Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
index cb0c889..d33de0b 100644
--- a/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 preferred-plugin-hostcc := $(if-success,[ $(gcc-version) -ge 40800 ],$(HOSTCXX),$(HOSTCC))
 
 config PLUGIN_HOSTCC
@@ -13,17 +14,19 @@
 	  An arch should select this symbol if it supports building with
 	  GCC plugins.
 
-menuconfig GCC_PLUGINS
-	bool "GCC plugins"
+config GCC_PLUGINS
+	bool
 	depends on HAVE_GCC_PLUGINS
 	depends on PLUGIN_HOSTCC != ""
+	default y
 	help
 	  GCC plugins are loadable modules that provide extra features to the
 	  compiler. They are useful for runtime instrumentation and static analysis.
 
-	  See Documentation/gcc-plugins.txt for details.
+	  See Documentation/core-api/gcc-plugins.rst for details.
 
-if GCC_PLUGINS
+menu "GCC plugins"
+	depends on GCC_PLUGINS
 
 config GCC_PLUGIN_CYC_COMPLEXITY
 	bool "Compute the cyclomatic complexity of a function" if EXPERT
@@ -66,39 +69,6 @@
 	   * https://grsecurity.net/
 	   * https://pax.grsecurity.net/
 
-config GCC_PLUGIN_STRUCTLEAK
-	bool "Force initialization of variables containing userspace addresses"
-	# Currently STRUCTLEAK inserts initialization out of live scope of
-	# variables from KASAN point of view. This leads to KASAN false
-	# positive reports. Prohibit this combination for now.
-	depends on !KASAN_EXTRA
-	help
-	  This plugin zero-initializes any structures containing a
-	  __user attribute. This can prevent some classes of information
-	  exposures.
-
-	  This plugin was ported from grsecurity/PaX. More information at:
-	   * https://grsecurity.net/
-	   * https://pax.grsecurity.net/
-
-config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
-	bool "Force initialize all struct type variables passed by reference"
-	depends on GCC_PLUGIN_STRUCTLEAK
-	depends on !COMPILE_TEST
-	help
-	  Zero initialize any struct type local variable that may be passed by
-	  reference without having been initialized.
-
-config GCC_PLUGIN_STRUCTLEAK_VERBOSE
-	bool "Report forcefully initialized variables"
-	depends on GCC_PLUGIN_STRUCTLEAK
-	depends on !COMPILE_TEST	# too noisy
-	help
-	  This option will cause a warning to be printed each time the
-	  structleak plugin finds a variable it thinks needs to be
-	  initialized. Since not all existing initializers are detected
-	  by the plugin, this can produce false positive warnings.
-
 config GCC_PLUGIN_RANDSTRUCT
 	bool "Randomize layout of sensitive kernel structures"
 	select MODVERSIONS if MODULES
@@ -139,4 +109,8 @@
 	  in structures.  This reduces the performance hit of RANDSTRUCT
 	  at the cost of weakened randomization.
 
