Merge tag 'gcc-plugin-cleanup-v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull gcc plugin cleanups from Kees Cook: - Kconfig and Makefile clean-ups (Masahiro Yamada, Kees Cook) - gcc-common.h definition clean-ups (Alexander Popov) * tag 'gcc-plugin-cleanup-v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: gcc-plugins: Clean up the cgraph_create_edge* macros gcc-plugins: Regularize Makefile.gcc-plugins gcc-plugins: split out Kconfig entries to scripts/gcc-plugins/Kconfig gcc-plugins: remove unused GCC_PLUGIN_SUBDIR

Linus Torvalds committed 8 years ago

Commit 7c7b5622 parents b125d90 45d9a1e5 files · +184 −172Browse files

Unified · Split

5 files

arch/Kconfig +2 −144
scripts/Makefile.gcc-plugins +24 −13
scripts/gcc-plugins/Kconfig +142 −0
scripts/gcc-plugins/Makefile +0 −5
scripts/gcc-plugins/gcc-common.h +16 −10

arch/Kconfig+2−144

@@ -408,150 +408,6 @@ config SECCOMP_FILTER · 407 unmodified lines
408	408
409	409	See Documentation/userspace-api/seccomp_filter.rst for details.
410	410
411		−preferred-plugin-hostcc := $(if-success,[ $(gcc-version) -ge 40800 ],$(HOSTCXX),$(HOSTCC))
412		−
413		−config PLUGIN_HOSTCC
414		− string
415		− default "$(shell,$(srctree)/scripts/gcc-plugin.sh "$(preferred-plugin-hostcc)" "$(HOSTCXX)" "$(CC)")"
416		− help
417		− Host compiler used to build GCC plugins. This can be $(HOSTCXX),
418		− $(HOSTCC), or a null string if GCC plugin is unsupported.
419		−
420		−config HAVE_GCC_PLUGINS
421		− bool
422		− help
423		− An arch should select this symbol if it supports building with
424		− GCC plugins.
425		−
426		−menuconfig GCC_PLUGINS
427		− bool "GCC plugins"
428		− depends on HAVE_GCC_PLUGINS
429		− depends on PLUGIN_HOSTCC != ""
430		− help
431		− GCC plugins are loadable modules that provide extra features to the
432		− compiler. They are useful for runtime instrumentation and static analysis.
433		−
434		− See Documentation/gcc-plugins.txt for details.
435		−
436		−config GCC_PLUGIN_CYC_COMPLEXITY
437		− bool "Compute the cyclomatic complexity of a function" if EXPERT
438		− depends on GCC_PLUGINS
439		− depends on !COMPILE_TEST # too noisy
440		− help
441		− The complexity M of a function's control flow graph is defined as:
442		− M = E - N + 2P
443		− where
444		−
445		− E = the number of edges
446		− N = the number of nodes
447		− P = the number of connected components (exit nodes).
448		−
449		− Enabling this plugin reports the complexity to stderr during the
450		− build. It mainly serves as a simple example of how to create a
451		− gcc plugin for the kernel.
452		−
453		−config GCC_PLUGIN_SANCOV
454		− bool
455		− depends on GCC_PLUGINS
456		− help
457		− This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
458		− basic blocks. It supports all gcc versions with plugin support (from
459		− gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
460		− by Dmitry Vyukov <dvyukov@google.com>.
461		−
462		−config GCC_PLUGIN_LATENT_ENTROPY
463		− bool "Generate some entropy during boot and runtime"
464		− depends on GCC_PLUGINS
465		− help
466		− By saying Y here the kernel will instrument some kernel code to
467		− extract some entropy from both original and artificially created
468		− program state. This will help especially embedded systems where
469		− there is little 'natural' source of entropy normally. The cost
470		− is some slowdown of the boot process (about 0.5%) and fork and
471		− irq processing.
472		−
473		− Note that entropy extracted this way is not cryptographically
474		− secure!
475		−
476		− This plugin was ported from grsecurity/PaX. More information at:
477		− * https://grsecurity.net/
478		− * https://pax.grsecurity.net/
479		−
480		−config GCC_PLUGIN_STRUCTLEAK
