/*
 *
 *   Copyright (C) 2016 AVM GmbH <fritzbox_info@avm.de>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *   backtrace-helper-functions for stackdump on smp etc.
 */


#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/init_task.h>
#include <asm/thread_info.h>
#include <asm/traps.h>
#include <asm/cacheflush.h>
#include <asm/cp15.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <avm/enh/irq_on.h>
#include <linux/delay.h>
#include <linux/mm_types.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <avm/sammel/simple_mempool.h>
#include <avm/sammel/debug.h>
#include <asm/sections.h>
#include <asm/unwind.h>
#include <asm/avm_enh/avm_enh.h>

#include <avm/rte/ipi.h>

#define snprintf_add(ptxt, txtlen, args...)	do {					\
	if (ptxt == NULL) {								\
		pr_err(args);								\
	} else {									\
		int local_add_len;							\
											\
		local_add_len = snprintf(ptxt, txtlen, args);				\
		if (local_add_len > 0) {						\
			int tail = min_t(int, txtlen, local_add_len);			\
											\
			(ptxt) += tail, (txtlen) -= tail;				\
		}									\
	}										\
	} while (0)

#if defined(CONFIG_AVM_FASTIRQ)
#include <asm/avm_enh/avm_fiq_os.h>
#include <asm/mach_avm.h>
#include <asm/avm_enh/avm_gic.h>
#include <asm/avm_enh/avm_gic_fiq.h>
#include <asm/avm_enh/avm_enh.h>
#include <asm/irq_regs.h>

static int rte_monitor_ipi;

enum _monitor_ipi_type {
	monitor_nop                = 0x0,
	monitor_bt                 = 0x1,
};

struct _monitor_bt {
	struct pt_regs ptregs;
	unsigned long svc_sp;   /*--- fuer current ---*/
	unsigned long transbase;
	unsigned long dac;
	unsigned long ctrl;
	unsigned int all_register_valid;
};

struct _monitor_ipi {
	enum _monitor_ipi_type type;
	union __monitor_ipi {
		struct _monitor_bt bt;
	} buf;
	unsigned int init;
	atomic_t     ready;
	spinlock_t   lock;
};
static struct _monitor_ipi IPI_Monitor[NR_CPUS];
static atomic_t backtrace_busy;

static const char *const processor_modes[] = {
	"USER_26", "FIQ_26", "IRQ_26",  "SVC_26",  "UK4_26",  "UK5_26",  "UK6_26",  "UK7_26",
	"UK8_26",  "UK9_26", "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
	"USER_32", "FIQ_32", "IRQ_32",  "SVC_32",  "UK4_32",  "UK5_32",  "UK6_32",  "ABT_32",
	"UK8_32",  "UK9_32", "UK10_32", "UND_32",  "UK12_32", "UK13_32", "UK14_32", "SYS_32"
};
static const char * const isa_modes[] = {
	"ARM", "Thumb", "Jazelle", "ThumbEE"
};

/**
 */
static void get_cp15_register(struct _monitor_bt *pbt)
{
#ifdef CONFIG_CPU_CP15
	unsigned int ctrl;
#ifdef CONFIG_CPU_CP15_MMU
	unsigned int transbase, dac;

	asm("mrc p15, 0, %0, c2, c0\n\t"
		"mrc p15, 0, %1, c3, c0\n"
				: "=r" (transbase), "=r" (dac));
	pbt->transbase = transbase;
	pbt->dac       = dac;
#endif
	asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
	pbt->ctrl = ctrl;
#endif
}

/**
 */
static inline long get_cpsr_reg(void)
{
	unsigned long cpsr_reg;

	asm volatile(
			"       mrs     %0, cpsr        @ get_cpsr\n"
			: "=r" (cpsr_reg)
			:
			: "memory", "cc");
	return cpsr_reg;
}

/**
 */
static int __get_userinfo(char *buf, unsigned int maxbuflen, struct mm_struct *mmm, unsigned long addr)
{
	struct vm_area_struct *vm;
	struct vm_area_struct *vm_last = NULL;
	unsigned int i = 0;

	if (!virt_addr_valid(mmm)) {
		return 1;
	}
	vm = mmm->mmap;
	while (vm) {
		/*--- pr_err("%s[%x]:%p %x - %x vm_mm %p\n", __func__, addr, vm, vm->vm_start, vm->vm_end, vm->vm_mm); ---*/
		if (!virt_addr_valid(vm)) {
			snprintf(buf, maxbuflen, "%s: error: corrupt vm %p vm_last=%pS\n", __func__, vm, vm_last);
			return 1;
		}
		if ((addr >= vm->vm_start) && (addr < vm->vm_end)) {
			snprintf(buf, maxbuflen, "seg=%3u of=0x%08lx/0x%lx [%s]", i, addr - (unsigned long)vm->vm_start,
					(unsigned long)vm->vm_end - (unsigned long)vm->vm_start,
					(vm->vm_file && vm->vm_file->f_path.dentry) ? (char *)vm->vm_file->f_path.dentry->d_name.name : ""
					);
			/*--- pr_err("%s", buf); ---*/
			return 0;
		}
		vm_last = vm;
		vm = vm->vm_next;
		i++;
	}
	return 1;
}

