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// SPDX-License-Identifier: GPL-2.0-only
#include <linux/sched/debug.h>
#include <linux/console.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
#include <linux/sysctl.h>
#include <linux/nmi.h>
#include <linux/sys_info.h>
struct sys_info_name {
unsigned long bit;
const char *name;
};
/*
* When 'si_names' gets updated, please make sure the 'sys_info_avail'
* below is updated accordingly.
*/
static const struct sys_info_name si_names[] = {
{ SYS_INFO_TASKS, "tasks" },
{ SYS_INFO_MEM, "mem" },
{ SYS_INFO_TIMERS, "timers" },
{ SYS_INFO_LOCKS, "locks" },
{ SYS_INFO_FTRACE, "ftrace" },
{ SYS_INFO_ALL_CPU_BT, "all_bt" },
{ SYS_INFO_BLOCKED_TASKS, "blocked_tasks" },
};
/* Expecting string like "xxx_sys_info=tasks,mem,timers,locks,ftrace,..." */
unsigned long sys_info_parse_param(char *str)
{
unsigned long si_bits = 0;
char *s, *name;
int i;
s = str;
while ((name = strsep(&s, ",")) && *name) {
for (i = 0; i < ARRAY_SIZE(si_names); i++) {
if (!strcmp(name, si_names[i].name)) {
si_bits |= si_names[i].bit;
break;
}
}
}
return si_bits;
}
#ifdef CONFIG_SYSCTL
static const char sys_info_avail[] __maybe_unused = "tasks,mem,timers,locks,ftrace,all_bt,blocked_tasks";
int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
void *buffer, size_t *lenp,
loff_t *ppos)
{
char names[sizeof(sys_info_avail) + 1];
struct ctl_table table;
unsigned long *si_bits_global;
si_bits_global = ro_table->data;
if (write) {
unsigned long si_bits;
int ret;
table = *ro_table;
table.data = names;
table.maxlen = sizeof(names);
ret = proc_dostring(&table, write, buffer, lenp, ppos);
if (ret)
return ret;
si_bits = sys_info_parse_param(names);
/* The access to the global value is not synchronized. */
WRITE_ONCE(*si_bits_global, si_bits);
return 0;
} else {
/* for 'read' operation */
char *delim = "";
int i, len = 0;
for (i = 0; i < ARRAY_SIZE(si_names); i++) {
if (*si_bits_global & si_names[i].bit) {
len += scnprintf(names + len, sizeof(names) - len,
"%s%s", delim, si_names[i].name);
delim = ",";
}
}
table = *ro_table;
table.data = names;
table.maxlen = sizeof(names);
return proc_dostring(&table, write, buffer, lenp, ppos);
}
}
#endif
void sys_info(unsigned long si_mask)
{
if (si_mask & SYS_INFO_TASKS)
show_state();
if (si_mask & SYS_INFO_MEM)
show_mem();
if (si_mask & SYS_INFO_TIMERS)
sysrq_timer_list_show();
if (si_mask & SYS_INFO_LOCKS)
debug_show_all_locks();
if (si_mask & SYS_INFO_FTRACE)
ftrace_dump(DUMP_ALL);
if (si_mask & SYS_INFO_ALL_CPU_BT)
trigger_all_cpu_backtrace();
if (si_mask & SYS_INFO_BLOCKED_TASKS)
show_state_filter(TASK_UNINTERRUPTIBLE);
}
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