[PATCH, Pointer Bounds Checker 9/x] Cgraph extension
Ilya Enkovich
enkovich.gnu@gmail.com
Fri Jun 27 08:12:00 GMT 2014
Ping
2014-05-06 16:13 GMT+04:00 Ilya Enkovich <enkovich.gnu@gmail.com>:
> Ping
>
> 2014-04-16 18:03 GMT+04:00 Ilya Enkovich <enkovich.gnu@gmail.com>:
>> Hi,
>>
>> This patch introduces changes in call graph for Pointer Bounds Checker.
>>
>> New fields instrumented_version, instrumentation_clone and orig_decl are added for cgraph_node:
>> - instrumentation_clone field is 1 for nodes created for instrumented version of functions
>> - instrumented_version points to instrumented/original node
>> - orig_decl holds original function declaration for instrumented nodes in case original node is removed
>>
>> IPA_REF_CHKP reference type is introduced for nodes to reference instrumented function versions from originals. It is used to have proper reachability analysis.
>>
>> When original function bodies are not needed anymore, functions are transformed into thunks having call edge to the instrumented function. Therefore new field appeared in cgraph_thunk_info to mark such thunks.
>>
>> Does it look OK?
>>
>> Bootstrapped and tested on linux-x86_64.
>>
>> Thanks,
>> Ilya
>> --
>> gcc/
>>
>> 2014-04-16 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.
>>
>>
>> diff --git a/gcc/cgraph.c b/gcc/cgraph.c
>> index be3661a..6210c68 100644
>> --- a/gcc/cgraph.c
>> +++ b/gcc/cgraph.c
>> @@ -1828,6 +1828,12 @@ cgraph_remove_node (struct cgraph_node *node)
>> }
>> cgraph_n_nodes--;
>>
>> + if (node->instrumented_version)
>> + {
>> + node->instrumented_version->instrumented_version = NULL;
>> + node->instrumented_version = NULL;
>> + }
>> +
>> /* Clear out the node to NULL all pointers and add the node to the free
>> list. */
>> memset (node, 0, sizeof (*node));
>> @@ -2070,6 +2076,11 @@ dump_cgraph_node (FILE *f, struct cgraph_node *node)
>> if (indirect_calls_count)
>> fprintf (f, " Has %i outgoing edges for indirect calls.\n",
>> indirect_calls_count);
>> +
>> + if (node->instrumentation_clone)
>> + fprintf (f, " Is instrumented version.\n");
>> + else if (node->instrumented_version)
>> + fprintf (f, " Has instrumented version.\n");
>> }
>>
>>
>> @@ -2850,7 +2861,9 @@ verify_cgraph_node (struct cgraph_node *node)
>> }
>> for (i = 0; ipa_ref_list_reference_iterate (&node->ref_list,
>> 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;
>> @@ -2868,6 +2881,35 @@ verify_cgraph_node (struct cgraph_node *node)
>> error_found = true;
>> }
>> }
>> +
>> + /* Check all nodes reference their instrumented versions. */
>> + if (node->analyzed
>> + && node->instrumented_version
>> + && !node->instrumentation_clone)
>> + {
>> + bool ref_found = false;
>> + int i;
>> + struct ipa_ref *ref;
>> +
>> + for (i = 0; ipa_ref_list_reference_iterate (&node->ref_list,
>> + i, ref); i++)
>> + if (ref->use == IPA_REF_CHKP)
>> + {
>> + if (ref_found)
>> + {
>> + error ("Node has more than one chkp reference");
>> + error_found = true;
>> + }
>> + ref_found = true;
>> + }
>> +
>> + if (!ref_found)
>> + {
>> + error ("Analyzed node has no reference to instrumented version");
>> + error_found = true;
>> + }
>> + }
>> +
>> if (node->analyzed && node->thunk.thunk_p)
>> {
>> if (!node->callees)
>> @@ -2885,6 +2927,12 @@ verify_cgraph_node (struct cgraph_node *node)
>> error ("Thunk is not supposed to have body");
>> error_found = true;
>> }
>> + if (node->thunk.add_pointer_bounds_args
>> + && node->callees->callee != node->instrumented_version)
>> + {
>> + error ("Instrumentation thunk has wrong edge callee");
>> + error_found = true;
>> + }
>> }
>> else if (node->analyzed && gimple_has_body_p (node->decl)
>> && !TREE_ASM_WRITTEN (node->decl)
>> diff --git a/gcc/cgraph.h b/gcc/cgraph.h
>> index a6a51cf..5e702a7 100644
>> --- a/gcc/cgraph.h
>> +++ b/gcc/cgraph.h
>> @@ -191,6 +191,7 @@ 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;
>> };
>> @@ -373,6 +374,13 @@ public:
>> struct cgraph_node *prev_sibling_clone;
>> struct cgraph_node *clones;
>> struct 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. */
>> + struct 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;
>> @@ -433,6 +441,9 @@ 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;
>> };
>>
>>
>> @@ -1412,6 +1423,8 @@ symtab_alias_target (symtab_node *n)
>> {
>> struct ipa_ref *ref;
>> ipa_ref_list_reference_iterate (&n->ref_list, 0, ref);
>> + if (ref->use == IPA_REF_CHKP)
>> + ipa_ref_list_reference_iterate (&n->ref_list, 1, ref);
