On Wed, Jun 22, 2016 at 01:35:02PM +0900, AKASHI Takahiro wrote:
 Signed-off-by: AKASHI Takahiro <takahiro.akashi(a)linaro.org>
 ---
  arm64.c | 504 +++++++++++++++++++++++++++++++++++++++++++---------------------
  defs.h  |   6 +
  2 files changed, 344 insertions(+), 166 deletions(-)
 
 diff --git a/arm64.c b/arm64.c
 index 06676d1..4f85772 100644
 --- a/arm64.c
 +++ b/arm64.c
 @@ -42,18 +42,18 @@ static void arm64_irq_stack_init(void);
  static void arm64_stackframe_init(void);
  static int arm64_eframe_search(struct bt_info *);
  static int arm64_is_kernel_exception_frame(struct bt_info *, ulong);
 -static int arm64_in_exception_text(ulong);
 +static int arm64_in_exp_entry(ulong);
  static void arm64_back_trace_cmd(struct bt_info *);
  static void arm64_print_text_symbols(struct bt_info *, struct arm64_stackframe *, FILE
*);
  static int arm64_print_stackframe_entry(struct bt_info *, int, struct arm64_stackframe
*, FILE *);
 -static void arm64_display_full_frame(struct bt_info *, ulong);
 -static int arm64_unwind_frame(struct bt_info *, struct arm64_stackframe *);
 +static void arm64_display_full_frame(struct bt_info *, struct arm64_stackframe *, struct
arm64_stackframe *);
 +static int arm64_unwind_frame(struct bt_info *, struct arm64_stackframe *, FILE *);
  static int arm64_get_dumpfile_stackframe(struct bt_info *, struct arm64_stackframe *);
  static int arm64_in_kdump_text(struct bt_info *, struct arm64_stackframe *);
  static int arm64_in_kdump_text_on_irq_stack(struct bt_info *);
 -static int arm64_switch_stack(struct bt_info *, struct arm64_stackframe *, FILE *);
  static int arm64_get_stackframe(struct bt_info *, struct arm64_stackframe *);
  static void arm64_get_stack_frame(struct bt_info *, ulong *, ulong *);
 +static void arm64_gen_hidden_frame(struct bt_info *bt, ulong, struct arm64_stackframe
*);
  static void arm64_print_exception_frame(struct bt_info *, ulong, int, FILE *);
  static void arm64_do_bt_reference_check(struct bt_info *, ulong, char *);
  static int arm64_translate_pte(ulong, void *, ulonglong);
 @@ -580,6 +580,10 @@ arm64_dump_machdep_table(ulong arg)
  	fprintf(fp, "  __exception_text_end: %lx\n", ms->__exception_text_end);
  	fprintf(fp, " __irqentry_text_start: %lx\n", ms->__irqentry_text_start);
  	fprintf(fp, "   __irqentry_text_end: %lx\n", ms->__irqentry_text_end);
 +	fprintf(fp, "      exp_entry1_start: %lx\n", ms->exp_entry1_start);
 +	fprintf(fp, "        exp_entry1_end: %lx\n", ms->exp_entry1_end);
 +	fprintf(fp, "      exp_entry2_start: %lx\n", ms->exp_entry2_start);
 +	fprintf(fp, "        exp_entry2_end: %lx\n", ms->exp_entry2_end);
  	fprintf(fp, "       panic_task_regs: %lx\n", (ulong)ms->panic_task_regs);
  	fprintf(fp, "         PTE_PROT_NONE: %lx\n", ms->PTE_PROT_NONE);
  	fprintf(fp, "              PTE_FILE: ");
 @@ -1286,6 +1290,15 @@ arm64_stackframe_init(void)
  		machdep->machspec->__irqentry_text_start = sp1->value; 
  		machdep->machspec->__irqentry_text_end = sp2->value; 
  	} 
 +	if ((sp1 = kernel_symbol_search("vectors")) &&
 +	    (sp1n = kernel_symbol_search("cpu_switch_to")) &&
 +	    (sp2 = kernel_symbol_search("ret_fast_syscall")) &&
 +	    (sp2n = kernel_symbol_search("sys_rt_sigreturn_wrapper"))) {
 +		machdep->machspec->exp_entry1_start = sp1->value;
 +		machdep->machspec->exp_entry1_end = sp1n->value;
 +		machdep->machspec->exp_entry2_start = sp2->value;
 +		machdep->machspec->exp_entry2_end = sp2n->value;
 +	}
  
