diff options
Diffstat (limited to 'scripts/gcc-plugins')
-rw-r--r-- | scripts/gcc-plugins/.gitignore | 1 | ||||
-rw-r--r-- | scripts/gcc-plugins/Makefile | 8 | ||||
-rw-r--r-- | scripts/gcc-plugins/cyc_complexity_plugin.c | 6 | ||||
-rw-r--r-- | scripts/gcc-plugins/gcc-common.h | 67 | ||||
-rw-r--r-- | scripts/gcc-plugins/gen-random-seed.sh | 8 | ||||
-rw-r--r-- | scripts/gcc-plugins/latent_entropy_plugin.c | 8 | ||||
-rw-r--r-- | scripts/gcc-plugins/randomize_layout_plugin.c | 1028 | ||||
-rw-r--r-- | scripts/gcc-plugins/sancov_plugin.c | 10 | ||||
-rw-r--r-- | scripts/gcc-plugins/structleak_plugin.c | 246 |
9 files changed, 1353 insertions, 29 deletions
diff --git a/scripts/gcc-plugins/.gitignore b/scripts/gcc-plugins/.gitignore new file mode 100644 index 000000000000..de92ed9e3d83 --- /dev/null +++ b/scripts/gcc-plugins/.gitignore @@ -0,0 +1 @@ +randomize_layout_seed.h diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile index 8b29dc17c73c..214eb2335c31 100644 --- a/scripts/gcc-plugins/Makefile +++ b/scripts/gcc-plugins/Makefile @@ -18,6 +18,14 @@ endif export HOSTLIBS +$(obj)/randomize_layout_plugin.o: $(objtree)/$(obj)/randomize_layout_seed.h +quiet_cmd_create_randomize_layout_seed = GENSEED $@ +cmd_create_randomize_layout_seed = \ + $(CONFIG_SHELL) $(srctree)/$(src)/gen-random-seed.sh $@ $(objtree)/include/generated/randomize_layout_hash.h +$(objtree)/$(obj)/randomize_layout_seed.h: FORCE + $(call if_changed,create_randomize_layout_seed) +targets = randomize_layout_seed.h randomize_layout_hash.h + $(HOSTLIBS)-y := $(foreach p,$(GCC_PLUGIN),$(if $(findstring /,$(p)),,$(p))) always := $($(HOSTLIBS)-y) diff --git a/scripts/gcc-plugins/cyc_complexity_plugin.c b/scripts/gcc-plugins/cyc_complexity_plugin.c index 8af7db06122d..1909ec617431 100644 --- a/scripts/gcc-plugins/cyc_complexity_plugin.c +++ b/scripts/gcc-plugins/cyc_complexity_plugin.c @@ -52,12 +52,8 @@ static unsigned int cyc_complexity_execute(void) __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version) { const char * const plugin_name = plugin_info->base_name; - struct register_pass_info cyc_complexity_pass_info; - cyc_complexity_pass_info.pass = make_cyc_complexity_pass(); - cyc_complexity_pass_info.reference_pass_name = "ssa"; - cyc_complexity_pass_info.ref_pass_instance_number = 1; - cyc_complexity_pass_info.pos_op = PASS_POS_INSERT_AFTER; + PASS_INFO(cyc_complexity, "ssa", 1, PASS_POS_INSERT_AFTER); if (!plugin_default_version_check(version, &gcc_version)) { error(G_("incompatible gcc/plugin versions")); diff --git a/scripts/gcc-plugins/gcc-common.h b/scripts/gcc-plugins/gcc-common.h index 12262c0cc691..6948898b3cdf 100644 --- a/scripts/gcc-plugins/gcc-common.h +++ b/scripts/gcc-plugins/gcc-common.h @@ -26,6 +26,9 @@ #include "except.h" #include "function.h" #include "toplev.h" +#if BUILDING_GCC_VERSION >= 5000 +#include "expr.h" +#endif #include "basic-block.h" #include "intl.h" #include "ggc.h" @@ -60,6 +63,13 @@ #endif #if BUILDING_GCC_VERSION >= 4006 +/* + * The c-family headers were moved into a subdirectory in GCC version + * 4.7, but most plugin-building users of GCC 4.6 are using the Debian + * or Ubuntu package, which has an out-of-tree patch to move this to the + * same location as found in 4.7 and later: + * https://sources.debian.net/src/gcc-4.6/4.6.3-14/debian/patches/pr45078.diff/ + */ #include "c-family/c-common.h" #else #include "c-common.h" @@ -80,6 +90,9 @@ #include "diagnostic.h" #include "tree-dump.h" #include "tree-pass.h" +#if BUILDING_GCC_VERSION >= 4009 +#include "pass_manager.h" +#endif #include "predict.h" #include "ipa-utils.h" @@ -119,20 +132,17 @@ #include "builtins.h" #endif -/* #include "expr.h" where are you... */ -extern rtx emit_move_insn(rtx x, rtx y); - /* missing from basic_block.h... */ -extern void debug_dominance_info(enum cdi_direction dir); -extern void debug_dominance_tree(enum cdi_direction dir, basic_block root); +void debug_dominance_info(enum cdi_direction dir); +void debug_dominance_tree(enum cdi_direction dir, basic_block root); #if BUILDING_GCC_VERSION == 4006 -extern void debug_gimple_stmt(gimple); -extern void debug_gimple_seq(gimple_seq); -extern void print_gimple_seq(FILE *, gimple_seq, int, int); -extern void print_gimple_stmt(FILE *, gimple, int, int); -extern void print_gimple_expr(FILE *, gimple, int, int); -extern void dump_gimple_stmt(pretty_printer *, gimple, int, int); +void debug_gimple_stmt(gimple); +void debug_gimple_seq(gimple_seq); +void print_gimple_seq(FILE *, gimple_seq, int, int); +void print_gimple_stmt(FILE *, gimple, int, int); +void print_gimple_expr(FILE *, gimple, int, int); +void dump_gimple_stmt(pretty_printer *, gimple, int, int); #endif #define __unused __attribute__((__unused__)) @@ -146,6 +156,29 @@ extern void dump_gimple_stmt(pretty_printer *, gimple, int, int); /* should come from c-tree.h if only it were installed for gcc 4.5... */ #define C_TYPE_FIELDS_READONLY(TYPE) TREE_LANG_FLAG_1(TYPE) +static inline tree build_const_char_string(int len, const char *str) +{ + tree cstr, elem, index, type; + + cstr = build_string(len, str); + elem = build_type_variant(char_type_node, 1, 0); + index = build_index_type(size_int(len - 1)); + type = build_array_type(elem, index); + TREE_TYPE(cstr) = type; + TREE_CONSTANT(cstr) = 1; + TREE_READONLY(cstr) = 1; + TREE_STATIC(cstr) = 1; + return cstr; +} + +#define