1 files changed, 93 insertions, 0 deletions
diff --git a/arch/mips/kernel/stacktrace.c b/arch/mips/kernel/stacktrace.c
new file mode 100644
index 0000000000..f2e7209405
--- /dev/null
+++ b/arch/mips/kernel/stacktrace.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Stack trace management functions
+ *
+ *  Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ */
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
+#include <linux/stacktrace.h>
+#include <linux/export.h>
+#include <asm/stacktrace.h>
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer:
+ */
+static void save_raw_context_stack(struct stack_trace *trace,
+	unsigned long reg29, int savesched)
+{
+	unsigned long *sp = (unsigned long *)reg29;
+	unsigned long addr;
+
+	while (!kstack_end(sp)) {
+		addr = *sp++;
+		if (__kernel_text_address(addr) &&
+		    (savesched || !in_sched_functions(addr))) {
+			if (trace->skip > 0)
+				trace->skip--;
+			else
+				trace->entries[trace->nr_entries++] = addr;
+			if (trace->nr_entries >= trace->max_entries)
+				break;
+		}
+	}
+}
+
+static void save_context_stack(struct stack_trace *trace,
+	struct task_struct *tsk, struct pt_regs *regs, int savesched)
+{
+	unsigned long sp = regs->regs[29];
+#ifdef CONFIG_KALLSYMS
+	unsigned long ra = regs->regs[31];
+	unsigned long pc = regs->cp0_epc;
+
+	if (raw_show_trace || !__kernel_text_address(pc)) {
+		unsigned long stack_page =
+			(unsigned long)task_stack_page(tsk);
+		if (stack_page && sp >= stack_page &&
+		    sp <= stack_page + THREAD_SIZE - 32)
+			save_raw_context_stack(trace, sp, savesched);
+		return;
+	}
+	do {
+		if (savesched || !in_sched_functions(pc)) {
+			if (trace->skip > 0)
+				trace->skip--;
+			else
+				trace->entries[trace->nr_entries++] = pc;
+			if (trace->nr_entries >= trace->max_entries)
+				break;
+		}
+		pc = unwind_stack(tsk, &sp, pc, &ra);
+	} while (pc);
+#else
+	save_raw_context_stack(trace, sp, savesched);
+#endif
+}
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace)
+{
+	save_stack_trace_tsk(current, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	struct pt_regs dummyregs;
+	struct pt_regs *regs = &dummyregs;
+
+	WARN_ON(trace->nr_entries || !trace->max_entries);
+
+	if (tsk != current) {
+		regs->regs[29] = tsk->thread.reg29;
+		regs->regs[31] = 0;
+		regs->cp0_epc = tsk->thread.reg31;
+	} else
+		prepare_frametrace(regs);
+	save_context_stack(trace, tsk, regs, tsk == current);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);