diff options
Diffstat (limited to 'lib/sys_info.c')
| -rw-r--r-- | lib/sys_info.c | 169 |
1 files changed, 106 insertions, 63 deletions
diff --git a/lib/sys_info.c b/lib/sys_info.c index 496f9151c9b6..f32a06ec9ed4 100644 --- a/lib/sys_info.c +++ b/lib/sys_info.c @@ -1,31 +1,35 @@ // SPDX-License-Identifier: GPL-2.0-only -#include <linux/sched/debug.h> +#include <linux/array_size.h> +#include <linux/bitops.h> +#include <linux/cleanup.h> #include <linux/console.h> +#include <linux/log2.h> #include <linux/kernel.h> #include <linux/ftrace.h> -#include <linux/sysctl.h> #include <linux/nmi.h> +#include <linux/sched/debug.h> +#include <linux/string.h> +#include <linux/sysctl.h> #include <linux/sys_info.h> -struct sys_info_name { - unsigned long bit; - const char *name; +static const char * const si_names[] = { + [ilog2(SYS_INFO_TASKS)] = "tasks", + [ilog2(SYS_INFO_MEM)] = "mem", + [ilog2(SYS_INFO_TIMERS)] = "timers", + [ilog2(SYS_INFO_LOCKS)] = "locks", + [ilog2(SYS_INFO_FTRACE)] = "ftrace", + [ilog2(SYS_INFO_PANIC_CONSOLE_REPLAY)] = "", + [ilog2(SYS_INFO_ALL_BT)] = "all_bt", + [ilog2(SYS_INFO_BLOCKED_TASKS)] = "blocked_tasks", }; /* - * When 'si_names' gets updated, please make sure the 'sys_info_avail' - * below is updated accordingly. + * Default kernel sys_info mask. + * If a kernel module calls sys_info() with "parameter == 0", then + * this mask will be used. */ -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" }, -}; +static unsigned long kernel_si_mask; /* Expecting string like "xxx_sys_info=tasks,mem,timers,locks,ftrace,..." */ unsigned long sys_info_parse_param(char *str) @@ -36,12 +40,9 @@ unsigned long sys_info_parse_param(char *str) 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; - } - } + i = match_string(si_names, ARRAY_SIZE(si_names), name); + if (i >= 0) + __set_bit(i, &si_bits); } return si_bits; @@ -49,56 +50,93 @@ unsigned long sys_info_parse_param(char *str) #ifdef CONFIG_SYSCTL -static const char sys_info_avail[] __maybe_unused = "tasks,mem,timers,locks,ftrace,all_bt,blocked_tasks"; +static int sys_info_write_handler(const struct ctl_table *table, + void *buffer, size_t *lenp, loff_t *ppos, + unsigned long *si_bits_global) +{ + unsigned long si_bits; + int ret; + + ret = proc_dostring(table, 1, buffer, lenp, ppos); + if (ret) + return ret; + + si_bits = sys_info_parse_param(table->data); + + /* The access to the global value is not synchronized. */ + WRITE_ONCE(*si_bits_global, si_bits); + + return 0; +} + +static int sys_info_read_handler(const struct ctl_table *table, + void *buffer, size_t *lenp, loff_t *ppos, + unsigned long *si_bits_global) +{ + unsigned long si_bits; + unsigned int len = 0; + char *delim = ""; + unsigned int i; + + /* The access to the global value is not synchronized. */ + si_bits = READ_ONCE(*si_bits_global); + + for_each_set_bit(i, &si_bits, ARRAY_SIZE(si_names)) { + if (*si_names[i]) { + len += scnprintf(table->data + len, table->maxlen - len, + "%s%s", delim, si_names[i]); + delim = ","; + } + } + + return proc_dostring(table, 0, buffer, lenp, ppos); +} 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)]; 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; - - names[0] = '\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 = ","; - } - } + unsigned int i; + size_t maxlen; - table = *ro_table; - table.data = names; - table.maxlen = sizeof(names); - return proc_dostring(&table, write, buffer, lenp, ppos); - } + maxlen = 0; + for (i = 0; i < ARRAY_SIZE(si_names); i++) + maxlen += strlen(si_names[i]) + 1; + + char *names __free(kfree) = kzalloc(maxlen, GFP_KERNEL); + if (!names) + return -ENOMEM; + + table = *ro_table; + table.data = names; + table.maxlen = maxlen; + + if (write) + return sys_info_write_handler(&table, buffer, lenp, ppos, ro_table->data); + else + return sys_info_read_handler(&table, buffer, lenp, ppos, ro_table->data); +} + +static const struct ctl_table sys_info_sysctls[] = { + { + .procname = "kernel_sys_info", + .data = &kernel_si_mask, + .maxlen = sizeof(kernel_si_mask), + .mode = 0644, + .proc_handler = sysctl_sys_info_handler, + }, +}; + +static int __init sys_info_sysctl_init(void) +{ + register_sysctl_init("kernel", sys_info_sysctls); + return 0; } +subsys_initcall(sys_info_sysctl_init); #endif -void sys_info(unsigned long si_mask) +static void __sys_info(unsigned long si_mask) { if (si_mask & SYS_INFO_TASKS) show_state(); @@ -115,9 +153,14 @@ void sys_info(unsigned long si_mask) if (si_mask & SYS_INFO_FTRACE) ftrace_dump(DUMP_ALL); - if (si_mask & SYS_INFO_ALL_CPU_BT) + if (si_mask & SYS_INFO_ALL_BT) trigger_all_cpu_backtrace(); if (si_mask & SYS_INFO_BLOCKED_TASKS) show_state_filter(TASK_UNINTERRUPTIBLE); } + +void sys_info(unsigned long si_mask) +{ + __sys_info(si_mask ? : kernel_si_mask); +} |