PASS_INFO(NAME, REF, ID, POS) \ +struct register_pass_info NAME##_pass_info = { \ + .pass = make_##NAME##_pass(), \ + .reference_pass_name = REF, \ + .ref_pass_instance_number = ID, \ + .pos_op = POS, \ +} + #if BUILDING_GCC_VERSION == 4005 #define FOR_EACH_LOCAL_DECL(FUN, I, D) \ for (tree vars = (FUN)->local_decls, (I) = 0; \ @@ -527,6 +560,8 @@ static inline const greturn *as_a_const_greturn(const_gimple stmt) #define section_name_prefix LTO_SECTION_NAME_PREFIX #define fatal_error(loc, gmsgid, ...) fatal_error((gmsgid), __VA_ARGS__) +rtx emit_move_insn(rtx x, rtx y); + typedef struct rtx_def rtx_insn; static inline const char *get_decl_section_name(const_tree decl) @@ -643,6 +678,11 @@ static inline const greturn *as_a_const_greturn(const_gimple stmt) #define NODE_DECL(node) (node)->decl #define cgraph_node_name(node) (node)->name() #define NODE_IMPLICIT_ALIAS(node) (node)->cpp_implicit_alias + +static inline opt_pass *get_pass_for_id(int id) +{ + return g->get_passes()->get_pass_for_id(id); +} #endif #if BUILDING_GCC_VERSION >= 5000 && BUILDING_GCC_VERSION < 6000 @@ -913,4 +953,9 @@ static inline void debug_gimple_stmt(const_gimple s) get_inner_reference(exp, pbitsize, pbitpos, poffset, pmode, punsignedp, preversep, pvolatilep) #endif +#if BUILDING_GCC_VERSION < 7000 +#define SET_DECL_ALIGN(decl, align) DECL_ALIGN(decl) = (align) +#define SET_DECL_MODE(decl, mode) DECL_MODE(decl) = (mode) +#endif + #endif diff --git a/scripts/gcc-plugins/gen-random-seed.sh b/scripts/gcc-plugins/gen-random-seed.sh new file mode 100644 index 000000000000..7514850f4815 --- /dev/null +++ b/scripts/gcc-plugins/gen-random-seed.sh @@ -0,0 +1,8 @@ +#!/bin/sh + +if [ ! -f "$1" ]; then + SEED=`od -A n -t x8 -N 32 /dev/urandom | tr -d ' \n'` + echo "const char *randstruct_seed = \"$SEED\";" > "$1" + HASH=`echo -n "$SEED" | sha256sum | cut -d" " -f1 | tr -d ' \n'` + echo "#define RANDSTRUCT_HASHED_SEED \"$HASH\"" > "$2" +fi diff --git a/scripts/gcc-plugins/latent_entropy_plugin.c b/scripts/gcc-plugins/latent_entropy_plugin.c index 8ff203ad4809..65264960910d 100644 --- a/scripts/gcc-plugins/latent_entropy_plugin.c +++ b/scripts/gcc-plugins/latent_entropy_plugin.c @@ -592,12 +592,6 @@ __visible int plugin_init(struct plugin_name_args *plugin_info, const struct plugin_argument * const argv = plugin_info->argv; int i; - struct register_pass_info latent_entropy_pass_info; - - latent_entropy_pass_info.pass = make_latent_entropy_pass(); - latent_entropy_pass_info.reference_pass_name = "optimized"; - latent_entropy_pass_info.ref_pass_instance_number = 1; - latent_entropy_pass_info.pos_op = PASS_POS_INSERT_BEFORE; static const struct ggc_root_tab gt_ggc_r_gt_latent_entropy[] = { { .base = &latent_entropy_decl, @@ -609,6 +603,8 @@ __visible int plugin_init(struct plugin_name_args *plugin_info, LAST_GGC_ROOT_TAB }; + PASS_INFO(latent_entropy, "optimized", 1, PASS_POS_INSERT_BEFORE); + if (!plugin_default_version_check(version, &gcc_version)) { error(G_("incompatible gcc/plugin versions")); return 1; diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c new file mode 100644 index 000000000000..cdaac8c66734 --- /dev/null +++ b/scripts/gcc-plugins/randomize_layout_plugin.c @@ -0,0 +1,1028 @@ +/* + * Copyright 2014-2016 by Open Source Security, Inc., Brad Spengler <spender@grsecurity.net> + * and PaX Team <pageexec@freemail.hu> + * Licensed under the GPL v2 + * + * Note: the choice of the license means that the compilation process is + * NOT 'eligible' as defined by gcc's library exception to the GPL v3, + * but for the kernel it doesn't matter since it doesn't link against + * any of the gcc libraries + * + * Usage: + * $ # for 4.5/4.6/C based 4.7 + * $ gcc -I`gcc -print-file-name=plugin`/include -I`gcc -print-file-name=plugin`/include/c-family -fPIC -shared -O2 -o randomize_layout_plugin.so randomize_layout_plugin.c + * $ # for C++ based 4.7/4.8+ + * $ g++ -I`g++ -print-file-name=plugin`/include -I`g++ -print-file-name=plugin`/include/c-family -fPIC -shared -O2 -o randomize_layout_plugin.so randomize_layout_plugin.c + * $ gcc -fplugin=./randomize_layout_plugin.so test.c -O2 + */ + +#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") + +#define INFORM(loc, msg, ...) inform(loc, "randstruct: " msg, ##__VA_ARGS__) +#define MISMATCH(loc, how, ...) INFORM(loc, "casting between randomized structure pointer types (" how "): %qT and %qT\n", __VA_ARGS__) + +__visible int plugin_is_GPL_compatible; + +static int performance_mode; + +static struct plugin_info randomize_layout_plugin_info = { + .version = "201402201816vanilla", + .help = "disable\t\t\tdo not activate plugin\n" + "performance-mode\tenable cacheline-aware layout randomization\n" +}; + +struct whitelist_entry { + const char *pathname; + const char *lhs; + const char *rhs; +}; + +static const struct whitelist_entry whitelist[] = { + /* NIU overloads mapping with page struct */ + { "drivers/net/ethernet/sun/niu.c", "page", "address_space" }, + /* unix_skb_parms via UNIXCB() buffer */ + { "net/unix/af_unix.c", "unix_skb_parms", "char" }, + /* big_key payload.data struct splashing */ + { "security/keys/big_key.c", "path", "void *" }, + /* walk struct security_hook_heads as an array of struct list_head */ + { "security/security.c", "list_head", "security_hook_heads" }, + { } +}; + +/* from old Linux dcache.h */ +static inline