/**
 *  Schwachstelle: thread/task nicht mehr valid (in dem Moment freigegeben)
 */
static char *get_user_symbol(char *txt, unsigned int maxttxlen, struct thread_info *thread, unsigned long addr)
{
	struct task_struct *task = NULL;
	unsigned long flags;

	txt[0] = 0;

	firq_local_irq_save(flags);

	if (!virt_addr_valid(thread)) {
		firq_local_irq_restore(flags);
		return txt;
	}

	task = thread->task;
	if (!virt_addr_valid(task)) {
		firq_local_irq_restore(flags);
		return txt;
	}
	if (firq_spin_trylock(&task->alloc_lock)) {
		/*--- kritisch: mmput()/get_task_mm() darf im FIrq-Kontext nicht verwendet werden, mmput hoffentlich nur im task_lock() ---*/
		__get_userinfo(txt, maxttxlen, task->mm, addr);
		firq_spin_unlock(&task->alloc_lock);
	}
	firq_local_irq_restore(flags);
	return txt;
}

/**
 * FAST-IRQ-Kontext
 */
static noinline void monitor_ipi_firq_context(struct _monitor_ipi *m_ipi)
{
	struct pt_regs *pregs;

	if (atomic_read(&m_ipi->ready)) {
		return;
	}

	/* Sind wir hier die crashende CPU? */
	if (avm_get_crashed_cpu() == raw_smp_processor_id()) {
		/* Nachschauen, ob von uns willentlich die exc_regs auf NULL gesetzt wurden (Panic-Fall) */
		pregs = get_exc_regs(raw_smp_processor_id());
		if (pregs == NULL) {
			/* PANIC! Die hat keinen eigenen Exception-Kontext, wir haben ihn aber durch den WD-FIQ bekommen */
			pregs = get_fiq_regs();
		}
		pr_info("[%s] slave cpu#%d is the crashed cpu!\n", __func__, raw_smp_processor_id());
	} else {
		/* Nein, wir sind eine der drei im FIQ gefangenen ... */
		pregs = get_fiq_regs();
		pr_info("[%s] slave cpu#%d\n", __func__, raw_smp_processor_id());
	}

	switch (m_ipi->type) {
	case monitor_bt:
		/* Sind wir hier die crashende CPU? */
		if (avm_get_crashed_cpu() == raw_smp_processor_id()) {
			/* Nachschauen, ob von uns willentlich die exc_regs auf NULL gesetzt wurden (Panic-Fall) */
			if (get_exc_regs(raw_smp_processor_id()) != NULL) {
				/* Der Exception-Kontext braucht nicht korrigiert zu werden, nur der FIQ-Kontext ... */
				memcpy(&m_ipi->buf.bt.ptregs, pregs, sizeof(m_ipi->buf.bt.ptregs));
				pr_info("[%s] just memcpy pregs!\n", __func__);
			/* PANIC! Die hat keinen eigenen Exception-Kontext, wir haben ihn aber durch den WD-FIQ bekommen */
			} else {
				/* Da wir nicht die ausführende CPU sind, hier an die Kontext-Korrektur denken! */
				copy_banked_regs_full(&m_ipi->buf.bt.ptregs, pregs);
				pr_info("[%s] copy_banked_regs_full!\n", __func__);
			}
		/* Nein, wir sind eine der übrigen drei ... */
		} else {
			/* und hier im FIQ, daher wieder Kontext-Korrektur! */
			copy_banked_regs_full(&m_ipi->buf.bt.ptregs, pregs);
			pr_info("[%s] copy_banked_regs_full!\n", __func__);
		}
		m_ipi->buf.bt.svc_sp = get_svc_sp();
		get_cp15_register(&m_ipi->buf.bt);
		m_ipi->buf.bt.all_register_valid = 1;
		break;
	case monitor_nop:
	default:
		break;
	}
	dsb();
	atomic_set(&m_ipi->ready, 1);
}

/**
 */
static void dump_instr(const char *lvl, struct pt_regs *regs)
{
	unsigned long addr = instruction_pointer(regs);
	const int thumb = thumb_mode(regs);
	const int width = thumb ? 4 : 8;
	mm_segment_t fs;
	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
	int i;

	/*
	 * We need to switch to kernel mode so that we can use __get_user
	 * to safely read from kernel space.  Note that we now dump the
	 * code first, just in case the backtrace kills us.
	 */
	fs = get_fs();
	set_fs(KERNEL_DS);

	for (i = -4; i < 1 + !!thumb; i++) {
		unsigned int val, bad;

		if (thumb)
			bad = __get_user(val, &((u16 *)addr)[i]);
		else
			bad = __get_user(val, &((u32 *)addr)[i]);

		if (!bad)
			p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
					width, val);
		else {
			p += sprintf(p, "bad PC value");
			break;
		}
	}
	printk("%sCode: %s\n", lvl, str);

	set_fs(fs);
}

#define UNALIGNED_MAX_SCORE_ENTRIES       8
#if defined(UNALIGNED_MAX_SCORE_ENTRIES)
/**
 */
struct _unaligned_access_score_entry {
	unsigned long unaligneds;
	unsigned long ts;
	char comm[TASK_COMM_LEN];                  /*--- Name mal sichern falls beendet ---*/
	pid_t pid;
	unsigned long pc;
};

