LXR linux/arch/um/kernel/kmsg

   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
  10static 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
  50static struct kmsg_dumper kmsg_dumper = {
  51        .dump = kmsg_dumper_stdout
  52};
  53
  54int __init kmsg_dumper_stdout_init(void)
  55{
  56        return kmsg_dump_register(&kmsg_dumper);
  57}
  58
  59__uml_postsetup(kmsg_dumper_stdout_init);
  60