unsigned long +partial_name_hash(unsigned long c, unsigned long prevhash) +{ + return (prevhash + (c << 4) + (c >> 4)) * 11; +} +static inline unsigned int +name_hash(const unsigned char *name) +{ + unsigned long hash = 0; + unsigned int len = strlen((const char *)name); + while (len--) + hash = partial_name_hash(*name++, hash); + return (unsigned int)hash; +} + +static tree handle_randomize_layout_attr(tree *node, tree name, tree args, int flags, bool *no_add_attrs) +{ + tree type; + + *no_add_attrs = true; + if (TREE_CODE(*node) == FUNCTION_DECL) { + error("%qE attribute does not apply to functions (%qF)", name, *node); + return NULL_TREE; + } + + if (TREE_CODE(*node) == PARM_DECL) { + error("%qE attribute does not apply to function parameters (%qD)", name, *node); + return NULL_TREE; + } + + if (TREE_CODE(*node) == VAR_DECL) { + error("%qE attribute does not apply to variables (%qD)", name, *node); + return NULL_TREE; + } + + if (TYPE_P(*node)) { + type = *node; + } else { + gcc_assert(TREE_CODE(*node) == TYPE_DECL); + type = TREE_TYPE(*node); + } + + if (TREE_CODE(type) != RECORD_TYPE) { + error("%qE attribute used on %qT applies to struct types only", name, type); + return NULL_TREE; + } + + if (lookup_attribute(IDENTIFIER_POINTER(name), TYPE_ATTRIBUTES(type))) { + error("%qE attribute is already applied to the type %qT", name, type); + return NULL_TREE; + } + + *no_add_attrs = false; + + return NULL_TREE; +} + +/* set on complete types that we don't need to inspect further at all */ +static tree handle_randomize_considered_attr(tree *node, tree name, tree args, int flags, bool *no_add_attrs) +{ + *no_add_attrs = false; + return NULL_TREE; +} + +/* + * set on types that we've performed a shuffle on, to prevent re-shuffling + * this does not preclude us from inspecting its fields for potential shuffles + */ +static tree handle_randomize_performed_attr(tree *node, tree name, tree args, int flags, bool *no_add_attrs) +{ + *no_add_attrs = false; + return NULL_TREE; +} + +/* + * 64bit variant of Bob Jenkins' public domain PRNG + * 256 bits of internal state + */ + +typedef unsigned long long u64; + +typedef struct ranctx { u64 a; u64 b; u64 c; u64 d; } ranctx; + +#define rot(x,k) (((x)<<(k))|((x)>>(64-(k)))) +static u64 ranval(ranctx *x) { + u64 e = x->a - rot(x->b, 7); + x->a = x->b ^ rot(x->c, 13); + x->b = x->c + rot(x->d, 37); + x->c = x->d + e; + x->d = e + x->a; + return x->d; +} + +static void raninit(ranctx *x, u64 *seed) { + int i; + + x->a = seed[0]; + x->b = seed[1]; + x->c = seed[2]; + x->d = seed[3]; + + for (i=0; i < 30; ++i) + (void)ranval(x); +} + +static u64 shuffle_seed[4]; + +struct partition_group { + tree tree_start; + unsigned long start; + unsigned long length; +}; + +static void partition_struct(tree *fields, unsigned long length, struct partition_group *size_groups, unsigned long *num_groups) +{ + unsigned long i; + unsigned long accum_size = 0; + unsigned long accum_length = 0; + unsigned long group_idx = 0; + + gcc_assert(length < INT_MAX); + + memset(size_groups, 0, sizeof(struct partition_group) * length); + + for (i = 0; i < length; i++) { + if (size_groups[group_idx].tree_start == NULL_TREE) { + size_groups[group_idx].tree_start = fields[i]; + size_groups[group_idx].start = i; + accum_length = 0; + accum_size = 0; + } + accum_size += (unsigned long)int_size_in_bytes(TREE_TYPE(fields[i])); + accum_length++; + if (accum_size >= 64) { + size_groups[group_idx].length = accum_length; + accum_length = 0; + group_idx++; + } + } + + if (size_groups[group_idx].tree_start != NULL_TREE && + !size_groups[group_idx].length) { + size_groups[group_idx].length = accum_length; + group_idx++; + } + + *num_groups = group_idx; +} + +static void performance_shuffle(tree *newtree, unsigned long length, ranctx *prng_state) +{ + unsigned long i, x; + 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); + for (i = num_groups - 1; i > 0; i--) { + struct partition_group tmp; + randnum = ranval(prng_state) % (i + 1); + tmp = size_group[i]; + size_group[i] = size_group[randnum]; + size_group[randnum] = tmp; + } + + for (x = 0; x < num_groups; x++) { + for (i = size_group[x].start + size_group[x].length - 1; i > size_group[x].start; i--) { + tree tmp; + if (DECL_BIT_FIELD_TYPE(newtree[i])) + continue; + randnum = ranval(prng_state) % (i + 1); + // we could handle this case differently if desired + if (DECL_BIT_FIELD_TYPE(newtree[randnum])) + continue; + tmp = newtree[i]; + newtree[i] = newtree[randnum]; + newtree[randnum] = tmp; + } + } +} + +static void full_shuffle(tree *newtree, unsigned long length, ranctx *prng_state) +{ + unsigned long i, randnum; + + for (i = length - 1; i > 0; i--) { + tree tmp; + randnum = ranval(prng_state) % (i + 1); + tmp = newtree[i]; + newtree[i] = newtree[randnum]; + newtree[randnum] = tmp; + } +} + +/* modern in-place Fisher-Yates shuffle */ +static void shuffle(const_tree type, tree *newtree, unsigned long length) +{ + unsigned long i; + u64 seed[4]; + ranctx prng_state; + const unsigned char *structname; + + if (length == 0) + return; + + gcc_assert(TREE_CODE(type) == RECORD_TYPE); + + structname = ORIG_TYPE_NAME(type); + +#ifdef __DEBUG_PLUGIN + fprintf(stderr, "Shuffling struct %s %p\n", (const char *)structname, type); +#ifdef __DEBUG_VERBOSE + debug_tree((tree)type); +#endif +#endif + + for (i = 0; i < 