/**
 * usermode: 0 Kernel
 */
static void add_unaligned_access_to_table(unsigned long pc, struct _unaligned_access_score_entry table[],
						unsigned int table_entries, unsigned int usermode)
{
	unsigned int ts_idx = 0, ts_score = 0;
	unsigned int i;

	for (i = 0; i < table_entries; i++) {
		if (table[i].unaligneds) {
			if (usermode) {
				if (task_pid_nr(current) != table[i].pid) {
					continue;
				}
			}
			if (pc == table[i].pc) {
				table[i].unaligneds++;
				/*--- pr_err("%s:[%u]add %s %s pid=%u pc=0x%lx %lu\n", __func__, i, usermode ? "USER" : "KERNEL",  current->comm, table[i].pid, pc, table[i].unaligneds); ---*/
				return;
			}
			continue;
		}
		/*--- pr_err("%s:[%u]initial %s %s pc=0x%lx pid=%u\n", __func__, i, usermode ? "USER" : "KERNEL",  current->comm, pc, table[i].pid); ---*/
		ts_idx = i;
		goto table_settings;
	}
	/*--- alle besetzt: bewerte per unaligneds / per time ---*/
	for (i = 0; i < table_entries; i++) {
		unsigned long diff = jiffies - table[i].ts;
		unsigned int score = diff / (table[i].unaligneds | 0x1);
		/*--- pr_err("%s:[%u]score %d diff %u unaligneds=%lu ts_score %u idx=%u\n", __func__,  i, score, diff, table[i].unaligneds, ts_score, ts_idx); ---*/
		if (score > ts_score) {
			ts_score = score;
			ts_idx = i;
		}
	}
	/*--- pr_err("%s:[%u]replace %s old: unaligneds=%lu pc=0x%lx pid=%u ts_score=%u new=%s pc=0x%lx\n", __func__, ts_idx, usermode ? "USER" : "KERNEL", table[ts_idx].unaligneds, table[ts_idx].pc, table[ts_idx].pid, ts_score, current->comm, pc); ---*/
table_settings:
	table[ts_idx].unaligneds = 1;
	table[ts_idx].pc         = pc;
	table[ts_idx].ts         = jiffies;
	table[ts_idx].pid        = task_pid_nr(current);
	memcpy(table[ts_idx].comm, current->comm, sizeof(table[ts_idx].comm));
}

/**
 * die Normierung erfolgt entsprechend des Zeitfensters
 */
static const char *norm_ai(unsigned long *ai, unsigned int sec)
{
	if (sec >= 60 * 60) {
		*ai *= 60 * 60;
		return "h";
	}
	if (sec >= 60) {
		*ai *= 60;
		return "min";
	}
	return "s";
}

/**
 */
static unsigned long show_unaligned_access_table(struct seq_file *seq, struct _unaligned_access_score_entry table[],
						unsigned int table_entries, unsigned int usermode)
{
	unsigned int i;
	unsigned long sum = 0;

	if (table[0].unaligneds) {
		seq_printf(seq, "%s:\nunaligneds\t unaligneds/time\t\n", usermode ? "User-Scorelist" : "System-Scorelist");
	}
	for (i = 0; i < table_entries; i++) {
		if (table[i].unaligneds) {
			unsigned long ai_per_time = table[i].unaligneds;
			unsigned long sec = (jiffies - table[i].ts) / HZ;
			const char *post_fix = norm_ai(&ai_per_time, sec);

			sum += table[i].unaligneds;
			if (sec == 0)
				sec = 1;
			if (usermode) {
				struct pid *ppid;
				struct task_struct *tsk = NULL;
				char *pcomm;

				ppid = find_get_pid(table[i].pid);
				if (ppid) {
					tsk = get_pid_task(ppid, PIDTYPE_PID);
				}
				if (tsk) {
					pcomm = tsk->comm;
				} else {
					pcomm = table[i].comm;
					tsk = NULL;
				}
				seq_printf(seq, "%10lu \t%5lu.%02lu/%s \t %s(%u) pc=0x%lx ",
						table[i].unaligneds,
						ai_per_time / sec, ((ai_per_time * 100) / sec) % 100,
						post_fix,
						pcomm,
						table[i].pid, table[i].pc);
				if (tsk) {
					put_task_struct(tsk);
				}
				if (ppid) {
					put_pid(ppid);
				}
				seq_puts(seq, "\n");
			} else {
				seq_printf(seq, "%10lu \t%5lu.%02lu/%s \t 0x%lx(%pS) ", table[i].unaligneds,
						ai_per_time / sec, ((ai_per_time * 100) / sec) % 100,
						post_fix,
						table[i].pc, (void *)table[i].pc);
				seq_puts(seq, "\n");
			}
		}
	}
	return sum;
}
static struct _unaligned_access_score_entry user_score_table[UNALIGNED_MAX_SCORE_ENTRIES],
				sys_score_table[UNALIGNED_MAX_SCORE_ENTRIES];
#endif/*--- #if defined(UNALIGNED_MAX_SCORE_ENTRIES) ---*/

/**
 * Dump memory
 */
static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
			 unsigned long top)
{
	unsigned long first;
	mm_segment_t fs;
	int i;

	/*
	 * We need to switch to kernel mode so that we can use __get_user
	 * to safely read from kernel space.  Note that we now dump the
	 * code first, just in case the backtrace kills us.
	 */
	fs = get_fs();
	set_fs(KERNEL_DS);

	printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top);

	for (first = bottom & ~31; first < top; first += 32) {
		unsigned long p;
		char str[sizeof(" 12345678") * 8 + 1];

		memset(str, ' ', sizeof(str));
		str[sizeof(str) - 1] = '\0';

		for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
			if (p >= bottom && p < top) {
				unsigned long val;

				if (__get_user(val, (unsigned long *)p) == 0)
					sprintf(str + i * 9, " %08lx", val);
				else
					sprintf(str + i * 9, " ????????");
			}
		}
		printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
	}

	set_fs(fs);
}

/**
 * wir sind auf der cpu nicht im firq: nun steht noch die Kontext-Frage:
 *  (a) Interrupt
 *  (b) Exception
 *  (c) direkter Aufruf
 */
extern struct pt_regs avm_die_pregs;
static void monitor_ipi_direct_context(struct _monitor_ipi *m_ipi, struct pt_regs *exception_regs)
{
	register unsigned long current_sp asm ("sp");
	struct pt_regs *regs;

