From 0abca47e977bdb882beae6c56194f2f005e895e3 Mon Sep 17 00:00:00 2001
From: Yichao Yu <address@hidden>
Date: Fri, 27 Oct 2017 13:50:58 +0000
Subject: [PATCH] .....

---
 src/dwarf/Gparser.c | 50 +++++++++++++++++++++++++-------------------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/src/dwarf/Gparser.c b/src/dwarf/Gparser.c
index 70e690f..438a78a 100644
--- a/src/dwarf/Gparser.c
+++ b/src/dwarf/Gparser.c
@@ -115,7 +115,7 @@ run_cfi_program (struct dwarf_cursor *c, dwarf_state_record_t *sr,
   /* Process everything up to and including the current 'end_ip',
      including all the DW_CFA_advance_loc instructions.  See
      'c->use_prev_instr' use in 'fetch_proc_info' for details. */
-  while (*ip <= end_ip && *addr < end_addr && ret >= 0)
+  while (*ip + c->use_prev_instr <= end_ip && *addr < end_addr && ret >= 0)
     {
       unw_word_t operand = 0, regnum, val, len;
       uint8_t u8, op;
@@ -289,10 +289,8 @@ run_cfi_program (struct dwarf_cursor *c, dwarf_state_record_t *sr,
               ret = -UNW_EINVAL;
               break;
             }
-          if (*ip < end_ip) {
-            memcpy (&sr->rs_current, &(*rs_stack)->state, sizeof (sr->rs_current));
-            pop_rstate_stack(rs_stack);
-          }
+          memcpy (&sr->rs_current, &(*rs_stack)->state, sizeof (sr->rs_current));
+          pop_rstate_stack(rs_stack);
           Debug (15, "CFA_restore_state\n");
           break;
 
@@ -384,11 +382,8 @@ run_cfi_program (struct dwarf_cursor *c, dwarf_state_record_t *sr,
         case DW_CFA_GNU_args_size:
           if ((ret = dwarf_read_uleb128 (as, a, addr, &val, arg)) < 0)
             break;
-          if (*ip < end_ip)
-            {
-              sr->args_size = val;
-              Debug (15, "CFA_GNU_args_size %lu\n", (long) val);
-            }
+          sr->args_size = val;
+          Debug (15, "CFA_GNU_args_size %lu\n", (long) val);
           break;
 
         case DW_CFA_GNU_negative_offset_extended:
@@ -429,7 +424,7 @@ run_cfi_program (struct dwarf_cursor *c, dwarf_state_record_t *sr,
 }
 
 static int
-fetch_proc_info (struct dwarf_cursor *c, unw_word_t ip, int need_unwind_info)
+fetch_proc_info (struct dwarf_cursor *c, unw_word_t ip)
 {
   int ret, dynamic = 1;
 
@@ -475,14 +470,6 @@ fetch_proc_info (struct dwarf_cursor *c, unw_word_t ip, int need_unwind_info)
   if (ret >= 0)
     tdep_fetch_frame (c, ip, 1);
 
-  /* Update use_prev_instr for the next frame. */
-  if (need_unwind_info)
-  {
-    assert(c->pi.unwind_info);
-    struct dwarf_cie_info *dci = c->pi.unwind_info;
-    c->use_prev_instr = ! dci->signal_frame;
-  }
-
   return ret;
 }
 
@@ -914,10 +901,17 @@ find_reg_state (struct dwarf_cursor *c, dwarf_state_record_t *sr)
     }
   else
     {
-      ret = fetch_proc_info (c, c->ip, 1);
-      if (ret >= 0)
+      ret = fetch_proc_info (c, c->ip);
+      int next_use_prev_instr = c->use_prev_instr;
+      if (ret >= 0) {
+	/* Update use_prev_instr for the next frame. */
+	assert(c->pi.unwind_info);
+	struct dwarf_cie_info *dci = c->pi.unwind_info;
+	next_use_prev_instr = ! dci->signal_frame;
 	ret = create_state_record_for (c, sr, c->ip);
+      }
       put_unwind_info (c, &c->pi);
+      c->use_prev_instr = next_use_prev_instr;
 
       if (cache && ret >= 0)
 	{
@@ -972,7 +966,7 @@ dwarf_make_proc_info (struct dwarf_cursor *c)
   int ret;
 
   /* Lookup it up the slow way... */
-  ret = fetch_proc_info (c, c->ip, 0);
+  ret = fetch_proc_info (c, c->ip);
   if (ret >= 0)
       ret = create_state_record_for (c, &sr, c->ip);
   put_unwind_info (c, &c->pi);
@@ -1006,8 +1000,8 @@ dwarf_reg_states_table_iterate(struct dwarf_cursor *c,
   while (ret >= 0 && curr_ip < c->pi.end_ip && addr < dci->fde_instr_end)
     {
       unw_word_t prev_ip = curr_ip;
-      ret = run_cfi_program (c, &sr, &curr_ip, prev_ip, &addr, dci->fde_instr_end,
-			     &rs_stack, dci);
+      ret = run_cfi_program (c, &sr, &curr_ip, prev_ip + c->use_prev_instr, &addr,
+			     dci->fde_instr_end, &rs_stack, dci);
       if (ret >= 0 && prev_ip < curr_ip)
 	ret = cb(token, &sr.rs_current, sizeof(sr.rs_current), prev_ip, curr_ip);
     }
@@ -1029,8 +1023,13 @@ dwarf_reg_states_iterate(struct dwarf_cursor *c,
 			 unw_reg_states_callback cb,
 			 void *token)
 {
-  int ret = fetch_proc_info (c, c->ip, 1);
+  int ret = fetch_proc_info (c, c->ip);
+  int next_use_prev_instr = c->use_prev_instr;
   if (ret >= 0)
+    /* Update use_prev_instr for the next frame. */
+    assert(c->pi.unwind_info);
+    struct dwarf_cie_info *dci = c->pi.unwind_info;
+    next_use_prev_instr = ! dci->signal_frame;
     switch (c->pi.format)
       {
       case UNW_INFO_FORMAT_TABLE:
@@ -1047,6 +1046,7 @@ dwarf_reg_states_iterate(struct dwarf_cursor *c,
 	ret = -UNW_EINVAL;
       }
   put_unwind_info (c, &c->pi);
+  c->use_prev_instr = next_use_prev_instr;
   return ret;
 }
 
-- 
2.14.3