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path: root/drivers/tty/sysrq.c
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Diffstat (limited to 'drivers/tty/sysrq.c')
-rw-r--r--drivers/tty/sysrq.c191
1 files changed, 126 insertions, 65 deletions
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index b6e70c5cfa17..1f78b0db3b25 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -98,14 +98,13 @@ static int __init sysrq_always_enabled_setup(char *str)
__setup("sysrq_always_enabled", sysrq_always_enabled_setup);
-static void sysrq_handle_loglevel(int key)
+static void sysrq_handle_loglevel(u8 key)
{
- int i;
+ u8 loglevel = key - '0';
- i = key - '0';
console_loglevel = CONSOLE_LOGLEVEL_DEFAULT;
- pr_info("Loglevel set to %d\n", i);
- console_loglevel = i;
+ pr_info("Loglevel set to %u\n", loglevel);
+ console_loglevel = loglevel;
}
static const struct sysrq_key_op sysrq_loglevel_op = {
.handler = sysrq_handle_loglevel,
@@ -115,7 +114,7 @@ static const struct sysrq_key_op sysrq_loglevel_op = {
};
#ifdef CONFIG_VT
-static void sysrq_handle_SAK(int key)
+static void sysrq_handle_SAK(u8 key)
{
struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
@@ -132,7 +131,7 @@ static const struct sysrq_key_op sysrq_SAK_op = {
#endif
#ifdef CONFIG_VT
-static void sysrq_handle_unraw(int key)
+static void sysrq_handle_unraw(u8 key)
{
vt_reset_unicode(fg_console);
}
@@ -147,7 +146,7 @@ static const struct sysrq_key_op sysrq_unraw_op = {
#define sysrq_unraw_op (*(const struct sysrq_key_op *)NULL)
#endif /* CONFIG_VT */
-static void sysrq_handle_crash(int key)
+static void sysrq_handle_crash(u8 key)
{
/* release the RCU read lock before crashing */
rcu_read_unlock();
@@ -161,7 +160,7 @@ static const struct sysrq_key_op sysrq_crash_op = {
.enable_mask = SYSRQ_ENABLE_DUMP,
};
-static void sysrq_handle_reboot(int key)
+static void sysrq_handle_reboot(u8 key)
{
lockdep_off();
local_irq_enable();
@@ -176,7 +175,7 @@ static const struct sysrq_key_op sysrq_reboot_op = {
const struct sysrq_key_op *__sysrq_reboot_op = &sysrq_reboot_op;
-static void sysrq_handle_sync(int key)
+static void sysrq_handle_sync(u8 key)
{
emergency_sync();
}
@@ -187,7 +186,7 @@ static const struct sysrq_key_op sysrq_sync_op = {
.enable_mask = SYSRQ_ENABLE_SYNC,
};
-static void sysrq_handle_show_timers(int key)
+static void sysrq_handle_show_timers(u8 key)
{
sysrq_timer_list_show();
}
@@ -198,7 +197,7 @@ static const struct sysrq_key_op sysrq_show_timers_op = {
.action_msg = "Show clockevent devices & pending hrtimers (no others)",
};
-static void sysrq_handle_mountro(int key)
+static void sysrq_handle_mountro(u8 key)
{
emergency_remount();
}
@@ -210,7 +209,7 @@ static const struct sysrq_key_op sysrq_mountro_op = {
};
#ifdef CONFIG_LOCKDEP
-static void sysrq_handle_showlocks(int key)
+static void sysrq_handle_showlocks(u8 key)
{
debug_show_all_locks();
}
@@ -250,7 +249,7 @@ static void sysrq_showregs_othercpus(struct work_struct *dummy)
static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus);
-static void sysrq_handle_showallcpus(int key)
+static void sysrq_handle_showallcpus(u8 key)
{
/*
* Fall back to the workqueue based printing if the
@@ -263,13 +262,14 @@ static void sysrq_handle_showallcpus(int key)
if (in_hardirq())
regs = get_irq_regs();
- pr_info("CPU%d:\n", smp_processor_id());
+ pr_info("CPU%d:\n", get_cpu());
if (regs)
show_regs(regs);
else
show_stack(NULL, NULL, KERN_INFO);
schedule_work(&sysrq_showallcpus);
+ put_cpu();
}
}
@@ -283,7 +283,7 @@ static const struct sysrq_key_op sysrq_showallcpus_op = {
#define sysrq_showallcpus_op (*(const struct sysrq_key_op *)NULL)
#endif
-static void sysrq_handle_showregs(int key)
+static void sysrq_handle_showregs(u8 key)
{
struct pt_regs *regs = NULL;