	if (atomic_read(&m_ipi->ready)) {
		return;
	}
	switch (m_ipi->type) {
	case monitor_bt:
		/* Sind wir hier die crashende CPU? */
		if (avm_get_crashed_cpu() == raw_smp_processor_id()) {
			/* Ist der uns übergebene Exception-Kontext gültig? */
			if (exception_regs) {
			/* Nachschauen, ob von uns willentlich die exc_regs auf NULL gesetzt wurden (Panic-Fall) */
				regs = get_exc_regs(avm_get_crashed_cpu());
				pr_info("[%s] MONITOR_BT exception_regs\n", __func__);
				/* PANIC! Die hat keinen eigenen Exception-Kontext, wir haben ihn aber durch den WD-FIQ bekommen */
				if (regs == NULL) {
					regs = get_fiq_regs();
					pr_info("[%s] use exchanged fiq_regs!\n", __func__);
				}
			} else if (in_interrupt()) {
				/*--- Irq-Kontext ---*/
				regs = get_irq_regs();
				pr_info("[%s] MONITOR_BT in_interrupt()==True, regs=0x%p\n", __func__, (void *)regs);
			} else {
				regs = NULL;
				pr_info("[%s] MONITOR_BT regs=NULL!\n", __func__);
			}
		} else {
		/* Nein, wir sind eine der übrigen drei ... */
			regs = get_fiq_regs();
			if (regs)
				pr_info("[%s] MONITOR_BT fiq_regs! PC=0x%p, LR=0x%p, SP=0x%p\n", __func__,
					(void *)regs->ARM_pc, (void *)regs->ARM_lr, (void *)regs->ARM_sp);
		}
		if (regs) {
			if (avm_get_crashed_cpu() == raw_smp_processor_id()) {
				pr_info("[%s] master cpu is crashed cpu!\n", __func__);
			} else {
				pr_info("[%s] master cpu is not crashed cpu!\n", __func__);
			}
			/* Die Master-CPU hat die Kontext-Korrektur schon vorab im WD-FIQ Einstieg erhalten */
			memcpy(&m_ipi->buf.bt.ptregs, regs, sizeof(m_ipi->buf.bt.ptregs));
			m_ipi->buf.bt.svc_sp = get_svc_sp();
			m_ipi->buf.bt.all_register_valid = 1;
			pr_info("[%s] BT register set valid!\n", __func__);
		} else {
			/**
			 * Wenn aus einer (Fault-)Exception ohne exception_regs:
			 * erstmal (unsinniger) Backtrace des Exception-Handlers, dabei
			 * erkennt der Backtracer hoffentlich das Exception-Text-Segment
			 * und liefert dann doch nochmal den relevanten Backtrace
			 */
			memset(&m_ipi->buf.bt, 0, sizeof(m_ipi->buf.bt));
			m_ipi->buf.bt.ptregs.ARM_fp   = (unsigned long)__builtin_frame_address(0);
			m_ipi->buf.bt.ptregs.ARM_pc   = _THIS_IP_;
			m_ipi->buf.bt.ptregs.ARM_lr   = _RET_IP_;
			m_ipi->buf.bt.ptregs.ARM_sp   = current_sp;
			m_ipi->buf.bt.ptregs.ARM_cpsr = get_cpsr_reg();
			m_ipi->buf.bt.all_register_valid = 0;         /*--- Registerdump sinnfrei ---*/
			m_ipi->buf.bt.svc_sp = current_sp;
			pr_info("[%s] NO_EXCEPTION_CONTEXT! BT register set not valid!\n", __func__);
		}
		get_cp15_register(&m_ipi->buf.bt);
		break;
	case monitor_nop:
	default:
		break;
	}
	dsb();
	atomic_set(&m_ipi->ready, 1);
}

/**
 * FAST-IRQ-Kontext
 */
static irqreturn_t firq_monitor(unsigned int ipi, struct pt_regs *regs, void *ctx)
{
	struct _monitor_ipi *m_ipi = &IPI_Monitor[raw_smp_processor_id()];

	monitor_ipi_firq_context(m_ipi);
	return IRQ_HANDLED;
}

/**
 * Absetzen eines Monitor-Befehls um synchron Infos von anderen CPU's zu erhalten
 * ret: 0 ok
 */
static noinline int trigger_firq_monitor(unsigned int cpu, enum _monitor_ipi_type type, void *buf, struct pt_regs *exception_regs)
{
	int ret = 0, os_context;
	unsigned long flags = 0, retry = 1000;
	struct _monitor_ipi *m_ipi = &IPI_Monitor[cpu];

	if (cpu > ARRAY_SIZE(IPI_Monitor)) {
		return -EINVAL;
	}
	if (m_ipi->init == 0) {
		return -EACCES;
	}
	os_context = !firq_is_avm_rte();
	if (os_context) {
		spin_lock_irqsave(&m_ipi->lock, flags);
	}
	atomic_set(&m_ipi->ready, 0);
	m_ipi->type = type;
	if (raw_smp_processor_id() == cpu) {
		if (is_cpu_mode_fiq()) {
			/*--- sind auf dieser CPU im fastirq ---*/
			monitor_ipi_firq_context(m_ipi);
		} else {
			/*--- sind auf dieser CPU (irq oder normaler kernel-kontext) ---*/
			monitor_ipi_direct_context(m_ipi, exception_regs);
		}
	} else {
		avm_rte_ipi_trigger_on(cpu, rte_monitor_ipi);
	}
	while (retry && atomic_read(&m_ipi->ready) == 0) {
		udelay(1);
		retry--;
	}
	if (atomic_read(&m_ipi->ready)) {
		switch (type) {
		case monitor_bt:
			memcpy(buf, &m_ipi->buf.bt, sizeof(m_ipi->buf.bt));
			break;
		case monitor_nop:
		default:
			break;
		}
	} else {
		pr_err("%s: for cpu%u on cpu%u%s timeout-error\n", __func__, cpu, raw_smp_processor_id(), os_context ? "" : "(fiq-context)");
		ret = -EACCES;
	}
	/*--- pr_err("%s: retry=%lu\n", __func__, retry); ---*/
	if (os_context) {
		spin_unlock_irqrestore(&m_ipi->lock, flags);
	}
	return ret;
}