481		− bool "Force initialization of variables containing userspace addresses"
482		− depends on GCC_PLUGINS
483		− # Currently STRUCTLEAK inserts initialization out of live scope of
484		− # variables from KASAN point of view. This leads to KASAN false
485		− # positive reports. Prohibit this combination for now.
486		− depends on !KASAN_EXTRA
487		− help
488		− This plugin zero-initializes any structures containing a
489		− __user attribute. This can prevent some classes of information
490		− exposures.
491		−
492		− This plugin was ported from grsecurity/PaX. More information at:
493		− * https://grsecurity.net/
494		− * https://pax.grsecurity.net/
495		−
496		−config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
497		− bool "Force initialize all struct type variables passed by reference"
498		− depends on GCC_PLUGIN_STRUCTLEAK
499		− depends on !COMPILE_TEST
500		− help
501		− Zero initialize any struct type local variable that may be passed by
502		− reference without having been initialized.
503		−
504		−config GCC_PLUGIN_STRUCTLEAK_VERBOSE
505		− bool "Report forcefully initialized variables"
506		− depends on GCC_PLUGIN_STRUCTLEAK
507		− depends on !COMPILE_TEST # too noisy
508		− help
509		− This option will cause a warning to be printed each time the
510		− structleak plugin finds a variable it thinks needs to be
511		− initialized. Since not all existing initializers are detected
512		− by the plugin, this can produce false positive warnings.
513		−
514		−config GCC_PLUGIN_RANDSTRUCT
515		− bool "Randomize layout of sensitive kernel structures"
516		− depends on GCC_PLUGINS
517		− select MODVERSIONS if MODULES
518		− help
519		− If you say Y here, the layouts of structures that are entirely
520		− function pointers (and have not been manually annotated with
521		− __no_randomize_layout), or structures that have been explicitly
522		− marked with __randomize_layout, will be randomized at compile-time.
523		− This can introduce the requirement of an additional information
524		− exposure vulnerability for exploits targeting these structure
525		− types.
526		−
527		− Enabling this feature will introduce some performance impact,
528		− slightly increase memory usage, and prevent the use of forensic
529		− tools like Volatility against the system (unless the kernel
530		− source tree isn't cleaned after kernel installation).
531		−
532		− The seed used for compilation is located at
533		− scripts/gcc-plgins/randomize_layout_seed.h. It remains after
534		− a make clean to allow for external modules to be compiled with
535		− the existing seed and will be removed by a make mrproper or
536		− make distclean.
537		−
538		− Note that the implementation requires gcc 4.7 or newer.
539		−
540		− This plugin was ported from grsecurity/PaX. More information at:
541		− * https://grsecurity.net/
542		− * https://pax.grsecurity.net/
543		−
544		−config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
545		− bool "Use cacheline-aware structure randomization"
546		− depends on GCC_PLUGIN_RANDSTRUCT
547		− depends on !COMPILE_TEST # do not reduce test coverage
548		− help
549		− If you say Y here, the RANDSTRUCT randomization will make a
550		− best effort at restricting randomization to cacheline-sized
551		− groups of elements. It will further not randomize bitfields
552		− in structures. This reduces the performance hit of RANDSTRUCT
553		− at the cost of weakened randomization.
554		−
555	411	config HAVE_STACKPROTECTOR
556	412	bool
557	413	help
@@ -975,3 +831,5 @@ config REFCOUNT_FULL · 417 unmodified lines
975	831	security flaw exploits.
976	832
977	833	source "kernel/gcov/Kconfig"
	834	+
	835	+source "scripts/gcc-plugins/Kconfig"