-endif
+config GCC_PLUGIN_ARM_SSP_PER_TASK
+	bool
+	depends on GCC_PLUGINS && ARM
+
+endmenu
diff --git a/scripts/gcc-plugins/arm_ssp_per_task_plugin.c b/scripts/gcc-plugins/arm_ssp_per_task_plugin.c
new file mode 100644
index 0000000..8c1af9b
--- /dev/null
+++ b/scripts/gcc-plugins/arm_ssp_per_task_plugin.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "gcc-common.h"
+
+__visible int plugin_is_GPL_compatible;
+
+static unsigned int sp_mask, canary_offset;
+
+static unsigned int arm_pertask_ssp_rtl_execute(void)
+{
+	rtx_insn *insn;
+
+	for (insn = get_insns(); insn; insn = NEXT_INSN(insn)) {
+		const char *sym;
+		rtx body;
+		rtx mask, masked_sp;
+
+		/*
+		 * Find a SET insn involving a SYMBOL_REF to __stack_chk_guard
+		 */
+		if (!INSN_P(insn))
+			continue;
+		body = PATTERN(insn);
+		if (GET_CODE(body) != SET ||
+		    GET_CODE(SET_SRC(body)) != SYMBOL_REF)
+			continue;
+		sym = XSTR(SET_SRC(body), 0);
+		if (strcmp(sym, "__stack_chk_guard"))
+			continue;
+
+		/*
+		 * Replace the source of the SET insn with an expression that
+		 * produces the address of the copy of the stack canary value
+		 * stored in struct thread_info
+		 */
+		mask = GEN_INT(sext_hwi(sp_mask, GET_MODE_PRECISION(Pmode)));
+		masked_sp = gen_reg_rtx(Pmode);
+
+		emit_insn_before(gen_rtx_set(masked_sp,
+					     gen_rtx_AND(Pmode,
+							 stack_pointer_rtx,
+							 mask)),
+				 insn);
+
+		SET_SRC(body) = gen_rtx_PLUS(Pmode, masked_sp,
+					     GEN_INT(canary_offset));
+	}
+	return 0;
+}
+
+#define PASS_NAME arm_pertask_ssp_rtl
+
+#define NO_GATE
+#include "gcc-generate-rtl-pass.h"
+
+#if BUILDING_GCC_VERSION >= 9000
+static bool no(void)
+{
+	return false;
+}
+
+static void arm_pertask_ssp_start_unit(void *gcc_data, void *user_data)
+{
+	targetm.have_stack_protect_combined_set = no;
+	targetm.have_stack_protect_combined_test = no;
+}
+#endif
+
+__visible int plugin_init(struct plugin_name_args *plugin_info,
+			  struct plugin_gcc_version *version)
+{
+	const char * const plugin_name = plugin_info->base_name;
+	const int argc = plugin_info->argc;
+	const struct plugin_argument *argv = plugin_info->argv;
+	int tso = 0;
+	int i;
+
+	if (!plugin_default_version_check(version, &gcc_version)) {
+		error(G_("incompatible gcc/plugin versions"));
+		return 1;
+	}
+
+	for (i = 0; i < argc; ++i) {
+		if (!strcmp(argv[i].key, "disable"))
+			return 0;
+
+		/* all remaining options require a value */
+		if (!argv[i].value) {
+			error(G_("no value supplied for option '-fplugin-arg-%s-%s'"),
+			      plugin_name, argv[i].key);
+			return 1;
+		}
+
+		if (!strcmp(argv[i].key, "tso")) {
+			tso = atoi(argv[i].value);
+			continue;
+		}
+
+		if (!strcmp(argv[i].key, "offset")) {
+			canary_offset = atoi(argv[i].value);
+			continue;
+		}
+		error(G_("unknown option '-fplugin-arg-%s-%s'"),
+		      plugin_name, argv[i].key);
+		return 1;
+	}
+
+	/* create the mask that produces the base of the stack */
+	sp_mask = ~((1U << (12 + tso)) - 1);
+
+	PASS_INFO(arm_pertask_ssp_rtl, "expand", 1, PASS_POS_INSERT_AFTER);
+
+	register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP,
+			  NULL, &arm_pertask_ssp_rtl_pass_info);
+
+#if BUILDING_GCC_VERSION >= 9000
+	register_callback(plugin_info->base_name, PLUGIN_START_UNIT,
+			  arm_pertask_ssp_start_unit, NULL);
+#endif
+
+	return 0;
+}
diff --git a/scripts/gcc-plugins/gcc-common.h b/scripts/gcc-plugins/gcc-common.h
index 552d5ef..17f0607 100644
--- a/scripts/gcc-plugins/gcc-common.h
+++ b/scripts/gcc-plugins/gcc-common.h
@@ -150,8 +150,12 @@
 void dump_gimple_stmt(pretty_printer *, gimple, int, int);
 #endif
 
+#ifndef __unused
 #define __unused __attribute__((__unused__))
+#endif
+#ifndef __visible
 #define __visible __attribute__((visibility("default")))
+#endif
 
 #define DECL_NAME_POINTER(node) IDENTIFIER_POINTER(DECL_NAME(node))
 #define DECL_NAME_LENGTH(node) IDENTIFIER_LENGTH(DECL_NAME(node))
diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c
index 6d5bbd3..bd29e4e 100644
--- a/scripts/gcc-plugins/randomize_layout_plugin.c
+++ b/scripts/gcc-plugins/randomize_layout_plugin.c
@@ -443,13 +443,13 @@
 		if (node == fieldtype)
 			continue;
 