/**
 */
static void _bt_show_regs(int cpu, struct _monitor_bt *pbt, struct thread_info *pthread, struct task_struct *curr_tsk)
{
	int os_context;
	unsigned int all_register_valid;
	struct pt_regs *regs;
	unsigned long flags, flag;
	char txtbuf[64];
	char buf[64];

	os_context = !firq_is_avm_rte();

	regs               = &pbt->ptregs;
	all_register_valid = pbt->all_register_valid;

	if (os_context) {
		firq_local_irq_save(flag);
	}

	pr_err("\n");
	pr_err("CPU: %d Pid: %d, comm: %20s\n", cpu, (curr_tsk ? task_pid_nr(curr_tsk) : -1),
			(curr_tsk ? curr_tsk->comm : "?"));
	pr_err("       %s  (%s %.*s)\n",        print_tainted(), init_utsname()->release,
			(int)strcspn(init_utsname()->version, " "),
			init_utsname()->version);
	if (user_mode(regs)) {
		pr_err("PC is at %s\n", get_user_symbol(txtbuf, sizeof(txtbuf), pthread, regs->ARM_pc));
		pr_err("LC is at %s\n", get_user_symbol(txtbuf, sizeof(txtbuf), pthread, regs->ARM_lr));
	} else {
		print_symbol("PC is at %s\n", instruction_pointer(regs));
		print_symbol("LR is at %s\n", regs->ARM_lr);
	}
	if (all_register_valid) {
		pr_err("pc :[<%08lx>] lr :[<%08lx>] psr: %08lx\n"
				"sp :  %08lx   ip :  %08lx   fp : %08lx\n",
				regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
				regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
		pr_err("r10:  %08lx   r9 :  %08lx   r8 : %08lx\n",
				regs->ARM_r10, regs->ARM_r9,
				regs->ARM_r8);
		pr_err("r7 :  %08lx   r6 : %08lx    r5 : %08lx r4 : %08lx\n",
				regs->ARM_r7, regs->ARM_r6,
				regs->ARM_r5, regs->ARM_r4);
		pr_err("r3 :  %08lx   r2 : %08lx    r1 : %08lx r0 : %08lx\n",
				regs->ARM_r3, regs->ARM_r2,
				regs->ARM_r1, regs->ARM_r0);
	} else {
		pr_err("pc :[<%08lx>] lr :[<%08lx>] psr: %08lx\n"
					   "sp :  %08lx   fp :  %08lx\n",
				regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
				regs->ARM_sp, regs->ARM_fp);
	}
	flags = regs->ARM_cpsr;
	buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
	buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
	buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
	buf[4] = '\0';

	pr_err("Flags: %s  IRQs o%s  FIQs o%s  Mode %s  ISA %s Segment %s\n",
		buf, interrupts_enabled(regs) ? "n" : "ff",
		fast_interrupts_enabled(regs) ? "n" : "ff",
		processor_modes[processor_mode(regs)],
		isa_modes[isa_mode(regs)],
		(pthread ? ((pthread->addr_limit == get_ds()) ? "kernel" : "user") : "?"));
#ifdef CONFIG_CPU_CP15
		buf[0] = '\0';
#ifdef CONFIG_CPU_CP15_MMU
		snprintf(buf, sizeof(buf), "  Table: %08lx  DAC: %08lx", pbt->transbase, pbt->dac);
#endif
		pr_err("Control: %08lx%s\n", pbt->ctrl, buf);
#endif

	if (os_context) {
		firq_local_irq_restore(flag);
	}
}

/**
 */
static void bt_show_regs(int cpu, struct _monitor_bt *pbt, struct thread_info *pthread)
{
	int os_context;
	unsigned long flag;
	struct pt_regs *regs;
	struct task_struct *curr_tsk = NULL;

	os_context = !firq_is_avm_rte();

	regs		= &pbt->ptregs;
	curr_tsk	= pthread->task;

	if (os_context) {
		firq_local_irq_save(flag);
	}

	_bt_show_regs(cpu, pbt, pthread, curr_tsk);

	arch_show_register_memoryclassifier(regs);

	if (os_context) {
		firq_local_irq_restore(flag);
	}
}

/**
 *	\brief: Backtrace aller CPU's ueber den FAST-IRQ
 *	\param: exception_context falls Ausgabe aus Exception passiert
 *			(sonst i.d.R. ueberfluessiger Backtrace des Exceptionhandlers)
 *	cpu_mask: NULL all cpu's - sonst cpu's entsprechend mask
 */
#define AVM_SAVE_BT_REGS()						\
	do {								\
		asm volatile(						\
			"push	{r0-r7}				\n"	\
			:						\
			:						\
			: "memory", "cc"				\
			)						\
	while (0)

#define AVM_RESTORE_BT_REGS()						\
	do {								\
		asm volatile(						\
			"pop	{r0-r7}				\n"	\
			:						\
			:						\
			: "memory", "cc"				\
			)						\
	while (0)