  	if ((sp1 = kernel_symbol_search("crash_kexec")) &&
  	    (sp1n = next_symbol(NULL, sp1)) && 
 @@ -1472,25 +1485,20 @@ arm64_eframe_search(struct bt_info *bt)
  }
  
  static int
 -arm64_in_exception_text(ulong ptr)
 +arm64_in_exp_entry(ulong addr)
  {
 -	struct machine_specific *ms = machdep->machspec;
 +	struct machine_specific *ms;
  
 -	if ((ptr >= ms->__exception_text_start) &&
 -	    (ptr < ms->__exception_text_end))
 +	ms = machdep->machspec;
 +	if ((ms->exp_entry1_start <= addr) && (addr < ms->exp_entry1_end))
  		return TRUE;
 -
 -	if (ms->__irqentry_text_start && ms->__irqentry_text_end &&
 -	    ((ptr >= ms->__irqentry_text_start) && 
 -	    (ptr < ms->__irqentry_text_end)))
 +	if ((ms->exp_entry2_start <= addr) && (addr < ms->exp_entry2_end))
  		return TRUE;
 -
  	return FALSE;
  }
  
  #define BACKTRACE_CONTINUE        (1)
  #define BACKTRACE_COMPLETE_KERNEL (2)
 -#define BACKTRACE_COMPLETE_USER   (3)
  
  static int 
  arm64_print_stackframe_entry(struct bt_info *bt, int level, struct arm64_stackframe
*frame, FILE *ofp)
 @@ -1511,11 +1519,6 @@ arm64_print_stackframe_entry(struct bt_info *bt, int level, struct
arm64_stackfr
                                  value_to_symstr(frame->pc, buf, bt->radix);
          }
  
 -	if ((bt->flags & BT_FULL) && level) {
 -		arm64_display_full_frame(bt, frame->fp);
 -		bt->frameptr = frame->fp;
 -	}
 -
          fprintf(ofp, "%s#%d [%8lx] %s at %lx", level < 10 ? " " :
"", level,
                  frame->fp ? frame->fp : bt->stacktop - USER_EFRAME_OFFSET, 
  		name_plus_offset ? name_plus_offset : name, frame->pc);
 @@ -1534,7 +1537,8 @@ arm64_print_stackframe_entry(struct bt_info *bt, int level, struct
arm64_stackfr
  			fprintf(ofp, "    %s\n", buf);
  	}
  
 -	if (STREQ(name, "start_kernel") || STREQ(name,
"secondary_start_kernel") ||
 +	if (STREQ(name, "start_kernel") ||
 +	    STREQ(name, "secondary_start_kernel") ||
  	    STREQ(name, "kthread") || STREQ(name, "kthreadd"))
  		return BACKTRACE_COMPLETE_KERNEL;
  
 @@ -1542,46 +1546,169 @@ arm64_print_stackframe_entry(struct bt_info *bt, int level,
struct arm64_stackfr
  }
  
  static void
 -arm64_display_full_frame(struct bt_info *bt, ulong sp)
 +arm64_display_full_frame(struct bt_info *bt, struct arm64_stackframe *cur,
 +						struct arm64_stackframe *next)
  {
 +	struct machine_specific *ms;
 +	ulong next_fp, stackbase;
 +	char *stackbuf;
  	int i, u_idx;
  	ulong *up;
  	ulong words, addr;
  	char buf[BUFSIZE];
  
 -	if (bt->frameptr == sp)
 -		return;
 +	stackbase = bt->stackbase;
 +	stackbuf = bt->stackbuf;
 +	ms = machdep->machspec;
  