@@ -300,7 +300,7 @@ static const struct sysrq_key_op sysrq_showregs_op = {
.enable_mask = SYSRQ_ENABLE_DUMP,
};
-static void sysrq_handle_showstate(int key)
+static void sysrq_handle_showstate(u8 key)
{
show_state();
show_all_workqueues();
@@ -312,7 +312,7 @@ static const struct sysrq_key_op sysrq_showstate_op = {
.enable_mask = SYSRQ_ENABLE_DUMP,
};
-static void sysrq_handle_showstate_blocked(int key)
+static void sysrq_handle_showstate_blocked(u8 key)
{
show_state_filter(TASK_UNINTERRUPTIBLE);
}
@@ -326,7 +326,7 @@ static const struct sysrq_key_op sysrq_showstate_blocked_op = {
#ifdef CONFIG_TRACING
#include <linux/ftrace.h>
-static void sysrq_ftrace_dump(int key)
+static void sysrq_ftrace_dump(u8 key)
{
ftrace_dump(DUMP_ALL);
}
@@ -340,9 +340,9 @@ static const struct sysrq_key_op sysrq_ftrace_dump_op = {
#define sysrq_ftrace_dump_op (*(const struct sysrq_key_op *)NULL)
#endif
-static void sysrq_handle_showmem(int key)
+static void sysrq_handle_showmem(u8 key)
{
- show_mem(0, NULL);
+ show_mem();
}
static const struct sysrq_key_op sysrq_showmem_op = {
.handler = sysrq_handle_showmem,
@@ -370,7 +370,7 @@ static void send_sig_all(int sig)
read_unlock(&tasklist_lock);
}
-static void sysrq_handle_term(int key)
+static void sysrq_handle_term(u8 key)
{
send_sig_all(SIGTERM);
console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
@@ -401,7 +401,7 @@ static void moom_callback(struct work_struct *ignored)
static DECLARE_WORK(moom_work, moom_callback);
-static void sysrq_handle_moom(int key)
+static void sysrq_handle_moom(u8 key)
{
schedule_work(&moom_work);
}
@@ -413,7 +413,7 @@ static const struct sysrq_key_op sysrq_moom_op = {
};
#ifdef CONFIG_BLOCK
-static void sysrq_handle_thaw(int key)
+static void sysrq_handle_thaw(u8 key)
{
emergency_thaw_all();
}
@@ -427,7 +427,7 @@ static const struct sysrq_key_op sysrq_thaw_op = {
#define sysrq_thaw_op (*(const struct sysrq_key_op *)NULL)
#endif
-static void sysrq_handle_kill(int key)
+static void sysrq_handle_kill(u8 key)
{
send_sig_all(SIGKILL);
console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
@@ -439,7 +439,7 @@ static const struct sysrq_key_op sysrq_kill_op = {
.enable_mask = SYSRQ_ENABLE_SIGNAL,
};
-static void sysrq_handle_unrt(int key)
+static void sysrq_handle_unrt(u8 key)
{
normalize_rt_tasks();
}
@@ -450,6 +450,17 @@ static const struct sysrq_key_op sysrq_unrt_op = {
.enable_mask = SYSRQ_ENABLE_RTNICE,
};
+static void sysrq_handle_replay_logs(u8 key)
+{
+ console_try_replay_all();
+}
+static struct sysrq_key_op sysrq_replay_logs_op = {
+ .handler = sysrq_handle_replay_logs,
+ .help_msg = "replay-kernel-logs(R)",
+ .action_msg = "Replay kernel logs on consoles",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+
/* Key Operations table and lock */
static DEFINE_SPINLOCK(sysrq_key_table_lock);
@@ -519,7 +530,8 @@ static const struct sysrq_key_op *sysrq_key_table[62] = {
NULL, /* O */
NULL, /* P */
NULL, /* Q */
- NULL, /* R */
+ &sysrq_replay_logs_op, /* R */
+ /* S: May be registered by sched_ext for resetting */
NULL, /* S */
NULL, /* T */
NULL, /* U */
@@ -531,25 +543,24 @@ static const struct sysrq_key_op *sysrq_key_table[62] = {
};
/* key2index calculation, -1 on invalid index */
-static int sysrq_key_table_key2index(int key)
+static int sysrq_key_table_key2index(u8 key)
{
- int retval;
-
- if ((key >= '0') && (key <= '9'))
- retval = key - '0';
- else if ((key >= 'a') && (key <= 'z'))
- retval = key + 10 - 'a';
- else if ((key >= 'A') && (key <= 'Z'))
- retval = key + 36 - 'A';
- else
- retval = -1;
- return retval;
+ switch (key) {
+ case '0' ... '9':
+ return key - '0';
+ case 'a' ... 'z':
+ return key - 'a' + 10;
+ case 'A' ... 'Z':
+ return key - 'A' + 10 + 26;
+ default:
+ return -1;
+ }
}
/*
* get and put functions for the table, exposed to modules.
