PR24623, DWARF errors
authorAlan Modra <amodra@gmail.com>
Wed, 14 Aug 2019 01:21:22 +0000 (10:51 +0930)
committerAlan Modra <amodra@gmail.com>
Wed, 14 Aug 2019 03:13:25 +0000 (12:43 +0930)
PR 24623
* dwarf2.c (stash_comp_unit): New function, extracted from..
(_bfd_dwarf2_find_nearest_line): ..here.
(find_abstract_instance): Parse comp units and decode line info
as needed.

bfd/ChangeLog
bfd/dwarf2.c

index 143350e11d0576bef1fb45eacec71800989ab037..8a028cf0323d88d60a5e3b48d2e6f57f9b26670b 100644 (file)
@@ -1,3 +1,11 @@
+2019-08-14  Alan Modra  <amodra@gmail.com>
+
+       PR 24623
+       * dwarf2.c (stash_comp_unit): New function, extracted from..
+       (_bfd_dwarf2_find_nearest_line): ..here.
+       (find_abstract_instance): Parse comp units and decode line info
+       as needed.
+
 2019-08-14  Alan Modra  <amodra@gmail.com>
 
        * dwarf2.c (comp_unit_maybe_decode_line_info): Declare.
index 65bb1e4e32d2ae552435d9f9aef49bc8bbce9dd7..057fd91317319105717ad8fa79d85e052b3d0117 100644 (file)
@@ -2804,6 +2804,7 @@ lookup_symbol_in_variable_table (struct comp_unit *unit,
   return FALSE;
 }
 
+static struct comp_unit *stash_comp_unit (struct dwarf2_debug *);
 static bfd_boolean comp_unit_maybe_decode_line_info (struct comp_unit *,
                                                     struct dwarf2_debug *);
 
@@ -2877,12 +2878,26 @@ find_abstract_instance (struct comp_unit *   unit,
              if (info_ptr >= u->info_ptr_unit && info_ptr < u->end_ptr)
                break;
 
-         if (u)
+         while (u == NULL)
            {
-             unit = u;
-             info_ptr_end = unit->end_ptr;
+             u = stash_comp_unit (unit->stash);
+             if (u == NULL)
+               break;
+             if (info_ptr >= u->info_ptr_unit && info_ptr < u->end_ptr)
+               break;
+             u = NULL;
            }
-         /* else FIXME: What do we do now ?  */
+
+         if (u == NULL)
+           {
+             _bfd_error_handler
+               (_("DWARF error: unable to locate abstract instance DIE ref %"
+                  PRIu64), (uint64_t) die_ref);
+             bfd_set_error (bfd_error_bad_value);
+             return FALSE;
+           }
+         unit = u;
+         info_ptr_end = unit->end_ptr;
        }
     }
   else if (attr_ptr->form == DW_FORM_GNU_ref_alt)
@@ -2982,6 +2997,8 @@ find_abstract_instance (struct comp_unit *   unit,
                    }
                  break;
                case DW_AT_decl_file:
+                 if (!comp_unit_maybe_decode_line_info (unit, unit->stash))
+                   return FALSE;
                  *filename_ptr = concat_filename (unit->line_table,
                                                   attr.u.val);
                  break;
@@ -3334,7 +3351,7 @@ scan_unit_for_symbols (struct comp_unit *unit)
   return FALSE;
 }
 
-/* Parse a DWARF2 compilation unit starting at INFO_PTR.  This
+/* Parse a DWARF2 compilation unit starting at INFO_PTR.  UNIT_LENGTH
    includes the compilation unit header that proceeds the DIE's, but
    does not include the length field that precedes each compilation
    unit header.  END_PTR points one past the end of this comp unit.
@@ -4451,6 +4468,90 @@ _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
   return TRUE;
 }
 
