xtensa: add stacktrace support (3e4196a5) · Commits · e / devices / android_kernel_fairphone_FP4

arch/xtensa/Kconfig

+3 −0

Original line number	Diff line number	Diff line
		@@ -52,6 +52,9 @@ config HZ
		source "init/Kconfig"
		source "kernel/Kconfig.freezer"

		config STACKTRACE_SUPPORT
		def_bool y

		config MMU
		def_bool n

arch/xtensa/include/asm/stacktrace.h

0 → 100644

+36 −0

Original line number	Diff line number	Diff line
		/*
		* 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 */

arch/xtensa/kernel/Makefile

+3 −3

Original line number	Diff line number	Diff line
		@@ -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

arch/xtensa/kernel/stacktrace.c

0 → 100644

+87 −0

Original line number	Diff line number	Diff line
		/*
		* 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

arch/xtensa/kernel/traps.c

+11 −38

Original line number	Diff line number	Diff line
		@@ -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 @@ void show_regs(struct pt_regs * regs)
		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");
		}