-		if (!is_fptr(fieldtype))
-			return 0;
-
-		if (code != RECORD_TYPE && code != UNION_TYPE)
+		if (code == RECORD_TYPE || code == UNION_TYPE) {
+			if (!is_pure_ops_struct(fieldtype))
+				return 0;
 			continue;
+		}
 
-		if (!is_pure_ops_struct(fieldtype))
+		if (!is_fptr(fieldtype))
 			return 0;
 	}
 
diff --git a/scripts/gcc-plugins/stackleak_plugin.c b/scripts/gcc-plugins/stackleak_plugin.c
new file mode 100644
index 0000000..dbd3746
--- /dev/null
+++ b/scripts/gcc-plugins/stackleak_plugin.c
@@ -0,0 +1,429 @@
+/*
+ * Copyright 2011-2017 by the PaX Team <pageexec@freemail.hu>
+ * Modified by Alexander Popov <alex.popov@linux.com>
+ * 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
+ *
+ * This gcc plugin is needed for tracking the lowest border of the kernel stack.
+ * It instruments the kernel code inserting stackleak_track_stack() calls:
+ *  - after alloca();
+ *  - for the functions with a stack frame size greater than or equal
+ *     to the "track-min-size" plugin parameter.
+ *
+ * This plugin is ported from grsecurity/PaX. For more information see:
+ *   https://grsecurity.net/
+ *   https://pax.grsecurity.net/
+ *
+ * Debugging:
+ *  - use fprintf() to stderr, debug_generic_expr(), debug_gimple_stmt(),
+ *     print_rtl() and print_simple_rtl();
+ *  - add "-fdump-tree-all -fdump-rtl-all" to the plugin CFLAGS in
+ *     Makefile.gcc-plugins to see the verbose dumps of the gcc passes;
+ *  - use gcc -E to understand the preprocessing shenanigans;
+ *  - use gcc with enabled CFG/GIMPLE/SSA verification (--enable-checking).
+ */
+
+#include "gcc-common.h"
+
+__visible int plugin_is_GPL_compatible;
+
+static int track_frame_size = -1;
+static const char track_function[] = "stackleak_track_stack";
+
+/*
+ * Mark these global variables (roots) for gcc garbage collector since
+ * they point to the garbage-collected memory.
+ */
+static GTY(()) tree track_function_decl;
+
+static struct plugin_info stackleak_plugin_info = {
+	.version = "201707101337",
+	.help = "track-min-size=nn\ttrack stack for functions with a stack frame size >= nn bytes\n"
+		"disable\t\tdo not activate the plugin\n"
+};
+
+static void stackleak_add_track_stack(gimple_stmt_iterator *gsi, bool after)
+{
+	gimple stmt;
+	gcall *stackleak_track_stack;
+	cgraph_node_ptr node;
+	int frequency;
+	basic_block bb;
+
+	/* Insert call to void stackleak_track_stack(void) */
+	stmt = gimple_build_call(track_function_decl, 0);
+	stackleak_track_stack = as_a_gcall(stmt);
+	if (after) {
+		gsi_insert_after(gsi, stackleak_track_stack,
+						GSI_CONTINUE_LINKING);
+	} else {
+		gsi_insert_before(gsi, stackleak_track_stack, GSI_SAME_STMT);
+	}
+
+	/* Update the cgraph */
+	bb = gimple_bb(stackleak_track_stack);
+	node = cgraph_get_create_node(track_function_decl);
+	gcc_assert(node);
+	frequency = compute_call_stmt_bb_frequency(current_function_decl, bb);
+	cgraph_create_edge(cgraph_get_node(current_function_decl), node,
+			stackleak_track_stack, bb->count, frequency);
+}
+
+static bool is_alloca(gimple stmt)
+{
+	if (gimple_call_builtin_p(stmt, BUILT_IN_ALLOCA))
+		return true;
+
+#if BUILDING_GCC_VERSION >= 4007
+	if (gimple_call_builtin_p(stmt, BUILT_IN_ALLOCA_WITH_ALIGN))
+		return true;
+#endif
+
+	return false;
+}
+
+/*
+ * Work with the GIMPLE representation of the code. Insert the
+ * stackleak_track_stack() call after alloca() and into the beginning
+ * of the function if it is not instrumented.
+ */
+static unsigned int stackleak_instrument_execute(void)
+{
+	basic_block bb, entry_bb;
+	bool prologue_instrumented = false, is_leaf = true;
