printk: move printk sysctl to printk/sysctl.c

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty dishes, this makes it very difficult to maintain. To help with this maintenance let's start by moving sysctls to places where they actually belong. The proc sysctl maintainers do not want to know what sysctl knobs you wish to add for your own piece of code, we just care about the core logic. So move printk sysctl from kernel/sysctl.c to kernel/printk/sysctl.c. Use register_sysctl() to register the sysctl interface. [mcgrof@kernel.org: fixed compile issues when PRINTK is not set, commit log update]

Xiaoming Ni committed 4 years ago

Commit faaa3571 parent 3ba442d5 files · +96 −69Browse files

Unified · Split

5 files

kernel/printk/Makefile +4 −1
kernel/printk/internal.h +6 −0
kernel/printk/printk.c +1 −0
kernel/printk/sysctl.c +85 −0
kernel/sysctl.c +0 −68

kernel/printk/Makefile+4−1

 obj-y	= printk.o
 obj-$(CONFIG_PRINTK)	+= printk_safe.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
-obj-$(CONFIG_PRINTK)	+= printk_ringbuffer.o
 obj-$(CONFIG_PRINTK_INDEX)	+= index.o
+obj-$(CONFIG_PRINTK)                 += printk_support.o
+printk_support-y	             := printk_ringbuffer.o
+printk_support-$(CONFIG_SYSCTL)	     += sysctl.o

kernel/printk/internal.h+6−0

  */
 #include <linux/percpu.h>
+#if defined(CONFIG_PRINTK) && defined(CONFIG_SYSCTL)
+void __init printk_sysctl_init(void);
+#else
+#define printk_sysctl_init() do { } while (0)
+#endif
 #ifdef CONFIG_PRINTK
 /* Flags for a single printk record. */

kernel/printk/printk.c+1−0

@@ -3211,6 +3211,7 @@ static int __init printk_late_init(void) · 3210 unmodified lines
3211	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online",	3211	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online",
3212	console_cpu_notify, NULL);	3212	console_cpu_notify, NULL);
3213	WARN_ON(ret < 0);	3213	WARN_ON(ret < 0);
		3214	printk_sysctl_init();
3214	return 0;	3215	return 0;
3215	}	3216	}
3216	late_initcall(printk_late_init);	3217	late_initcall(printk_late_init);

kernel/printk/sysctl.c+85−0

@@ -0,0 +1,85 @@
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* sysctl.c: General linux system control interface
	4	*/
	5
	6	#include <linux/sysctl.h>
	7	#include <linux/printk.h>
	8	#include <linux/capability.h>
	9	#include <linux/ratelimit.h>
	10	#include "internal.h"
	11
	12	static const int ten_thousand = 10000;
	13
	14	static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
	15	void __user buffer, size_t lenp, loff_t *ppos)
	16	{
	17	if (write && !capable(CAP_SYS_ADMIN))
	18	return -EPERM;
	19
	20	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
	21	}
	22
	23	static struct ctl_table printk_sysctls[] = {
	24	{
	25	.procname = "printk",
	26	.data = &console_loglevel,
	27	.maxlen = 4*sizeof(int),
	28	.mode = 0644,
	29	.proc_handler = proc_dointvec,
	30	},
	31	{
	32	.procname = "printk_ratelimit",
	33	.data = &printk_ratelimit_state.interval,
	34	.maxlen = sizeof(int),
	35	.mode = 0644,
	36	.proc_handler = proc_dointvec_jiffies,
	37	},
	38	{
	39	.procname = "printk_ratelimit_burst",
	40	.data = &printk_ratelimit_state.burst,
	41	.maxlen = sizeof(int),
	42	.mode = 0644,
	43	.proc_handler = proc_dointvec,
	44	},
	45	{
	46	.procname = "printk_delay",
	47	.data = &printk_delay_msec,
	48	.maxlen = sizeof(int),
	49	.mode = 0644,
	50	.proc_handler = proc_dointvec_minmax,
	51	.extra1 = SYSCTL_ZERO,
	52	.extra2 = (void *)&ten_thousand,
	53	},
	54	{
	55	.procname = "printk_devkmsg",
	56	.data = devkmsg_log_str,
	57	.maxlen = DEVKMSG_STR_MAX_SIZE,
	58	.mode = 0644,
	59	.proc_handler = devkmsg_sysctl_set_loglvl,
	60	},
	61	{
	62	.procname = "dmesg_restrict",
	63	.data = &dmesg_restrict,
	64	.maxlen = sizeof(int),
	65	.mode = 0644,
	66	.proc_handler = proc_dointvec_minmax_sysadmin,
	67	.extra1 = SYSCTL_ZERO,
	68	.extra2 = SYSCTL_ONE,
	69	},
	70	{
	71	.procname = "kptr_restrict",
	72	.data = &kptr_restrict,
	73	.maxlen = sizeof(int),
	74	.mode = 0644,
	75	.proc_handler = proc_dointvec_minmax_sysadmin,
	76	.extra1 = SYSCTL_ZERO,
	77	.extra2 = SYSCTL_TWO,
	78	},
	79	{}
	80	};
	81
	82	void __init printk_sysctl_init(void)
	83	{
	84	register_sysctl_init("kernel", printk_sysctls);
	85	}

