diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | include/linux/kmsg_dump.h | 9 | ||||
| -rw-r--r-- | kernel/printk.c | 6 |
3 files changed, 19 insertions, 2 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 033d4e69b43..d99fd9c0ec0 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2211,6 +2211,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. default: off. + printk.always_kmsg_dump= + Trigger kmsg_dump for cases other than kernel oops or + panics + Format: <bool> (1/Y/y=enable, 0/N/n=disable) + default: disabled + printk.time= Show timing data prefixed to each printk message line Format: <bool> (1/Y/y=enable, 0/N/n=disable) diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index fee66317e07..35f7237ec97 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -15,13 +15,18 @@ #include <linux/errno.h> #include <linux/list.h> +/* + * Keep this list arranged in rough order of priority. Anything listed after + * KMSG_DUMP_OOPS will not be logged by default unless printk.always_kmsg_dump + * is passed to the kernel. + */ enum kmsg_dump_reason { - KMSG_DUMP_OOPS, KMSG_DUMP_PANIC, + KMSG_DUMP_OOPS, + KMSG_DUMP_EMERG, KMSG_DUMP_RESTART, KMSG_DUMP_HALT, KMSG_DUMP_POWEROFF, - KMSG_DUMP_EMERG, }; /** diff --git a/kernel/printk.c b/kernel/printk.c index 13c0a1143f4..32690a0b7a1 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -702,6 +702,9 @@ static bool printk_time = 0; #endif module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR); +static bool always_kmsg_dump; +module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR); + /* Check if we have any console registered that can be called early in boot. */ static int have_callable_console(void) { @@ -1732,6 +1735,9 @@ void kmsg_dump(enum kmsg_dump_reason reason) unsigned long l1, l2; unsigned long flags; + if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump) + return; + /* Theoretically, the log could move on after we do this, but there's not a lot we can do about that. The new messages will overwrite the start of what we dump. */ |