xtensa: add stacktrace support
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index a9bdb1c..13280f2 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -52,6 +52,9 @@
source "init/Kconfig"
source "kernel/Kconfig.freezer"
+config STACKTRACE_SUPPORT
+ def_bool y
+
config MMU
def_bool n
diff --git a/arch/xtensa/include/asm/stacktrace.h b/arch/xtensa/include/asm/stacktrace.h
new file mode 100644
index 0000000..6a05fcb
--- /dev/null
+++ b/arch/xtensa/include/asm/stacktrace.h
@@ -0,0 +1,36 @@
+/*
+ * arch/xtensa/include/asm/stacktrace.h
+ *
+ * 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.
+ */
+#ifndef _XTENSA_STACKTRACE_H
+#define _XTENSA_STACKTRACE_H
+
+#include <linux/sched.h>
+
+struct stackframe {
+ unsigned long pc;
+ unsigned long sp;
+};
+
+static __always_inline unsigned long *stack_pointer(struct task_struct *task)
+{
+ unsigned long *sp;
+
+ if (!task || task == current)
+ __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
+ else
+ sp = (unsigned long *)task->thread.sp;
+
+ return sp;
+}
+
+void walk_stackframe(unsigned long *sp,
+ int (*fn)(struct stackframe *frame, void *data),
+ void *data);
+
+#endif /* _XTENSA_STACKTRACE_H */
diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile
index c433a56..1e7fc87 100644
--- a/arch/xtensa/kernel/Makefile
+++ b/arch/xtensa/kernel/Makefile
@@ -4,9 +4,9 @@
extra-y := head.o vmlinux.lds
-obj-y := align.o entry.o irq.o coprocessor.o process.o ptrace.o \
- setup.o signal.o syscall.o time.o traps.o vectors.o platform.o \
- pci-dma.o
+obj-y := align.o coprocessor.o entry.o irq.o pci-dma.o platform.o process.o \
+ ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \
+ vectors.o
obj-$(CONFIG_KGDB) += xtensa-stub.o
obj-$(CONFIG_PCI) += pci.o
diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c
new file mode 100644
index 0000000..e3aff95
--- /dev/null
+++ b/arch/xtensa/kernel/stacktrace.c
@@ -0,0 +1,87 @@
+/*
+ * 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
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 923db5c..cf065e1 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -11,7 +11,7 @@
*
* Essentially rewritten for the Xtensa architecture port.
*
- * Copyright (C) 2001 - 2005 Tensilica Inc.
+ * Copyright (C) 2001 - 2013 Tensilica Inc.
*
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
* Chris Zankel <chris@zankel.net>
@@ -32,6 +32,7 @@
#include <linux/delay.h>
#include <linux/hardirq.h>
+#include <asm/stacktrace.h>
#include <asm/ptrace.h>
#include <asm/timex.h>
#include <asm/uaccess.h>
@@ -402,53 +403,25 @@
regs->syscall);
}
-static __always_inline unsigned long *stack_pointer(struct task_struct *task)
+static int show_trace_cb(struct stackframe *frame, void *data)
{
- unsigned long *sp;
-
- if (!task || task == current)
- __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
- else
- sp = (unsigned long *)task->thread.sp;
-
- return sp;
+ if (kernel_text_address(frame->pc)) {
+ printk(" [<%08lx>] ", frame->pc);
+ print_symbol("%s\n", frame->pc);
+ }
+ return 0;
}
void show_trace(struct task_struct *task, unsigned long *sp)
{
- unsigned long a0, a1, pc;
- unsigned long sp_start, sp_end;
-
- if (sp)
- a1 = (unsigned long)sp;
- else
- a1 = (unsigned long)stack_pointer(task);
-
- sp_start = a1 & ~(THREAD_SIZE-1);
- sp_end = sp_start + THREAD_SIZE;
+ if (!sp)
+ sp = stack_pointer(task);
printk("Call Trace:");
#ifdef CONFIG_KALLSYMS
printk("\n");
#endif
- spill_registers();
-
- while (a1 > sp_start && a1 < sp_end) {
- sp = (unsigned long*)a1;
-
- a0 = *(sp - 4);
- a1 = *(sp - 3);
-
- if (a1 <= (unsigned long) sp)
- break;
-
- pc = MAKE_PC_FROM_RA(a0, a1);
-
- if (kernel_text_address(pc)) {
- printk(" [<%08lx>] ", pc);
- print_symbol("%s\n", pc);
- }
- }
+ walk_stackframe(sp, show_trace_cb, NULL);
printk("\n");
}