[PATCH, Pointer Bounds Checker 9/x] Cgraph extension

Ilya Enkovich enkovich.gnu@gmail.com
Mon Sep 15 07:51:00 GMT 2014


On 03 Sep 13:32, Jeff Law wrote:
> On 07/24/14 03:59, Ilya Enkovich wrote:
> >--
> >2014-07-24  Ilya Enkovich  <ilya.enkovich@intel.com>
> >
> >	* cgraph.h (cgraph_thunk_info): Add add_pointer_bounds_args
> >	field.
> >	(cgraph_node): Add instrumented_version, orig_decl and
> >	instrumentation_clone fields.
> >	(symtab_alias_target): Allow IPA_REF_CHKP reference.
> >	* cgraph.c (cgraph_remove_node): Fix instrumented_version
> >	of the referenced node if any.
> >	(dump_cgraph_node): Dump instrumentation_clone and
> >	instrumented_version fields.
> >	(verify_cgraph_node): Check correctness of IPA_REF_CHKP
> >	references and instrumentation thunks.
> >	* cgraphbuild.c (rebuild_cgraph_edges): Rebuild IPA_REF_CHKP
> >	reference.
> >	(cgraph_rebuild_references): Likewise.
> >	* cgraphunit.c (assemble_thunks_and_aliases): Skip thunks
> >	calling instrumneted function version.
> >	* ipa-ref.h (ipa_ref_use): Add IPA_REF_CHKP.
> >	(ipa_ref): increase size of use field.
> >	* ipa-ref.c (ipa_ref_use_name): Add element for IPA_REF_CHKP.
> >	* lto-cgraph.c (lto_output_node): Output instrumentation_clone,
> >	thunk.add_pointer_bounds_args and orig_decl field.
> >	(lto_output_ref): Adjust to new ipa_ref::use field size.
> >	(input_overwrite_node): Read instrumentation_clone field.
> >	(input_node): Read thunk.add_pointer_bounds_args and orig_decl
> >	fields.
> >	(input_ref): Adjust to new ipa_ref::use field size.
> >	(input_cgraph_1): Compute instrumented_version fields and restore
> >	IDENTIFIER_TRANSPARENT_ALIAS chains.
> >	* lto-streamer.h (LTO_minor_version): Change minor version from
> >	0 to 1.
> >	* ipa.c (symtab_remove_unreachable_nodes): Consider instrumented
> >	clone as address taken if the original one is address taken.
> >	(cgraph_externally_visible_p): Mark instrumented 'main' as
> >	externally visible.
> >	(function_and_variable_visibility): Filter instrumentation
> >	thunks.
> Thanks for adding the additional checking.
> 
> 
> >@@ -513,6 +517,11 @@ cgraph_rebuild_references (void)
> >  	ipa_record_stmt_references (node, gsi_stmt (gsi));
> >      }
> >    record_eh_tables (node, cfun);
> >+
> >+
> >+  if (node->instrumented_version
> >+      && !node->instrumentation_clone)
> >+    ipa_record_reference (node, node->instrumented_version, IPA_REF_CHKP, NULL);
> >  }
> Trivial nit here -- just one vertical space here.
> 
> With that nit fixed, this is OK.
> 
> jeff
> 

Thanks for review!  Below is an updated version.  It also includes usage of syntab classes.  No functional changes added.

