*/
struct console_cmdline
{
- char name[8]; /* Name of the driver */
+ char name[16]; /* Name of the driver */
int index; /* Minor dev. to use */
char *options; /* Options for the driver */
#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
{
struct console *con;
- trace_console(text, len);
+ trace_console_rcuidle(text, len);
if (level >= console_loglevel && !ignore_loglevel)
return;
static u64 seen_seq;
unsigned long flags;
bool wake_klogd = false;
- bool retry;
+ bool do_cond_resched, retry;
#ifdef LOG_TOO_MUCH_WARNING
unsigned long total_log_size = 0;
unsigned long long t1 = 0, t2 = 0;
int org_loglevel = console_loglevel;
#endif
+
if (console_suspended) {
up(&console_sem);
return;
}
+ /*
+ * Console drivers are called under logbuf_lock, so
+ * @console_may_schedule should be cleared before; however, we may
+ * end up dumping a lot of lines, for example, if called from
+ * console registration path, and should invoke cond_resched()
+ * between lines if allowable. Not doing so can cause a very long
+ * scheduling stall on a slow console leading to RCU stall and
+ * softlockup warnings which exacerbate the issue with more
+ * messages practically incapacitating the system.
+ */
+ do_cond_resched = console_may_schedule;
console_may_schedule = 0;
/* flush buffered message fragment immediately to console */
call_console_drivers(level, text, len);
#endif
local_irq_restore(flags);
+
+ if (do_cond_resched)
+ cond_resched();
}
console_locked = 0;
mutex_release(&console_lock_dep_map, 1, _RET_IP_);
console_unlock();
}
+/**
+ * console_flush_on_panic - flush console content on panic
+ *
+ * Immediately output all pending messages no matter what.
+ */
+void console_flush_on_panic(void)
+{
+ /*
+ * If someone else is holding the console lock, trylock will fail
+ * and may_schedule may be set. Ignore and proceed to unlock so
+ * that messages are flushed out. As this can be called from any
+ * context and we don't want to get preempted while flushing,
+ * ensure may_schedule is cleared.
+ */
+ console_trylock();
+ console_may_schedule = 0;
+ console_unlock();
+}
+
/*
* Return the console tty driver structure and its associated index
*/
*/
for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
i++) {
+ BUILD_BUG_ON(sizeof(console_cmdline[i].name) !=
+ sizeof(newcon->name));
if (strcmp(console_cmdline[i].name, newcon->name) != 0)
continue;
if (newcon->index >= 0 &&