Re: [PATCH] Instrument aggregate call arguments even with -fsanitize=object-size (PR sanitizer/81094)

[Richard Biener <rguenther at suse dot de>]

On Wed, 14 Jun 2017, Jakub Jelinek wrote:

> Hi!
> 
> -fsanitize=object-size is yet another sanitization that ignored aggregate
> function arguments.  Fixed thusly (plus some small cleanup for
> instrument_null), bootstrapped/regtested on x86_64-linux and i686-linux, ok
> for trunk?

Ok.

Richard.

> 2017-06-14  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR sanitizer/81094
> 	* ubsan.c (instrument_null): Add T argument, use it instead
> 	of computing it based on IS_LHS.
> 	(instrument_object_size): Likewise.
> 	(pass_ubsan::execute): Adjust instrument_null and
> 	instrument_object_size callers to pass gimple_get_lhs or
> 	gimple_assign_rhs1 result to it.  Use instrument_null instead of
> 	calling get_base_address and instrument_mem_ref.  Handle
> 	aggregate call arguments for object-size sanitization.
> 
> 	* c-c++-common/ubsan/object-size-11.c: New test.
> 
> --- gcc/ubsan.c.jj	2017-06-14 14:40:39.000000000 +0200
> +++ gcc/ubsan.c	2017-06-14 14:49:17.702131958 +0200
> @@ -1204,10 +1204,8 @@ instrument_mem_ref (tree mem, tree base,
>  /* Perform the pointer instrumentation.  */
>  
>  static void
> -instrument_null (gimple_stmt_iterator gsi, bool is_lhs)
> +instrument_null (gimple_stmt_iterator gsi, tree t, bool is_lhs)
>  {
> -  gimple *stmt = gsi_stmt (gsi);
> -  tree t = is_lhs ? gimple_get_lhs (stmt) : gimple_assign_rhs1 (stmt);
>    /* Handle also e.g. &s->i.  */
>    if (TREE_CODE (t) == ADDR_EXPR)
>      t = TREE_OPERAND (t, 0);
> @@ -1754,11 +1752,10 @@ instrument_nonnull_return (gimple_stmt_i
>     points to an out-of-bounds location.  */
>  
>  static void
> -instrument_object_size (gimple_stmt_iterator *gsi, bool is_lhs)
> +instrument_object_size (gimple_stmt_iterator *gsi, tree t, bool is_lhs)
>  {
>    gimple *stmt = gsi_stmt (*gsi);
>    location_t loc = gimple_location (stmt);
> -  tree t = is_lhs ? gimple_get_lhs (stmt) : gimple_assign_rhs1 (stmt);
>    tree type;
>    tree index = NULL_TREE;
>    HOST_WIDE_INT size_in_bytes;
> @@ -1989,9 +1986,9 @@ pass_ubsan::execute (function *fun)
>  	  if (sanitize_flags_p (SANITIZE_NULL | SANITIZE_ALIGNMENT, fun->decl))
>  	    {
>  	      if (gimple_store_p (stmt))
> -		instrument_null (gsi, true);
> +		instrument_null (gsi, gimple_get_lhs (stmt), true);
>  	      if (gimple_assign_single_p (stmt))
> -		instrument_null (gsi, false);
> +		instrument_null (gsi, gimple_assign_rhs1 (stmt), false);
>  	      if (is_gimple_call (stmt))
>  		{
>  		  unsigned args_num = gimple_call_num_args (stmt);
> @@ -2000,10 +1997,7 @@ pass_ubsan::execute (function *fun)
>  		      tree arg = gimple_call_arg (stmt, i);
>  		      if (is_gimple_reg (arg) || is_gimple_min_invariant (arg))
>  			continue;
> -		      tree base = get_base_address (arg);
> -		      if (TREE_CODE (base) == MEM_REF
> -			  && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
> -			instrument_mem_ref (arg, base, &gsi, false);
> +		      instrument_null (gsi, arg, false);
>  		    }
>  		}
>  	    }
> @@ -2033,9 +2027,21 @@ pass_ubsan::execute (function *fun)
>  	  if (sanitize_flags_p (SANITIZE_OBJECT_SIZE, fun->decl))
>  	    {
>  	      if (gimple_store_p (stmt))
> -		instrument_object_size (&gsi, true);
> +		instrument_object_size (&gsi, gimple_get_lhs (stmt), true);
>  	      if (gimple_assign_load_p (stmt))
> -		instrument_object_size (&gsi, false);
> +		instrument_object_size (&gsi, gimple_assign_rhs1 (stmt),
> +					false);
> +	      if (is_gimple_call (stmt))
> +		{
> +		  unsigned args_num = gimple_call_num_args (stmt);
> +		  for (unsigned i = 0; i < args_num; ++i)
> +		    {
> +		      tree arg = gimple_call_arg (stmt, i);
> +		      if (is_gimple_reg (arg) || is_gimple_min_invariant (arg))
> +			continue;
> +		      instrument_object_size (&gsi, arg, false);
> +		    }
> +		}
>  	    }
>  
>  	  gsi_next (&gsi);
> --- gcc/testsuite/c-c++-common/ubsan/object-size-11.c.jj	2017-06-14 16:16:43.192137010 +0200
> +++ gcc/testsuite/c-c++-common/ubsan/object-size-11.c	2017-06-14 16:16:22.000000000 +0200
> @@ -0,0 +1,53 @@
> +/* PR sanitizer/81094 */
> +/* { dg-do run } */
> +/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
> +/* { dg-options "-fsanitize=object-size" } */
> +
> +#define N 20
> +
> +struct S { int i; };
> +
> +__attribute__((noinline, noclone)) void
> +f0 (struct S s)
> +{
> +  asm volatile ("" : : "r" (s.i) : "memory");
> +}
> +
> +__attribute__((noinline, noclone)) void
> +f1 (int i)
> +{
> +  char *orig;
> +  struct S *p;
> +  orig = (char *) __builtin_calloc (N, sizeof (struct S));
> +  p = (struct S *) orig;
> +  f0 (*(p + i));
> +  f0 (p[i]);
> +  p++;
> +  f0 (p[i - 1]);
> +  f0 (*(p + i - 1));
> +  __builtin_free (orig);
> +}
> +
> +/* { dg-output "load of address \[^\n\r]* with insufficient space for an object of type 'struct S'\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*note: pointer points here\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*\\^\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*load of address \[^\n\r]* with insufficient space for an object of type 'struct S'\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*note: pointer points here\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*\\^\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*load of address \[^\n\r]* with insufficient space for an object of type 'struct S'\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*note: pointer points here\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*\\^\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*load of address \[^\n\r]* with insufficient space for an object of type 'struct S'\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*note: pointer points here\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*\\^" } */
> +
> +int
> +main ()
> +{
> +  f1 (N);
> +  return 0;
> +}
> 
> 	Jakub
> 
> 

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