Thanks,
Ilya
--
2014-09-15  Ilya Enkovich  <ilya.enkovich@intel.com>

	* cgraph.h (cgraph_thunk_info): Add add_pointer_bounds_args
	field.
	(cgraph_node): Add instrumented_version, orig_decl and
	instrumentation_clone fields.
	(symtab_node::get_alias_target): Allow IPA_REF_CHKP reference.
	* cgraph.c (cgraph_node::remove): Fix instrumented_version
	of the referenced node if any.
	(cgraph_node::dump): Dump instrumentation_clone and
	instrumented_version fields.
	(cgraph_node::verify_node): Check correctness of IPA_REF_CHKP
	references and instrumentation thunks.
	* cgraphbuild.c (rebuild_cgraph_edges): Rebuild IPA_REF_CHKP
	reference.
	(cgraph_rebuild_references): Likewise.
	* cgraphunit.c (assemble_thunks_and_aliases): Skip thunks
	calling instrumneted function version.
	* ipa-ref.h (ipa_ref_use): Add IPA_REF_CHKP.
	(ipa_ref): increase size of use field.
	* symtab.c (ipa_ref_use_name): Add element for IPA_REF_CHKP.
	* lto-cgraph.c (lto_output_node): Output instrumentation_clone,
	thunk.add_pointer_bounds_args and orig_decl field.
	(lto_output_ref): Adjust to new ipa_ref::use field size.
	(input_overwrite_node): Read instrumentation_clone field.
	(input_node): Read thunk.add_pointer_bounds_args and orig_decl
	fields.
	(input_ref): Adjust to new ipa_ref::use field size.
	(input_cgraph_1): Compute instrumented_version fields and restore
	IDENTIFIER_TRANSPARENT_ALIAS chains.
	* lto-streamer.h (LTO_minor_version): Change minor version from
	0 to 1.
	* ipa.c (symtab_remove_unreachable_nodes): Consider instrumented
	clone as address taken if the original one is address taken.
	* ipa-visibility.c (cgraph_externally_visible_p): Mark
	instrumented 'main' as externally visible.
	(function_and_variable_visibility): Filter instrumentation
	thunks.


diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index 5a0b903..d8fdda1 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -1823,6 +1823,12 @@ cgraph_node::remove (void)
     }
   cgraph_n_nodes--;
 
+  if (instrumented_version)
+    {
+      instrumented_version->instrumented_version = NULL;
+      instrumented_version = NULL;
+    }
+
   /* Clear out the node to NULL all pointers and add the node to the free
      list.  */
   memset (this, 0, sizeof (*this));
@@ -2069,6 +2075,11 @@ cgraph_node::dump (FILE *f)
   if (indirect_calls_count)
     fprintf (f, "  Has %i outgoing edges for indirect calls.\n",
 	     indirect_calls_count);
+
+  if (instrumentation_clone)
+    fprintf (f, "  Is instrumented version.\n");
+  else if (instrumented_version)
+    fprintf (f, "  Has instrumented version.\n");
 }
 
 /* Dump call graph node NODE to stderr.  */
@@ -2834,7 +2845,9 @@ cgraph_node::verify_node (void)
           error_found = true;
 	}
       for (i = 0; iterate_reference (i, ref); i++)
-	if (ref->use != IPA_REF_ALIAS)
+	if (ref->use == IPA_REF_CHKP)
+	  ;
+	else if (ref->use != IPA_REF_ALIAS)
 	  {
 	    error ("Alias has non-alias reference");
 	    error_found = true;
@@ -2852,6 +2865,64 @@ cgraph_node::verify_node (void)
 	    error_found = true;
 	  }
     }
+
+  /* Check instrumented version reference.  */
+  if (instrumented_version
+      && instrumented_version->instrumented_version != this)
+    {
+      error ("Instrumentation clone does not reference original node");
+      error_found = true;
+    }
+
+  /* Cannot have orig_decl for not instrumented nodes.  */
+  if (!instrumentation_clone && orig_decl)
+    {
+      error ("Not instrumented node has non-NULL original declaration");
+      error_found = true;
+    }
+
+  /* If original not instrumented node still exists then we may check
+     original declaration is set properly.  */
+  if (instrumented_version
+      && orig_decl
+      && orig_decl != instrumented_version->decl)
+    {
+      error ("Instrumented node has wrong original declaration");
+      error_found = true;
+    }
+
+  /* Check all nodes have chkp reference to their instrumented versions.  */
+  if (analyzed
+      && instrumented_version
+      && !instrumentation_clone)
+    {
+      bool ref_found = false;
+      int i;
+      struct ipa_ref *ref;
+
+      for (i = 0; iterate_reference (i, ref); i++)
+	if (ref->use == IPA_REF_CHKP)
+	  {
+	    if (ref_found)
+	      {
+		error ("Node has more than one chkp reference");
+		error_found = true;
+	      }
+	    if (ref->referred != instrumented_version)
+	      {
+		error ("Wrong node is referenced with chkp reference");
+		error_found = true;
+	      }
+	    ref_found = true;
+	  }
+
+      if (!ref_found)
+	{
+	  error ("Analyzed node has no reference to instrumented version");
+	  error_found = true;
+	}
+    }
+
   if (analyzed && thunk.thunk_p)
     {
       if (!callees)
@@ -2869,6 +2940,12 @@ cgraph_node::verify_node (void)
 	  error ("Thunk is not supposed to have body");
           error_found = true;
         }
+      if (thunk.add_pointer_bounds_args
+	  && !instrumented_version->semantically_equivalent_p (callees->callee))
+	{
+	  error ("Instrumentation thunk has wrong edge callee");
+          error_found = true;
+	}
     }
   else if (analyzed && gimple_has_body_p (decl)
 	   && !TREE_ASM_WRITTEN (decl)
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index eb1aad6..cc045f6 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -516,6 +516,7 @@ struct GTY(()) cgraph_thunk_info {
   tree alias;
   bool this_adjusting;
   bool virtual_offset_p;
+  bool add_pointer_bounds_args;
   /* Set to true when alias node is thunk.  */
   bool thunk_p;
 };
@@ -1139,6 +1140,13 @@ public:
   cgraph_node *prev_sibling_clone;
   cgraph_node *clones;
   cgraph_node *clone_of;
+  /* If instrumentation_clone is 1 then instrumented_version points
+     to the original function used to make instrumented version.
+     Otherwise points to instrumented version of the function.  */
+  cgraph_node *instrumented_version;
+  /* If instrumentation_clone is 1 then orig_decl is the original
+     function declaration.  */
+  tree orig_decl;
   /* For functions with many calls sites it holds map from call expression
      to the edge to speed up cgraph_edge function.  */
   htab_t GTY((param_is (struct cgraph_edge))) call_site_hash;
@@ -1199,6 +1207,9 @@ public:
   /* True if this decl calls a COMDAT-local function.  This is set up in
      compute_inline_parameters and inline_call.  */
   unsigned calls_comdat_local : 1;
+  /* True when function is clone created for Pointer Bounds Checker
+     instrumentation.  */
+  unsigned instrumentation_clone : 1;
 };
 
