Add a kmsg_dumper, that dumps the kmsg buffer to stdout, when no
console is available.
This an enables the printing of early panic() calls triggered in
uml_postsetup().
Signed-off-by: Thomas Meyer <tho...@m3y3r.de>
---
diff -r ee0ba83fd81e arch/um/kernel/Makefile
--- a/arch/um/kernel/Makefile Sat Oct 11 18:55:17 2014 +0200
+++ b/arch/um/kernel/Makefile Sun Oct 12 14:42:48 2014 +0200
@@ -13,7 +13,7 @@
obj-y = config.o exec.o exitcode.o irq.o ksyms.o mem.o \
physmem.o process.o ptrace.o reboot.o sigio.o \
signal.o smp.o syscall.o sysrq.o time.o tlb.o trap.o \
- um_arch.o umid.o maccess.o skas/
+ um_arch.o umid.o maccess.o kmsg_dump.o skas/
obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
obj-$(CONFIG_GPROF) += gprof_syms.o
diff -r ee0ba83fd81e arch/um/kernel/kmsg_dump.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/arch/um/kernel/kmsg_dump.c Sun Oct 12 14:42:48 2014 +0200
@@ -0,0 +1,43 @@
+#include <linux/kmsg_dump.h>
+#include <linux/console.h>
+#include <shared/init.h>
+#include <shared/kern.h>
+#include <os.h>
+
+static void kmsg_dumper_stdout(struct kmsg_dumper *dumper,
+ enum kmsg_dump_reason reason)
+{
+ static char line[1024];
+
+ size_t len = 0;
+ bool con_available = false;
+
+ /* only dump kmsg when no console is available */
+ if (!console_trylock())
+ return;
+
+ if (console_drivers != NULL)
+ con_available = true;
+
+ console_unlock();
+
+ if (con_available == true)
+ return;
+
+ printf("kmsg_dump:\n");
+ while (kmsg_dump_get_line(dumper, true, line, sizeof(line), &len)) {
+ line[len] = '\0';
+ printf("%s", line);
+ }
+}
+
+static struct kmsg_dumper kmsg_dumper = {
+ .dump = kmsg_dumper_stdout
+};
+
+int __init kmsg_dumper_stdout_init(void)
+{
+ return kmsg_dump_register(&kmsg_dumper);
+}
+
+__uml_postsetup(kmsg_dumper_stdout_init);
diff -r ee0ba83fd81e arch/um/kernel/um_arch.c
--- a/arch/um/kernel/um_arch.c Sat Oct 11 18:55:17 2014 +0200
+++ b/arch/um/kernel/um_arch.c Sun Oct 12 14:42:48 2014 +0200
@@ -11,6 +11,7 @@
#include <linux/string.h>
#include <linux/utsname.h>
#include <linux/sched.h>
+#include <linux/kmsg_dump.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/sections.h>
@@ -234,6 +235,7 @@
static int panic_exit(struct notifier_block *self, unsigned long unused1,
void *unused2)
{
+ kmsg_dump(KMSG_DUMP_PANIC);
bust_spinlocks(1);
bust_spinlocks(0);
uml_exitcode = 1;
------------------------------------------------------------------------------
Comprehensive Server Monitoring with Site24x7.
Monitor 10 servers for $9/Month.
Get alerted through email, SMS, voice calls or mobile push notifications.
Take corrective actions from your mobile device.
http://p.sf.net/sfu/Zoho
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
