1  // SPDX-License-Identifier: GPL-2.0
2  #include <linux/kmsg_dump.h>
3  #include <linux/spinlock.h>
4  #include <linux/console.h>
5  #include <linux/string.h>
6  #include <shared/init.h>
7  #include <shared/kern.h>
8  #include <os.h>
9  
kmsg_dumper_stdout(struct kmsg_dumper * dumper,enum kmsg_dump_reason reason)10  static void kmsg_dumper_stdout(struct kmsg_dumper *dumper,
11  				enum kmsg_dump_reason reason)
12  {
13  	static struct kmsg_dump_iter iter;
14  	static DEFINE_SPINLOCK(lock);
15  	static char line[1024];
16  	struct console *con;
17  	unsigned long flags;
18  	size_t len = 0;
19  
20  	/* only dump kmsg when no console is available */
21  	if (!console_trylock())
22  		return;
23  
24  	for_each_console(con) {
25  		if(strcmp(con->name, "tty") == 0 &&
26  		   (con->flags & (CON_ENABLED | CON_CONSDEV)) != 0) {
27  			break;
28  		}
29  	}
30  
31  	console_unlock();
32  
33  	if (con)
34  		return;
35  
36  	if (!spin_trylock_irqsave(&lock, flags))
37  		return;
38  
39  	kmsg_dump_rewind(&iter);
40  
41  	printf("kmsg_dump:\n");
42  	while (kmsg_dump_get_line(&iter, true, line, sizeof(line), &len)) {
43  		line[len] = '\0';
44  		printf("%s", line);
45  	}
46  
47  	spin_unlock_irqrestore(&lock, flags);
48  }
49  
50  static struct kmsg_dumper kmsg_dumper = {
51  	.dump = kmsg_dumper_stdout
52  };
53  
kmsg_dumper_stdout_init(void)54  int __init kmsg_dumper_stdout_init(void)
55  {
56  	return kmsg_dump_register(&kmsg_dumper);
57  }
58  
59  __uml_postsetup(kmsg_dumper_stdout_init);
60