mtk-lk/lib/debug/stack_protector.c

/* Copyright Statement:
*
* This software/firmware and related documentation ("MediaTek Software") are
* protected under relevant copyright laws. The information contained herein
* is confidential and proprietary to MediaTek Inc. and/or its licensors.
* Without the prior written permission of MediaTek inc. and/or its licensors,
* any reproduction, modification, use or disclosure of MediaTek Software,
* and information contained herein, in whole or in part, shall be strictly prohibited.
*/
/* MediaTek Inc. (C) 2017. All rights reserved.
*
* BY OPENING THIS FILE, RECEIVER HEREBY UNEQUIVOCALLY ACKNOWLEDGES AND AGREES
* THAT THE SOFTWARE/FIRMWARE AND ITS DOCUMENTATIONS ("MEDIATEK SOFTWARE")
* RECEIVED FROM MEDIATEK AND/OR ITS REPRESENTATIVES ARE PROVIDED TO RECEIVER ON
* AN "AS-IS" BASIS ONLY. MEDIATEK EXPRESSLY DISCLAIMS ANY AND ALL WARRANTIES,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT.
* NEITHER DOES MEDIATEK PROVIDE ANY WARRANTY WHATSOEVER WITH RESPECT TO THE
* SOFTWARE OF ANY THIRD PARTY WHICH MAY BE USED BY, INCORPORATED IN, OR
* SUPPLIED WITH THE MEDIATEK SOFTWARE, AND RECEIVER AGREES TO LOOK ONLY TO SUCH
* THIRD PARTY FOR ANY WARRANTY CLAIM RELATING THERETO. RECEIVER EXPRESSLY ACKNOWLEDGES
* THAT IT IS RECEIVER'S SOLE RESPONSIBILITY TO OBTAIN FROM ANY THIRD PARTY ALL PROPER LICENSES
* CONTAINED IN MEDIATEK SOFTWARE. MEDIATEK SHALL ALSO NOT BE RESPONSIBLE FOR ANY MEDIATEK
* SOFTWARE RELEASES MADE TO RECEIVER'S SPECIFICATION OR TO CONFORM TO A PARTICULAR
* STANDARD OR OPEN FORUM. RECEIVER'S SOLE AND EXCLUSIVE REMEDY AND MEDIATEK'S ENTIRE AND
* CUMULATIVE LIABILITY WITH RESPECT TO THE MEDIATEK SOFTWARE RELEASED HEREUNDER WILL BE,
* AT MEDIATEK'S OPTION, TO REVISE OR REPLACE THE MEDIATEK SOFTWARE AT ISSUE,
* OR REFUND ANY SOFTWARE LICENSE FEES OR SERVICE CHARGE PAID BY RECEIVER TO
* MEDIATEK FOR SUCH MEDIATEK SOFTWARE AT ISSUE.
*/

#include <debug.h>
#include <arch/arm.h>


/******************************************************************************
* The code generated by the gcc 4.9 compiler is always a 4-byte bl instruction
* to branch-and-link to __stack_chk_fail().
* FIXME: Use a smart way to determine the instruction size.
******************************************************************************/
//#ifdef __thumb__
//#define INSTRUCTION_SIZE		2
//#else
#define INSTRUCTION_SIZE		4
//#endif


/******************************************************************************
******************************************************************************/
unsigned long __stack_chk_guard = 0x5a5aa5a5;


/******************************************************************************
******************************************************************************/
void __stack_chk_fail(void)
{
	dprintf(CRITICAL, "Error: stack overflow!\n");

	void *p = __builtin_return_address(0);

	#ifdef __thumb__
	p = (void*)((unsigned)p & ~0x1);  // Clear the Thumb bit if there is one.
	#endif

	if ((unsigned)p >= INSTRUCTION_SIZE)
	{
		p -= INSTRUCTION_SIZE;
	}

	printf("Backtrace[0]: 0x%x\n", (unsigned int)p);

	while (1);
}