+	gimple_stmt_iterator gsi;
+
+	/*
+	 * ENTRY_BLOCK_PTR is a basic block which represents possible entry
+	 * point of a function. This block does not contain any code and
+	 * has a CFG edge to its successor.
+	 */
+	gcc_assert(single_succ_p(ENTRY_BLOCK_PTR_FOR_FN(cfun)));
+	entry_bb = single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun));
+
+	/*
+	 * Loop through the GIMPLE statements in each of cfun basic blocks.
+	 * cfun is a global variable which represents the function that is
+	 * currently processed.
+	 */
+	FOR_EACH_BB_FN(bb, cfun) {
+		for (gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi)) {
+			gimple stmt;
+
+			stmt = gsi_stmt(gsi);
+
+			/* Leaf function is a function which makes no calls */
+			if (is_gimple_call(stmt))
+				is_leaf = false;
+
+			if (!is_alloca(stmt))
+				continue;
+
+			/* Insert stackleak_track_stack() call after alloca() */
+			stackleak_add_track_stack(&gsi, true);
+			if (bb == entry_bb)
+				prologue_instrumented = true;
+		}
+	}
+
+	if (prologue_instrumented)
+		return 0;
+
+	/*
+	 * Special cases to skip the instrumentation.
+	 *
+	 * Taking the address of static inline functions materializes them,
+	 * but we mustn't instrument some of them as the resulting stack
+	 * alignment required by the function call ABI will break other
+	 * assumptions regarding the expected (but not otherwise enforced)
+	 * register clobbering ABI.
+	 *
+	 * Case in point: native_save_fl on amd64 when optimized for size
+	 * clobbers rdx if it were instrumented here.
+	 *
+	 * TODO: any more special cases?
+	 */
+	if (is_leaf &&
+	    !TREE_PUBLIC(current_function_decl) &&
+	    DECL_DECLARED_INLINE_P(current_function_decl)) {
+		return 0;
+	}
+
+	if (is_leaf &&
+	    !strncmp(IDENTIFIER_POINTER(DECL_NAME(current_function_decl)),
+		     "_paravirt_", 10)) {
+		return 0;
+	}
+
+	/* Insert stackleak_track_stack() call at the function beginning */
+	bb = entry_bb;
+	if (!single_pred_p(bb)) {
+		/* gcc_assert(bb_loop_depth(bb) ||
+				(bb->flags & BB_IRREDUCIBLE_LOOP)); */
+		split_edge(single_succ_edge(ENTRY_BLOCK_PTR_FOR_FN(cfun)));
+		gcc_assert(single_succ_p(ENTRY_BLOCK_PTR_FOR_FN(cfun)));
+		bb = single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun));
+	}
+	gsi = gsi_after_labels(bb);
+	stackleak_add_track_stack(&gsi, false);
+
+	return 0;
+}
+
+static bool large_stack_frame(void)
+{
+#if BUILDING_GCC_VERSION >= 8000
+	return maybe_ge(get_frame_size(), track_frame_size);
+#else
+	return (get_frame_size() >= track_frame_size);
+#endif
+}
+
+/*
+ * Work with the RTL representation of the code.
+ * Remove the unneeded stackleak_track_stack() calls from the functions
+ * which don't call alloca() and don't have a large enough stack frame size.
+ */
+static unsigned int stackleak_cleanup_execute(void)
+{
+	rtx_insn *insn, *next;
+
+	if (cfun->calls_alloca)
+		return 0;
+
+	if (large_stack_frame())
+		return 0;
+
+	/*
+	 * Find stackleak_track_stack() calls. Loop through the chain of insns,
+	 * which is an RTL representation of the code for a function.
+	 *
+	 * The example of a matching insn:
+	 *  (call_insn 8 4 10 2 (call (mem (symbol_ref ("stackleak_track_stack")
+	 *  [flags 0x41] <function_decl 0x7f7cd3302a80 stackleak_track_stack>)
+	 *  [0 stackleak_track_stack S1 A8]) (0)) 675 {*call} (expr_list
+	 *  (symbol_ref ("stackleak_track_stack") [flags 0x41] <function_decl
+	 *  0x7f7cd3302a80 stackleak_track_stack>) (expr_list (0) (nil))) (nil))
+	 */
+	for (insn = get_insns(); insn; insn = next) {
+		rtx body;
+
+		next = NEXT_INSN(insn);
+