4; i++) { + seed[i] = shuffle_seed[i]; + seed[i] ^= name_hash(structname); + } + + raninit(&prng_state, (u64 *)&seed); + + if (performance_mode) + performance_shuffle(newtree, length, &prng_state); + else + full_shuffle(newtree, length, &prng_state); +} + +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); + + 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; +} + +static int relayout_struct(tree type) +{ + unsigned long num_fields = (unsigned long)list_length(TYPE_FIELDS(type)); + unsigned long shuffle_length = num_fields; + tree field; + tree newtree[num_fields]; + unsigned long i; + tree list; + tree variant; + tree main_variant; + expanded_location xloc; + bool has_flexarray = false; + + if (TYPE_FIELDS(type) == NULL_TREE) + return 0; + + if (num_fields < 2) + return 0; + + gcc_assert(TREE_CODE(type) == RECORD_TYPE); + + gcc_assert(num_fields < INT_MAX); + + if (lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(type)) || + lookup_attribute("no_randomize_layout", TYPE_ATTRIBUTES(TYPE_MAIN_VARIANT(type)))) + return 0; + + /* Workaround for 3rd-party VirtualBox source that we can't modify ourselves */ + if (!strcmp((const char *)ORIG_TYPE_NAME(type), "INTNETTRUNKFACTORY") || + !strcmp((const char *)ORIG_TYPE_NAME(type), "RAWPCIFACTORY")) + return 0; + + /* throw out any structs in uapi */ + xloc = expand_location(DECL_SOURCE_LOCATION(TYPE_FIELDS(type))); + + if (strstr(xloc.file, "/uapi/")) + error(G_("attempted to randomize userland API struct %s"), ORIG_TYPE_NAME(type)); + + for (field = TYPE_FIELDS(type), i = 0; field; field = TREE_CHAIN(field), i++) { + gcc_assert(TREE_CODE(field) == FIELD_DECL); + newtree[i] = field; + } + + /* + * 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 + */ + if (is_flexible_array(newtree[num_fields - 1])) { + has_flexarray = true; + shuffle_length--; + } + + 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; + + 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)); + } + + /* + * force a re-layout of the main variant + * the TYPE_SIZE for all variants will be recomputed + * by finalize_type_size() + */ + TYPE_SIZE(main_variant) = NULL_TREE; + layout_type(main_variant); + gcc_assert(TYPE_SIZE(main_variant) != NULL_TREE); + + return 1; +} + +/* from constify plugin */ +static const_tree get_field_type(const_tree field) +{ + return strip_array_types(TREE_TYPE(field)); +} + +/* from constify plugin */ +static bool is_fptr(const_tree fieldtype) +{ + if (TREE_CODE(fieldtype) != POINTER_TYPE) + return false; + + return TREE_CODE(TREE_TYPE(fieldtype)) == FUNCTION_TYPE; +} + +/* derived from constify plugin */ +static int is_pure_ops_struct(const_tree node) +{ + const_tree field; + + gcc_assert(TREE_CODE(node) == RECORD_TYPE || TREE_CODE(node) == UNION_TYPE); + + /* XXX: Do not apply randomization to all-ftpr structs yet. */ + return 0; + + for (field = TYPE_FIELDS(node); field; field = TREE_CHAIN(field)) { + const_tree fieldtype = get_field_type(field); + enum tree_code code = TREE_CODE(fieldtype); + + if (node == fieldtype) + continue; + + if (!is_fptr(fieldtype)) + return 0; + + if (code != RECORD_TYPE && code != UNION_TYPE) + continue; + + if (!is_pure_ops_struct(fieldtype)) + return 0; + } + + return 1; +} + +static void randomize_type(tree type) +{ + tree variant; + + gcc_assert(TREE_CODE(type) == RECORD_TYPE); + + if (lookup_attribute("randomize_considered", TYPE_ATTRIBUTES(type))) + return; + + 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)); + } +#ifdef __DEBUG_PLUGIN + fprintf(stderr, "Marking randomize_considered on struct %s\n", ORIG_TYPE_NAME(type)); +#ifdef __DEBUG_VERBOSE + debug_tree(type); +#endif +#endif +} + +static void update_decl_size(tree decl) +{ + tree lastval, lastidx, field, init, type, flexsize; + unsigned HOST_WIDE_INT len; + + type = TREE_TYPE(decl); + + if (!lookup_attribute("has_flexarray", TYPE_ATTRIBUTES(type))) + return; + + init = DECL_INITIAL(decl); + if (init == NULL_TREE || init == error_mark_node) + return; + + if (TREE_CODE(init) != CONSTRUCTOR) + return; + + len = CONSTRUCTOR_NELTS(init); + if (!len) + return; + + lastval = CONSTRUCTOR_ELT(init, CONSTRUCTOR_NELTS(init) - 1)->value; + lastidx = CONSTRUCTOR_ELT(init, CONSTRUCTOR_NELTS(init) - 1)->index; + + for (field = TYPE_FIELDS(TREE_TYPE(decl)); TREE_CHAIN(field); field = TREE_CHAIN(field)) + ; + + if (lastidx != field) + return; + + if (TREE_CODE(lastval) != STRING_CST) { + error("Only string constants are supported as initializers " + "for randomized structures with flexible arrays"); + return; + } + + flexsize = bitsize_int(TREE_STRING_LENGTH(lastval) * + tree_to_uhwi(TYPE_SIZE(TREE_TYPE(TREE_TYPE(lastval))))); + + DECL_SIZE(decl) = size_binop(PLUS_EXPR, TYPE_SIZE(type), flexsize); + + return; +} + + +static void randomize_layout_finish_decl(void *event_data, void *data) +{ + tree decl = (tree)event_data; + tree type; + + if (decl == NULL_TREE || decl == error_mark_node) + return; + + type = TREE_TYPE(decl); + + if (TREE_CODE(decl) != VAR_DECL) + return; + + if (TREE_CODE(type) != RECORD_TYPE && TREE_CODE(type) != UNION_TYPE) + return; + + if (!lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(type))) + return; + + DECL_SIZE(decl) = 0; + DECL_SIZE_UNIT(decl) = 0; + SET_DECL_ALIGN(decl, 0); + SET_DECL_MODE (decl, VOIDmode); + SET_DECL_RTL(decl, 0); + update_decl_size(decl); + layout_decl(decl, 