stacktrace: provide save_stack_trace_tsk() weak alias
Impact: build fix
Some architectures have not implemented save_stack_trace_tsk() yet:
fs/built-in.o: In function `proc_pid_stack':
base.c:(.text+0x3f140): undefined reference to `save_stack_trace_tsk'
So warn about that if the facility is used.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index 94b527e..eb212f8 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -6,6 +6,7 @@
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*/
#include <linux/sched.h>
+#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>
@@ -24,3 +25,13 @@
}
EXPORT_SYMBOL_GPL(print_stack_trace);
+/*
+ * Architectures that do not implement save_stack_trace_tsk get this
+ * weak alias and a once-per-bootup warning (whenever this facility
+ * is utilized - for example by procfs):
+ */
+__weak void
+save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
+}
