1 files changed, 71 insertions, 34 deletions

diff --git a/libdw/dwarf_ranges.c b/libdw/dwarf_ranges.c
index 1eef617b..50fb6ba2 100644
--- a/libdw/dwarf_ranges.c
+++ b/libdw/dwarf_ranges.c
@@ -55,6 +55,52 @@
 #include <dwarf.h>
 #include <assert.h>
 
+/* Read up begin/end pair and increment read pointer.
+    - If it's normal range record, set up `*beginp' and `*endp' and return 0.
+    - If it's base address selection record, set up `*basep' and return 1.
+    - If it's end of rangelist, don't set anything and return 2
+    - If an error occurs, don't set anything and return -1.  */
+internal_function int
+__libdw_read_begin_end_pair_inc (Dwarf *dbg, int sec_index,
+				 unsigned char **addrp, int width,
+				 Dwarf_Addr *beginp, Dwarf_Addr *endp,
+				 Dwarf_Addr *basep)
+{
+  Dwarf_Addr escape = (width == 8 ? (Elf64_Addr) -1
+		       : (Elf64_Addr) (Elf32_Addr) -1);
+  Dwarf_Addr begin;
+  Dwarf_Addr end;
+
+  unsigned char *addr = *addrp;
+  bool begin_relocated = READ_AND_RELOCATE (__libdw_relocate_address, begin);
+  bool end_relocated = READ_AND_RELOCATE (__libdw_relocate_address, end);
+  *addrp = addr;
+
+  /* Unrelocated escape for begin means base address selection.  */
+  if (begin == escape && !begin_relocated)
+    {
+      if (unlikely (end == escape))
+	{
+	  __libdw_seterrno (DWARF_E_INVALID_DWARF);
+	  return -1;
+	}
+
+      if (basep != NULL)
+	*basep = end;
+      return 1;
+    }
+
+  /* Unrelocated pair of zeroes means end of range list.  */
+  if (begin == 0 && end == 0 && !begin_relocated && !end_relocated)
+    return 2;
+
+  /* Don't check for begin_relocated == end_relocated.  Serve the data
+     to the client even though it may be buggy.  */
+  *beginp = begin;
+  *endp = end;
+
+  return 0;
+}
 
 ptrdiff_t
 dwarf_ranges (Dwarf_Die *die, ptrdiff_t offset, Dwarf_Addr *basep,
@@ -80,11 +126,12 @@ dwarf_ranges (Dwarf_Die *die, ptrdiff_t offset, Dwarf_Addr *basep,
   const Elf_Data *d = die->cu->dbg->sectiondata[IDX_debug_ranges];
   if (d == NULL && offset != 0)
     {
-    no_ranges:
       __libdw_seterrno (DWARF_E_NO_DEBUG_RANGES);
       return -1;
     }
 
+  unsigned char *readp;
+  unsigned char *readendp;
   if (offset == 0)
     {
       Dwarf_Attribute attr_mem;
@@ -94,14 +141,12 @@ dwarf_ranges (Dwarf_Die *die, ptrdiff_t offset, Dwarf_Addr *basep,
 	/* No PC attributes in this DIE at all, so an empty range list.  */
 	return 0;
 
-      /* Must have the form data4 or data8 which act as an offset.  */
       Dwarf_Word start_offset;
-      if (INTUSE(dwarf_formudata) (attr, &start_offset) != 0)
+      if ((readp = __libdw_formptr (attr, IDX_debug_ranges,
+				    DWARF_E_NO_DEBUG_RANGES,
+				    &readendp, &start_offset)) == NULL)
 	return -1;
 
-      if (d == NULL)
-	goto no_ranges;
-
       offset = start_offset;
       assert ((Dwarf_Word) offset == start_offset);
 
@@ -127,45 +172,37 @@ dwarf_ranges (Dwarf_Die *die, ptrdiff_t offset, Dwarf_Addr *basep,
 	  return -1;
 	}
     }
-  else if (offset < 0 || (size_t) offset >= d->d_size)
+  else
     {
-      __libdw_seterrno (DWARF_E_INVALID_OFFSET);
-      return -1l;
-    }
+      if (__libdw_offset_in_section (die->cu->dbg,
+				     IDX_debug_ranges, offset, 1))
+	return -1l;
 
-  unsigned char *readp = d->d_buf + offset;
+      readp = d->d_buf + offset;
+      readendp = d->d_buf + d->d_size;
+    }
 
  next:
-  if ((unsigned char *) d->d_buf + d->d_size - readp
-      < die->cu->address_size * 2)
+  if (readendp - readp < die->cu->address_size * 2)
     goto invalid;
 
   Dwarf_Addr begin;
   Dwarf_Addr end;
-  if (die->cu->address_size == 8)
-    {
-      begin = read_8ubyte_unaligned_inc (die->cu->dbg, readp);
-      end = read_8ubyte_unaligned_inc (die->cu->dbg, readp);
-      if (begin == (uint64_t) -1l) /* Base address entry.  */
-	{
-	  *basep = end;
-	  goto next;
-	}
-    }
-  else
+
+  switch (__libdw_read_begin_end_pair_inc (die->cu->dbg, IDX_debug_ranges,
+					   &readp, die->cu->address_size,
+					   &begin, &end, basep))
     {
-      begin = read_4ubyte_unaligned_inc (die->cu->dbg, readp);
-      end = read_4ubyte_unaligned_inc (die->cu->dbg, readp);
-      if (begin == (uint32_t) -1) /* Base address entry.  */
-	{
-	  *basep = end;
-	  goto next;
-	}
+    case 0:
+      break;
+    case 1:
+      goto next;
+    case 2:
+      return 0;
+    default:
+      return -1l;
     }
 
-  if (begin == 0 && end == 0) /* End of list entry.  */
-    return 0;
-
   /* We have an address range entry.  */
   *startp = *basep + begin;
   *endp = *basep + end;