+/* Parse the next DWARF2 compilation unit at STASH->INFO_PTR.  */
+
+static struct comp_unit *
+stash_comp_unit (struct dwarf2_debug *stash)
+{
+  bfd_size_type length;
+  unsigned int offset_size;
+  bfd_byte *info_ptr_unit = stash->info_ptr;
+
+  if (stash->info_ptr >= stash->info_ptr_end)
+    return NULL;
+
+  length = read_4_bytes (stash->bfd_ptr, stash->info_ptr,
+                        stash->info_ptr_end);
+  /* A 0xffffff length is the DWARF3 way of indicating
+     we use 64-bit offsets, instead of 32-bit offsets.  */
+  if (length == 0xffffffff)
+    {
+      offset_size = 8;
+      length = read_8_bytes (stash->bfd_ptr, stash->info_ptr + 4,
+                            stash->info_ptr_end);
+      stash->info_ptr += 12;
+    }
+  /* A zero length is the IRIX way of indicating 64-bit offsets,
+     mostly because the 64-bit length will generally fit in 32
+     bits, and the endianness helps.  */
+  else if (length == 0)
+    {
+      offset_size = 8;
+      length = read_4_bytes (stash->bfd_ptr, stash->info_ptr + 4,
+                            stash->info_ptr_end);
+      stash->info_ptr += 8;
+    }
+  /* In the absence of the hints above, we assume 32-bit DWARF2
+     offsets even for targets with 64-bit addresses, because:
+     a) most of the time these targets will not have generated
+     more than 2Gb of debug info and so will not need 64-bit
+     offsets,
+     and
+     b) if they do use 64-bit offsets but they are not using
+     the size hints that are tested for above then they are
+     not conforming to the DWARF3 standard anyway.  */
+  else
+    {
+      offset_size = 4;
+      stash->info_ptr += 4;
+    }
+
+  if (length != 0
+      && stash->info_ptr + length <= stash->info_ptr_end
+      && stash->info_ptr + length > stash->info_ptr)
+    {
+      struct comp_unit *each = parse_comp_unit (stash, length, info_ptr_unit,
+                                               offset_size);
+      if (each)
+       {
+         if (stash->all_comp_units)
+           stash->all_comp_units->prev_unit = each;
+         else
+           stash->last_comp_unit = each;
+
+         each->next_unit = stash->all_comp_units;
+         stash->all_comp_units = each;
+
+         stash->info_ptr += length;
+
+         if ((bfd_size_type) (stash->info_ptr - stash->sec_info_ptr)
+             == stash->sec->size)
+           {
+             stash->sec = find_debug_info (stash->bfd_ptr,
+                                           stash->debug_sections,
+                                           stash->sec);
+             stash->sec_info_ptr = stash->info_ptr;
+           }
+         return each;
+       }
+    }
+
+  /* Don't trust any of the DWARF info after a corrupted length or
+     parse error.  */
+  stash->info_ptr = stash->info_ptr_end;
+  return NULL;
+}
+
 /* Scan the debug information in PINFO looking for a DW_TAG_subprogram
    abbrev with a DW_AT_low_pc attached to it.  Then lookup that same
    symbol in SYMBOLS and return the difference between the low_pc and
@@ -4699,113 +4800,33 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd,
     }
 
