMPACTION
-static int min_extfrag_threshold;
-static int max_extfrag_threshold = 1000;
+static const int min_extfrag_threshold;
+static const int max_extfrag_threshold = 1000;
#endif
#endif /* CONFIG_SYSCTL */
@@ -2176,8 +2175,8 @@ static struct ctl_table kern_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &minolduid,
- .extra2 = &maxolduid,
+ .extra1 = (void *)&minolduid,
+ .extra2 = (void *)&maxolduid,
},
{
.procname = "overflowgid",
@@ -2185,8 +2184,8 @@ static struct ctl_table kern_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &minolduid,
- .extra2 = &maxolduid,
+ .extra1 = (void *)&minolduid,
+ .extra2 = (void *)&maxolduid,
},
#ifdef CONFIG_S390
{
@@ -2260,7 +2259,7 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = &ten_thousand,
+ .extra2 = (void *)&ten_thousand,
},
{
.procname = "printk_devkmsg",
@@ -2472,7 +2471,7 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = perf_event_max_stack_handler,
.extra1 = SYSCTL_ZERO,
- .extra2 = &six_hundred_forty_kb,
+ .extra2 = (void *)&six_hundred_forty_kb,
},
{
.procname = "perf_event_max_contexts_per_stack",
@@ -2628,7 +2627,7 @@ static struct ctl_table vm_table[] = {
.maxlen = sizeof(dirty_background_bytes),
.mode = 0644,
.proc_handler = dirty_background_bytes_handler,
- .extra1 = &one_ul,
+ .extra1 = (void *)&one_ul,
},
{
.procname = "dirty_ratio",
@@ -2645,7 +2644,7 @@ static struct ctl_table vm_table[] = {
.maxlen = sizeof(vm_dirty_bytes),
.mode = 0644,
.proc_handler = dirty_bytes_handler,
- .extra1 = &dirty_bytes_min,
+ .extra1 = (void *)&dirty_bytes_min,
},
{
.procname = "dirty_writeback_centisecs",
@@ -2759,8 +2758,8 @@ static struct ctl_table vm_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &min_extfrag_threshold,
- .extra2 = &max_extfrag_threshold,
+ .extra1 = (void *)&min_extfrag_threshold,
+ .extra2 = (void *)&max_extfrag_threshold,
},
{
.procname = "compact_unevictable_allowed",
@@ -3046,8 +3045,8 @@ static struct ctl_table fs_table[] = {
.maxlen = sizeof(files_stat.max_files),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
- .extra1 = &zero_ul,
- .extra2 = &long_max,
+ .extra1 = (void *)&zero_ul,
+ .extra2 = (void *)&long_max,
},
{
.procname = "nr_open",
@@ -3071,8 +3070,8 @@ static struct ctl_table fs_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &minolduid,
- .extra2 = &maxolduid,
+ .extra1 = (void *)&minolduid,
+ .extra2 = (void *)&maxolduid,
},
{
.procname = "overflowgid",
@@ -3080,8 +3079,8 @@ static struct ctl_table fs_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &minolduid,
- .extra2 = &maxolduid,
+ .extra1 = (void *)&minolduid,
+ .extra2 = (void *)&maxolduid,
},
#ifdef CONFIG_FILE_LOCKING
{
_
Patches currently in -mm which might be from nixiaoming@xxxxxxxxxx are
sysctl-add-a-new-register_sysctl_init-interface.patch
sysctl-move-some-boundary-constants-from-sysctlc-to-sysctl_vals.patch
hung_task-move-hung_task-sysctl-interface-to-hung_taskc.patch
watchdog-move-watchdog-sysctl-interface-to-watchdogc.patch
sysctl-use-const-for-typically-used-max-min-proc-sysctls.patch
sysctl-use-sysctl_zero-to-replace-some-static-int-zero-uses.patch
aio-move-aio-sysctl-to-aioc.patch
dnotify-move-dnotify-sysctl-to-dnotifyc.patch
inotify-simplify-subdirectory-registration-with-register_sysctl.patch
eventpoll-simplify-sysctl-declaration-with-register_sysctl.patch
