Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 854a0d95 authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARC: DWARF2 .debug_frame based stack unwinder 



-Originally written by Rajeshwar Ranga
-Derived off of generic unwinder in 2.6.19 and adapted to ARC

Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
parent 41195d23

arch/arc/Kconfig

+15 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ config ARC 
	select HAVE_ARCH_TRACEHOOK

	select HAVE_GENERIC_HARDIRQS

	select HAVE_MEMBLOCK

	select HAVE_MOD_ARCH_SPECIFIC if ARC_DW2_UNWIND

	select HAVE_OPROFILE

	select IRQ_DOMAIN

	select MODULES_USE_ELF_RELA
@@ -344,6 +345,20 @@ menuconfig ARC_DBG 
	bool "ARC debugging"

	default y



config ARC_DW2_UNWIND

	bool "Enable DWARF specific kernel stack unwind"

	depends on ARC_DBG

	default y

	select KALLSYMS

	help

	  Compiles the kernel with DWARF unwind information and can be used

	  to get stack backtraces.



	  If you say Y here the resulting kernel image will be slightly larger

	  but not slower, and it will give very useful debugging information.

	  If you don't debug the kernel, you can say N, but we may not be able

	  to solve problems without frame unwind information



config ARC_DBG_TLB_PARANOIA

	bool "Paranoia Checks in Low Level TLB Handlers"

	depends on ARC_DBG && !SMP

arch/arc/include/asm/module.h

+7 −0
Original line number Diff line number Diff line
@@ -14,6 +14,13 @@ 


#include <asm-generic/module.h>



#ifdef CONFIG_ARC_DW2_UNWIND

struct mod_arch_specific {

	void *unw_info;

	int unw_sec_idx;

};

#endif



#define MODULE_PROC_FAMILY "ARC700"



#define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY

arch/arc/include/asm/unwind.h

0 → 100644
+163 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */



#ifndef _ASM_ARC_UNWIND_H

#define _ASM_ARC_UNWIND_H



#ifdef CONFIG_ARC_DW2_UNWIND



#include <linux/sched.h>



struct arc700_regs {

	unsigned long r0;

	unsigned long r1;

	unsigned long r2;

	unsigned long r3;

	unsigned long r4;

	unsigned long r5;

	unsigned long r6;

	unsigned long r7;

	unsigned long r8;

	unsigned long r9;

	unsigned long r10;

	unsigned long r11;

	unsigned long r12;

	unsigned long r13;

	unsigned long r14;

	unsigned long r15;

	unsigned long r16;

	unsigned long r17;

	unsigned long r18;

	unsigned long r19;

	unsigned long r20;

	unsigned long r21;

	unsigned long r22;

	unsigned long r23;

	unsigned long r24;

	unsigned long r25;

	unsigned long r26;

	unsigned long r27;	/* fp */

	unsigned long r28;	/* sp */

	unsigned long r29;

	unsigned long r30;

	unsigned long r31;	/* blink */

	unsigned long r63;	/* pc */

};



struct unwind_frame_info {

	struct arc700_regs regs;

	struct task_struct *task;

	unsigned call_frame:1;

};



#define UNW_PC(frame)		((frame)->regs.r63)

#define UNW_SP(frame)		((frame)->regs.r28)

#define UNW_BLINK(frame)	((frame)->regs.r31)



/* Rajesh FIXME */

#ifdef CONFIG_FRAME_POINTER

#define UNW_FP(frame)		((frame)->regs.r27)

#define FRAME_RETADDR_OFFSET	4

#define FRAME_LINK_OFFSET	0

#define STACK_BOTTOM_UNW(tsk)	STACK_LIMIT((tsk)->thread.ksp)

#define STACK_TOP_UNW(tsk)	((tsk)->thread.ksp)

#else

#define UNW_FP(frame)		((void)(frame), 0)

#endif



#define STACK_LIMIT(ptr)	(((ptr) - 1) & ~(THREAD_SIZE - 1))



