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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/xtensa/kernel/stacktrace.c
Initial import
Diffstat (limited to 'arch/xtensa/kernel/stacktrace.c')
-rw-r--r--arch/xtensa/kernel/stacktrace.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c
new file mode 100644
index 000000000..7d2c317bd
--- /dev/null
+++ b/arch/xtensa/kernel/stacktrace.c
@@ -0,0 +1,120 @@
+/*
+ * arch/xtensa/kernel/stacktrace.c
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2013 Tensilica Inc.
+ */
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+
+#include <asm/stacktrace.h>
+#include <asm/traps.h>
+
+void walk_stackframe(unsigned long *sp,
+ int (*fn)(struct stackframe *frame, void *data),
+ void *data)
+{
+ unsigned long a0, a1;
+ unsigned long sp_end;
+
+ a1 = (unsigned long)sp;
+ sp_end = ALIGN(a1, THREAD_SIZE);
+
+ spill_registers();
+
+ while (a1 < sp_end) {
+ struct stackframe frame;
+
+ sp = (unsigned long *)a1;
+
+ a0 = *(sp - 4);
+ a1 = *(sp - 3);
+
+ if (a1 <= (unsigned long)sp)
+ break;
+
+ frame.pc = MAKE_PC_FROM_RA(a0, a1);
+ frame.sp = a1;
+
+ if (fn(&frame, data))
+ return;
+ }
+}
+
+#ifdef CONFIG_STACKTRACE
+
+struct stack_trace_data {
+ struct stack_trace *trace;
+ unsigned skip;
+};
+
+static int stack_trace_cb(struct stackframe *frame, void *data)
+{
+ struct stack_trace_data *trace_data = data;
+ struct stack_trace *trace = trace_data->trace;
+
+ if (trace_data->skip) {
+ --trace_data->skip;
+ return 0;
+ }
+ if (!kernel_text_address(frame->pc))
+ return 0;
+
+ trace->entries[trace->nr_entries++] = frame->pc;
+ return trace->nr_entries >= trace->max_entries;
+}
+
+void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace)
+{
+ struct stack_trace_data trace_data = {
+ .trace = trace,
+ .skip = trace->skip,
+ };
+ walk_stackframe(stack_pointer(task), stack_trace_cb, &trace_data);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+void save_stack_trace(struct stack_trace *trace)
+{
+ save_stack_trace_tsk(current, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+#endif
+
+#ifdef CONFIG_FRAME_POINTER
+
+struct return_addr_data {
+ unsigned long addr;
+ unsigned skip;
+};
+
+static int return_address_cb(struct stackframe *frame, void *data)
+{
+ struct return_addr_data *r = data;
+
+ if (r->skip) {
+ --r->skip;
+ return 0;
+ }
+ if (!kernel_text_address(frame->pc))
+ return 0;
+ r->addr = frame->pc;
+ return 1;
+}
+
+unsigned long return_address(unsigned level)
+{
+ struct return_addr_data r = {
+ .skip = level + 1,
+ };
+ walk_stackframe(stack_pointer(NULL), return_address_cb, &r);
+ return r.addr;
+}
+EXPORT_SYMBOL(return_address);
+
+#endif