Fix PR 21337: segfault when re-reading symbols.

[deliverable/binutils-gdb.git] / gdb / symfile.c

diff --git a/gdb/symfile.c b/gdb/symfile.c
index aa5341536170b4033fdb6fd9c2314a1159b00b3d..9cbd6e52138ee9728301340a32da22bb19f40b27 100644 (file)
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -2587,6 +2587,9 @@ reread_symbols (void)
          /* Free the obstacks for non-reusable objfiles.  */
          psymbol_bcache_free (objfile->psymbol_cache);
          objfile->psymbol_cache = psymbol_bcache_init ();
+
+         /* NB: after this call to obstack_free, objfiles_changed
+            will need to be called (see discussion below).  */
          obstack_free (&objfile->objfile_obstack, 0);
          objfile->sections = NULL;
          objfile->compunit_symtabs = NULL;
@@ -2639,6 +2642,23 @@ reread_symbols (void)
          clear_complaints (&symfile_complaints, 1, 1);
 
          objfile->flags &= ~OBJF_PSYMTABS_READ;
+
+         /* We are about to read new symbols and potentially also
+            DWARF information.  Some targets may want to pass addresses
+            read from DWARF DIE's through an adjustment function before
+            saving them, like MIPS, which may call into
+            "find_pc_section".  When called, that function will make
+            use of per-objfile program space data.
+
+            Since we discarded our section information above, we have
+            dangling pointers in the per-objfile program space data
+            structure.  Force GDB to update the section mapping
+            information by letting it know the objfile has changed,
+            making the dangling pointers point to correct data
+            again.  */
+
+         objfiles_changed ();
+
          read_symbols (objfile, 0);
 
          if (!objfile_has_symbols (objfile))
@@ -2671,9 +2691,6 @@ reread_symbols (void)
 
   if (!new_objfiles.empty ())
     {
-      /* Notify objfiles that we've modified objfile sections.  */
-      objfiles_changed ();
-
       clear_symtab_users (0);
 
       /* clear_objfile_data for each objfile was called before freeing it and