[PATCH, Pointer Bounds Checker 9/x] Cgraph extension
Ilya Enkovich
enkovich.gnu@gmail.com
Thu Jul 24 09:59:00 GMT 2014
On 22 Jul 21:56, Jeff Law wrote:
> On 04/16/14 08:03, Ilya Enkovich wrote:
> >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
> >@@ -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;
> Is there any checking you can/should be doing here? And I'm
> asking because I'm pretty sure there's something you ought to be
> checking here :-)
>
> There's a general desire for key datastructures to sanity check them
> as much as possible.
Thanks for comments! I added additional check for chkp references. It is performed later because this piece of code is for aliases only.
>
> >+ /* 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;
> So I don't see anything which checks these two invariants.
>
> Mostly it looks good. I do want to look at it again once the
> verification stuff is beefed up.
>
>
> Jeff
Added checks for all new fields. Below is a new patch version.
Thanks,
Ilya
--
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.
diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index be3661a..cfd8708 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 +2881,65 @@ verify_cgraph_node (struct cgraph_node *node)
error_found = true;
}
}
+
+ /* Check instrumented version reference. */
+ if (node->instrumented_version
+ && node->instrumented_version->instrumented_version != node)
+ {
+ error ("Instrumentation clone does not reference original node");
+ error_found = true;
+ }
+
+ /* Cannot have orig_decl for not instrumented nodes. */
+ if (!node->instrumentation_clone && node->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 (node->instrumented_version
+ && node->orig_decl
+ && node->orig_decl != node->instrumented_version->decl)
+ {
+ error ("Instrumented node has wrong original declaration");
+ error_found = true;
+ }
+
+ /* Check all nodes have chkp reference to 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;
+ }
+ if (ref->referred != node->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 (node->analyzed && node->thunk.thunk_p)
{
if (!node->callees)
@@ -2885,6 +2957,12 @@ 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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