scripts/Makefile.gcc-plugins+24−13

@@ -1,33 +1,44 @@
1	1	# SPDX-License-Identifier: GPL-2.0
	2	+
2	3	gcc-plugin-$(CONFIG_GCC_PLUGIN_CYC_COMPLEXITY) += cyc_complexity_plugin.so
3	4
4	5	gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so
5		−gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += -DLATENT_ENTROPY_PLUGIN
	6	+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) \
	7	+ += -DLATENT_ENTROPY_PLUGIN
6	8	ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
7		− DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable
	9	+ DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable
8	10	endif
	11	+export DISABLE_LATENT_ENTROPY_PLUGIN
9	12
10	13	gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV) += sancov_plugin.so
	14	+
11	15	gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += structleak_plugin.so
12		−gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE) += -fplugin-arg-structleak_plugin-verbose
13		−gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL) += -fplugin-arg-structleak_plugin-byref-all
14		−gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += -DSTRUCTLEAK_PLUGIN
	16	+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE) \
	17	+ += -fplugin-arg-structleak_plugin-verbose
	18	+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL) \
	19	+ += -fplugin-arg-structleak_plugin-byref-all
	20	+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) \
	21	+ += -DSTRUCTLEAK_PLUGIN
15	22
16	23	gcc-plugin-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += randomize_layout_plugin.so
17		−gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += -DRANDSTRUCT_PLUGIN
18		−gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE) += -fplugin-arg-randomize_layout_plugin-performance-mode
	24	+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) \
	25	+ += -DRANDSTRUCT_PLUGIN
	26	+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE) \
	27	+ += -fplugin-arg-randomize_layout_plugin-performance-mode
19	28
	29	+# All the plugin CFLAGS are collected here in case a build target needs to
	30	+# filter them out of the KBUILD_CFLAGS.
20	31	GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))
21		−
22		−export GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR
23		−export DISABLE_LATENT_ENTROPY_PLUGIN
24		−
25		−# sancov_plugin.so can be only in CFLAGS_KCOV because avoid duplication.
	32	+# The sancov_plugin.so is included via CFLAGS_KCOV, so it is removed here.
26	33	GCC_PLUGINS_CFLAGS := $(filter-out %/sancov_plugin.so, $(GCC_PLUGINS_CFLAGS))
	34	+export GCC_PLUGINS_CFLAGS
27	35
	36	+# Add the flags to the build!
28	37	KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)
	38	+
	39	+# All enabled GCC plugins are collected here for building below.
29	40	GCC_PLUGIN := $(gcc-plugin-y)
30		−GCC_PLUGIN_SUBDIR := $(gcc-plugin-subdir-y)
	41	+export GCC_PLUGIN
31	42
32	43	# Actually do the build, if requested.
33	44	PHONY += gcc-plugins

