* dbxread.c (dbx_symfile_init): Make size of the string table

	size field a define (DBX_STRINGTAB_SIZE_SIZE).  Ensure that the
	offset to the string table is nonzero and handle the nonexistant
	string table case, should it occur.  Ensure that the string table
	size read from the file is reasonable, with a minimum lower bound
	of DBX_STRINGTAB_SIZE_SIZE instead of zero.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 8606ce2c57fff361e5d7a3702cafd86161b8e685..32ecd0fb39abe30b63170fa2bf310c8f81201691 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+Wed Mar  3 15:51:28 1993  Fred Fish  (fnf@cygnus.com)
+
+       * dbxread.c (dbx_symfile_init):  Make size of the string table
+       size field a define (DBX_STRINGTAB_SIZE_SIZE).  Ensure that the
+       offset to the string table is nonzero and handle the nonexistant
+       string table case, should it occur.  Ensure that the string table
+       size read from the file is reasonable, with a minimum lower bound
+       of DBX_STRINGTAB_SIZE_SIZE instead of zero.
+
 Wed Mar  3 07:23:03 1993  Ian Lance Taylor  (ian@cygnus.com)
 
        * Makefile.in: Changes to build testsuite correctly.

diff --git a/gdb/dbxread.c b/gdb/dbxread.c
index 3cb4bcdd965fa78c496e4ecfb9eac38a748be9e9..3f9334b579b537cfd8d1ffbe16f79892317f790e 100644 (file)
--- a/gdb/dbxread.c
+++ b/gdb/dbxread.c
@@ -515,6 +515,8 @@ dbx_new_init (ignore)
    be called unless this is an a.out (or very similar) file. 
    FIXME, there should be a cleaner peephole into the BFD environment here.  */
 
+#define DBX_STRINGTAB_SIZE_SIZE sizeof(long)   /* FIXME */
+
 static void
 dbx_symfile_init (objfile)
      struct objfile *objfile;
@@ -522,7 +524,7 @@ dbx_symfile_init (objfile)
   int val;
   bfd *sym_bfd = objfile->obfd;
   char *name = bfd_get_filename (sym_bfd);
-  unsigned char size_temp[sizeof(long)];
+  unsigned char size_temp[DBX_STRINGTAB_SIZE_SIZE];
 
   /* Allocate struct to keep track of the symfile */
   objfile->sym_private = (PTR)
@@ -552,41 +554,48 @@ dbx_symfile_init (objfile)
      table size would be so totally bogus that the malloc would fail.  Now
      that we put in on the psymbol_obstack, we can't do this since gdb gets
      a fatal error (out of virtual memory) if the size is bogus.  We can
-     however at least check to see if the size is zero or some negative
-     value.  */
-
-  val = bfd_seek (sym_bfd, STRING_TABLE_OFFSET, L_SET);
-  if (val < 0)
-    perror_with_name (name);
-
-  memset (size_temp, 0, sizeof (size_temp));
-  val = bfd_read ((PTR)size_temp, sizeof (long), 1, sym_bfd);
-  if (val < 0)
-    perror_with_name (name);
+     however at least check to see if the size is less than the size of
+     the size field itself, or larger than the size of the entire file.
+     Note that all valid string tables have a size greater than zero, since
+     the bytes used to hold the size are included in the count. */
 
-  DBX_STRINGTAB_SIZE (objfile) = bfd_h_get_32 (sym_bfd, size_temp);
-
-  if (DBX_STRINGTAB_SIZE (objfile) == 0)
-    error ("%s has no string table.", name);
-
-  if (DBX_STRINGTAB_SIZE (objfile) < 0
-      || DBX_STRINGTAB_SIZE (objfile) > bfd_get_size (sym_bfd))
-    error ("ridiculous string table size (%d bytes).",
-          DBX_STRINGTAB_SIZE (objfile));
-
-  DBX_STRINGTAB (objfile) =
-    (char *) obstack_alloc (&objfile -> psymbol_obstack,
-                           DBX_STRINGTAB_SIZE (objfile));
-
-  /* Now read in the string table in one big gulp.  */
-
-  val = bfd_seek (sym_bfd, STRING_TABLE_OFFSET, L_SET);
-  if (val < 0)
-    perror_with_name (name);
-  val = bfd_read (DBX_STRINGTAB (objfile), DBX_STRINGTAB_SIZE (objfile), 1,
-                 sym_bfd);
-  if (val != DBX_STRINGTAB_SIZE (objfile))
-    perror_with_name (name);
+  if (STRING_TABLE_OFFSET == 0)
+    {
+      DBX_STRINGTAB_SIZE (objfile) = 0;
+      DBX_STRINGTAB (objfile) = NULL;
+    }
+  else
+    {
+      val = bfd_seek (sym_bfd, STRING_TABLE_OFFSET, L_SET);
+      if (val < 0)
+       perror_with_name (name);
+      
+      memset ((PTR) size_temp, 0, sizeof (size_temp));
+      val = bfd_read ((PTR) size_temp, sizeof (size_temp), 1, sym_bfd);
+      if (val < 0)
+       perror_with_name (name);
+      
+      DBX_STRINGTAB_SIZE (objfile) = bfd_h_get_32 (sym_bfd, size_temp);
+      
+      if (DBX_STRINGTAB_SIZE (objfile) < sizeof (size_temp)
+         || DBX_STRINGTAB_SIZE (objfile) > bfd_get_size (sym_bfd))
+       error ("ridiculous string table size (%d bytes).",
+              DBX_STRINGTAB_SIZE (objfile));
+      
+      DBX_STRINGTAB (objfile) =
+       (char *) obstack_alloc (&objfile -> psymbol_obstack,
+                               DBX_STRINGTAB_SIZE (objfile));
+      
+      /* Now read in the string table in one big gulp.  */
+      
+      val = bfd_seek (sym_bfd, STRING_TABLE_OFFSET, L_SET);
+      if (val < 0)
+       perror_with_name (name);
+      val = bfd_read (DBX_STRINGTAB (objfile), DBX_STRINGTAB_SIZE (objfile), 1,
+                     sym_bfd);
+      if (val != DBX_STRINGTAB_SIZE (objfile))
+       perror_with_name (name);
+    }
 }
 
 /* Perform any local cleanups required when we are done with a particular