kernel/sysctl.c+0−68

@@ -908,17 +908,6 @@ static int proc_taint(struct ctl_table *table, int write, · 907 unmodified lines
908	return err;	908	return err;
909	}	909	}
910		910
911	#ifdef CONFIG_PRINTK
912	static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
913	void buffer, size_t lenp, loff_t *ppos)
914	{
915	if (write && !capable(CAP_SYS_ADMIN))
916	return -EPERM;
917
918	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
919	}
920	#endif
921
922	/**	911	/**
923	* struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure	912	* struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
924	* @min: pointer to minimum allowable value	913	* @min: pointer to minimum allowable value
@@ -2210,63 +2199,6 @@ static struct ctl_table kern_table[] = { · 1285 unmodified lines
2210	.mode = 0644,	2199	.mode = 0644,
2211	.proc_handler = proc_doulongvec_minmax,	2200	.proc_handler = proc_doulongvec_minmax,
2212	},	2201	},
2213	#if defined CONFIG_PRINTK
2214	{
2215	.procname = "printk",
2216	.data = &console_loglevel,
2217	.maxlen = 4*sizeof(int),
2218	.mode = 0644,
2219	.proc_handler = proc_dointvec,
2220	},
2221	{
2222	.procname = "printk_ratelimit",
2223	.data = &printk_ratelimit_state.interval,
2224	.maxlen = sizeof(int),
2225	.mode = 0644,
2226	.proc_handler = proc_dointvec_jiffies,
2227	},
2228	{
2229	.procname = "printk_ratelimit_burst",
2230	.data = &printk_ratelimit_state.burst,
2231	.maxlen = sizeof(int),
2232	.mode = 0644,
2233	.proc_handler = proc_dointvec,
2234	},
2235	{
2236	.procname = "printk_delay",
2237	.data = &printk_delay_msec,
2238	.maxlen = sizeof(int),
2239	.mode = 0644,
2240	.proc_handler = proc_dointvec_minmax,
2241	.extra1 = SYSCTL_ZERO,
2242	.extra2 = (void *)&ten_thousand,
2243	},
2244	{
2245	.procname = "printk_devkmsg",
2246	.data = devkmsg_log_str,
2247	.maxlen = DEVKMSG_STR_MAX_SIZE,
2248	.mode = 0644,
2249	.proc_handler = devkmsg_sysctl_set_loglvl,
2250	},
2251	{
2252	.procname = "dmesg_restrict",
2253	.data = &dmesg_restrict,
2254	.maxlen = sizeof(int),
2255	.mode = 0644,
2256	.proc_handler = proc_dointvec_minmax_sysadmin,
2257	.extra1 = SYSCTL_ZERO,
2258	.extra2 = SYSCTL_ONE,
2259	},
2260	{
2261	.procname = "kptr_restrict",
2262	.data = &kptr_restrict,
2263	.maxlen = sizeof(int),
2264	.mode = 0644,
2265	.proc_handler = proc_dointvec_minmax_sysadmin,
2266	.extra1 = SYSCTL_ZERO,
2267	.extra2 = SYSCTL_TWO,
2268	},
2269	#endif
2270	{	2202	{
2271	.procname = "ngroups_max",	2203	.procname = "ngroups_max",
2272	.data = (void *)&ngroups_max,	2204	.data = (void *)&ngroups_max,

printk: move printk sysctl to printk/sysctl.c

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