 /* A cgraph node set is a collection of cgraph nodes.  A cgraph node
@@ -1690,6 +1701,8 @@ symtab_node::get_alias_target (void)
 {
   struct ipa_ref *ref = NULL;
   iterate_reference (0, ref);
+  if (ref->use == IPA_REF_CHKP)
+    iterate_reference (1, ref);
   gcc_checking_assert (ref->use == IPA_REF_ALIAS);
   return ref->referred;
 }
diff --git a/gcc/cgraphbuild.c b/gcc/cgraphbuild.c
index a04958f..f3e6f17 100644
--- a/gcc/cgraphbuild.c
+++ b/gcc/cgraphbuild.c
@@ -458,6 +458,10 @@ rebuild_cgraph_edges (void)
   record_eh_tables (node, cfun);
   gcc_assert (!node->global.inlined_to);
 
+  if (node->instrumented_version
+      && !node->instrumentation_clone)
+    node->add_reference (node->instrumented_version, IPA_REF_CHKP, NULL);
+
   return 0;
 }
 
@@ -490,6 +494,10 @@ cgraph_rebuild_references (void)
 	node->record_stmt_references (gsi_stmt (gsi));
     }
   record_eh_tables (node, cfun);
+
+  if (node->instrumented_version
+      && !node->instrumentation_clone)
+    node->add_reference (node->instrumented_version, IPA_REF_CHKP, NULL);
 }
 
 namespace {
diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index d9acc65..52e4242 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -1705,7 +1705,8 @@ assemble_thunks_and_aliases (struct cgraph_node *node)
   struct ipa_ref *ref;
 
   for (e = node->callers; e;)
-    if (e->caller->thunk.thunk_p)
+    if (e->caller->thunk.thunk_p
+	&& !e->caller->thunk.add_pointer_bounds_args)
       {
 	struct cgraph_node *thunk = e->caller;
 
diff --git a/gcc/ipa-ref.h b/gcc/ipa-ref.h
index b8b1f9e..e0d8ffd 100644
--- a/gcc/ipa-ref.h
+++ b/gcc/ipa-ref.h
@@ -29,7 +29,8 @@ enum GTY(()) ipa_ref_use
   IPA_REF_LOAD,
   IPA_REF_STORE,
   IPA_REF_ADDR,
-  IPA_REF_ALIAS
+  IPA_REF_ALIAS,
+  IPA_REF_CHKP
 };
 