/**
 */
bool avm_trigger_all_cpu_backtrace(struct pt_regs *exception_regs, cpumask_t *cpu_mask)
{
	struct _monitor_bt bt;
	unsigned int cpu;
	cpumask_t cpu_bt_stat;

	if (cpu_mask)
		cpu_bt_stat = *cpu_mask;
	else
		cpumask_setall(&cpu_bt_stat);

	if (atomic_add_return(1, &backtrace_busy) > 1) {
		return 0;
	}
	for_each_online_cpu(cpu) {
		unsigned long sp;
		struct thread_info *pthread = NULL;
		struct task_struct *curr_tsk = NULL;

		if (cpu_mask && (cpumask_test_cpu(cpu, cpu_mask) == 0)) {
			continue;
		}
		memset(&bt, 0, sizeof(bt));
		if (trigger_firq_monitor(cpu, monitor_bt, &bt, exception_regs)) {
			cpumask_clear_cpu(cpu, &cpu_bt_stat);
			continue;
		}
		sp = bt.svc_sp;
		if (virt_addr_valid(sp)) {
			pthread = thread_info_by_sp(sp);
			if (virt_addr_valid(pthread)) {
				curr_tsk = pthread->task;
			} else {
				pthread = NULL;
			}
		}
		if (!virt_addr_valid(curr_tsk)) {
			_bt_show_regs(cpu, &bt, pthread, NULL);
			pr_emerg("Backtrace: skipped ...\n");
			if (virt_addr_valid(bt.ptregs.ARM_sp)) {
				dump_mem(KERN_ERR, "Stack: ", bt.ptregs.ARM_sp,
					min((bt.ptregs.ARM_sp & (~(THREAD_SIZE - 1))) + THREAD_SIZE,
						(bt.ptregs.ARM_sp + (PAGE_SIZE >> 1))));
			}
			continue;
		}
		bt_show_regs(cpu, &bt, pthread);
		if (!user_mode(&bt.ptregs) || in_interrupt()) {
#ifdef CONFIG_ARM_UNWIND
			pr_emerg("Backtrace:\n");
			unwind_backtrace(&bt.ptregs, NULL);
#else
			show_stack(curr_tsk, (void *)bt.ptregs.ARM_sp);
#endif/*--- #ifdef CONFIG_ARM_UNWIND ---*/
			if (!is_cpu_mode_fiq()) {
				dump_instr(KERN_ERR, &bt.ptregs);
			}
			dump_mem(KERN_ERR, "Stack: ", bt.ptregs.ARM_sp,
					min((bt.ptregs.ARM_sp & (~(THREAD_SIZE - 1))) + THREAD_SIZE,
						(bt.ptregs.ARM_sp + (PAGE_SIZE >> 1))));
#if defined(show_stacktrace_memoryclassifier)
			show_stacktrace_memoryclassifier(&bt.ptregs);
#endif/*--- #if defined(show_stacktrace_memoryclassifier) ---*/
		}
	}
	atomic_set(&backtrace_busy, 0);
	return cpumask_weight(&cpu_bt_stat) ? 1 : 0;
}

/**
 * installiere auf jeder CPU ein monitor-ipi-linux-firq
 */
static int monitor_ipi_init(void)
{
	int cpu;
	int ret;

	for_each_cpu(cpu, cpu_online_mask) {
		spin_lock_init(&IPI_Monitor[cpu].lock);
		IPI_Monitor[cpu].init = 0;
	}

	ret = avm_rte_ipi_request(AVM_RTE_IPI_ALLOC_NR, firq_monitor, NULL, AVM_RTE_IPI_SECURE, 0x0, "RTE monitor");

	if (ret)
		rte_monitor_ipi = ret;
	else
		pr_err("Could not register sgi monitor ipi\n");

	for_each_cpu(cpu, cpu_online_mask)
		IPI_Monitor[cpu].init = 1;

	atomic_set(&backtrace_busy, 0);
	return 0;
}
late_initcall(monitor_ipi_init);
#endif/*--- #if defined(CONFIG_AVM_FASTIRQ) ---*/

/**
 */
void ai_add_to_scorelist(unsigned long pc, int user)
{
#if defined(UNALIGNED_MAX_SCORE_ENTRIES)
	if (user) {
		add_unaligned_access_to_table(pc, user_score_table, UNALIGNED_MAX_SCORE_ENTRIES, 1);
		return;
	}
	add_unaligned_access_to_table(pc, sys_score_table, UNALIGNED_MAX_SCORE_ENTRIES, 0);
#endif/*--- #if defined(UNALIGNED_MAX_SCORE_ENTRIES) ---*/
}

/**
 */
unsigned long ai_show_scorelist(struct seq_file *seq, int user)
{
#if defined(UNALIGNED_MAX_SCORE_ENTRIES)
	if (user) {
		return show_unaligned_access_table(seq, user_score_table, UNALIGNED_MAX_SCORE_ENTRIES, 1);
	}
	return show_unaligned_access_table(seq, sys_score_table, UNALIGNED_MAX_SCORE_ENTRIES, 0);
#else
	return 0;
#endif/*--- #if defined(UNALIGNED_MAX_SCORE_ENTRIES) ---*/
}

/**
 */
void print_code_range(struct seq_file *seq, const char *prefix, unsigned long addr, unsigned int thumb)
{
	const int width = thumb ? 4 : 8;
	mm_segment_t fs;
	char str[sizeof("0x00000000 ") * 10 + 2 + 1], *p = str;
	int i;
	unsigned long start_addr = 0;