 -	if (!INSTACK(sp, bt) || !INSTACK(bt->frameptr, bt)) {
 -		if (sp == 0)
 -			sp = bt->stacktop - USER_EFRAME_OFFSET;
 -		else
 -			return;
 -	}
 +	/* Calc next fp for dump */
 +	if (next->fp == 0)
 +		/* last stackframe on kernel tack */
 +		next_fp = bt->stacktop - 0x10;
 +	else if (!INSTACK(cur->sp, bt)) {
 +		/* We have just switched over stacks */
 +		next_fp = ms->irq_stacks[bt->tc->processor]
 +				+ ms->irq_stack_size - 0x10;
  
 -	words = (sp - bt->frameptr) / sizeof(ulong);
 +		/*
 +		 * We are already buffering a process stack.
 +		 * So use an old buffer for IRQ stack.
 +		 */
 +		stackbase = ms->irq_stacks[bt->tc->processor];
 +		stackbuf = ms->irq_stackbuf;
 +	} else
 +		next_fp = next->fp;
  
 -	addr = bt->frameptr;
 -	u_idx = (bt->frameptr - bt->stackbase)/sizeof(ulong);
 +	if (CRASHDEBUG(1))
 +		fprintf(fp, "    frame <%016lx:%016lx>\n", cur->fp, next_fp);
 +
 +	/* Check here because we want to see a debug message above. */
 +	if (!(bt->flags & BT_FULL))
 +		return;
 +
 +	/* Dump */
 +	words = (next_fp - cur->fp) / sizeof(ulong);
 +	addr = cur->fp;
 +	u_idx = (cur->fp - stackbase)/sizeof(ulong);
  	for (i = 0; i < words; i++, u_idx++) {
  		if (!(i & 1)) 
  			fprintf(fp, "%s    %lx: ", i ? "\n" : "", addr);
  
 -		up = (ulong *)(&bt->stackbuf[u_idx*sizeof(ulong)]);
 +		up = (ulong *)(&stackbuf[u_idx*sizeof(ulong)]);
  		fprintf(fp, "%s ", format_stack_entry(bt, buf, *up, 0));
  
  		addr += sizeof(ulong);
  	}
  	fprintf(fp, "\n");
 +
 +	if (stackbuf == ms->irq_stackbuf)
 +		FREEBUF(stackbuf);
  }
  
 -static int 
 -arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame)
 +/*
 + * (1)Normal frame:
 + *     +------+
 + *     | pfp  |
 + *     | cpc  |
 + * psp +      +
 + *     |      |
 + *     |      |
 + * pfp +------+ <--- :prev stackframe = <pfp, psp, ppc>
 + *     | cfp  |
 + *     | npc  |
 + * csp +      +
 + *     |      |
 + *     |      |
 + * cfp +------+ <--- :curr stackframe = <cfp, csp, cpc>
 + *     | nfp  |   |                         cfp = *pfp
 + *     | Npc  |   |                         csp = pfp + 0x10
 + * nsp +      +  real stackframe
 + *     |      |   |         at cpc
 + *     |      |   |
 + * nfp +------+ <--- :next stackframe = <nfp, nsp, npc>
 + *     |      |
 + *
 + * (2)Exception:
 + *     +------+
 + *     | pfp  |
 + *     | cpc  |
 + * psp +      +
 + *     |      |
 + *     |      |
 + * pfp +------+ <--- :prev stackframe = <pfp, psp, ppc>
 + *     | cfp  |
 + *     | npc  |
 + * csp +      +
 + *     |      |
 + *     |      |
 + * cfp +------+ <--- :stackframe = <cfp, csp, cpc>
 + *     | nfp  |
 + *     | epc  |
 + *     +      +
 + *     |      |
 + *     |      |       calced dummy
 + * esp +------+ <--- :exp stackframe = <---, esp, epc>
 + *     |      |                           esp = nsp - sizeof(pt_regs)
 + *     |      |
 + *     | Npc  |
 + *     | nfp  |
 + *     | nsp  |
 + *     | npc  |
 + * nsp +      +
 + *     |      |       calced missing
 + * nfp +------+ <--- :task stackframe = <nfp, nsp, npc>
 + *     | Nfp  |
 + *     | NNpc |
 + * Nsp +      +
 + *     |      |
 + * Nfp +------+ <--- :task stackframe = <Nfp, Nsp, Npc>
 + *     | NNfp |
 + *
 + * (3)At interrupt:
 + *     +------+
 + *     | pfp  |
 + *     | cpc  |
 + * psp +      +
 + *     |      |
 + *     |      |
 + * pfp +------+ <--- :prev stackframe = <pfp, psp, ppc>
 + *     | cfp  |
 + *     | epc  |
 + * csp +      +
 + *     |      |
 + *     |      |       calced dummy
 + * cfp +------+ <--- :irq stackframe = <cfp, csp, epc>
 + *     | nfp  |                          | if (cfp == IRQ_STACK_PTR)
 + *     | esp  |                          V
 + * top +------+                        <---, esp, epc>
 + *     IRQ stack
 + *
 + *                    calced dummy
 + * esp +------+ <--- :exp stackframe = <---, esp, epc>
 + *     |      |                            esp = nsp - sizeof(pt_regs)
 + *     |      |
 + *     | Npc  |
 + *     | nfp  |
 + *     | nsp  |
 + *     | npc  |       calced missing
 + * nfp +------+ <--- :task stackframe = <nfp, nsp, npc>
 + *     | Nfp  |
 + *     | NNpc |
 + * Nsp +      +
 + *     |      |
 + * Nfp +------+ <--- :task stackframe = <Nfp, Nsp, Npc>
 + *     | NNfp |
 + */
 +
 +static struct arm64_stackframe ext_frame;
 +
 +static int
 +arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame,
 +								FILE *ofp)
  {
  	unsigned long high, low, fp;
  	unsigned long stack_mask;
 -	unsigned long irq_stack_ptr, orig_sp;
 -	struct arm64_pt_regs *ptregs;
 +	unsigned long irq_stack_ptr;
  	struct machine_specific *ms;
  