 /* Record of reference in callgraph or varpool.  */
@@ -54,7 +55,7 @@ public:
   gimple stmt;
   unsigned int lto_stmt_uid;
   unsigned int referred_index;
-  ENUM_BITFIELD (ipa_ref_use) use:2;
+  ENUM_BITFIELD (ipa_ref_use) use:3;
   unsigned int speculative:1;
 };
 
diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
index bca2bc7..4fdf804 100644
--- a/gcc/ipa-visibility.c
+++ b/gcc/ipa-visibility.c
@@ -260,6 +260,10 @@ cgraph_externally_visible_p (struct cgraph_node *node,
   if (MAIN_NAME_P (DECL_NAME (node->decl)))
     return true;
 
+  if (node->instrumentation_clone
+      && MAIN_NAME_P (DECL_NAME (node->orig_decl)))
+    return true;
+
   return false;
 }
 
@@ -535,6 +539,7 @@ function_and_variable_visibility (bool whole_program)
 	}
 
       if (node->thunk.thunk_p
+	  && !node->thunk.add_pointer_bounds_args
 	  && TREE_PUBLIC (node->decl))
 	{
 	  struct cgraph_node *decl_node = node;
diff --git a/gcc/ipa.c b/gcc/ipa.c
index ce0fc34..a37ad03 100644
--- a/gcc/ipa.c
+++ b/gcc/ipa.c
@@ -490,6 +490,12 @@ symtab_remove_unreachable_nodes (bool before_inlining_p, FILE *file)
 	      node->remove_from_same_comdat_group ();
 	      node->remove_all_references ();
 	      changed = true;
+	      if (node->thunk.thunk_p
+		  && node->thunk.add_pointer_bounds_args)
+		{
+		  node->thunk.thunk_p = false;
+		  node->thunk.add_pointer_bounds_args = false;
+		}
 	    }
 	}
       else
@@ -564,7 +570,10 @@ symtab_remove_unreachable_nodes (bool before_inlining_p, FILE *file)
 	&& !node->used_from_other_partition)
       {
 	if (!node->call_for_symbol_thunks_and_aliases
-	  (has_addr_references_p, NULL, true))
+	    (has_addr_references_p, NULL, true)
+	    && (!node->instrumentation_clone
+		|| !node->instrumented_version
+		|| !node->instrumented_version->address_taken))
 	  {
 	    if (file)
 	      fprintf (file, " %s", node->name ());
diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c
index ed715f1..3cbff8a 100644
--- a/gcc/lto-cgraph.c
+++ b/gcc/lto-cgraph.c
@@ -541,6 +541,7 @@ lto_output_node (struct lto_simple_output_block *ob, struct cgraph_node *node,
   bp_pack_value (&bp, node->thunk.thunk_p && !boundary_p, 1);
   bp_pack_enum (&bp, ld_plugin_symbol_resolution,
 	        LDPR_NUM_KNOWN, node->resolution);
+  bp_pack_value (&bp, node->instrumentation_clone, 1);
   streamer_write_bitpack (&bp);
   streamer_write_data_stream (ob->main_stream, section, strlen (section) + 1);
 
@@ -549,7 +550,8 @@ lto_output_node (struct lto_simple_output_block *ob, struct cgraph_node *node,
       streamer_write_uhwi_stream
 	 (ob->main_stream,
 	  1 + (node->thunk.this_adjusting != 0) * 2
-	  + (node->thunk.virtual_offset_p != 0) * 4);
+	  + (node->thunk.virtual_offset_p != 0) * 4
+	  + (node->thunk.add_pointer_bounds_args != 0) * 8);
       streamer_write_uhwi_stream (ob->main_stream, node->thunk.fixed_offset);
       streamer_write_uhwi_stream (ob->main_stream, node->thunk.virtual_value);
     }
@@ -558,6 +560,9 @@ lto_output_node (struct lto_simple_output_block *ob, struct cgraph_node *node,
     streamer_write_hwi_stream (ob->main_stream, node->get_init_priority ());
   if (DECL_STATIC_DESTRUCTOR (node->decl))
     streamer_write_hwi_stream (ob->main_stream, node->get_fini_priority ());
+
+  if (node->instrumentation_clone)
+    lto_output_fn_decl_index (ob->decl_state, ob->main_stream, node->orig_decl);
 }
 