0); +} + +static void finish_type(void *event_data, void *data) +{ + tree type = (tree)event_data; + + if (type == NULL_TREE || type == error_mark_node) + return; + + if (TREE_CODE(type) != RECORD_TYPE) + return; + + if (TYPE_FIELDS(type) == NULL_TREE) + return; + + if (lookup_attribute("randomize_considered", TYPE_ATTRIBUTES(type))) + return; + +#ifdef __DEBUG_PLUGIN + fprintf(stderr, "Calling randomize_type on %s\n", ORIG_TYPE_NAME(type)); +#endif +#ifdef __DEBUG_VERBOSE + debug_tree(type); +#endif + randomize_type(type); + + return; +} + +static struct attribute_spec randomize_layout_attr = { + .name = "randomize_layout", + // related to args + .min_length = 0, + .max_length = 0, + .decl_required = false, + // need type declaration + .type_required = true, + .function_type_required = false, + .handler = handle_randomize_layout_attr, +#if BUILDING_GCC_VERSION >= 4007 + .affects_type_identity = true +#endif +}; + +static struct attribute_spec no_randomize_layout_attr = { + .name = "no_randomize_layout", + // related to args + .min_length = 0, + .max_length = 0, + .decl_required = false, + // need type declaration + .type_required = true, + .function_type_required = false, + .handler = handle_randomize_layout_attr, +#if BUILDING_GCC_VERSION >= 4007 + .affects_type_identity = true +#endif +}; + +static struct attribute_spec randomize_considered_attr = { + .name = "randomize_considered", + // related to args + .min_length = 0, + .max_length = 0, + .decl_required = false, + // need type declaration + .type_required = true, + .function_type_required = false, + .handler = handle_randomize_considered_attr, +#if BUILDING_GCC_VERSION >= 4007 + .affects_type_identity = false +#endif +}; + +static struct attribute_spec randomize_performed_attr = { + .name = "randomize_performed", + // related to args + .min_length = 0, + .max_length = 0, + .decl_required = false, + // need type declaration + .type_required = true, + .function_type_required = false, + .handler = handle_randomize_performed_attr, +#if BUILDING_GCC_VERSION >= 4007 + .affects_type_identity = false +#endif +}; + +static void register_attributes(void *event_data, void *data) +{ + register_attribute(&randomize_layout_attr); + register_attribute(&no_randomize_layout_attr); + register_attribute(&randomize_considered_attr); + register_attribute(&randomize_performed_attr); +} + +static void check_bad_casts_in_constructor(tree var, tree init) +{ + unsigned HOST_WIDE_INT idx; + tree field, val; + tree field_type, val_type; + + FOR_EACH_CONSTRUCTOR_ELT(CONSTRUCTOR_ELTS(init), idx, field, val) { + if (TREE_CODE(val) == CONSTRUCTOR) { + check_bad_casts_in_constructor(var, val); + continue; + } + + /* pipacs' plugin creates franken-arrays that differ from those produced by + normal code which all have valid 'field' trees. work around this */ + if (field == NULL_TREE) + continue; + field_type = TREE_TYPE(field); + val_type = TREE_TYPE(val); + + if (TREE_CODE(field_type) != POINTER_TYPE || TREE_CODE(val_type) != POINTER_TYPE) + continue; + + if (field_type == val_type) + continue; + + field_type = TYPE_MAIN_VARIANT(strip_array_types(TYPE_MAIN_VARIANT(TREE_TYPE(field_type)))); + val_type = TYPE_MAIN_VARIANT(strip_array_types(TYPE_MAIN_VARIANT(TREE_TYPE(val_type)))); + + if (field_type == void_type_node) + continue; + if (field_type == val_type) + continue; + if (TREE_CODE(val_type) != RECORD_TYPE) + continue; + + if (!lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(val_type))) + continue; + MISMATCH(DECL_SOURCE_LOCATION(var), "constructor\n", TYPE_MAIN_VARIANT(field_type), TYPE_MAIN_VARIANT(val_type)); + } +} + +/* derived from the constify plugin */ +static void check_global_variables(void *event_data, void *data) +{ + struct varpool_node *node; + tree init; + + FOR_EACH_VARIABLE(node) { + tree var = NODE_DECL(node); + init = DECL_INITIAL(var); + if (init == NULL_TREE) + continue; + + if (TREE_CODE(init) != CONSTRUCTOR) + continue; + + check_bad_casts_in_constructor(var, init); + } +} + +static bool dominated_by_is_err(const_tree rhs, basic_block bb) +{ + basic_block dom; + gimple dom_stmt; + gimple call_stmt; + const_tree dom_lhs; + const_tree poss_is_err_cond; + const_tree poss_is_err_func; + const_tree is_err_arg; + + dom = get_immediate_dominator(CDI_DOMINATORS, bb); + if (!dom) + return false; + + dom_stmt = last_stmt(dom); + if (!dom_stmt) + return false; + + if (gimple_code(dom_stmt) != GIMPLE_COND) + return false; + + if (gimple_cond_code(dom_stmt) != NE_EXPR) + return false; + + if (!integer_zerop(gimple_cond_rhs(dom_stmt))) + return false; + + poss_is_err_cond = gimple_cond_lhs(dom_stmt); + + if (TREE_CODE(poss_is_err_cond) != SSA_NAME) + return false; + + call_stmt = SSA_NAME_DEF_STMT(poss_is_err_cond); + + if (gimple_code(call_stmt) != GIMPLE_CALL) + return false; + + dom_lhs = gimple_get_lhs(call_stmt); + poss_is_err_func = gimple_call_fndecl(call_stmt); + if (!poss_is_err_func) + return false; + if (dom_lhs != poss_is_err_cond) + return false; + if (strcmp(DECL_NAME_POINTER(poss_is_err_func), "IS_ERR")) + return false; + + is_err_arg = gimple_call_arg(call_stmt, 0); + if (!is_err_arg) + return false; + + if (is_err_arg != rhs) + return false; + + return true; +} + +static void handle_local_var_initializers(void) +{ + tree var; + unsigned int i; + + FOR_EACH_LOCAL_DECL(cfun, i, var) { + tree init = DECL_INITIAL(var); + if (!init) + continue; + if (TREE_CODE(init) != CONSTRUCTOR) + continue; + check_bad_casts_in_constructor(var, init); + } +} + +static bool type_name_eq(gimple stmt, const_tree type_tree, const char *wanted_name) +{ + const char *type_name; + + if (type_tree == NULL_TREE) + return false; + + switch (TREE_CODE(type_tree)) { + case RECORD_TYPE: + type_name = TYPE_NAME_POINTER(type_tree); + break; + case INTEGER_TYPE: + if (TYPE_PRECISION(type_tree) == CHAR_TYPE_SIZE) + type_name = "char"; + else { + INFORM(gimple_location(stmt), "found non-char INTEGER_TYPE cast comparison: %qT\n", type_tree); + debug_tree(type_tree); + return false; + } + break; + case POINTER_TYPE: + if (TREE_CODE(TREE_TYPE(type_tree)) == VOID_TYPE) { + type_name = "void *"; + break; + } else { + INFORM(gimple_location(stmt), "found non-void POINTER_TYPE cast comparison %qT\n", type_tree); + debug_tree(type_tree); + return false; + } + default: + INFORM(gimple_location(stmt), "unhandled cast comparison: %qT\n", type_tree); + debug_tree(type_tree); + return false; + } + + return strcmp(type_name, wanted_name) == 0; +} + +static bool whitelisted_cast(gimple stmt, const_tree lhs_tree, const_tree rhs_tree) +{ + const struct whitelist_entry *entry; + expanded_location xloc = expand_location(gimple_location(stmt)); + + for (entry = whitelist; entry->pathname; entry++) { + if (!strstr(xloc.file, entry->pathname)) + continue; + + if (type_name_eq(stmt, lhs_tree, entry->lhs) && type_name_eq(stmt, rhs_tree, entry->rhs)) + return true; + } + + return false; +} + +/* + * iterate over all statements to find "bad" casts: + * those where the address of the start of a structure is cast + * to a pointer of a structure of a different type, or a + * structure pointer type is cast to a different structure pointer type + */ +static unsigned int find_bad_casts_execute(void) +{ + basic_block bb; + + handle_local_var_initializers(); + + FOR_EACH_BB_FN(bb, cfun) { + gimple_stmt_iterator gsi; + + for (gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi)) { + gimple stmt; + const_tree lhs; + const_tree lhs_type; + const_tree rhs1; + const_tree rhs_type; + const_tree ptr_lhs_type; + const_tree ptr_rhs_type; + const_tree op0; + const_tree op0_type; + enum tree_code rhs_code; + + stmt = gsi_stmt(gsi); + +#ifdef __DEBUG_PLUGIN +#ifdef __DEBUG_VERBOSE + debug_gimple_stmt(stmt); + debug_tree(gimple_get_lhs(stmt)); +#endif +#endif + + if (gimple_code(stmt) != GIMPLE_ASSIGN) + continue; + +#ifdef __DEBUG_PLUGIN +#ifdef __DEBUG_VERBOSE + debug_tree(gimple_assign_rhs1(stmt)); +#endif +#endif + + + rhs_code = gimple_assign_rhs_code(stmt); + + if (rhs_code != ADDR_EXPR && rhs_code != SSA_NAME) + continue; + + lhs = gimple_get_lhs(stmt); + lhs_type = TREE_TYPE(lhs); + rhs1 = gimple_assign_rhs1(stmt); + rhs_type = TREE_TYPE(rhs1); + + if (TREE_CODE(rhs_type) != POINTER_TYPE || + TREE_CODE(lhs_type) != POINTER_TYPE) + continue; + + ptr_lhs_type = TYPE_MAIN_VARIANT(strip_array_types(TYPE_MAIN_VARIANT(TREE_TYPE(lhs_type)))); + ptr_rhs_type = TYPE_MAIN_VARIANT(strip_array_types(TYPE_MAIN_VARIANT(TREE_TYPE(rhs_type)))); + + if (ptr_rhs_type == void_type_node) + continue; + + if (ptr_lhs_type == void_type_node) + continue; + + if (dominated_by_is_err(rhs1, bb)) + continue; + + if (TREE_CODE(ptr_rhs_type) != RECORD_TYPE) { +#ifndef __DEBUG_PLUGIN + if (lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(ptr_lhs_type))) +#endif + { + if (!whitelisted_cast(stmt, ptr_lhs_type, ptr_rhs_type)) + MISMATCH(gimple_location(stmt), "rhs", ptr_lhs_type, ptr_rhs_type); + } + continue; + } + + if (rhs_code == SSA_NAME && ptr_lhs_type == ptr_rhs_type) + continue; + + if (rhs_code == ADDR_EXPR) { + op0 = TREE_OPERAND(rhs1, 0); + + if (op0 == NULL_TREE) + continue; + + if (TREE_CODE(op0) != VAR_DECL) + continue; + + op0_type = TYPE_MAIN_VARIANT(strip_array_types(TYPE_MAIN_VARIANT(TREE_TYPE(op0)))); + if (op0_type == ptr_lhs_type) + continue; + +#ifndef __DEBUG_PLUGIN + if (lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(op0_type))) +#endif + { + if (!whitelisted_cast(stmt, ptr_lhs_type, op0_type)) + MISMATCH(gimple_location(stmt), "op0", ptr_lhs_type, op0_type); + } + } else { + const_tree ssa_name_var = SSA_NAME_VAR(rhs1); + /* skip bogus type casts introduced by container_of */ + if (ssa_name_var != NULL_TREE && DECL_NAME(ssa_name_var) && + !strcmp((const char *)DECL_NAME_POINTER(ssa_name_var), "__mptr")) + continue; +#ifndef __DEBUG_PLUGIN + if (lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(ptr_rhs_type))) +#endif + { + if (!whitelisted_cast(stmt, ptr_lhs_type, ptr_rhs_type)) + MISMATCH(gimple_location(stmt), "ssa", ptr_lhs_type, ptr_rhs_type); + } + } + + } + } + return 0; +} + +#define PASS_NAME find_bad_casts +#define NO_GATE +#define TODO_FLAGS_FINISH TODO_dump_func +#include "gcc-generate-gimple-pass.h" + +__visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version) +{ + int i; + const char * const plugin_name = plugin_info->base_name; + const int argc = plugin_info->argc; + const struct plugin_argument * const argv = plugin_info->argv; + bool enable = true; + int obtained_seed = 0; + struct register_pass_info find_bad_casts_pass_info; + + find_bad_casts_pass_info.pass = make_find_bad_casts_pass(); + find_bad_casts_pass_info.reference_pass_name = "ssa"; + find_bad_casts_pass_info.ref_pass_instance_number = 1; + find_bad_casts_pass_info.pos_op = PASS_POS_INSERT_AFTER; + + if (!plugin_default_version_check(version, &gcc_version)) { + error(G_("incompatible gcc/plugin versions")); + return 1; + } + + if (strncmp(lang_hooks.name, "GNU C", 5) && !strncmp(lang_hooks.name, "GNU C+", 6)) { + inform(UNKNOWN_LOCATION, G_("%s supports C only, not %s"), plugin_name, lang_hooks.name); + enable = false; + } + + for (i = 0; i < argc; ++i) { + if (!strcmp(argv[i].key, "disable")) { + enable = false; + continue; + } + if (!strcmp(argv[i].key, "performance-mode")) { + performance_mode = 1; + continue; + } + error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key); + } + + if (strlen(randstruct_seed) != 64) { + error(G_("invalid seed value supplied for %s plugin"), plugin_name); + return 1; + } + obtained_seed = sscanf(randstruct_seed, "%016llx%016llx%016llx%016llx", + &shuffle_seed[0], &shuffle_seed[1], &shuffle_seed[2], &shuffle_seed[3]); + if (obtained_seed != 4) { + error(G_("Invalid seed supplied for %s plugin"), plugin_name); + return 1; + } + + register_callback(plugin_name, PLUGIN_INFO, NULL, &randomize_layout_plugin_info); + if (enable) { + register_callback(plugin_name, PLUGIN_ALL_IPA_PASSES_START, check_global_variables, NULL); + register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &find_bad_casts_pass_info); + register_callback(plugin_name, PLUGIN_FINISH_TYPE, finish_type, NULL); + register_callback(plugin_name, PLUGIN_FINISH_DECL, randomize_layout_finish_decl, NULL); + } + register_callback(plugin_name, PLUGIN_ATTRIBUTES, register_attributes, NULL); + + return 0; +} diff --git a/scripts/gcc-plugins/sancov_plugin.c b/scripts/gcc-plugins/sancov_plugin.c index 70f5fe0d590a..0f98634c20a0 100644 --- a/scripts/gcc-plugins/sancov_plugin.c +++ b/scripts/gcc-plugins/sancov_plugin.c @@ -89,7 +89,6 @@ static void sancov_start_unit(void __unused *gcc_data, void __unused *user_data) __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version) { int i; - struct register_pass_info sancov_plugin_pass_info; const char * const plugin_name = plugin_info->base_name; const int argc = plugin_info->argc; const struct plugin_argument * const argv = plugin_info->argv; @@ -107,14 +106,11 @@ __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gc }; /* BBs can be split afterwards?? */ - sancov_plugin_pass_info.pass = make_sancov_pass(); #if BUILDING_GCC_VERSION >= 4009 - sancov_plugin_pass_info.reference_pass_name = "asan"; + PASS_INFO(sancov, "asan", 0, PASS_POS_INSERT_BEFORE); #else - sancov_plugin_pass_info.reference_pass_name = "nrv"; + PASS_INFO(sancov, "nrv", 1, PASS_POS_INSERT_BEFORE); #endif - sancov_plugin_pass_info.ref_pass_instance_number = 0; - sancov_plugin_pass_info.pos_op = PASS_POS_INSERT_BEFORE; if (!plugin_default_version_check(version, &gcc_version)) { error(G_("incompatible gcc/plugin versions")); @@ -137,7 +133,7 @@ __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gc #if BUILDING_GCC_VERSION < 6000 register_callback(plugin_name, PLUGIN_START_UNIT, &sancov_start_unit, NULL); register_callback(plugin_name, PLUGIN_REGISTER_GGC_ROOTS, NULL, (void *)>_ggc_r_gt_sancov); - register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &sancov_plugin_pass_info); + register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &sancov_pass_info); #endif return 0; diff --git a/scripts/gcc-plugins/structleak_plugin.c b/scripts/gcc-plugins/structleak_plugin.c new file mode 100644 index 000000000000..fa3d7a4b26f2 --- /dev/null +++ b/scripts/gcc-plugins/structleak_plugin.c @@ -0,0 +1,246 @@ +/* + * Copyright 2013-2017 by PaX Team <pageexec@freemail.hu> + * Licensed under the GPL v2 + * + * Note: the choice of the license means that the compilation process is + * NOT 'eligible' as defined by gcc's library exception to the GPL v3, + * but for the kernel it doesn't matter since it doesn't link against + * any of the gcc libraries + * + * gcc plugin to forcibly initialize certain local variables that could + * otherwise leak kernel stack to userland if they aren't properly initialized + * by later code + * + * Homepage: http://pax.grsecurity.net/ + * + * Options: + * -fplugin-arg-structleak_plugin-disable + * -fplugin-arg-structleak_plugin-verbose + * + * Usage: + * $ # for 4.5/4.6/C based 4.7 + * $ gcc -I`gcc -print-file-name=plugin`/include -I`gcc -print-file-name=plugin`/include/c-family -fPIC -shared -O2 -o structleak_plugin.so structleak_plugin.c + * $ # for C++ based 4.7/4.8+ + * $ g++ -I`g++ -print-file-name=plugin`/include -I`g++ -print-file-name=plugin`/include/c-family -fPIC -shared -O2 -o structleak_plugin.so structleak_plugin.c + * $ gcc -fplugin=./structleak_plugin.so test.c -O2 + * + * TODO: eliminate redundant initializers + * increase type coverage + */ + +#include "gcc-common.h" + +/* unused C type flag in all versions 4.5-6 */ +#define TYPE_USERSPACE(TYPE) TYPE_LANG_FLAG_5(TYPE) + +__visible int plugin_is_GPL_compatible; + +static struct plugin_info structleak_plugin_info = { + .version = "201607271510vanilla", + .help = "disable\tdo not activate plugin\n" + "verbose\tprint all initialized variables\n", +}; + +static bool verbose; + +static tree handle_user_attribute(tree *node, tree name, tree args, int flags, bool *no_add_attrs) +{ + *no_add_attrs = true; + + /* check for types? for now accept everything linux has to offer */ + if (TREE_CODE(*node) != FIELD_DECL) + return NULL_TREE; + + *no_add_attrs = false; + return NULL_TREE; +} + +static struct attribute_spec user_attr = { + .name = "user", + .min_length = 0, + .max_length = 0, + .decl_required = false, + .type_required = false, + .function_type_required = false, + .handler = handle_user_attribute, +#if BUILDING_GCC_VERSION >= 4007 + .affects_type_identity = true +#endif +}; + +static void register_attributes(void *event_data, void *data) +{ + register_attribute(&user_attr); +} + +static tree get_field_type(tree field) +{ + return strip_array_types(TREE_TYPE(field)); +} + +static bool is_userspace_type(tree type) +{ + tree field; + + for (field = TYPE_FIELDS(type); field; field = TREE_CHAIN(field)) { + tree fieldtype = get_field_type(field); + enum tree_code code = TREE_CODE(fieldtype); + + if (code == RECORD_TYPE || code == UNION_TYPE) + if (is_userspace_type(fieldtype)) + return true; + + if (lookup_attribute("user", DECL_ATTRIBUTES(field))) + return true; + } + return false; +} + +static void finish_type(void *event_data, void *data) +{ + tree type = (tree)event_data; + + if (type == NULL_TREE || type == error_mark_node) + return; + +#if BUILDING_GCC_VERSION >= 5000 + if (TREE_CODE(type) == ENUMERAL_TYPE) + return; +#endif + + if (TYPE_USERSPACE(type)) + return; + + if (is_userspace_type(type)) + TYPE_USERSPACE(type) = 1; +} + +static void initialize(tree var) +{ + basic_block bb; + gimple_stmt_iterator gsi; + tree initializer; + gimple init_stmt; + + /* this is the original entry bb before the forced split */ + bb = single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun)); + + /* first check if variable is already initialized, warn otherwise */ + for (gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi)) { + gimple stmt = gsi_stmt(gsi); + tree rhs1; + + /* we're looking for an assignment of a single rhs... */ + if (!gimple_assign_single_p(stmt)) + continue; + rhs1 = gimple_assign_rhs1(stmt); +#if BUILDING_GCC_VERSION >= 4007 + /* ... of a non-clobbering expression... */ + if (TREE_CLOBBER_P(rhs1)) + continue; +#endif + /* ... to our variable... */ + if (gimple_get_lhs(stmt) != var) + continue; + /* if it's an initializer then we're good */ + if (TREE_CODE(rhs1) == CONSTRUCTOR) + return; + } + + /* these aren't the 0days you're looking for */ + if (verbose) + inform(DECL_SOURCE_LOCATION(var), + "userspace variable will be forcibly initialized"); + + /* build the initializer expression */ + initializer = build_constructor(TREE_TYPE(var), NULL); + + /* build the initializer stmt */ + init_stmt = gimple_build_assign(var, initializer); + gsi = gsi_after_labels(single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun))); + gsi_insert_before(&gsi, init_stmt, GSI_NEW_STMT); + update_stmt(init_stmt); +} + +static unsigned int structleak_execute(void) +{ + basic_block bb; + unsigned int ret = 0; + tree var; + unsigned int i; + + /* split the first bb where we can put the forced initializers */ + gcc_assert(single_succ_p(ENTRY_BLOCK_PTR_FOR_FN(cfun))); + bb = single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun)); + if (!single_pred_p(bb)) { + split_edge(single_succ_edge(ENTRY_BLOCK_PTR_FOR_FN(cfun))); + gcc_assert(single_succ_p(ENTRY_BLOCK_PTR_FOR_FN(cfun))); + } + + /* enumerate all local variables and forcibly initialize our targets */ + FOR_EACH_LOCAL_DECL(cfun, i, var) { + tree type = TREE_TYPE(var); + + gcc_assert(DECL_P(var)); + if (!auto_var_in_fn_p(var, current_function_decl)) + continue; + + /* only care about structure types */ + if (TREE_CODE(type) != RECORD_TYPE && TREE_CODE(type) != UNION_TYPE) + continue; + + /* if the type is of interest, examine the variable */ + if (TYPE_USERSPACE(type)) + initialize(var); + } + + return ret; +} + +#define PASS_NAME structleak +#define NO_GATE +#define PROPERTIES_REQUIRED PROP_cfg +#define TODO_FLAGS_FINISH TODO_verify_il | TODO_verify_ssa | TODO_verify_stmts | TODO_dump_func | TODO_remove_unused_locals | TODO_update_ssa | TODO_ggc_collect | TODO_verify_flow +#include "gcc-generate-gimple-pass.h" + +__visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version) +{ + int i; + const char * const plugin_name = plugin_info->base_name; + const int argc = plugin_info->argc; + const struct plugin_argument * const argv = plugin_info->argv; + bool enable = true; + + PASS_INFO(structleak, "early_optimizations", 1, PASS_POS_INSERT_BEFORE); + + if (!plugin_default_version_check(version, &gcc_version)) { + error(G_("incompatible gcc/plugin versions")); + return 1; + } + + if (strncmp(lang_hooks.name, "GNU C", 5) && !strncmp(lang_hooks.name, "GNU C+", 6)) { + inform(UNKNOWN_LOCATION, G_("%s supports C only, not %s"), plugin_name, lang_hooks.name); + enable = false; + } + + for (i = 0; i < argc; ++i) { + if (!strcmp(argv[i].key, "disable")) { + enable = false; + continue; + } + if (!strcmp(argv[i].key, "verbose")) { + verbose = true; + continue; + } + error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key); + } + + register_callback(plugin_name, PLUGIN_INFO, NULL, &structleak_plugin_info); + if (enable) { + register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &structleak_pass_info); + register_callback(plugin_name, PLUGIN_FINISH_TYPE, finish_type, NULL); + } + register_callback(plugin_name, PLUGIN_ATTRIBUTES, register_attributes, NULL); + + return 0; +} |