+		/* Check the expression code of the insn */
+		if (!CALL_P(insn))
+			continue;
+
+		/*
+		 * Check the expression code of the insn body, which is an RTL
+		 * Expression (RTX) describing the side effect performed by
+		 * that insn.
+		 */
+		body = PATTERN(insn);
+
+		if (GET_CODE(body) == PARALLEL)
+			body = XVECEXP(body, 0, 0);
+
+		if (GET_CODE(body) != CALL)
+			continue;
+
+		/*
+		 * Check the first operand of the call expression. It should
+		 * be a mem RTX describing the needed subroutine with a
+		 * symbol_ref RTX.
+		 */
+		body = XEXP(body, 0);
+		if (GET_CODE(body) != MEM)
+			continue;
+
+		body = XEXP(body, 0);
+		if (GET_CODE(body) != SYMBOL_REF)
+			continue;
+
+		if (SYMBOL_REF_DECL(body) != track_function_decl)
+			continue;
+
+		/* Delete the stackleak_track_stack() call */
+		delete_insn_and_edges(insn);
+#if BUILDING_GCC_VERSION >= 4007 && BUILDING_GCC_VERSION < 8000
+		if (GET_CODE(next) == NOTE &&
+		    NOTE_KIND(next) == NOTE_INSN_CALL_ARG_LOCATION) {
+			insn = next;
+			next = NEXT_INSN(insn);
+			delete_insn_and_edges(insn);
+		}
+#endif
+	}
+
+	return 0;
+}
+
+static bool stackleak_gate(void)
+{
+	tree section;
+
+	section = lookup_attribute("section",
+				   DECL_ATTRIBUTES(current_function_decl));
+	if (section && TREE_VALUE(section)) {
+		section = TREE_VALUE(TREE_VALUE(section));
+
+		if (!strncmp(TREE_STRING_POINTER(section), ".init.text", 10))
+			return false;
+		if (!strncmp(TREE_STRING_POINTER(section), ".devinit.text", 13))
+			return false;
+		if (!strncmp(TREE_STRING_POINTER(section), ".cpuinit.text", 13))
+			return false;
+		if (!strncmp(TREE_STRING_POINTER(section), ".meminit.text", 13))
+			return false;
+	}
+
+	return track_frame_size >= 0;
+}
+
+/* Build the function declaration for stackleak_track_stack() */
+static void stackleak_start_unit(void *gcc_data __unused,
+				 void *user_data __unused)
+{
+	tree fntype;
+
+	/* void stackleak_track_stack(void) */
+	fntype = build_function_type_list(void_type_node, NULL_TREE);
+	track_function_decl = build_fn_decl(track_function, fntype);
+	DECL_ASSEMBLER_NAME(track_function_decl); /* for LTO */
+	TREE_PUBLIC(track_function_decl) = 1;
+	TREE_USED(track_function_decl) = 1;
+	DECL_EXTERNAL(track_function_decl) = 1;
+	DECL_ARTIFICIAL(track_function_decl) = 1;
+	DECL_PRESERVE_P(track_function_decl) = 1;
+}
+
+/*
+ * Pass gate function is a predicate function that gets executed before the
+ * corresponding pass. If the return value is 'true' the pass gets executed,
+ * otherwise, it is skipped.
+ */
+static bool stackleak_instrument_gate(void)
+{
+	return stackleak_gate();
+}
+
+#define PASS_NAME stackleak_instrument
+#define PROPERTIES_REQUIRED PROP_gimple_leh | PROP_cfg
+#define TODO_FLAGS_START TODO_verify_ssa | TODO_verify_flow | TODO_verify_stmts
+#define TODO_FLAGS_FINISH TODO_verify_ssa | TODO_verify_stmts | TODO_dump_func \
+			| TODO_update_ssa | TODO_rebuild_cgraph_edges
+#include "gcc-generate-gimple-pass.h"
+
+static bool stackleak_cleanup_gate(void)
+{
+	return stackleak_gate();
+}
+
+#define PASS_NAME stackleak_cleanup
+#define TODO_FLAGS_FINISH TODO_dump_func
+#include "gcc-generate-rtl-pass.h"
+
+/*
+ * Every gcc plugin exports a plugin_init() function that is called right
+ * after the plugin is loaded. This function is responsible for registering
+ * the plugin callbacks and doing other required initialization.
+ */
+__visible int plugin_init(struct plugin_name_args *plugin_info,
+			  struct plugin_gcc_version *version)
+{
+	const char * const plugin_name = plugin_info->base_name;
+	const int argc = plugin_info->argc;
