diff options
Diffstat (limited to 'scripts/gcc-plugins/randomize_layout_plugin.c')
| -rw-r--r-- | scripts/gcc-plugins/randomize_layout_plugin.c | 68 |
1 files changed, 21 insertions, 47 deletions
diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c index 951b74ba1b24..ff65a4f87f24 100644 --- a/scripts/gcc-plugins/randomize_layout_plugin.c +++ b/scripts/gcc-plugins/randomize_layout_plugin.c @@ -19,10 +19,6 @@ #include "gcc-common.h" #include "randomize_layout_seed.h" -#if BUILDING_GCC_MAJOR < 4 || (BUILDING_GCC_MAJOR == 4 && BUILDING_GCC_MINOR < 7) -#error "The RANDSTRUCT plugin requires GCC 4.7 or newer." -#endif - #define ORIG_TYPE_NAME(node) \ (TYPE_NAME(TYPE_MAIN_VARIANT(node)) != NULL_TREE ? ((const unsigned char *)IDENTIFIER_POINTER(TYPE_NAME(TYPE_MAIN_VARIANT(node)))) : (const unsigned char *)"anonymous") @@ -77,6 +73,9 @@ static tree handle_randomize_layout_attr(tree *node, tree name, tree args, int f if (TYPE_P(*node)) { type = *node; + } else if (TREE_CODE(*node) == FIELD_DECL) { + *no_add_attrs = false; + return NULL_TREE; } else { gcc_assert(TREE_CODE(*node) == TYPE_DECL); type = TREE_TYPE(*node); @@ -191,12 +190,14 @@ static void partition_struct(tree *fields, unsigned long length, struct partitio static void performance_shuffle(tree *newtree, unsigned long length, ranctx *prng_state) { - unsigned long i, x; + unsigned long i, x, index; struct partition_group size_group[length]; unsigned long num_groups = 0; unsigned long randnum; partition_struct(newtree, length, (struct partition_group *)&size_group, &num_groups); + + /* FIXME: this group shuffle is currently a no-op. */ for (i = num_groups - 1; i > 0; i--) { struct partition_group tmp; randnum = ranval(prng_state) % (i + 1); @@ -206,11 +207,14 @@ static void performance_shuffle(tree *newtree, unsigned long length, ranctx *prn } for (x = 0; x < num_groups; x++) { - for (i = size_group[x].start + size_group[x].length - 1; i > size_group[x].start; i--) { + for (index = size_group[x].length - 1; index > 0; index--) { tree tmp; + + i = size_group[x].start + index; if (DECL_BIT_FIELD_TYPE(newtree[i])) continue; - randnum = ranval(prng_state) % (i + 1); + randnum = ranval(prng_state) % (index + 1); + randnum += size_group[x].start; // we could handle this case differently if desired if (DECL_BIT_FIELD_TYPE(newtree[randnum])) continue; @@ -273,8 +277,6 @@ static bool is_flexible_array(const_tree field) { const_tree fieldtype; const_tree typesize; - const_tree elemtype; - const_tree elemsize; fieldtype = TREE_TYPE(field); typesize = TYPE_SIZE(fieldtype); @@ -282,20 +284,12 @@ static bool is_flexible_array(const_tree field) if (TREE_CODE(fieldtype) != ARRAY_TYPE) return false; - elemtype = TREE_TYPE(fieldtype); - elemsize = TYPE_SIZE(elemtype); - /* size of type is represented in bits */ if (typesize == NULL_TREE && TYPE_DOMAIN(fieldtype) != NULL_TREE && TYPE_MAX_VALUE(TYPE_DOMAIN(fieldtype)) == NULL_TREE) return true; - if (typesize != NULL_TREE && - (TREE_CONSTANT(typesize) && (!tree_to_uhwi(typesize) || - tree_to_uhwi(typesize) == tree_to_uhwi(elemsize)))) - return true; - return false; } @@ -344,8 +338,7 @@ static int relayout_struct(tree type) /* * enforce that we don't randomize the layout of the last - * element of a struct if it's a 0 or 1-length array - * or a proper flexible array + * element of a struct if it's a proper flexible array */ if (is_flexible_array(newtree[num_fields - 1])) { has_flexarray = true; @@ -354,35 +347,18 @@ static int relayout_struct(tree type) shuffle(type, (tree *)newtree, shuffle_length); - /* - * set up a bogus anonymous struct field designed to error out on unnamed struct initializers - * as gcc provides no other way to detect such code - */ - list = make_node(FIELD_DECL); - TREE_CHAIN(list) = newtree[0]; - TREE_TYPE(list) = void_type_node; - DECL_SIZE(list) = bitsize_zero_node; - DECL_NONADDRESSABLE_P(list) = 1; - DECL_FIELD_BIT_OFFSET(list) = bitsize_zero_node; - DECL_SIZE_UNIT(list) = size_zero_node; - DECL_FIELD_OFFSET(list) = size_zero_node; - DECL_CONTEXT(list) = type; - // to satisfy the constify plugin - TREE_READONLY(list) = 1; - for (i = 0; i < num_fields - 1; i++) TREE_CHAIN(newtree[i]) = newtree[i+1]; TREE_CHAIN(newtree[num_fields - 1]) = NULL_TREE; + add_type_attr(type, "randomize_performed", NULL_TREE); + add_type_attr(type, "designated_init", NULL_TREE); + if (has_flexarray) + add_type_attr(type, "has_flexarray", NULL_TREE); + main_variant = TYPE_MAIN_VARIANT(type); - for (variant = main_variant; variant; variant = TYPE_NEXT_VARIANT(variant)) { - TYPE_FIELDS(variant) = list; - TYPE_ATTRIBUTES(variant) = copy_list(TYPE_ATTRIBUTES(variant)); - TYPE_ATTRIBUTES(variant) = tree_cons(get_identifier("randomize_performed"), NULL_TREE, TYPE_ATTRIBUTES(variant)); - TYPE_ATTRIBUTES(variant) = tree_cons(get_identifier("designated_init"), NULL_TREE, TYPE_ATTRIBUTES(variant)); - if (has_flexarray) - TYPE_ATTRIBUTES(type) = tree_cons(get_identifier("has_flexarray"), NULL_TREE, TYPE_ATTRIBUTES(type)); - } + for (variant = main_variant; variant; variant = TYPE_NEXT_VARIANT(variant)) + TYPE_FIELDS(variant) = newtree[0]; /* * force a re-layout of the main variant @@ -450,10 +426,8 @@ static void randomize_type(tree type) if (lookup_attribute("randomize_layout", TYPE_ATTRIBUTES(TYPE_MAIN_VARIANT(type))) || is_pure_ops_struct(type)) relayout_struct(type); - for (variant = TYPE_MAIN_VARIANT(type); variant; variant = TYPE_NEXT_VARIANT(variant)) { - TYPE_ATTRIBUTES(type) = copy_list(TYPE_ATTRIBUTES(type)); - TYPE_ATTRIBUTES(type) = tree_cons(get_identifier("randomize_considered"), NULL_TREE, TYPE_ATTRIBUTES(type)); - } + add_type_attr(type, "randomize_considered", NULL_TREE); + #ifdef __DEBUG_PLUGIN fprintf(stderr, "Marking randomize_considered on struct %s\n", ORIG_TYPE_NAME(type)); #ifdef __DEBUG_VERBOSE |