assert: Print the backtrace for critical and kernel assertions

Improve debug ergonomics by allowing developers to backtrack from the
assertion through the call-stack. This is important for generic code,
for example, when dealing with assertions inside free().

Change-Id: I0c9c767c50acf3ee3bbe0a891441429299e2d239
Signed-off-by: Andrew Jeffery <andrewrj@au1.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/66118
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Corey V. Swenson <cswenson@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/lib/assert.C

@@ -37,16 +37,25 @@
 #include <kernel/terminate.H>
 #include <sys/misc.h>
 #include <kernel/kernel_reasoncodes.H>
+#include <kernel/taskmgr.H>
 
 /** Hook location for trace module to set up when loaded. */
 namespace TRACE { void (*traceCallback)(void*, size_t) = NULL; };
 
 extern "C" void __assert(AssertBehavior i_assertb, const char* i_file,
                          int i_line)
 {
-    if ((i_assertb == ASSERT_CRITICAL) && (KernelMisc::in_kernel_mode()))
+
+    task_t* task = NULL;
+
+    if (KernelMisc::in_kernel_mode())
     {
-        i_assertb = ASSERT_KERNEL;
+        task = TaskManager::getCurrentTask();
+
+        if (i_assertb == ASSERT_CRITICAL)
+        {
+            i_assertb = ASSERT_KERNEL;
+        }
     }
 
     switch (i_assertb)
@@ -72,6 +81,8 @@ extern "C" void __assert(AssertBehavior i_assertb, const char* i_file,
             printk("Assertion failed @%p on line %s:%d. (Crit_Assert)\n",
                    linkRegister(), i_file, i_line);
 
+            KernelMisc::printkBacktrace(task);
+
             // Need to call the external CritAssert system call
             cpu_crit_assert(reinterpret_cast<uint64_t>(linkRegister()));
             break;
@@ -80,6 +91,8 @@ extern "C" void __assert(AssertBehavior i_assertb, const char* i_file,
             printk("Assertion failed @%p on line %s:%d. (kassert)\n",
                    linkRegister(), i_file, i_line);
 
+            KernelMisc::printkBacktrace(task);
+
             /*@
              * @errortype
              * @moduleid     KERNEL::MOD_KERNEL_INVALID