InitFatalReboot: Trigger panic explicitly for init_fatal_panic
The exit of init panics the system *after* process context (mm, stack,
...etc.) are recycled, according to Linux kernel's 'do_exit'
implementation. To preserve most init process context for debugging,
triggers the panic via proc-sysrq explicitly.
Note: after this change, there will be no "Attempt to kill init" panic
when androidboot.init_fatal_panic is set.
Test: Insert data abort fault in init, the full process context is
preserved in memory dump captured after panic.
Bug: 155940351
Change-Id: I3393bd00f99b8cb432cfa19a105b7d636b411764
diff --git a/init/reboot_utils.cpp b/init/reboot_utils.cpp
index 485188b..76460a5 100644
--- a/init/reboot_utils.cpp
+++ b/init/reboot_utils.cpp
@@ -29,6 +29,7 @@
#include <cutils/android_reboot.h>
#include "capabilities.h"
+#include "reboot_utils.h"
namespace android {
namespace init {
@@ -138,6 +139,9 @@
LOG(ERROR) << backtrace->FormatFrameData(i);
}
if (init_fatal_panic) {
+ LOG(ERROR) << __FUNCTION__ << ": Trigger crash";
+ android::base::WriteStringToFile("c", PROC_SYSRQ);
+ LOG(ERROR) << __FUNCTION__ << ": Sys-Rq failed to crash the system; fallback to exit().";
_exit(signal_number);
}
RebootSystem(ANDROID_RB_RESTART2, init_fatal_reboot_target);