scripts/gcc-plugins/Kconfig+142−0

@@ -0,0 +1,142 @@
	1	+preferred-plugin-hostcc := $(if-success,[ $(gcc-version) -ge 40800 ],$(HOSTCXX),$(HOSTCC))
	2	+
	3	+config PLUGIN_HOSTCC
	4	+ string
	5	+ default "$(shell,$(srctree)/scripts/gcc-plugin.sh "$(preferred-plugin-hostcc)" "$(HOSTCXX)" "$(CC)")"
	6	+ help
	7	+ Host compiler used to build GCC plugins. This can be $(HOSTCXX),
	8	+ $(HOSTCC), or a null string if GCC plugin is unsupported.
	9	+
	10	+config HAVE_GCC_PLUGINS
	11	+ bool
	12	+ help
	13	+ An arch should select this symbol if it supports building with
	14	+ GCC plugins.
	15	+
	16	+menuconfig GCC_PLUGINS
	17	+ bool "GCC plugins"
	18	+ depends on HAVE_GCC_PLUGINS
	19	+ depends on PLUGIN_HOSTCC != ""
	20	+ help
	21	+ GCC plugins are loadable modules that provide extra features to the
	22	+ compiler. They are useful for runtime instrumentation and static analysis.
	23	+
	24	+ See Documentation/gcc-plugins.txt for details.
	25	+
	26	+if GCC_PLUGINS
	27	+
	28	+config GCC_PLUGIN_CYC_COMPLEXITY
	29	+ bool "Compute the cyclomatic complexity of a function" if EXPERT
	30	+ depends on !COMPILE_TEST # too noisy
	31	+ help
	32	+ The complexity M of a function's control flow graph is defined as:
	33	+ M = E - N + 2P
	34	+ where
	35	+
	36	+ E = the number of edges
	37	+ N = the number of nodes
	38	+ P = the number of connected components (exit nodes).
	39	+
	40	+ Enabling this plugin reports the complexity to stderr during the
	41	+ build. It mainly serves as a simple example of how to create a
	42	+ gcc plugin for the kernel.
	43	+
	44	+config GCC_PLUGIN_SANCOV
	45	+ bool
	46	+ help
	47	+ This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
	48	+ basic blocks. It supports all gcc versions with plugin support (from
	49	+ gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
	50	+ by Dmitry Vyukov <dvyukov@google.com>.
	51	+
	52	+config GCC_PLUGIN_LATENT_ENTROPY
	53	+ bool "Generate some entropy during boot and runtime"
	54	+ help
	55	+ By saying Y here the kernel will instrument some kernel code to
	56	+ extract some entropy from both original and artificially created
	57	+ program state. This will help especially embedded systems where
	58	+ there is little 'natural' source of entropy normally. The cost
	59	+ is some slowdown of the boot process (about 0.5%) and fork and
	60	+ irq processing.
	61	+
	62	+ Note that entropy extracted this way is not cryptographically
	63	+ secure!
	64	+
	65	+ This plugin was ported from grsecurity/PaX. More information at:
	66	+ * https://grsecurity.net/
	67	+ * https://pax.grsecurity.net/
	68	+
	69	+config GCC_PLUGIN_STRUCTLEAK
	70	+ bool "Force initialization of variables containing userspace addresses"
	71	+ # Currently STRUCTLEAK inserts initialization out of live scope of
	72	+ # variables from KASAN point of view. This leads to KASAN false
	73	+ # positive reports. Prohibit this combination for now.
	74	+ depends on !KASAN_EXTRA
	75	+ help
	76	+ This plugin zero-initializes any structures containing a
	77	+ __user attribute. This can prevent some classes of information
	78	+ exposures.
	79	+
	80	+ This plugin was ported from grsecurity/PaX. More information at:
	81	+ * https://grsecurity.net/
	82	+ * https://pax.grsecurity.net/
	83	+
	84	+config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
	85	+ bool "Force initialize all struct type variables passed by reference"
	86	+ depends on GCC_PLUGIN_STRUCTLEAK
	87	+ depends on !COMPILE_TEST
	88	+ help
	89	+ Zero initialize any struct type local variable that may be passed by
	90	+ reference without having been initialized.
	91	+
	92	+config GCC_PLUGIN_STRUCTLEAK_VERBOSE
	93	+ bool "Report forcefully initialized variables"
	94	+ depends on GCC_PLUGIN_STRUCTLEAK
	95	+ depends on !COMPILE_TEST # too noisy
	96	+ help
	97	+ This option will cause a warning to be printed each time the
	98	+ structleak plugin finds a variable it thinks needs to be
	99	+ initialized. Since not all existing initializers are detected
	100	+ by the plugin, this can produce false positive warnings.
	101	+
	102	+config GCC_PLUGIN_RANDSTRUCT
	103	+ bool "Randomize layout of sensitive kernel structures"
	104	+ select MODVERSIONS if MODULES
	105	+ help
	106	+ If you say Y here, the layouts of structures that are entirely
	107	+ function pointers (and have not been manually annotated with
	108	+ __no_randomize_layout), or structures that have been explicitly
	109	+ marked with __randomize_layout, will be randomized at compile-time.
	110	+ This can introduce the requirement of an additional information
	111	+ exposure vulnerability for exploits targeting these structure
	112	+ types.
	113	+
	114	+ Enabling this feature will introduce some performance impact,
	115	+ slightly increase memory usage, and prevent the use of forensic
	116	+ tools like Volatility against the system (unless the kernel
	117	+ source tree isn't cleaned after kernel installation).
	118	+
	119	+ The seed used for compilation is located at
	120	+ scripts/gcc-plgins/randomize_layout_seed.h. It remains after
	121	+ a make clean to allow for external modules to be compiled with
	122	+ the existing seed and will be removed by a make mrproper or
	123	+ make distclean.
	124	+
	125	+ Note that the implementation requires gcc 4.7 or newer.
	126	+
	127	+ This plugin was ported from grsecurity/PaX. More information at:
	128	+ * https://grsecurity.net/
	129	+ * https://pax.grsecurity.net/
	130	+
	131	+config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
	132	+ bool "Use cacheline-aware structure randomization"
	133	+ depends on GCC_PLUGIN_RANDSTRUCT
	134	+ depends on !COMPILE_TEST # do not reduce test coverage
	135	+ help
	136	+ If you say Y here, the RANDSTRUCT randomization will make a
	137	+ best effort at restricting randomization to cacheline-sized
	138	+ groups of elements. It will further not randomize bitfields
	139	+ in structures. This reduces the performance hit of RANDSTRUCT
	140	+ at the cost of weakened randomization.
	141	+
	142	+endif