	/*
	 * We need to switch to kernel mode so that we can use __get_user
	 * to safely read from kernel space.  Note that we now dump the
	 * code first, just in case the backtrace kills us.
	 */
	fs = get_fs();
	set_fs(KERNEL_DS);

	for (i = -2; i < 3 + !!thumb; i++) {
		unsigned int val, bad;

		if (thumb) {
			bad = __get_user(val, &((u16 *)addr)[i]);
			if (start_addr == 0)
				start_addr = (unsigned long)&((u16 *)addr)[i];
		} else {
			bad = __get_user(val, &((u32 *)addr)[i]);
			if (start_addr == 0)
				start_addr = (unsigned long)&((u32 *)addr)[i];
		}

		if (!bad)
			p += sprintf(p, i == 0 ? "<0x%0*x> " : "0x%0*x ", width, val);
		else {
			p += sprintf(p, "bad PC value");
			break;
		}
	}
	set_fs(fs);
	if (seq) {
		seq_printf(seq, "%s Code(0x%08lx): %s\n", prefix, start_addr, str);
	} else {
		pr_err("%s Code(0x%08lx): %s\n", prefix, start_addr, str);
	}
}

/**
 */
#define IS_KERNEL_ADDR		  0x1
#define IS_MODULE_ADDR		  0x2
#define IS_VMALLOC_ADDR		  0x3
#define IS_STACK_ADDR		  0x4

int memory_classifier(unsigned long addr)
{
	if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_end)) {
		return IS_KERNEL_ADDR;
	} else if (is_module_text_address(addr)) {
		return IS_MODULE_ADDR;
	} else if (is_vmalloc_addr((void *)addr)) {
		return IS_VMALLOC_ADDR;
	} else if (object_is_on_stack((void *)addr)) {
		return IS_STACK_ADDR;
	}
	return 0;
}
/**
 * @return NULL no virtual addr
 */
static struct page *memory_page_classifier(unsigned long addr)
{
	if (virt_addr_valid(addr)) {
		return virt_to_head_page((void *)addr);
	}
	return NULL;
}
/**
 */
static char *print_vmflags(char *txt, unsigned int txtlen, unsigned long vm_flags)
{
	char *txt_start = txt;

	if (txt == NULL)
		return NULL;
	txt[0] = 0;
	if (vm_flags & VM_IOREMAP)
		snprintf_add(txt, txtlen, "ioremap ");
	if (vm_flags & VM_ALLOC)
		snprintf_add(txt, txtlen, "vmalloc ");
	if (vm_flags & VM_MAP)
		snprintf_add(txt, txtlen, "vmap ");
	if (vm_flags & VM_USERMAP)
		snprintf_add(txt, txtlen, "user ");
	if (vm_flags & VM_VPAGES)
		snprintf_add(txt, txtlen, "vpages ");
	if (vm_flags & VM_KASAN)
		snprintf_add(txt, txtlen, "kasan ");
	if (txt_start[0] == 0)
		snprintf_add(txt, txtlen, "vm_flags=0x%lx ", vm_flags);
	return txt_start;
}
/**
 */
char *arch_print_memory_classifier(char *txt, unsigned int txtlen, unsigned long addr, int include_addr_prefix)
{
	char *modname __maybe_unused;
	char sym[KSYM_SYMBOL_LEN];
	char txtbuf[TASK_COMM_LEN + 16];
	char *txt_start = txt;
	unsigned long caller, size, offset __maybe_unused, start, flags, vmflags;
	int freed, type;
	const char *name;
	static struct page *page;
	struct zone *zone;

	if (include_addr_prefix) {
		snprintf_add(txt, txtlen, "0x%08lx ", addr);
	} else {
		txt[0] = 0;
	}
	type = memory_classifier(addr);
	switch (type) {
	case IS_KERNEL_ADDR:
	case IS_MODULE_ADDR:
#ifdef CONFIG_KALLSYMS
		name = kallsyms_lookup(addr, &size, &offset, &modname, sym);
		if (!name) {
			return txt_start;
		}
		snprintf_add(txt, txtlen, "%s+%#lx/%#lx", name, offset, size);
		if (modname) {
			snprintf_add(txt, txtlen, " [%s]", modname);
		}
#else
#if defined(CONFIG_AVM_BOOTMEM)
		if (!IS_ERR(module_alloc_find_module_name)) {
			module_alloc_find_module_name(txt, txt + txtlen, addr);
		}
#endif /*--- #if defined(CONFIG_AVM_BOOTMEM) ---*/
#endif
		return txt_start;
	case IS_VMALLOC_ADDR:
#if defined(CONFIG_AVM_FASTIRQ)
		if (is_cpu_mode_fiq()) {
			return txt_start;
		}
#endif
		start = get_vmap_area(addr, &caller, &size, &vmflags);
		if (start) {
			snprintf(txt, txtlen, "[%s: size:%lu start:%p+0x%lx alloced by:%pS]",
							print_vmflags(txtbuf, sizeof(txtbuf), vmflags),
							size, (void *)start, addr - start,  (void *)caller);
		}
		return txt_start;
	case IS_STACK_ADDR:
		break;
	default:
		break;
	}
	start = get_taskstack_area(addr, txtbuf, sizeof(txtbuf), type == IS_STACK_ADDR ? 1 : 0);
	if (start) {
		snprintf(txt, txtlen, "[%s: %p+0x%lx]", txtbuf, (void *)start, addr - start);
		return txt_start;
	}
#ifdef CONFIG_AVM_RTE
	start = get_simplemempool_area(addr, &caller, txtbuf, sizeof(txtbuf), &size, &freed);
	if (start) {
		if (caller) {
			snprintf(sym, sizeof(sym), " allocated by:%pS ", (void *)caller);
		} else {
			sym[0] = 0;
		}
		snprintf(txt, txtlen, "[smempool: type:%s size:%lu start:%p%c0x%lx %s%s]", txtbuf,
							size,
							(void *)start,
							addr >= start ? '+' : '-',
							addr >= start ? addr - start : start - addr,
							sym,
							freed == 0   ? "" :
							freed == 1   ? "free" :
							freed == 2   ? "ctrl" : "padding");
		return txt_start;
	}
	if (is_cpu_mode_fiq()) {
		return txt_start;
	}
#endif
	page = memory_page_classifier(addr);
	if (!page) {
		return txt_start;
	}
	zone = page_zone(page);
	if (!spin_trylock_irqsave(&zone->lock, flags)) {
		return txt_start;
	}
	if (PageSlab(page)) {
		start = get_kmemalloc_area(addr, &caller, &name, &size, &freed);
		if (start) {
			if (caller) {
				snprintf(sym, sizeof(sym), " %s by:%pS", freed ? "freed" : "allocated", (void *)caller);
			} else {
				sym[0] = 0;
			}
			snprintf(txt, txtlen, "[slab: type:%s size:%lu start:0x%p+0x%lx%s]", name, size, (void *)start,
							addr - start,
							sym);
		}
	} else if (PageReserved(page)) {
		snprintf(txt, txtlen, "[page: type:reserved]");
	} else if ((atomic_read(&page->_count))) {
		char ordertxt[32];
		unsigned int order;
		unsigned long current_pc = 0;
#if defined(CONFIG_AVM_PAGE_TRACE)
		current_pc = avm_get_page_current_pc(page);
#endif/*--- #if defined(CONFIG_AVM_PAGE_TRACE) ---*/

