Kbuild: remove structleak gcc plugin

gcc-12 and higher support the -ftrivial-auto-var-init= flag, after
gcc-8 is the minimum version, this is half of the supported ones, and
the vast majority of the versions that users are actually likely to
have, so it seems like a good time to stop having the fallback
plugin implementation

Older toolchains are still able to build kernels normally without
this plugin, but won't be able to use variable initialization..

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Author: arndb

drivers/gpu/drm/panel/panel-tpo-td028ttec1.c

@@ -86,11 +86,7 @@ struct td028ttec1_panel {
 
 #define to_td028ttec1_device(p) container_of(p, struct td028ttec1_panel, panel)
 
-/*
- * noinline_for_stack so we don't get multiple copies of tx_buf
- * on the stack in case of gcc-plugin-structleak
- */
-static int noinline_for_stack
+static int
 jbt_ret_write_0(struct td028ttec1_panel *lcd, u8 reg, int *err)
 {
 	struct spi_device *spi = lcd->spi;

lib/Kconfig.debug

@@ -2870,9 +2870,7 @@ config STACKINIT_KUNIT_TEST
 	help
 	  Test if the kernel is zero-initializing stack variables and
 	  padding. Coverage is controlled by compiler flags,
-	  CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
-	  CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
-	  or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
+	  CONFIG_INIT_STACK_ALL_PATTERN or CONFIG_INIT_STACK_ALL_ZERO.
 
 config FORTIFY_KUNIT_TEST
 	tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS

lib/tests/stackinit_kunit.c

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Test cases for compiler-based stack variable zeroing via
- * -ftrivial-auto-var-init={zero,pattern} or CONFIG_GCC_PLUGIN_STRUCTLEAK*.
+ * -ftrivial-auto-var-init={zero,pattern}.
  * For example, see:
  * "Running tests with kunit_tool" at Documentation/dev-tools/kunit/start.rst
  *	./tools/testing/kunit/kunit.py run stackinit [--raw_output] \
@@ -376,14 +376,6 @@ union test_small_end {
 # define USER_PASS	XFAIL
 # define BYREF_PASS	XFAIL
 # define STRONG_PASS	XFAIL
-#elif defined(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER)
-# define USER_PASS	WANT_SUCCESS
-# define BYREF_PASS	XFAIL
-# define STRONG_PASS	XFAIL
-#elif defined(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF)
-# define USER_PASS	WANT_SUCCESS
-# define BYREF_PASS	WANT_SUCCESS
-# define STRONG_PASS	XFAIL
 #else
 # define USER_PASS	WANT_SUCCESS
 # define BYREF_PASS	WANT_SUCCESS

mm/mm_init.c

@@ -2668,12 +2668,6 @@ static void __init report_meminit(void)
 		stack = "all(pattern)";
 	else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
 		stack = "all(zero)";
-	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
-		stack = "byref_all(zero)";
-	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
-		stack = "byref(zero)";
-	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
-		stack = "__user(zero)";
 	else
 		stack = "off";
 

scripts/Makefile.gcc-plugins

@@ -8,20 +8,6 @@ ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
 endif
 export DISABLE_LATENT_ENTROPY_PLUGIN
 
-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-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF)		\
-		+= -fplugin-arg-structleak_plugin-byref
-gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)	\
-		+= -fplugin-arg-structleak_plugin-byref-all
-ifdef CONFIG_GCC_PLUGIN_STRUCTLEAK
-    DISABLE_STRUCTLEAK_PLUGIN += -fplugin-arg-structleak_plugin-disable
-endif
-export DISABLE_STRUCTLEAK_PLUGIN
-gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK)		\
-		+= -DSTRUCTLEAK_PLUGIN
-
 gcc-plugin-$(CONFIG_GCC_PLUGIN_STACKLEAK)	+= stackleak_plugin.so
 gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK)		\
 		+= -DSTACKLEAK_PLUGIN