From 852faf805539484968aa8cc93866008b7a6d0d52 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 7 Apr 2025 17:10:52 +0200 Subject: [PATCH] gcc-plugins: remove SANCOV gcc plugin With the minimum gcc version raised to 8.1, all supported compilers now understand the -fsanitize-coverage=trace-pc option, and there is no longer a need for the separate compiler plugin. Since only gcc-5 was able to use the plugin for several year now, it was already likely unused. Signed-off-by: Arnd Bergmann --- lib/Kconfig.debug | 6 -- scripts/Makefile.gcc-plugins | 2 - scripts/Makefile.kcov | 1 - scripts/gcc-plugins/Kconfig | 10 --- scripts/gcc-plugins/sancov_plugin.c | 134 ---------------------------- 5 files changed, 153 deletions(-) delete mode 100644 scripts/gcc-plugins/sancov_plugin.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index de19d43666e3b..cde3d15ed272e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2153,18 +2153,12 @@ config ARCH_HAS_KCOV build and run with CONFIG_KCOV. This typically requires disabling instrumentation for some early boot code. -config CC_HAS_SANCOV_TRACE_PC - def_bool $(cc-option,-fsanitize-coverage=trace-pc) - - config KCOV bool "Code coverage for fuzzing" depends on ARCH_HAS_KCOV - depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \ GCC_VERSION >= 120000 || CC_IS_CLANG select DEBUG_FS - select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC select OBJTOOL if HAVE_NOINSTR_HACK help KCOV exposes kernel code coverage information in a form suitable diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins index b25f254f9a680..ba792b7284125 100644 --- a/scripts/Makefile.gcc-plugins +++ b/scripts/Makefile.gcc-plugins @@ -38,8 +38,6 @@ KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS) # Some plugins are enabled outside of this Makefile, but they still need to # be included in GCC_PLUGIN so they can get built. -gcc-plugin-external-$(CONFIG_GCC_PLUGIN_SANCOV) \ - += sancov_plugin.so gcc-plugin-external-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) \ += randomize_layout_plugin.so diff --git a/scripts/Makefile.kcov b/scripts/Makefile.kcov index 67e8cfe3474b7..67de7942b3e73 100644 --- a/scripts/Makefile.kcov +++ b/scripts/Makefile.kcov @@ -1,6 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only kcov-flags-$(CONFIG_CC_HAS_SANCOV_TRACE_PC) += -fsanitize-coverage=trace-pc kcov-flags-$(CONFIG_KCOV_ENABLE_COMPARISONS) += -fsanitize-coverage=trace-cmp -kcov-flags-$(CONFIG_GCC_PLUGIN_SANCOV) += -fplugin=$(objtree)/scripts/gcc-plugins/sancov_plugin.so export CFLAGS_KCOV := $(kcov-flags-y) diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig index e383cda05367a..ba868d1eef3d8 100644 --- a/scripts/gcc-plugins/Kconfig +++ b/scripts/gcc-plugins/Kconfig @@ -19,16 +19,6 @@ menuconfig GCC_PLUGINS if GCC_PLUGINS -config GCC_PLUGIN_SANCOV - bool - # Plugin can be removed once the kernel only supports GCC 6+ - depends on !CC_HAS_SANCOV_TRACE_PC - help - This plugin inserts a __sanitizer_cov_trace_pc() call at the start of - basic blocks. It supports all gcc versions with plugin support (from - gcc-4.5 on). It is based on the commit "Add fuzzing coverage support" - by Dmitry Vyukov . - config GCC_PLUGIN_LATENT_ENTROPY bool "Generate some entropy during boot and runtime" help diff --git a/scripts/gcc-plugins/sancov_plugin.c b/scripts/gcc-plugins/sancov_plugin.c deleted file