>> gcc_checking_assert (ref->use == IPA_REF_ALIAS);
>> return ref->referred;
>> }
>> diff --git a/gcc/cgraphbuild.c b/gcc/cgraphbuild.c
>> index 19961e2..a2b2106 100644
>> --- a/gcc/cgraphbuild.c
>> +++ b/gcc/cgraphbuild.c
>> @@ -481,6 +481,10 @@ rebuild_cgraph_edges (void)
>> record_eh_tables (node, cfun);
>> gcc_assert (!node->global.inlined_to);
>>
>> + if (node->instrumented_version
>> + && !node->instrumentation_clone)
>> + ipa_record_reference (node, node->instrumented_version, IPA_REF_CHKP, NULL);
>> +
>> return 0;
>> }
>>
>> @@ -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);
>> }
>>
>> namespace {
>> diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
>> index 06283fc..ceb4060 100644
>> --- a/gcc/cgraphunit.c
>> +++ b/gcc/cgraphunit.c
>> @@ -1702,7 +1702,8 @@ 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.c b/gcc/ipa-ref.c
>> index 6aa41e6..3a055d9 100644
>> --- a/gcc/ipa-ref.c
>> +++ b/gcc/ipa-ref.c
>> @@ -27,7 +27,7 @@ along with GCC; see the file COPYING3. If not see
>> #include "cgraph.h"
>> #include "ipa-utils.h"
>>
>> -static const char *ipa_ref_use_name[] = {"read","write","addr","alias"};
>> +static const char *ipa_ref_use_name[] = {"read","write","addr","alias","chkp"};
>>
>> /* Return ipa reference from REFERING_NODE or REFERING_VARPOOL_NODE
>> to REFERED_NODE or REFERED_VARPOOL_NODE. USE_TYPE specify type
>> diff --git a/gcc/ipa-ref.h b/gcc/ipa-ref.h
>> index 4ce5f8d..d0df0bf 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. */
>> @@ -40,7 +41,7 @@ struct GTY(()) ipa_ref
>> 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.c b/gcc/ipa.c
>> index 5ab3aed..1d7fa35 100644
>> --- a/gcc/ipa.c
>> +++ b/gcc/ipa.c
>> @@ -508,6 +508,12 @@ symtab_remove_unreachable_nodes (bool before_inlining_p, FILE *file)
>> cgraph_node_remove_callees (node);
>> ipa_remove_all_references (&node->ref_list);
>> 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
>> @@ -583,7 +589,10 @@ symtab_remove_unreachable_nodes (bool before_inlining_p, FILE *file)
>> if (node->address_taken
>> && !node->used_from_other_partition)
>> {
>> - if (!cgraph_for_node_and_aliases (node, has_addr_references_p, NULL, true))
>> + if (!cgraph_for_node_and_aliases (node, has_addr_references_p, NULL, true)
>> + && (!node->instrumentation_clone
>> + || !node->instrumented_version
>> + || !node->instrumented_version->address_taken))
>> {
>> if (file)
>> fprintf (file, " %s", node->name ());
>> @@ -814,6 +823,10 @@ 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;
>> }
>>
>> @@ -1016,6 +1029,7 @@ 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/lto-cgraph.c b/gcc/lto-cgraph.c
>> index 999ce3d..58105f0 100644
>> --- a/gcc/lto-cgraph.c
>> +++ b/gcc/lto-cgraph.c
>> @@ -526,6 +526,7 @@ 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);
>>
>> if (node->thunk.thunk_p && !boundary_p)
>> @@ -533,11 +534,15 @@ 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);
>> }
>> streamer_write_hwi_stream (ob->main_stream, node->profile_id);
>> +
>> + if (node->instrumentation_clone)
>> + lto_output_fn_decl_index (ob->decl_state, ob->main_stream, node->orig_decl);
>> }
>>
>> /* Output the varpool NODE to OB.
>> @@ -613,7 +618,7 @@ 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);
>> @@ -1002,6 +1007,7 @@ 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));
>> @@ -1112,10 +1118,19 @@ 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);
>> node->profile_id = 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;
>> }
>>
>> @@ -1196,7 +1211,7 @@ 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 = ipa_record_reference (referring_node, node, use, NULL);
>> @@ -1337,6 +1352,22 @@ input_cgraph_1 (struct lto_file_decl_data *file_data,
>> cgraph (node)->global.inlined_to = cgraph (nodes[ref]);
>> else
>> cnode->global.inlined_to = NULL;
>> +
>> + /* Compute instrumented_version. */
>> + if (cnode->instrumentation_clone)
>> + {
>> + gcc_assert (cnode->orig_decl);
>> +
>> + cnode->instrumented_version = cgraph_get_node (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/lto-streamer.h b/gcc/lto-streamer.h
>> index 51b1903..62a5fe0 100644
>> --- a/gcc/lto-streamer.h
>> +++ b/gcc/lto-streamer.h
>> @@ -141,7 +141,7 @@ along with GCC; see the file COPYING3. If not see
>> #define LTO_SECTION_NAME_PREFIX ".gnu.lto_"
>>
>> #define LTO_major_version 3
>> -#define LTO_minor_version 0
>> +#define LTO_minor_version 1
>>
>> typedef unsigned char lto_decl_flags_t;
>>
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