  	stack_mask = (unsigned long)(ARM64_STACK_SIZE) - 1;
 @@ -1593,54 +1720,115 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe
*frame)
  	if (fp < low || fp > high || fp & 0xf)
  		return FALSE;
  
 -	frame->sp = fp + 0x10;
 -	frame->fp = GET_STACK_ULONG(fp);
 +	if (CRASHDEBUG(1))
 +		fprintf(ofp, "    cur fp:%016lx sp:%016lx pc:%016lx\n",
 +					frame->fp, frame->sp, frame->pc);
 +
 +	if (ext_frame.pc) {
 +		/*
 +		 * Previous frame was a dummy for exception entry.
 +		 * So insert a hidden (real) stackframe.
 +		*/
 +		frame->fp = ext_frame.fp;
 +		frame->sp = ext_frame.sp;
 +		frame->pc = ext_frame.pc;
 +
 +		ext_frame.pc = 0; /* back to normal unwinding */
 +
 +		goto unwind_done;
 +	}
 +
  	frame->pc = GET_STACK_ULONG(fp + 8);
 +	if (!arm64_in_exp_entry(frame->pc)) {
 +		/* Normal stack frame */
  
 -	/*
 -	 * The kernel's manner of determining the end of the IRQ stack:
 -	 *
 -	 *  #define THREAD_SIZE        16384
 -	 *  #define THREAD_START_SP    (THREAD_SIZE - 16)
 -	 *  #define IRQ_STACK_START_SP THREAD_START_SP
 -	 *  #define IRQ_STACK_PTR(cpu) ((unsigned long)per_cpu(irq_stack, cpu) +
IRQ_STACK_START_SP)
 -	 *  #define IRQ_STACK_TO_TASK_STACK(ptr) (*((unsigned long *)((ptr) - 0x08)))
 -	 *
 -	 *  irq_stack_ptr = IRQ_STACK_PTR(raw_smp_processor_id());
 -	 *  orig_sp = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr);   (pt_regs pointer on process
stack)
 -	 */
 -	if (machdep->flags & IRQ_STACKS) {
 -		ms = machdep->machspec;
 -		irq_stack_ptr = ms->irq_stacks[bt->tc->processor] + ms->irq_stack_size -
16;
 -
 -		if (frame->sp == irq_stack_ptr) {
 -			orig_sp = GET_STACK_ULONG(irq_stack_ptr - 8);
 -			arm64_set_process_stack(bt);
 -			if (INSTACK(orig_sp, bt) && (INSTACK(frame->fp, bt) || (frame->fp ==
0))) {
 -				ptregs = (struct arm64_pt_regs
*)&bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(orig_sp))];
 -				frame->sp = orig_sp;
 -				frame->pc = ptregs->pc;
 -				bt->bptr = fp;
 -				if (CRASHDEBUG(1))
 -					error(INFO, 
 -					    "arm64_unwind_frame: switch stacks: fp: %lx sp: %lx  pc: %lx\n",
 -						frame->fp, frame->sp, frame->pc);
 +		frame->sp = fp + 0x10;
 +		frame->fp = GET_STACK_ULONG(fp);
 +	} else {
 +		/*
 +		 * We are in exception entry code, and so need to
 +		 *   - fake a dummy frame for exception frame, and
