From d73840ec2f747b860331bbba53677d0ce38fb9c1 Mon Sep 17 00:00:00 2001 From: Xiaoming Ni Date: Fri, 21 Jan 2022 22:11:14 -0800 Subject: [PATCH] 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@kernel.org: commit log love] Link: https://lkml.kernel.org/r/20211123202347.818157-7-mcgrof@kernel.org Signed-off-by: Xiaoming Ni Signed-off-by: Luis Chamberlain Cc: Al Viro Cc: Amir Goldstein Cc: Andy Shevchenko Cc: Benjamin LaHaise Cc: "Eric W. Biederman" Cc: Greg Kroah-Hartman Cc: Iurii Zaikin Cc: Jan Kara Cc: Kees Cook Cc: Paul Turner Cc: Peter Zijlstra Cc: Petr Mladek Cc: Qing Wang Cc: Sebastian Reichel Cc: Sergey Senozhatsky Cc: Stephen Kitt Cc: Tetsuo Handa Cc: Antti Palosaari Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Clemens Ladisch Cc: David Airlie Cc: Jani Nikula Cc: Joel Becker Cc: Joonas Lahtinen Cc: Joseph Qi Cc: Julia Lawall Cc: Lukas Middendorf Cc: Mark Fasheh Cc: Phillip Potter Cc: Rodrigo Vivi Cc: Douglas Gilbert Cc: James E.J. Bottomley Cc: Jani Nikula Cc: John Ogness Cc: Martin K. Petersen Cc: "Rafael J. Wysocki" Cc: Steven Rostedt (VMware) Cc: Suren Baghdasaryan Cc: "Theodore Ts'o" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 53 ++++++++++++++++++++++++------------------------- 1 file changed, 26 insertions(+), 27 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 29babf1f0d4a..134c2cb9ed4e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -108,27 +108,26 @@ /* 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 #endif @@ -172,8 +171,8 @@ 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 */ @@ -2177,8 +2176,8 @@ 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", @@ -2186,8 +2185,8 @@ 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 { @@ -2261,7 +2260,7 @@ 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", @@ -2473,7 +2472,7 @@ 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", @@ -2629,7 +2628,7 @@ 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", @@ -2646,7 +2645,7 @@ 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", @@ -2760,8 +2759,8 @@ 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", @@ -3047,8 +3046,8 @@ 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", @@ -3072,8 +3071,8 @@ 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", @@ -3081,8 +3080,8 @@ 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 {