+	const struct plugin_argument * const argv = plugin_info->argv;
+	int i = 0;
+
+	/* Extra GGC root tables describing our GTY-ed data */
+	static const struct ggc_root_tab gt_ggc_r_gt_stackleak[] = {
+		{
+			.base = &track_function_decl,
+			.nelt = 1,
+			.stride = sizeof(track_function_decl),
+			.cb = &gt_ggc_mx_tree_node,
+			.pchw = &gt_pch_nx_tree_node
+		},
+		LAST_GGC_ROOT_TAB
+	};
+
+	/*
+	 * The stackleak_instrument pass should be executed before the
+	 * "optimized" pass, which is the control flow graph cleanup that is
+	 * performed just before expanding gcc trees to the RTL. In former
+	 * versions of the plugin this new pass was inserted before the
+	 * "tree_profile" pass, which is currently called "profile".
+	 */
+	PASS_INFO(stackleak_instrument, "optimized", 1,
+						PASS_POS_INSERT_BEFORE);
+
+	/*
+	 * The stackleak_cleanup pass should be executed before the "*free_cfg"
+	 * pass. It's the moment when the stack frame size is already final,
+	 * function prologues and epilogues are generated, and the
+	 * machine-dependent code transformations are not done.
+	 */
+	PASS_INFO(stackleak_cleanup, "*free_cfg", 1, PASS_POS_INSERT_BEFORE);
+
+	if (!plugin_default_version_check(version, &gcc_version)) {
+		error(G_("incompatible gcc/plugin versions"));
+		return 1;
+	}
+
+	/* Parse the plugin arguments */
+	for (i = 0; i < argc; i++) {
+		if (!strcmp(argv[i].key, "disable"))
+			return 0;
+
+		if (!strcmp(argv[i].key, "track-min-size")) {
+			if (!argv[i].value) {
+				error(G_("no value supplied for option '-fplugin-arg-%s-%s'"),
+					plugin_name, argv[i].key);
+				return 1;
+			}
+
+			track_frame_size = atoi(argv[i].value);
+			if (track_frame_size < 0) {
+				error(G_("invalid option argument '-fplugin-arg-%s-%s=%s'"),
+					plugin_name, argv[i].key, argv[i].value);
+				return 1;
+			}
+		} else {
+			error(G_("unknown option '-fplugin-arg-%s-%s'"),
+					plugin_name, argv[i].key);
+			return 1;
+		}
+	}
+
+	/* Give the information about the plugin */
+	register_callback(plugin_name, PLUGIN_INFO, NULL,
+						&stackleak_plugin_info);
+
+	/* Register to be called before processing a translation unit */
+	register_callback(plugin_name, PLUGIN_START_UNIT,
+					&stackleak_start_unit, NULL);
+
+	/* Register an extra GCC garbage collector (GGC) root table */
+	register_callback(plugin_name, PLUGIN_REGISTER_GGC_ROOTS, NULL,
+					(void *)&gt_ggc_r_gt_stackleak);
+
+	/*
+	 * Hook into the Pass Manager to register new gcc passes.
+	 *
+	 * The stack frame size info is available only at the last RTL pass,
+	 * when it's too late to insert complex code like a function call.
+	 * So we register two gcc passes to instrument every function at first
+	 * and remove the unneeded instrumentation later.
+	 */
+	register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL,
+					&stackleak_instrument_pass_info);
+	register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL,
+					&stackleak_cleanup_pass_info);
+
+	return 0;
+}
diff --git a/scripts/gcc-plugins/structleak_plugin.c b/scripts/gcc-plugins/structleak_plugin.c
index 10292f7..e89be8f 100644
--- a/scripts/gcc-plugins/structleak_plugin.c
+++ b/scripts/gcc-plugins/structleak_plugin.c
@@ -16,6 +16,7 @@
  * Options:
  * -fplugin-arg-structleak_plugin-disable
  * -fplugin-arg-structleak_plugin-verbose
+ * -fplugin-arg-structleak_plugin-byref
  * -fplugin-arg-structleak_plugin-byref-all
  *
  * Usage:
@@ -26,7 +27,6 @@
  * $ gcc -fplugin=./structleak_plugin.so test.c -O2
  *
  * TODO: eliminate redundant initializers
- *       increase type coverage
  */
 