 +		 *   - complement a stackframe hidden by exception
 +		 */
 +
 +		ext_frame.fp = GET_STACK_ULONG(fp);
 +		if (ext_frame.fp == 0) {
 +			/*
 +			 * Either on process stack or on IRQ stack,
 +			 * the next frame is the last one on process stack.
 +			 */
 +
 +			frame->sp = bt->stacktop
 +				    - sizeof(struct arm64_pt_regs) - 0x10;
 +			frame->fp = frame->sp;
 +		} else if (!arm64_on_irq_stack(bt->tc->processor, frame->sp)) {
 +			/*
 +			 * We are on process stack. Just fake a dummy frame
 +			 */
 +
 +			if (!arm64_on_irq_stack(bt->tc->processor, fp)) 
Obviously I meant "if (arm64_on_irq_stack(bt->tc->processor,fp))"
 +				/*
 +				 * Very rare corner case:
 +				 * We have already exited an irq handler,
 +				 * and switched from IRQ stack to process
 +				 * stack but fp is not yet restored.
 +				 * Fp still points to IRQ stack, sigh.
 +				 * For example,
 +				 *   ret_to_user() after irq_handler in el0_irq
 +				 */
 +				frame->sp = bt->stacktop
 +					    - sizeof(struct arm64_pt_regs)
 +					    - 0x10; 
Anyhow, this logic seems to still have some bug.
I will try to fix it.
Sorry for any confusion.
-Takahiro AKASHI
 +			else
 +				frame->sp = ext_frame.fp
 +					    - sizeof(struct arm64_pt_regs);
 +			frame->fp = frame->sp;
 +		} else {
 +			/* We are on IRQ stack */
 +
 +			ms = machdep->machspec;
 +			irq_stack_ptr = ms->irq_stacks[bt->tc->processor]
 +						+ ms->irq_stack_size - 0x20;
 +			if (ext_frame.fp != irq_stack_ptr) {
 +				/* Just fake a dummy frame */
 +
 +				frame->sp = ext_frame.fp
 +					    - sizeof(struct arm64_pt_regs);
 +				frame->fp = frame->sp;
  			} else {
 -				error(WARNING, 
 -				    "arm64_unwind_frame: on IRQ stack: oriq_sp: %lx%s fp: %lx%s\n",
 -					orig_sp, INSTACK(orig_sp, bt) ? "" : " (?)",
 -					frame->fp, INSTACK(frame->fp, bt) ? "" : " (?)");
 -				return FALSE;
 +				/*
 +				 * switch from IRQ stack to process stack
 +				 */
 +
 +				frame->sp = GET_STACK_ULONG(irq_stack_ptr + 8);
 +				frame->fp = frame->sp;
 +
 +				/*
 +				 * Keep a buffer for a while until
 +				 * displaying the last frame on IRQ stack.
 +				 * Ugly?
 +				 */
 +				if (bt->flags | BT_FULL)
 +					ms->irq_stackbuf = bt->stackbuf;
 +
 +				arm64_set_process_stack(bt);
  			}
  		}
 +
 +		arm64_gen_hidden_frame(bt, frame->sp, &ext_frame);
  	}
  