scripts/gcc-plugins/Makefile+0−5

@@ -14,8 +14,6 @@ else · 13 unmodified lines
14	14	export HOST_EXTRACXXFLAGS
15	15	endif
16	16
17		−export HOSTLIBS
18		−
19	17	$(obj)/randomize_layout_plugin.o: $(objtree)/$(obj)/randomize_layout_seed.h
20	18	quiet_cmd_create_randomize_layout_seed = GENSEED $@
21	19	cmd_create_randomize_layout_seed = \
@@ -29,7 +27,4 @@ always := $($(HOSTLIBS)-y) · 7 unmodified lines
29	27
30	28	$(foreach p,$($(HOSTLIBS)-y:%.so=%),$(eval $(p)-objs := $(p).o))
31	29
32		−subdir-y := $(GCC_PLUGIN_SUBDIR)
33		−subdir- += $(GCC_PLUGIN_SUBDIR)
34		−
35	30	clean-files += *.so

scripts/gcc-plugins/gcc-common.h+16−10

@@ -392,13 +392,6 @@ static inline struct cgraph_node cgraph_alias_target(struct cgraph_node n) · 391 unmodified lines
392	392	}
393	393	#endif
394	394
395		−#if BUILDING_GCC_VERSION >= 4007 && BUILDING_GCC_VERSION <= 4009
396		−#define cgraph_create_edge(caller, callee, call_stmt, count, freq, nest) \
397		− cgraph_create_edge((caller), (callee), (call_stmt), (count), (freq))
398		−#define cgraph_create_edge_including_clones(caller, callee, old_call_stmt, call_stmt, count, freq, nest, reason) \
399		− cgraph_create_edge_including_clones((caller), (callee), (old_call_stmt), (call_stmt), (count), (freq), (reason))
400		−#endif
401		−
402	395	#if BUILDING_GCC_VERSION <= 4008
403	396	#define ENTRY_BLOCK_PTR_FOR_FN(FN) ENTRY_BLOCK_PTR_FOR_FUNCTION(FN)
404	397	#define EXIT_BLOCK_PTR_FOR_FN(FN) EXIT_BLOCK_PTR_FOR_FUNCTION(FN)
@@ -723,10 +716,23 @@ static inline const char *get_decl_section_name(const_tree decl) · 318 unmodified lines
723	716	#define varpool_get_node(decl) varpool_node::get(decl)
724	717	#define dump_varpool_node(file, node) (node)->dump(file)
725	718
726		−#define cgraph_create_edge(caller, callee, call_stmt, count, freq, nest) \
	719	+#if BUILDING_GCC_VERSION >= 8000
	720	+#define cgraph_create_edge(caller, callee, call_stmt, count, freq) \
	721	+ (caller)->create_edge((callee), (call_stmt), (count))
	722	+
	723	+#define cgraph_create_edge_including_clones(caller, callee, \
	724	+ old_call_stmt, call_stmt, count, freq, reason) \
	725	+ (caller)->create_edge_including_clones((callee), \
	726	+ (old_call_stmt), (call_stmt), (count), (reason))
	727	+#else
	728	+#define cgraph_create_edge(caller, callee, call_stmt, count, freq) \
727	729	(caller)->create_edge((callee), (call_stmt), (count), (freq))
728		−#define cgraph_create_edge_including_clones(caller, callee, old_call_stmt, call_stmt, count, freq, nest, reason) \
729		− (caller)->create_edge_including_clones((callee), (old_call_stmt), (call_stmt), (count), (freq), (reason))
	730	+
	731	+#define cgraph_create_edge_including_clones(caller, callee, \
	732	+ old_call_stmt, call_stmt, count, freq, reason) \
	733	+ (caller)->create_edge_including_clones((callee), \
	734	+ (old_call_stmt), (call_stmt), (count), (freq), (reason))
	735	+#endif
730	736
731	737	typedef struct cgraph_node *cgraph_node_ptr;
732	738	typedef struct cgraph_edge *cgraph_edge_p;

Merge tag 'gcc-plugin-cleanup-v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Keyboard shortcuts

General

Issues and pull requests

Issues, pull requests and Inbox

Repository code