 /* Output the varpool NODE to OB. 
@@ -656,7 +661,7 @@ lto_output_ref (struct lto_simple_output_block *ob, struct ipa_ref *ref,
   struct cgraph_node *node;
 
   bp = bitpack_create (ob->main_stream);
-  bp_pack_value (&bp, ref->use, 2);
+  bp_pack_value (&bp, ref->use, 3);
   bp_pack_value (&bp, ref->speculative, 1);
   streamer_write_bitpack (&bp);
   nref = lto_symtab_encoder_lookup (encoder, ref->referred);
@@ -1080,6 +1085,7 @@ input_overwrite_node (struct lto_file_decl_data *file_data,
   node->thunk.thunk_p = bp_unpack_value (bp, 1);
   node->resolution = bp_unpack_enum (bp, ld_plugin_symbol_resolution,
 				     LDPR_NUM_KNOWN);
+  node->instrumentation_clone = bp_unpack_value (bp, 1);
   gcc_assert (flag_ltrans
 	      || (!node->in_other_partition
 		  && !node->used_from_other_partition));
@@ -1203,6 +1209,7 @@ input_node (struct lto_file_decl_data *file_data,
       node->thunk.this_adjusting = (type & 2);
       node->thunk.virtual_value = virtual_value;
       node->thunk.virtual_offset_p = (type & 4);
+      node->thunk.add_pointer_bounds_args = (type & 8);
     }
   if (node->alias && !node->analyzed && node->weakref)
     node->alias_target = get_alias_symbol (node->decl);
@@ -1211,6 +1218,14 @@ input_node (struct lto_file_decl_data *file_data,
     node->set_init_priority (streamer_read_hwi (ib));
   if (DECL_STATIC_DESTRUCTOR (node->decl))
     node->set_fini_priority (streamer_read_hwi (ib));
+
+  if (node->instrumentation_clone)
+    {
+      decl_index = streamer_read_uhwi (ib);
+      fn_decl = lto_file_decl_data_get_fn_decl (file_data, decl_index);
+      node->orig_decl = fn_decl;
+    }
+
   return node;
 }
 
@@ -1307,7 +1322,7 @@ input_ref (struct lto_input_block *ib,
   struct ipa_ref *ref;
 
   bp = streamer_read_bitpack (ib);
-  use = (enum ipa_ref_use) bp_unpack_value (&bp, 2);
+  use = (enum ipa_ref_use) bp_unpack_value (&bp, 3);
   speculative = (enum ipa_ref_use) bp_unpack_value (&bp, 1);
   node = nodes[streamer_read_hwi (ib)];
   ref = referring_node->add_reference (node, use);
@@ -1449,6 +1464,22 @@ input_cgraph_1 (struct lto_file_decl_data *file_data,
 	      = dyn_cast<cgraph_node *> (nodes[ref]);
 	  else
 	    cnode->global.inlined_to = NULL;
+
+	  /* Compute instrumented_version.  */
+	  if (cnode->instrumentation_clone)
+	    {
+	      gcc_assert (cnode->orig_decl);
+
+	      cnode->instrumented_version = cgraph_node::get (cnode->orig_decl);
+	      if (cnode->instrumented_version)
+		cnode->instrumented_version->instrumented_version = cnode;
+
+	      /* Restore decl names reference.  */
+	      if (IDENTIFIER_TRANSPARENT_ALIAS (DECL_ASSEMBLER_NAME (cnode->decl))
+		  && !TREE_CHAIN (DECL_ASSEMBLER_NAME (cnode->decl)))
+		TREE_CHAIN (DECL_ASSEMBLER_NAME (cnode->decl))
+		  = DECL_ASSEMBLER_NAME (cnode->orig_decl);
+	    }
 	}
 
       ref = (int) (intptr_t) node->same_comdat_group;
diff --git a/gcc/symtab.c b/gcc/symtab.c
index a93c299..f975682 100644
--- a/gcc/symtab.c
+++ b/gcc/symtab.c
@@ -45,7 +45,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "ipa-utils.h"
 #include "calls.h"
 
-static const char *ipa_ref_use_name[] = {"read","write","addr","alias"};
+static const char *ipa_ref_use_name[] = {"read","write","addr","alias","chkp"};
 
 const char * const ld_plugin_symbol_resolution_names[]=
 {



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