Commit c054ee3

# ifdef STRUCTLEAK_PLUGIN

# define __user __attribute__((user))

# define __user

gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += structleak_plugin.so

gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE) += -fplugin-arg-structleak_plugin-verbose

gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += -DSTRUCTLEAK_PLUGIN

#include "gcc-common.h"

#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

};

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;

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;

/* ... 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;

}