From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Tue, 15 Dec 2015 14:52:16 -0300
Subject: Linux-libre 4.3.2-gnu

---
 arch/cris/kernel/Makefile     |  1 +
 arch/cris/kernel/irq.c        |  6 +++-
 arch/cris/kernel/stacktrace.c | 76 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 arch/cris/kernel/stacktrace.c

(limited to 'arch/cris/kernel')

diff --git a/arch/cris/kernel/Makefile b/arch/cris/kernel/Makefile
index edef71f12..5fae398ca 100644
--- a/arch/cris/kernel/Makefile
+++ b/arch/cris/kernel/Makefile
@@ -8,6 +8,7 @@ extra-y	:= vmlinux.lds
 
 obj-y   := process.o traps.o irq.o ptrace.o setup.o time.o sys_cris.o
 obj-y += devicetree.o
+obj-y += stacktrace.o
 
 obj-$(CONFIG_MODULES)    += crisksyms.o
 obj-$(CONFIG_MODULES)	 += module.o
diff --git a/arch/cris/kernel/irq.c b/arch/cris/kernel/irq.c
index dd0be5de5..694850e8f 100644
--- a/arch/cris/kernel/irq.c
+++ b/arch/cris/kernel/irq.c
@@ -45,7 +45,11 @@
 asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
 {
 	unsigned long sp;
-	struct pt_regs *old_regs = set_irq_regs(regs);
+	struct pt_regs *old_regs;
+
+	trace_hardirqs_off();
+
+	old_regs = set_irq_regs(regs);
 	irq_enter();
 	sp = rdsp();
 	if (unlikely((sp & (PAGE_SIZE - 1)) < (PAGE_SIZE/8))) {
diff --git a/arch/cris/kernel/stacktrace.c b/arch/cris/kernel/stacktrace.c
new file mode 100644
index 000000000..99838c744
--- /dev/null
+++ b/arch/cris/kernel/stacktrace.c
@@ -0,0 +1,76 @@
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/stacktrace.h>
+#include <asm/stacktrace.h>
+
+void walk_stackframe(unsigned long sp,
+		     int (*fn)(unsigned long addr, void *data),
+		     void *data)
+{
+	unsigned long high = ALIGN(sp, THREAD_SIZE);
+
+	for (; sp <= high - 4; sp += 4) {
+		unsigned long addr = *(unsigned long *) sp;
+
+		if (!kernel_text_address(addr))
+			continue;
+
+		if (fn(addr, data))
+			break;
+	}
+}
+
+struct stack_trace_data {
+	struct stack_trace *trace;
+	unsigned int no_sched_functions;
+	unsigned int skip;
+};
+
+#ifdef CONFIG_STACKTRACE
+
+static int save_trace(unsigned long addr, void *d)
+{
+	struct stack_trace_data *data = d;
+	struct stack_trace *trace = data->trace;
+
+	if (data->no_sched_functions && in_sched_functions(addr))
+		return 0;
+
+	if (data->skip) {
+		data->skip--;
+		return 0;
+	}
+
+	trace->entries[trace->nr_entries++] = addr;
+
+	return trace->nr_entries >= trace->max_entries;
+}
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	struct stack_trace_data data;
+	unsigned long sp;
+
+	data.trace = trace;
+	data.skip = trace->skip;
+
+	if (tsk != current) {
+		data.no_sched_functions = 1;
+		sp = tsk->thread.ksp;
+	} else {
+		data.no_sched_functions = 0;
+		sp = rdsp();
+	}
+
+	walk_stackframe(sp, save_trace, &data);
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+	save_stack_trace_tsk(current, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+#endif /* CONFIG_STACKTRACE */
-- 
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