 +unwind_done:
 +	if (CRASHDEBUG(1))
 +		fprintf(ofp, "    nxt fp:%016lx sp:%016lx pc:%016lx\n",
 +					frame->fp, frame->sp, frame->pc);
 +
  	return TRUE;
  }
  
 -/* 
 +/*
   *  A layout of a stack frame in a function looks like:
 - *  
 + *
   *           stack grows to lower addresses.
   *             /|\
   *              |
 @@ -1658,7 +1846,7 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe
*frame)
   *           | vars |
   *  old fp   +------+
   *           |      |
 - *  
 + *
   *  - On function entry, sp is decremented down to new fp.
   *
   *  - and old fp and sp are saved into this stack frame.
 @@ -1680,13 +1868,13 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe
*frame)
   *    sp shows "callee's static local variables", old fp and sp.
   *
   *  Diagram and explanation courtesy of Takahiro Akashi
 - */  
 + */
  
  static void 
  arm64_back_trace_cmd(struct bt_info *bt)
  {
 -	struct arm64_stackframe stackframe;
 -	int level;
 +	struct arm64_stackframe stackframe, cur_frame;
 +	int level, mode;
  	ulong exception_frame;
  	FILE *ofp;
  
 @@ -1708,17 +1896,7 @@ arm64_back_trace_cmd(struct bt_info *bt)
  		stackframe.fp = GET_STACK_ULONG(bt->bptr - 8);
  		stackframe.pc = GET_STACK_ULONG(bt->bptr);
  		stackframe.sp = bt->bptr + 8;
 -		bt->frameptr = stackframe.sp;
 -	} else if (bt->hp && bt->hp->esp) {
 -		if (arm64_on_irq_stack(bt->tc->processor, bt->hp->esp)) {
 -			arm64_set_irq_stack(bt);
 -			bt->flags |= BT_IRQSTACK;
 -		}
 -		stackframe.fp = GET_STACK_ULONG(bt->hp->esp - 8);
 -		stackframe.pc = bt->hp->eip ? 
 -			bt->hp->eip : GET_STACK_ULONG(bt->hp->esp);
 -		stackframe.sp = bt->hp->esp + 8;
 -		bt->flags &= ~BT_REGS_NOT_FOUND;
 +		bt->frameptr = stackframe.fp;
  	} else {
  		stackframe.sp = bt->stkptr;
  		stackframe.pc = bt->instptr;
 @@ -1739,8 +1917,14 @@ arm64_back_trace_cmd(struct bt_info *bt)
  		return;
  
  	if (!(bt->flags & BT_KDUMP_ADJUST)) {
 -		if (bt->flags & BT_USER_SPACE)
 -			goto complete_user;
 +		if (bt->flags & BT_USER_SPACE) {
 +			exception_frame = bt->stacktop - USER_EFRAME_OFFSET;
 +			arm64_print_exception_frame(bt, exception_frame,
 +							USER_MODE, ofp);
 +			fprintf(ofp, " #0 [user space]\n");
 +
 +			return;
 +		}
  
  		if (DUMPFILE() && is_task_active(bt->task)) {
  			exception_frame = stackframe.fp - SIZE(pt_regs);
 @@ -1750,53 +1934,55 @@ arm64_back_trace_cmd(struct bt_info *bt)
  		}
  	}
  
 -	level = exception_frame = 0;
 -	while (1) {
 +	for (level = 0;; level++) {
  		bt->instptr = stackframe.pc;
  
 -		switch (arm64_print_stackframe_entry(bt, level, &stackframe, ofp))
 -		{
 -		case BACKTRACE_COMPLETE_KERNEL:
 -			return;
 -		case BACKTRACE_COMPLETE_USER:
 -			goto complete_user;
 -		case BACKTRACE_CONTINUE:
 +		/*
 +		 * Show one-line stackframe info
 +		 */
 +		if (arm64_print_stackframe_entry(bt, level, &stackframe, ofp)
 +		    == BACKTRACE_COMPLETE_KERNEL)
  			break;
 -		}
 -
 -		if (exception_frame) {
 -			arm64_print_exception_frame(bt, exception_frame, KERNEL_MODE, ofp);
 -			exception_frame = 0;
 -		}
  