*/
-static const struct sysrq_key_op *__sysrq_get_key_op(int key)
+static const struct sysrq_key_op *__sysrq_get_key_op(u8 key)
{
const struct sysrq_key_op *op_p = NULL;
int i;
@@ -561,7 +572,7 @@ static const struct sysrq_key_op *__sysrq_get_key_op(int key)
return op_p;
}
-static void __sysrq_put_key_op(int key, const struct sysrq_key_op *op_p)
+static void __sysrq_put_key_op(u8 key, const struct sysrq_key_op *op_p)
{
int i = sysrq_key_table_key2index(key);
@@ -569,10 +580,9 @@ static void __sysrq_put_key_op(int key, const struct sysrq_key_op *op_p)
sysrq_key_table[i] = op_p;
}
-void __handle_sysrq(int key, bool check_mask)
+void __handle_sysrq(u8 key, bool check_mask)
{
const struct sysrq_key_op *op_p;
- int orig_log_level;
int orig_suppress_printk;
int i;
@@ -582,13 +592,12 @@ void __handle_sysrq(int key, bool check_mask)
rcu_sysrq_start();
rcu_read_lock();
/*
- * Raise the apparent loglevel to maximum so that the sysrq header
- * is shown to provide the user with positive feedback. We do not
- * simply emit this at KERN_EMERG as that would change message
- * routing in the consumers of /proc/kmsg.
+ * Enter in the force_console context so that sysrq header is shown to
+ * provide the user with positive feedback. We do not simply emit this
+ * at KERN_EMERG as that would change message routing in the consumers
+ * of /proc/kmsg.
*/
- orig_log_level = console_loglevel;
- console_loglevel = CONSOLE_LOGLEVEL_DEFAULT;
+ printk_force_console_enter();
op_p = __sysrq_get_key_op(key);
if (op_p) {
@@ -598,11 +607,11 @@ void __handle_sysrq(int key, bool check_mask)
*/
if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
pr_info("%s\n", op_p->action_msg);
- console_loglevel = orig_log_level;
+ printk_force_console_exit();
op_p->handler(key);
} else {
pr_info("This sysrq operation is disabled.\n");
- console_loglevel = orig_log_level;
+ printk_force_console_exit();
}
} else {
pr_info("HELP : ");
@@ -620,7 +629,7 @@ void __handle_sysrq(int key, bool check_mask)
}
}
pr_cont("\n");
- console_loglevel = orig_log_level;
+ printk_force_console_exit();
}
rcu_read_unlock();
rcu_sysrq_end();
@@ -628,7 +637,7 @@ void __handle_sysrq(int key, bool check_mask)
suppress_printk = orig_suppress_printk;
}
-void handle_sysrq(int key)
+void handle_sysrq(u8 key)
{
if (sysrq_on())
__handle_sysrq(key, true);
@@ -703,7 +712,8 @@ static void sysrq_parse_reset_sequence(struct sysrq_state *state)
static void sysrq_do_reset(struct timer_list *t)
{
- struct sysrq_state *state = from_timer(state, t, keyreset_timer);
+ struct sysrq_state *state = timer_container_of(state, t,
+ keyreset_timer);
state->reset_requested = true;
@@ -734,7 +744,7 @@ static void sysrq_detect_reset_sequence(struct sysrq_state *state,
*/
if (value && state->reset_seq_cnt) {
state->reset_canceled = true;
- del_timer(&state->keyreset_timer);
+ timer_delete(&state->keyreset_timer);
}
} else if (value == 0) {
/*
@@ -742,7 +752,7 @@ static void sysrq_detect_reset_sequence(struct sysrq_state *state,
* to be pressed and held for the reset timeout
* to hold.