mode 100644 index b76cb9c42cec0..0000000000000 --- a/scripts/gcc-plugins/sancov_plugin.c +++ /dev/null @@ -1,134 +0,0 @@ -/* - * Copyright 2011-2016 by Emese Revfy - * Licensed under the GPL v2, or (at your option) v3 - * - * Homepage: - * https://github.com/ephox-gcc-plugins/sancov - * - * This plugin inserts a __sanitizer_cov_trace_pc() call at the start of basic blocks. - * It supports all gcc versions with plugin support (from gcc-4.5 on). - * It is based on the commit "Add fuzzing coverage support" by Dmitry Vyukov . - * - * You can read about it more here: - * https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296 - * https://lwn.net/Articles/674854/ - * https://github.com/google/syzkaller - * https://lwn.net/Articles/677764/ - * - * Usage: - * make run - */ - -#include "gcc-common.h" - -__visible int plugin_is_GPL_compatible; - -tree sancov_fndecl; - -static struct plugin_info sancov_plugin_info = { - .version = PLUGIN_VERSION, - .help = "sancov plugin\n", -}; - -static unsigned int sancov_execute(void) -{ - basic_block bb; - - /* Remove this line when this plugin and kcov will be in the kernel. - if (!strcmp(DECL_NAME_POINTER(current_function_decl), DECL_NAME_POINTER(sancov_fndecl))) - return 0; - */ - - FOR_EACH_BB_FN(bb, cfun) { - const_gimple stmt; - gcall *gcall; - gimple_stmt_iterator gsi = gsi_after_labels(bb); - - if (gsi_end_p(gsi)) - continue; - - stmt = gsi_stmt(gsi); - gcall = as_a_gcall(gimple_build_call(sancov_fndecl, 0)); - gimple_set_location(gcall, gimple_location(stmt)); - gsi_insert_before(&gsi, gcall, GSI_SAME_STMT); - } - return 0; -} - -#define PASS_NAME sancov - -#define NO_GATE -#define TODO_FLAGS_FINISH TODO_dump_func | TODO_verify_stmts | TODO_update_ssa_no_phi | TODO_verify_flow - -#include "gcc-generate-gimple-pass.h" - -static void sancov_start_unit(void __unused *gcc_data, void __unused *user_data) -{ - tree leaf_attr, nothrow_attr; - tree BT_FN_VOID = build_function_type_list(void_type_node, NULL_TREE); - - sancov_fndecl = build_fn_decl("__sanitizer_cov_trace_pc", BT_FN_VOID); - - DECL_ASSEMBLER_NAME(sancov_fndecl); - TREE_PUBLIC(sancov_fndecl) = 1; - DECL_EXTERNAL(sancov_fndecl) = 1; - DECL_ARTIFICIAL(sancov_fndecl) = 1; - DECL_PRESERVE_P(sancov_fndecl) = 1; - DECL_UNINLINABLE(sancov_fndecl) = 1; - TREE_USED(sancov_fndecl) = 1; - - nothrow_attr = tree_cons(get_identifier("nothrow"), NULL, NULL); - decl_attributes(&sancov_fndecl, nothrow_attr, 0); - gcc_assert(TREE_NOTHROW(sancov_fndecl)); - leaf_attr = tree_cons(get_identifier("leaf"), NULL, NULL); - decl_attributes(&sancov_fndecl, leaf_attr, 0); -} - -__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; - - static const struct ggc_root_tab gt_ggc_r_gt_sancov[] = { - { - .base = &sancov_fndecl, - .nelt = 1, - .stride = sizeof(sancov_fndecl), - .cb = >_ggc_mx_tree_node, - .pchw = >_pch_nx_tree_node - }, - LAST_GGC_ROOT_TAB - }; - - /* BBs can be split afterwards?? */ - PASS_INFO(sancov, "asan", 0, PASS_POS_INSERT_BEFORE); - - 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, "no-sancov")) { - enable = false; - continue; - } - error(G_("unknown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key); - } - - register_callback(plugin_name, PLUGIN_INFO, NULL, &sancov_plugin_info); - - if (!enable) - return 0; - -#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_pass_info); -#endif - - return 0; -} -- 2.39.5