1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/array_size.h> 3 #include <linux/bitops.h> 4 #include <linux/cleanup.h> 5 #include <linux/console.h> 6 #include <linux/log2.h> 7 #include <linux/kernel.h> 8 #include <linux/ftrace.h> 9 #include <linux/nmi.h> 10 #include <linux/sched/debug.h> 11 #include <linux/string.h> 12 #include <linux/sysctl.h> 13 14 #include <linux/sys_info.h> 15 16 static const char * const si_names[] = { 17 [ilog2(SYS_INFO_TASKS)] = "tasks", 18 [ilog2(SYS_INFO_MEM)] = "mem", 19 [ilog2(SYS_INFO_TIMERS)] = "timers", 20 [ilog2(SYS_INFO_LOCKS)] = "locks", 21 [ilog2(SYS_INFO_FTRACE)] = "ftrace", 22 [ilog2(SYS_INFO_PANIC_CONSOLE_REPLAY)] = "", 23 [ilog2(SYS_INFO_ALL_BT)] = "all_bt", 24 [ilog2(SYS_INFO_BLOCKED_TASKS)] = "blocked_tasks", 25 }; 26 27 /* Expecting string like "xxx_sys_info=tasks,mem,timers,locks,ftrace,..." */ 28 unsigned long sys_info_parse_param(char *str) 29 { 30 unsigned long si_bits = 0; 31 char *s, *name; 32 int i; 33 34 s = str; 35 while ((name = strsep(&s, ",")) && *name) { 36 i = match_string(si_names, ARRAY_SIZE(si_names), name); 37 if (i >= 0) 38 __set_bit(i, &si_bits); 39 } 40 41 return si_bits; 42 } 43 44 #ifdef CONFIG_SYSCTL 45 46 static int sys_info_write_handler(const struct ctl_table *table, 47 void *buffer, size_t *lenp, loff_t *ppos, 48 unsigned long *si_bits_global) 49 { 50 unsigned long si_bits; 51 int ret; 52 53 ret = proc_dostring(table, 1, buffer, lenp, ppos); 54 if (ret) 55 return ret; 56 57 si_bits = sys_info_parse_param(table->data); 58 59 /* The access to the global value is not synchronized. */ 60 WRITE_ONCE(*si_bits_global, si_bits); 61 62 return 0; 63 } 64 65 static int sys_info_read_handler(const struct ctl_table *table, 66 void *buffer, size_t *lenp, loff_t *ppos, 67 unsigned long *si_bits_global) 68 { 69 unsigned long si_bits; 70 unsigned int len = 0; 71 char *delim = ""; 72 unsigned int i; 73 74 /* The access to the global value is not synchronized. */ 75 si_bits = READ_ONCE(*si_bits_global); 76 77 for_each_set_bit(i, &si_bits, ARRAY_SIZE(si_names)) { 78 if (*si_names[i]) { 79 len += scnprintf(table->data + len, table->maxlen - len, 80 "%s%s", delim, si_names[i]); 81 delim = ","; 82 } 83 } 84 85 return proc_dostring(table, 0, buffer, lenp, ppos); 86 } 87 88 int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write, 89 void *buffer, size_t *lenp, 90 loff_t *ppos) 91 { 92 struct ctl_table table; 93 unsigned int i; 94 size_t maxlen; 95 96 maxlen = 0; 97 for (i = 0; i < ARRAY_SIZE(si_names); i++) 98 maxlen += strlen(si_names[i]) + 1; 99 100 char *names __free(kfree) = kzalloc(maxlen, GFP_KERNEL); 101 if (!names) 102 return -ENOMEM; 103 104 table = *ro_table; 105 table.data = names; 106 table.maxlen = maxlen; 107 108 if (write) 109 return sys_info_write_handler(&table, buffer, lenp, ppos, ro_table->data); 110 else 111 return sys_info_read_handler(&table, buffer, lenp, ppos, ro_table->data); 112 } 113 #endif 114 115 void sys_info(unsigned long si_mask) 116 { 117 if (si_mask & SYS_INFO_TASKS) 118 show_state(); 119 120 if (si_mask & SYS_INFO_MEM) 121 show_mem(); 122 123 if (si_mask & SYS_INFO_TIMERS) 124 sysrq_timer_list_show(); 125 126 if (si_mask & SYS_INFO_LOCKS) 127 debug_show_all_locks(); 128 129 if (si_mask & SYS_INFO_FTRACE) 130 ftrace_dump(DUMP_ALL); 131 132 if (si_mask & SYS_INFO_ALL_BT) 133 trigger_all_cpu_backtrace(); 134 135 if (si_mask & SYS_INFO_BLOCKED_TASKS) 136 show_state_filter(TASK_UNINTERRUPTIBLE); 137 } 138