 -		if (!arm64_unwind_frame(bt, &stackframe))
 +		cur_frame = stackframe;
 +		if (!arm64_unwind_frame(bt, &stackframe, ofp))
  			break;
  
 -		if (arm64_in_exception_text(bt->instptr) && INSTACK(stackframe.fp, bt)) {
 -			if (!(bt->flags & BT_IRQSTACK) ||
 -			    (((stackframe.sp + SIZE(pt_regs)) < bt->stacktop)))
 -				exception_frame = stackframe.fp - SIZE(pt_regs);
 -		}
 +		/*
 +		 * Dump the contents of the current stackframe.
 +		 * We need to know the next stackframe to determine
 +		 * the dump range:
 +		 *    <cur_frame.fp:stackframe.fp>
 +		 */
 +		arm64_display_full_frame(bt, &cur_frame, &stackframe);
  
 -		if ((bt->flags & BT_IRQSTACK) &&
 -		    !arm64_on_irq_stack(bt->tc->processor, stackframe.sp)) {
 -			bt->flags &= ~BT_IRQSTACK;
 -			if (arm64_switch_stack(bt, &stackframe, ofp) == USER_MODE)
 -				break;
 -		}
 +		/*
 +		 * If we are in a normal stackframe, just continue,
 +		 * otherwise show an exception frame.
 +		 * Since exception entry code doesn't have a real
 +		 * stackframe, we fake a dummy frame here.
 +		 */
 +		if (!arm64_in_exp_entry(stackframe.pc))
 +			continue;
  
 +		if (!INSTACK(cur_frame.sp, bt))
 +			fprintf(ofp, "--- <IRQ stack> ---\n");
  
 -		level++;
 -	}
 +		arm64_print_stackframe_entry(bt, ++level, &stackframe, ofp);
 +		cur_frame = stackframe;
 +		arm64_unwind_frame(bt, &stackframe, ofp);
  
 -	if (is_kernel_thread(bt->tc->task)) 
 -		return;
 +		/*
 +		 * and don't show the contenxts. Instead,
 +		 * show an exception frame below
 +		 */
 +		mode = (stackframe.pc < machdep->machspec->userspace_top) ?
 +				USER_MODE : KERNEL_MODE;
 +		arm64_print_exception_frame(bt, cur_frame.sp, mode, ofp);
  
 -complete_user:
 -	exception_frame = bt->stacktop - USER_EFRAME_OFFSET;
 -	arm64_print_exception_frame(bt, exception_frame, USER_MODE, ofp);
 -	if ((bt->flags & (BT_USER_SPACE|BT_KDUMP_ADJUST)) == BT_USER_SPACE)
 -		fprintf(ofp, " #0 [user space]\n");
 +		if (mode == USER_MODE)
 +			break;
 +	}
  }
  
  static void
 @@ -1932,41 +2118,6 @@ arm64_in_kdump_text_on_irq_stack(struct bt_info *bt)
  	return FALSE;
  }
  