*/
- del_timer(&state->keyreset_timer);
+ timer_delete(&state->keyreset_timer);
if (--state->reset_seq_cnt == 0)
state->reset_canceled = false;
@@ -760,8 +770,6 @@ static void sysrq_of_get_keyreset_config(void)
{
u32 key;
struct device_node *np;
- struct property *prop;
- const __be32 *p;
np = of_find_node_by_path("/chosen/linux,sysrq-reset-seq");
if (!np) {
@@ -772,7 +780,7 @@ static void sysrq_of_get_keyreset_config(void)
/* Reset in case a __weak definition was present */
sysrq_reset_seq_len = 0;
- of_property_for_each_u32(np, "keyset", prop, p, key) {
+ of_property_for_each_u32(np, "keyset", key) {
if (key == KEY_RESERVED || key > KEY_MAX ||
sysrq_reset_seq_len == SYSRQ_KEY_RESET_MAX)
break;
@@ -1112,7 +1120,47 @@ int sysrq_toggle_support(int enable_mask)
}
EXPORT_SYMBOL_GPL(sysrq_toggle_support);
-static int __sysrq_swap_key_ops(int key, const struct sysrq_key_op *insert_op_p,
+static int sysrq_sysctl_handler(const struct ctl_table *table, int write,
+ void *buffer, size_t *lenp, loff_t *ppos)
+{
+ int tmp, ret;
+ struct ctl_table t = *table;
+
+ tmp = sysrq_mask();
+ t.data = &tmp;
+
+ /*
+ * Behaves like do_proc_dointvec as t does not have min nor max.
+ */
+ ret = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
+ if (ret)
+ return ret;
+
+ if (write)
+ sysrq_toggle_support(tmp);
+
+ return 0;
+}
+
+static const struct ctl_table sysrq_sysctl_table[] = {
+ {
+ .procname = "sysrq",
+ .data = NULL,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = sysrq_sysctl_handler,
+ },
+};
+
+static int __init init_sysrq_sysctl(void)
+{
+ register_sysctl_init("kernel", sysrq_sysctl_table);
+ return 0;
+}
+
+subsys_initcall(init_sysrq_sysctl);
+
+static int __sysrq_swap_key_ops(u8 key, const struct sysrq_key_op *insert_op_p,
const struct sysrq_key_op *remove_op_p)
{
int retval;
@@ -1136,13 +1184,13 @@ static int __sysrq_swap_key_ops(int key, const struct sysrq_key_op *insert_op_p,
return retval;
}
-int register_sysrq_key(int key, const struct sysrq_key_op *op_p)
+int register_sysrq_key(u8 key, const struct sysrq_key_op *op_p)
{
return __sysrq_swap_key_ops(key, op_p, NULL);
}
EXPORT_SYMBOL(register_sysrq_key);
-int unregister_sysrq_key(int key, const struct sysrq_key_op *op_p)
+int unregister_sysrq_key(u8 key, const struct sysrq_key_op *op_p)
{
return __sysrq_swap_key_ops(key, NULL, op_p);
}
@@ -1151,16 +1199,29 @@ EXPORT_SYMBOL(unregister_sysrq_key);
#ifdef CONFIG_PROC_FS
/*
* writing 'C' to /proc/sysrq-trigger is like sysrq-C
+ * Normally, only the first character written is processed.
+ * However, if the first character is an underscore,
+ * all characters are processed.
*/
static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- if (count) {
+ bool bulk = false;
+ size_t i;
+
+ for (i = 0; i < count; i++) {
char c;
- if (get_user(c, buf))
+ if (get_user(c, buf + i))
return -EFAULT;
- __handle_sysrq(c, false);
+
+ if (c == '_')
+ bulk = true;
+ else
+ __handle_sysrq(c, false);
+
+ if (!bulk)
+ break;
}
return count;
generated by cgit (git 2.34.1) at 2025-12-21 19:46:50 +0000