   /* Read each remaining comp. units checking each as they are read.  */
-  while (stash->info_ptr < stash->info_ptr_end)
+  while ((each = stash_comp_unit (stash)) != NULL)
     {
-      bfd_vma length;
-      unsigned int offset_size;
-      bfd_byte *info_ptr_unit = stash->info_ptr;
-
-      length = read_4_bytes (stash->bfd_ptr, stash->info_ptr, stash->info_ptr_end);
-      /* A 0xffffff length is the DWARF3 way of indicating
-        we use 64-bit offsets, instead of 32-bit offsets.  */
-      if (length == 0xffffffff)
-       {
-         offset_size = 8;
-         length = read_8_bytes (stash->bfd_ptr, stash->info_ptr + 4, stash->info_ptr_end);
-         stash->info_ptr += 12;
-       }
-      /* A zero length is the IRIX way of indicating 64-bit offsets,
-        mostly because the 64-bit length will generally fit in 32
-        bits, and the endianness helps.  */
-      else if (length == 0)
-       {
-         offset_size = 8;
-         length = read_4_bytes (stash->bfd_ptr, stash->info_ptr + 4, stash->info_ptr_end);
-         stash->info_ptr += 8;
-       }
-      /* In the absence of the hints above, we assume 32-bit DWARF2
-        offsets even for targets with 64-bit addresses, because:
-          a) most of the time these targets will not have generated
-             more than 2Gb of debug info and so will not need 64-bit
-             offsets,
-        and
-          b) if they do use 64-bit offsets but they are not using
-             the size hints that are tested for above then they are
-             not conforming to the DWARF3 standard anyway.  */
+      /* DW_AT_low_pc and DW_AT_high_pc are optional for
+        compilation units.  If we don't have them (i.e.,
+        unit->high == 0), we need to consult the line info table
+        to see if a compilation unit contains the given
+        address.  */
+      if (do_line)
+       found = (((symbol->flags & BSF_FUNCTION) == 0
+                 || each->arange.high == 0
+                 || comp_unit_contains_address (each, addr))
+                && comp_unit_find_line (each, symbol, addr,
+                                        filename_ptr,
+                                        linenumber_ptr,
+                                        stash));
       else
-       {
-         offset_size = 4;
-         stash->info_ptr += 4;
-       }
-
-      if (length > 0)
-       {
-         bfd_byte * new_ptr;
-
-         /* PR 21151  */
-         if (stash->info_ptr + length > stash->info_ptr_end)
-           return FALSE;
-
-         each = parse_comp_unit (stash, length, info_ptr_unit,
-                                 offset_size);
-         if (!each)
-           /* The dwarf information is damaged, don't trust it any
-              more.  */
-           break;
-
-         new_ptr = stash->info_ptr + length;
-         /* PR 17512: file: 1500698c.  */
-         if (new_ptr < stash->info_ptr)
-           {
-             /* A corrupt length value - do not trust the info any more.  */
-             found = FALSE;
-             break;
-           }
-         else
-           stash->info_ptr = new_ptr;
-
-         if (stash->all_comp_units)
-           stash->all_comp_units->prev_unit = each;
-         else
-           stash->last_comp_unit = each;
-
-         each->next_unit = stash->all_comp_units;
-         stash->all_comp_units = each;
-
-         /* DW_AT_low_pc and DW_AT_high_pc are optional for
-            compilation units.  If we don't have them (i.e.,
-            unit->high == 0), we need to consult the line info table
-            to see if a compilation unit contains the given
-            address.  */
-         if (do_line)
-           found = (((symbol->flags & BSF_FUNCTION) == 0
-                     || each->arange.high == 0
-                     || comp_unit_contains_address (each, addr))
-                    && comp_unit_find_line (each, symbol, addr,
-                                            filename_ptr,
-                                            linenumber_ptr,
-                                            stash));
-         else
-           found = ((each->arange.high == 0
-                     || comp_unit_contains_address (each, addr))
-                    && comp_unit_find_nearest_line (each, addr,
-                                                    filename_ptr,
-                                                    &function,
-                                                    linenumber_ptr,
-                                                    discriminator_ptr,
-                                                    stash) != 0);
-
-         if ((bfd_vma) (stash->info_ptr - stash->sec_info_ptr)
-             == stash->sec->size)
-           {
-             stash->sec = find_debug_info (stash->bfd_ptr, debug_sections,
-                                           stash->sec);
-             stash->sec_info_ptr = stash->info_ptr;
-           }
-
-         if (found)
-           goto done;
-       }
+       found = ((each->arange.high == 0
+                 || comp_unit_contains_address (each, addr))
+                && comp_unit_find_nearest_line (each, addr,
+                                                filename_ptr,
+                                                &function,
+                                                linenumber_ptr,
+                                                discriminator_ptr,
+                                                stash) != 0);
+
+      if (found)
+       break;
     }
 
  done: