[PATCH] Fix yet another -fsanitize=undefined ubsan_encode_value ICE (PR sanitizer/81125)

Richard Biener rguenther@suse.de
Mon Jun 19 14:56:00 GMT 2017


On Mon, 19 Jun 2017, Jakub Jelinek wrote:

> Hi!
> 
> And here is another ICE.  While we have a current_function_decl
> in this case, still create_tmp_var's called gimple_add_tmp_var
> and mark_addressable don't work too well when the current function
> is a C++ ctor or dtor that the FE then duplicates.
> 
> Fixed by telling ubsan_encode_value whether it is called from the
> FE (when it shouldn't use gimple_add_tmp_var nor mark_addressable
> and should use TARGET_EXPR), or from GIMPLE passes (when it should
> do what it did before with in_expand_p == false) or from RTL expansion
> (when it should do what it did with in_expand_p == true).
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Ugh.

Ok.

Thanks,
Richard.

> 2017-06-19  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR sanitizer/81125
> 	* ubsan.h (enum ubsan_encode_value_phase): New.
> 	(ubsan_encode_value): Change second argument to
> 	enum ubsan_encode_value_phase with default value of
> 	UBSAN_ENCODE_VALUE_GENERIC.
> 	* ubsan.c (ubsan_encode_value): Change second argument to
> 	enum ubsan_encode_value_phase PHASE from bool IN_EXPAND_P,
> 	adjust uses, for UBSAN_ENCODE_VALUE_GENERIC use just
> 	create_tmp_var_raw instead of create_tmp_var and use a
> 	TARGET_EXPR.
> 	(ubsan_expand_bounds_ifn, ubsan_build_overflow_builtin,
> 	instrument_bool_enum_load, ubsan_instrument_float_cast): Adjust
> 	ubsan_encode_value callers.
> 
> 	* g++.dg/ubsan/pr81125.C: New test.
> 
> --- gcc/ubsan.h.jj	2017-06-19 08:26:17.000000000 +0200
> +++ gcc/ubsan.h	2017-06-19 10:06:52.723664974 +0200
> @@ -42,6 +42,13 @@ enum ubsan_print_style {
>    UBSAN_PRINT_ARRAY
>  };
>  
> +/* This controls ubsan_encode_value behavior.  */
> +enum ubsan_encode_value_phase {
> +  UBSAN_ENCODE_VALUE_GENERIC,
> +  UBSAN_ENCODE_VALUE_GIMPLE,
> +  UBSAN_ENCODE_VALUE_RTL
> +};
> +
>  extern bool ubsan_expand_bounds_ifn (gimple_stmt_iterator *);
>  extern bool ubsan_expand_null_ifn (gimple_stmt_iterator *);
>  extern bool ubsan_expand_objsize_ifn (gimple_stmt_iterator *);
> @@ -49,7 +56,8 @@ extern bool ubsan_expand_vptr_ifn (gimpl
>  extern bool ubsan_instrument_unreachable (gimple_stmt_iterator *);
>  extern tree ubsan_create_data (const char *, int, const location_t *, ...);
>  extern tree ubsan_type_descriptor (tree, enum ubsan_print_style = UBSAN_PRINT_NORMAL);
> -extern tree ubsan_encode_value (tree, bool = false);
> +extern tree ubsan_encode_value (tree, enum ubsan_encode_value_phase
> +				      = UBSAN_ENCODE_VALUE_GENERIC);
>  extern bool is_ubsan_builtin_p (tree);
>  extern tree ubsan_build_overflow_builtin (tree_code, location_t, tree, tree,
>  					  tree, tree *);
> --- gcc/ubsan.c.jj	2017-06-19 10:27:33.000000000 +0200
> +++ gcc/ubsan.c	2017-06-19 10:13:53.434541556 +0200
> @@ -114,10 +114,10 @@ decl_for_type_insert (tree type, tree de
>  /* Helper routine, which encodes a value in the pointer_sized_int_node.
>     Arguments with precision <= POINTER_SIZE are passed directly,
>     the rest is passed by reference.  T is a value we are to encode.
> -   IN_EXPAND_P is true if this function is called during expansion.  */
> +   PHASE determines when this function is called.  */
>  
>  tree
> -ubsan_encode_value (tree t, bool in_expand_p)
> +ubsan_encode_value (tree t, enum ubsan_encode_value_phase phase)
>  {
>    tree type = TREE_TYPE (t);
>    const unsigned int bitsize = GET_MODE_BITSIZE (TYPE_MODE (type));
> @@ -144,7 +144,7 @@ ubsan_encode_value (tree t, bool in_expa
>  	  /* The reason for this is that we don't want to pessimize
>  	     code by making vars unnecessarily addressable.  */
>  	  tree var;
> -	  if (current_function_decl)
> +	  if (phase != UBSAN_ENCODE_VALUE_GENERIC)
>  	    {
>  	      var = create_tmp_var (type);
>  	      mark_addressable (var);
> @@ -154,7 +154,7 @@ ubsan_encode_value (tree t, bool in_expa
>  	      var = create_tmp_var_raw (type);
>  	      TREE_ADDRESSABLE (var) = 1;
>  	    }
> -	  if (in_expand_p)
> +	  if (phase == UBSAN_ENCODE_VALUE_RTL)
>  	    {
>  	      rtx mem
>  		= assign_stack_temp_for_type (TYPE_MODE (type),
> @@ -164,7 +164,7 @@ ubsan_encode_value (tree t, bool in_expa
>  	      expand_assignment (var, t, false);
>  	      return build_fold_addr_expr (var);
>  	    }
> -	  if (current_function_decl)
> +	  if (phase != UBSAN_ENCODE_VALUE_GENERIC)
>  	    {
>  	      tree tem = build2 (MODIFY_EXPR, void_type_node, var, t);
>  	      t = build_fold_addr_expr (var);
> @@ -725,9 +725,9 @@ ubsan_expand_bounds_ifn (gimple_stmt_ite
>  	  ? BUILT_IN_UBSAN_HANDLE_OUT_OF_BOUNDS
>  	  : BUILT_IN_UBSAN_HANDLE_OUT_OF_BOUNDS_ABORT;
>        tree fn = builtin_decl_explicit (bcode);
> -      tree val
> -	= force_gimple_operand_gsi (gsi, ubsan_encode_value (orig_index), true,
> -				    NULL_TREE, true, GSI_SAME_STMT);
> +      tree val = ubsan_encode_value (orig_index, UBSAN_ENCODE_VALUE_GIMPLE);
> +      val = force_gimple_operand_gsi (gsi, val, true, NULL_TREE, true,
> +				      GSI_SAME_STMT);
>        g = gimple_build_call (fn, 2, data, val);
>      }
>    gimple_set_location (g, loc);
> @@ -1283,9 +1283,11 @@ ubsan_build_overflow_builtin (tree_code
>    tree fn = builtin_decl_explicit (fn_code);
>    return build_call_expr_loc (loc, fn, 2 + (code != NEGATE_EXPR),
>  			      build_fold_addr_expr_loc (loc, data),
> -			      ubsan_encode_value (op0, true),
> -			      op1 ? ubsan_encode_value (op1, true)
> -				  : NULL_TREE);
> +			      ubsan_encode_value (op0, UBSAN_ENCODE_VALUE_RTL),
> +			      op1
> +			      ? ubsan_encode_value (op1,
> +						    UBSAN_ENCODE_VALUE_RTL)
> +			      : NULL_TREE);
>  }
>  
>  /* Perform the signed integer instrumentation.  GSI is the iterator
> @@ -1476,9 +1478,9 @@ instrument_bool_enum_load (gimple_stmt_i
>  	  : BUILT_IN_UBSAN_HANDLE_LOAD_INVALID_VALUE_ABORT;
>        tree fn = builtin_decl_explicit (bcode);
>  
> -      tree val = force_gimple_operand_gsi (&gsi2, ubsan_encode_value (urhs),
> -					   true, NULL_TREE, true,
> -					   GSI_SAME_STMT);
> +      tree val = ubsan_encode_value (urhs, UBSAN_ENCODE_VALUE_GIMPLE);
> +      val = force_gimple_operand_gsi (&gsi2, val, true, NULL_TREE, true,
> +				      GSI_SAME_STMT);
>        g = gimple_build_call (fn, 2, data, val);
>      }
>    gimple_set_location (g, loc);
> @@ -1642,7 +1644,7 @@ ubsan_instrument_float_cast (location_t
>        fn = builtin_decl_explicit (bcode);
>        fn = build_call_expr_loc (loc, fn, 2,
>  				build_fold_addr_expr_loc (loc, data),
> -				ubsan_encode_value (expr, false));
> +				ubsan_encode_value (expr));
>      }
>  
>    return fold_build3 (COND_EXPR, void_type_node, t, fn, integer_zero_node);
> --- gcc/testsuite/g++.dg/ubsan/pr81125.C.jj	2017-06-19 10:21:58.607642573 +0200
> +++ gcc/testsuite/g++.dg/ubsan/pr81125.C	2017-06-19 10:21:28.000000000 +0200
> @@ -0,0 +1,20 @@
> +// PR sanitizer/81125
> +// { dg-do compile }
> +// { dg-options "-fsanitize=undefined" }
> +
> +#ifdef __SIZEOF_INT128__
> +typedef __int128 T;
> +#else
> +typedef long long int T;
> +#endif
> +
> +struct A
> +{
> +  A (long);
> +  T a;
> +};
> +
> +A::A (long c)
> +{
> +  long b = a % c;
> +}
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)



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