From 8d97fb393c5cbae23389317615f2bf30a559ed17 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 2 Apr 2020 00:53:47 -0700 Subject: [PATCH 1/2] gcc-plugins/stackleak: Avoid assignment for unused macro argument MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With GCC version >= 8, the cgraph_create_edge() macro argument using "frequency" goes unused. Instead of assigning a temporary variable for the argument, pass the compute_call_stmt_bb_frequency() call directly as the macro argument so that it will just not be called when it is not wanted by the macros. Silences the warning: scripts/gcc-plugins/stackleak_plugin.c:54:6: warning: variable ‘frequency’ set but not used [-Wunused-but-set-variable] Now builds cleanly with gcc-7 and gcc-9. Both boot and pass STACKLEAK_ERASING LKDTM test. Signed-off-by: Kees Cook --- scripts/gcc-plugins/stackleak_plugin.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/scripts/gcc-plugins/stackleak_plugin.c b/scripts/gcc-plugins/stackleak_plugin.c index dbd37460c573..cc75eeba0be1 100644 --- a/scripts/gcc-plugins/stackleak_plugin.c +++ b/scripts/gcc-plugins/stackleak_plugin.c @@ -51,7 +51,6 @@ 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) */ @@ -68,9 +67,9 @@ static void stackleak_add_track_stack(gimple_stmt_iterator *gsi, bool after) 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); + stackleak_track_stack, bb->count, + compute_call_stmt_bb_frequency(current_function_decl, bb)); } static bool is_alloca(gimple stmt) From c7527373fe28f97d8a196ab562db5589be0d34b9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Pierret=20=28fepitre=29?= Date: Tue, 7 Apr 2020 13:32:59 +0200 Subject: [PATCH 2/2] gcc-common.h: Update for GCC 10 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Remove "params.h" include, which has been dropped in GCC 10. Remove is_a_helper() macro, which is now defined in gimple.h, as seen when running './scripts/gcc-plugin.sh g++ g++ gcc': In file included from :1: ./gcc-plugins/gcc-common.h:852:13: error: redefinition of ‘static bool is_a_helper::test(U*) [with U = const gimple; T = const ggoto*]’ 852 | inline bool is_a_helper::test(const_gimple gs) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from ./gcc-plugins/gcc-common.h:125, from :1: /usr/lib/gcc/x86_64-redhat-linux/10/plugin/include/gimple.h:1037:1: note: ‘static bool is_a_helper::test(U*) [with U = const gimple; T = const ggoto*]’ previously declared here 1037 | is_a_helper ::test (const gimple *gs) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ Add -Wno-format-diag to scripts/gcc-plugins/Makefile to avoid meaningless warnings from error() formats used by plugins: scripts/gcc-plugins/structleak_plugin.c: In function ‘int plugin_init(plugin_name_args*, plugin_gcc_version*)’: scripts/gcc-plugins/structleak_plugin.c:253:12: warning: unquoted sequence of 2 consecutive punctuation characters ‘'-’ in format [-Wformat-diag] 253 | error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Frédéric Pierret (fepitre) Link: https://lore.kernel.org/r/20200407113259.270172-1-frederic.pierret@qubes-os.org [kees: include -Wno-format-diag for plugin builds] Signed-off-by: Kees Cook --- scripts/gcc-plugins/Makefile | 1 + scripts/gcc-plugins/gcc-common.h | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile index f22858b2c3d6..80f354289eeb 100644 --- a/scripts/gcc-plugins/Makefile +++ b/scripts/gcc-plugins/Makefile @@ -4,6 +4,7 @@ GCC_PLUGINS_DIR := $(shell $(CC) -print-file-name=plugin) HOST_EXTRACXXFLAGS += -I$(GCC_PLUGINS_DIR)/include -I$(src) -std=gnu++98 -fno-rtti HOST_EXTRACXXFLAGS += -fno-exceptions -fasynchronous-unwind-tables -ggdb HOST_EXTRACXXFLAGS += -Wno-narrowing -Wno-unused-variable -Wno-c++11-compat +HOST_EXTRACXXFLAGS += -Wno-format-diag $(obj)/randomize_layout_plugin.o: $(objtree)/$(obj)/randomize_layout_seed.h quiet_cmd_create_randomize_layout_seed = GENSEED $@ diff --git a/scripts/gcc-plugins/gcc-common.h b/scripts/gcc-plugins/gcc-common.h index 17f06079a712..9ad76b7f3f10 100644 --- a/scripts/gcc-plugins/gcc-common.h +++ b/scripts/gcc-plugins/gcc-common.h @@ -35,7 +35,9 @@ #include "ggc.h" #include "timevar.h" +#if BUILDING_GCC_VERSION < 10000 #include "params.h" +#endif #if BUILDING_GCC_VERSION <= 4009 #include "pointer-set.h" @@ -847,6 +849,7 @@ static inline gimple gimple_build_assign_with_ops(enum tree_code subcode, tree l return gimple_build_assign(lhs, subcode, op1, op2 PASS_MEM_STAT); } +#if BUILDING_GCC_VERSION < 10000 template <> template <> inline bool is_a_helper::test(const_gimple gs) @@ -860,6 +863,7 @@ inline bool is_a_helper::test(const_gimple gs) { return gs->code == GIMPLE_RETURN; } +#endif static inline gasm *as_a_gasm(gimple stmt) {