Add a kmsg_dumper, that dumps the kmsg buffer to stderr, 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>
---
arch/um/drivers/ubd_kern.c | 5 +++--
arch/um/include/shared/os.h | 1 +
arch/um/kernel/Makefile | 2 +-
arch/um/kernel/kmsg_dump.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
arch/um/kernel/um_arch.c | 2 ++
arch/um/os-Linux/util.c | 12 ++++++++++++
6 files changed, 63 insertions(+), 3 deletions(-)
create mode 100644 arch/um/kernel/kmsg_dump.c
diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index 08eec0b..36741f4 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -238,6 +238,7 @@ extern void setup_hostinfo(char *buf, int len);
extern void os_dump_core(void) __attribute__ ((noreturn));
extern void um_early_printk(const char *s, unsigned int n);
extern void os_fix_helper_signals(void);
+extern int os_printf_stderr(const char *fmt, ...);
/* time.c */
extern void idle_sleep(unsigned long long nsecs);
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index d8b78a0..572e781 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -13,7 +13,7 @@ clean-files :=
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 --git a/arch/um/kernel/kmsg_dump.c b/arch/um/kernel/kmsg_dump.c
new file mode 100644
index 0000000..8047ca5a3
--- /dev/null
+++ b/arch/um/kernel/kmsg_dump.c
@@ -0,0 +1,44 @@
+#include <linux/kmsg_dump.h>
+#include <linux/console.h>
+#include <shared/init.h>
+#include <shared/kern.h>
+#include <os.h>
+
+static struct kmsg_dumper kmsg_dumper;
+
+static void kmsg_dumper_stderr(struct kmsg_dumper *dumper,
+ enum kmsg_dump_reason reason)
+{
+ static char line[1024];
+
+ size_t len = 0;
+ int con_count = 0;
+ struct console *con = NULL;
+
+ /* only dump kmsg when no console is available */
+ if (!console_trylock()) {
+ return;
+ }
+ for_each_console(con) {
+ con_count++;
+ }
+ console_unlock();
+
+ if (con_count > 0) {
+ return;
+ }
+
+ os_printf_stderr("kmsg_dump:\n");
+ while (kmsg_dump_get_line(dumper, true, line, sizeof(line), &len)) {
+ line[len] = '\0';
+ os_printf_stderr("%s", line);
+ }
+}
+
+int __init kmsg_dumper_stderr_init(void)
+{
+ kmsg_dumper.dump = kmsg_dumper_stderr;
+ return kmsg_dump_register(&kmsg_dumper);
+}
+
+__uml_initcall(kmsg_dumper_stderr_init);
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index ab72560..4f6fc24 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -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 void __init uml_postsetup(void)
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;
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index faee55e..a4cc3a0 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -152,3 +152,15 @@ void um_early_printk(const char *s, unsigned int n)
{
printf("%.*s", n, s);
}
+
+int os_printf_stderr(const char *fmt, ...)
+{
+ va_list list;
+ int rc;
+
+ va_start(list, fmt);
+ rc = vfprintf(stderr, fmt, list);
+ va_end(list);
+
+ return rc;
+}
--
1.9.3
------------------------------------------------------------------------------
Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer
Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports
Are you Audit-Ready for PCI DSS 3.0 Compliance? Download White paper
Comply to PCI DSS 3.0 Requirement 10 and 11.5 with EventLog Analyzer
http://pubads.g.doubleclick.net/gampad/clk?id=154622311&iu=/4140/ostg.clktrk
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