 #include "gcc-common.h"
@@ -37,13 +37,18 @@
 __visible int plugin_is_GPL_compatible;
 
 static struct plugin_info structleak_plugin_info = {
-	.version	= "201607271510vanilla",
+	.version	= "20190125vanilla",
 	.help		= "disable\tdo not activate plugin\n"
-			   "verbose\tprint all initialized variables\n",
+			  "byref\tinit structs passed by reference\n"
+			  "byref-all\tinit anything passed by reference\n"
+			  "verbose\tprint all initialized variables\n",
 };
 
+#define BYREF_STRUCT	1
+#define BYREF_ALL	2
+
 static bool verbose;
-static bool byref_all;
+static int byref;
 
 static tree handle_user_attribute(tree *node, tree name, tree args, int flags, bool *no_add_attrs)
 {
@@ -118,6 +123,7 @@
 	gimple_stmt_iterator gsi;
 	tree initializer;
 	gimple init_stmt;
+	tree type;
 
 	/* this is the original entry bb before the forced split */
 	bb = single_succ(ENTRY_BLOCK_PTR_FOR_FN(cfun));
@@ -148,11 +154,15 @@
 	if (verbose)
 		inform(DECL_SOURCE_LOCATION(var),
 			"%s variable will be forcibly initialized",
-			(byref_all && TREE_ADDRESSABLE(var)) ? "byref"
-							     : "userspace");
+			(byref && TREE_ADDRESSABLE(var)) ? "byref"
+							 : "userspace");
 
 	/* build the initializer expression */
-	initializer = build_constructor(TREE_TYPE(var), NULL);
+	type = TREE_TYPE(var);
+	if (AGGREGATE_TYPE_P(type))
+		initializer = build_constructor(type, NULL);
+	else
+		initializer = fold_convert(type, integer_zero_node);
 
 	/* build the initializer stmt */
 	init_stmt = gimple_build_assign(var, initializer);
@@ -184,13 +194,13 @@
 		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)
+		/* only care about structure types unless byref-all */
+		if (byref != BYREF_ALL && TREE_CODE(type) != RECORD_TYPE && TREE_CODE(type) != UNION_TYPE)
 			continue;
 
 		/* if the type is of interest, examine the variable */
 		if (TYPE_USERSPACE(type) ||
-		    (byref_all && TREE_ADDRESSABLE(var)))
+		    (byref && TREE_ADDRESSABLE(var)))
 			initialize(var);
 	}
 
@@ -232,8 +242,12 @@
 			verbose = true;
 			continue;
 		}
+		if (!strcmp(argv[i].key, "byref")) {
+			byref = BYREF_STRUCT;
+			continue;
+		}
 		if (!strcmp(argv[i].key, "byref-all")) {
-			byref_all = true;
+			byref = BYREF_ALL;
 			continue;
 		}
 		error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);