		if (current_pc) {
			snprintf(sym, sizeof(sym), " by:%pS", (void *)current_pc);
		} else {
			sym[0] = 0;
		}
		order = compound_order(page);
		if (order) {
			snprintf(ordertxt, sizeof(ordertxt), " O%u[%lu]",
				 order,
				 virt_to_pfn(addr) - page_to_pfn(page));
		} else {
			ordertxt[0] = 0;
		}
		snprintf(txt, txtlen, "[page%s: type:alloc%s]", ordertxt, sym);
	}
	spin_unlock_irqrestore(&zone->lock, flags);
	return txt_start;
}
EXPORT_SYMBOL(print_memory_classifier);
/**
 */
static int match_data(unsigned long data, unsigned long data_array[], unsigned int array_elements)
{
	unsigned int i;

	for (i = 0; i < array_elements; i++) {
		if (data_array[i] == 0) {
			data_array[i] = data;
			return 0;
		}
		if (data_array[i] == data) {
			return 1;
		}
	}
	return 0;
}

/**
 */
void arch_show_stacktrace_memoryclassifier(const struct pt_regs *pregs)
{
	unsigned long data_hist[40];
	char txt[KSYM_SYMBOL_LEN];
	unsigned long sp, sp_top;
	unsigned int start = 0, limit = 0;
	unsigned long stackdata;
	int fs;

	if (pregs == NULL) {
		return;
	}
	if (user_mode(pregs)) {
		return;
	}
	fs = get_fs();
	set_fs(KERNEL_DS);

	sp     = kernel_stack_pointer((struct pt_regs *)pregs);
	sp_top = (sp & ~(THREAD_SIZE - 1)) + THREAD_SIZE;

	for (; sp < sp_top; sp += 4) {
		if (limit > 60) {
			break;
		}
		if (__get_user(stackdata, (unsigned long *)sp)) {
			break;
		}
		if (start >= ARRAY_SIZE(data_hist)) {
			pr_err("...\n");
			break;
		}
		if (stackdata && match_data(stackdata, data_hist, ARRAY_SIZE(data_hist))) {
			continue;
		}
		print_memory_classifier(txt, sizeof(txt), stackdata, 0);
		if (txt[0]) {
			if (start == 0) {
				pr_err("Classified pointer on stack:\n");
			}
			start++;
			pr_err("%08lx %s\n", stackdata, txt);
		}
		limit++;
	}
	set_fs(fs);
}
static char *reg_name[] = {"r0 ", "r1 ", "r2 ", "r3 ", "r4 ", "r5 ", "r6 ", "r7 ", "r8 ", "r9 ", "r10", "ip ", "fp "};
/**
 */
void arch_show_register_memoryclassifier(const struct pt_regs *regs)
{
	unsigned long reg[13];
	char txt[KSYM_SYMBOL_LEN];
	unsigned int i, start = 0;

	if (regs == NULL) {
		return;
	}
	if (user_mode(regs)) {
		return;
	}
	reg[0]  = regs->ARM_r0, reg[1]  = regs->ARM_r1, reg[2] = regs->ARM_r2, reg[3]  = regs->ARM_r3;
	reg[4]  = regs->ARM_r4, reg[5]  = regs->ARM_r5, reg[6] = regs->ARM_r6, reg[7]  = regs->ARM_r7;
	reg[7]  = regs->ARM_r7, reg[8]  = regs->ARM_r8, reg[9] = regs->ARM_r9, reg[10] = regs->ARM_r10;
	reg[11] = regs->ARM_ip, reg[12] = regs->ARM_fp;

	for (i = 0; i < ARRAY_SIZE(reg); i++) {
		print_memory_classifier(txt, sizeof(txt), reg[i], 0);
		if (txt[0]) {
			if (start == 0) {
				start = 1;
				pr_err("Classified pointer on registers:\n");
			}
			pr_err("%s: %08lx %s\n", reg_name[i], reg[i], txt);
		}
	}
}