#define UNW_REGISTER_INFO \

	PTREGS_INFO(r0), \

	PTREGS_INFO(r1), \

	PTREGS_INFO(r2), \

	PTREGS_INFO(r3), \

	PTREGS_INFO(r4), \

	PTREGS_INFO(r5), \

	PTREGS_INFO(r6), \

	PTREGS_INFO(r7), \

	PTREGS_INFO(r8), \

	PTREGS_INFO(r9), \

	PTREGS_INFO(r10), \

	PTREGS_INFO(r11), \

	PTREGS_INFO(r12), \

	PTREGS_INFO(r13), \

	PTREGS_INFO(r14), \

	PTREGS_INFO(r15), \

	PTREGS_INFO(r16), \

	PTREGS_INFO(r17), \

	PTREGS_INFO(r18), \

	PTREGS_INFO(r19), \

	PTREGS_INFO(r20), \

	PTREGS_INFO(r21), \

	PTREGS_INFO(r22), \

	PTREGS_INFO(r23), \

	PTREGS_INFO(r24), \

	PTREGS_INFO(r25), \

	PTREGS_INFO(r26), \

	PTREGS_INFO(r27), \

	PTREGS_INFO(r28), \

	PTREGS_INFO(r29), \

	PTREGS_INFO(r30), \

	PTREGS_INFO(r31), \

	PTREGS_INFO(r63)



#define UNW_DEFAULT_RA(raItem, dataAlign) \

	((raItem).where == Memory && !((raItem).value * (dataAlign) + 4))



extern int arc_unwind(struct unwind_frame_info *frame);

extern void arc_unwind_init(void);

extern void arc_unwind_setup(void);

extern void *unwind_add_table(struct module *module, const void *table_start,

			      unsigned long table_size);

extern void unwind_remove_table(void *handle, int init_only);



static inline int

arch_unwind_init_running(struct unwind_frame_info *info,

			 int (*callback) (struct unwind_frame_info *info,

					  void *arg),

			 void *arg)

{

	return 0;

}



static inline int arch_unw_user_mode(const struct unwind_frame_info *info)

{

	return 0;

}



static inline void arch_unw_init_blocked(struct unwind_frame_info *info)

{

	return;

}



static inline void arch_unw_init_frame_info(struct unwind_frame_info *info,

					    struct pt_regs *regs)

{

	return;

}



#else



#define UNW_PC(frame) ((void)(frame), 0)

#define UNW_SP(frame) ((void)(frame), 0)

#define UNW_FP(frame) ((void)(frame), 0)



static inline void arc_unwind_init(void)

{

}



static inline void arc_unwind_setup(void)

{

}

#define unwind_add_table(a, b, c)

#define unwind_remove_table(a, b)



#endif /* CONFIG_ARC_DW2_UNWIND */



#endif /* _ASM_ARC_UNWIND_H */

arch/arc/kernel/Makefile

+6 −0
Original line number Diff line number Diff line
@@ -14,10 +14,16 @@ obj-y += devtree.o 


obj-$(CONFIG_MODULES)			+= arcksyms.o module.o

obj-$(CONFIG_SMP) 			+= smp.o

obj-$(CONFIG_ARC_DW2_UNWIND)		+= unwind.o



obj-$(CONFIG_ARC_FPU_SAVE_RESTORE)	+= fpu.o

CFLAGS_fpu.o   += -mdpfp



ifdef CONFIG_ARC_DW2_UNWIND

CFLAGS_ctx_sw.o += -fno-omit-frame-pointer

obj-y += ctx_sw.o

else

obj-y += ctx_sw_asm.o

endif



extra-y := vmlinux.lds head.o

arch/arc/kernel/entry.S

+9 −0
Original line number Diff line number Diff line
@@ -815,3 +815,12 @@ ARC_ENTRY sys_clone_wrapper 


	b ret_from_system_call

ARC_EXIT sys_clone_wrapper



#ifdef CONFIG_ARC_DW2_UNWIND

; Workaround for bug 94179 (STAR ):

; Despite -fasynchronous-unwind-tables, linker is not making dwarf2 unwinder

; section (.debug_frame) as loadable. So we force it here.

; This also fixes STAR 9000487933 where the prev-workaround (objcopy --setflag)

; would not work after a clean build due to kernel build system dependencies.

.section .debug_frame, "wa",@progbits

#endif