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 *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 | } |
86 | |