* Makefile.in: Update dependencies.

	* dwarf2expr.c: New include "gdb_assert.h".
	(new_dwarf_expr_context): Initialize MAX_RECURSION_DEPTH.
	(dwarf_expr_eval): Sanity check the RECURSION_DEPTH count.
	(execute_stack_op): Error out on too large RECURSION_DEPTH.
	Increase/decrease RECURSION_DEPTH around the function.

3 files changed, 26 insertions, 1 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2845468..a9e209f 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2008-06-05  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* Makefile.in: Update dependencies.
+	* dwarf2expr.c: New include "gdb_assert.h".
+	(new_dwarf_expr_context): Initialize MAX_RECURSION_DEPTH.
+	(dwarf_expr_eval): Sanity check the RECURSION_DEPTH count.
+	(execute_stack_op): Error out on too large RECURSION_DEPTH.
+	Increase/decrease RECURSION_DEPTH around the function.
+
 2008-06-05  Daniel Jacobowitz  <dan@codesourcery.com>
 
 	* remote.c (get_offsets): Handle a single segment.
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 1e1fc3c..7132b48 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -2087,7 +2087,7 @@ dummy-frame.o: dummy-frame.c $(defs_h) $(dummy_frame_h) $(regcache_h) \
 dfp.o: dfp.c $(defs_h) $(expression_h) $(gdbtypes_h) $(value_h) $(dfp_h) \
 	$(decimal128_h) $(decimal64_h) $(decimal32_h)
 dwarf2expr.o: dwarf2expr.c $(defs_h) $(symtab_h) $(gdbtypes_h) $(value_h) \
-	$(gdbcore_h) $(elf_dwarf2_h) $(dwarf2expr_h)
+	$(gdbcore_h) $(elf_dwarf2_h) $(dwarf2expr_h) $(gdb_assert_h)
 dwarf2-frame.o: dwarf2-frame.c $(defs_h) $(dwarf2expr_h) $(elf_dwarf2_h) \
 	$(frame_h) $(frame_base_h) $(frame_unwind_h) $(gdbcore_h) \
 	$(gdbtypes_h) $(symtab_h) $(objfiles_h) $(regcache_h) \
diff --git a/gdb/dwarf2expr.c b/gdb/dwarf2expr.c
index a099878..93772a1 100644
--- a/gdb/dwarf2expr.c
+++ b/gdb/dwarf2expr.c
@@ -27,6 +27,7 @@
 #include "gdbcore.h"
 #include "elf/dwarf2.h"
 #include "dwarf2expr.h"
+#include "gdb_assert.h"
 
 /* Local prototypes.  */
 
@@ -46,6 +47,7 @@ new_dwarf_expr_context (void)
   retval->stack = xmalloc (retval->stack_allocated * sizeof (CORE_ADDR));
   retval->num_pieces = 0;
   retval->pieces = 0;
+  retval->max_recursion_depth = 0x100;
   return retval;
 }
 
@@ -134,7 +136,13 @@ add_piece (struct dwarf_expr_context *ctx,
 void
 dwarf_expr_eval (struct dwarf_expr_context *ctx, gdb_byte *addr, size_t len)
 {
+  int old_recursion_depth = ctx->recursion_depth;
+
   execute_stack_op (ctx, addr, addr + len);
+
+  /* CTX RECURSION_DEPTH becomes invalid if an exception was thrown here.  */
+
+  gdb_assert (ctx->recursion_depth == old_recursion_depth);
 }
 
 /* Decode the unsigned LEB128 constant at BUF into the variable pointed to
@@ -281,6 +289,11 @@ execute_stack_op (struct dwarf_expr_context *ctx,
   ctx->in_reg = 0;
   ctx->initialized = 1;  /* Default is initialized.  */
 
+  if (ctx->recursion_depth > ctx->max_recursion_depth)
+    error (_("DWARF-2 expression error: Loop detected (%d)."),
+	   ctx->recursion_depth);
+  ctx->recursion_depth++;
+
   while (op_ptr < op_end)
     {
       enum dwarf_location_atom op = *op_ptr++;
@@ -739,4 +752,7 @@ execute_stack_op (struct dwarf_expr_context *ctx,
       dwarf_expr_push (ctx, result);
     no_push:;
     }
+
+  ctx->recursion_depth--;
+  gdb_assert (ctx->recursion_depth >= 0);
 }