 -static int 
 -arm64_switch_stack(struct bt_info *bt, struct arm64_stackframe *frame, FILE *ofp)
 -{
 -	int i;
 -	ulong stacktop, words, addr;
 -	ulong *stackbuf;
 -	char buf[BUFSIZE];
 -	struct machine_specific *ms = machdep->machspec;
 -
 -	if (bt->flags & BT_FULL) {
 -		stacktop = ms->irq_stacks[bt->tc->processor] + ms->irq_stack_size;
 -		words = (stacktop - bt->bptr) / sizeof(ulong);
 -		stackbuf = (ulong *)GETBUF(words * sizeof(ulong));
 -		readmem(bt->bptr, KVADDR, stackbuf, words * sizeof(long), 
 -			"top of IRQ stack", FAULT_ON_ERROR);
 -
 -		addr = bt->bptr;
 -		for (i = 0; i < words; i++) {
 -			if (!(i & 1))
 -				fprintf(ofp, "%s    %lx: ", i ? "\n" : "", addr);
 -			fprintf(ofp, "%s ", format_stack_entry(bt, buf, stackbuf[i], 0));
 -			addr += sizeof(ulong);
 -		}
 -		fprintf(ofp, "\n");
 -		FREEBUF(stackbuf);
 -	}
 -	fprintf(ofp, "--- <IRQ stack> ---\n");
 -
 -	if (frame->fp == 0)
 -		return USER_MODE;
 -
 -	arm64_print_exception_frame(bt, frame->sp, KERNEL_MODE, ofp);
 -	return KERNEL_MODE;
 -}
 -
  static int
  arm64_get_dumpfile_stackframe(struct bt_info *bt, struct arm64_stackframe *frame)
  {
 @@ -2047,6 +2198,20 @@ arm64_get_stack_frame(struct bt_info *bt, ulong *pcp, ulong *spp)
  }
  
  static void
 +arm64_gen_hidden_frame(struct bt_info *bt, ulong sp,
 +					struct arm64_stackframe *frame)
 +{
 +	struct arm64_pt_regs *ptregs;
 +
 +	ptregs = (struct arm64_pt_regs *)
 +		 &bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(sp))];
 +
 +	frame->pc = ptregs->pc;
 +	frame->fp = ptregs->regs[29];
 +	frame->sp = ptregs->sp;
 +}
 +
 +static void
  arm64_print_exception_frame(struct bt_info *bt, ulong pt_regs, int mode, FILE *ofp)
  {
  	int i, r, rows, top_reg, is_64_bit;
 @@ -2055,10 +2220,16 @@ arm64_print_exception_frame(struct bt_info *bt, ulong pt_regs,
int mode, FILE *o
  	ulong LR, SP, offset;
  	char buf[BUFSIZE];
  
 +	if (mode == KERNEL_MODE)
 +		fprintf(ofp, "--- <Exception in kernel> ---\n");
 +	else
 +		fprintf(ofp, "--- <Exception in user> ---\n");
 +
  	if (CRASHDEBUG(1)) 
  		fprintf(ofp, "pt_regs: %lx\n", pt_regs);
  
 -	regs = (struct arm64_pt_regs
*)&bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(pt_regs))];
 +	regs = (struct arm64_pt_regs *)
 +	       &bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(pt_regs))];
  
  	if ((mode == USER_MODE) && (regs->pstate & PSR_MODE32_BIT)) {
  		LR = regs->regs[14];
 @@ -2130,10 +2301,11 @@ arm64_print_exception_frame(struct bt_info *bt, ulong pt_regs,
int mode, FILE *o
  	}
  
  	if (is_64_bit) {
 -		fprintf(ofp, "ORIG_X0: %016lx  SYSCALLNO: %lx",
 -			(ulong)regs->orig_x0, (ulong)regs->syscallno);
 -		if (mode == USER_MODE)
 +		if (mode == USER_MODE) {
 +			fprintf(ofp, "ORIG_X0: %016lx  SYSCALLNO: %lx",
 +				(ulong)regs->orig_x0, (ulong)regs->syscallno);
  			fprintf(ofp, "  PSTATE: %08lx", (ulong)regs->pstate);
 +		}
  		fprintf(ofp, "\n");
  	}
  
 diff --git a/defs.h b/defs.h
 index d6f719c..f7ea5a0 100644
 --- a/defs.h
 +++ b/defs.h
 @@ -3058,8 +3058,14 @@ struct machine_specific {
  	ulong kernel_flags;
  	ulong irq_stack_size;
  	ulong *irq_stacks;
 +	char  *irq_stackbuf;
  	ulong __irqentry_text_start;
  	ulong __irqentry_text_end;
 +	/* for exception vector code */
 +	ulong exp_entry1_start;
 +	ulong exp_entry1_end;
 +	ulong exp_entry2_start;
 +	ulong exp_entry2_end;
  	/* only needed for v4.6 or later kernel */
  	ulong kimage_voffset;
  	ulong kimage_text;
 -- 
 2.9.0