Merge tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/l…

…inux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - Comprehensive interface overhaul:
   =================================

   Objtool's interface has some issues:

     - Several features are done unconditionally, without any way to
       turn them off. Some of them might be surprising. This makes
       objtool tricky to use, and prevents porting individual features
       to other arches.

     - The config dependencies are too coarse-grained. Objtool
       enablement is tied to CONFIG_STACK_VALIDATION, but it has several
       other features independent of that.

     - The objtool subcmds ("check" and "orc") are clumsy: "check" is
       really a subset of "orc", so it has all the same options.

       The subcmd model has never really worked for objtool, as it only
       has a single purpose: "do some combination of things on an object
       file".

     - The '--lto' and '--vmlinux' options are nonsensical and have
       surprising behavior.

   Overhaul the interface:

      - get rid of subcmds

      - make all features individually selectable

      - remove and/or clarify confusing/obsolete options

      - update the documentation

      - fix some bugs found along the way

 - Fix x32 regression

 - Fix Kbuild cleanup bugs

 - Add scripts/objdump-func helper script to disassemble a single
   function from an object file.

 - Rewrite scripts/faddr2line to be section-aware, by basing it on
   'readelf', moving it away from 'nm', which doesn't handle multiple
   sections well, which can result in decoding failure.

 - Rewrite & fix symbol handling - which had a number of bugs wrt.
   object files that don't have global symbols - which is rare but
   possible. Also fix a bunch of symbol handling bugs found along the
   way.

* tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  objtool: Fix objtool regression on x32 systems
  objtool: Fix symbol creation
  scripts/faddr2line: Fix overlapping text section failures
  scripts: Create objdump-func helper script
  objtool: Remove libsubcmd.a when make clean
  objtool: Remove inat-tables.c when make clean
  objtool: Update documentation
  objtool: Remove --lto and --vmlinux in favor of --link
  objtool: Add HAVE_NOINSTR_VALIDATION
  objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"
  objtool: Make noinstr hacks optional
  objtool: Make jump label hack optional
  objtool: Make static call annotation optional
  objtool: Make stack validation frame-pointer-specific
  objtool: Add CONFIG_OBJTOOL
  objtool: Extricate sls from stack validation
  objtool: Rework ibt and extricate from stack validation
  objtool: Make stack validation optional
  objtool: Add option to print section addresses
  objtool: Don't print parentheses in function addresses
  ...

Makefile

@@ -1302,7 +1302,7 @@ install: sub_make_done :=
 # ---------------------------------------------------------------------------
 # Tools
 
-ifdef CONFIG_STACK_VALIDATION
+ifdef CONFIG_OBJTOOL
 prepare: tools/objtool
 endif
 

arch/Kconfig

@@ -54,6 +54,7 @@ config JUMP_LABEL
 	bool "Optimize very unlikely/likely branches"
 	depends on HAVE_ARCH_JUMP_LABEL
 	depends on CC_HAS_ASM_GOTO
+	select OBJTOOL if HAVE_JUMP_LABEL_HACK
 	help
 	 This option enables a transparent branch optimization that
 	 makes certain almost-always-true or almost-always-false branch
@@ -1034,11 +1035,23 @@ config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
 	depends on MMU
 	select ARCH_HAS_ELF_RANDOMIZE
 
+config HAVE_OBJTOOL
+	bool
+
+config HAVE_JUMP_LABEL_HACK
+	bool
+
+config HAVE_NOINSTR_HACK
+	bool
+
+config HAVE_NOINSTR_VALIDATION
+	bool
+
 config HAVE_STACK_VALIDATION
 	bool
 	help
-	  Architecture supports the 'objtool check' host tool command, which
-	  performs compile-time stack metadata validation.
+	  Architecture supports objtool compile-time frame pointer rule
+	  validation.
 
 config HAVE_RELIABLE_STACKTRACE
 	bool
@@ -1308,6 +1321,7 @@ config HAVE_STATIC_CALL
 config HAVE_STATIC_CALL_INLINE
 	bool
 	depends on HAVE_STATIC_CALL
+	select OBJTOOL
 
 config HAVE_PREEMPT_DYNAMIC
 	bool

arch/x86/Kconfig

@@ -188,7 +188,7 @@ config X86
 	select HAVE_CONTEXT_TRACKING		if X86_64
 	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
 	select HAVE_C_RECORDMCOUNT
-	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
+	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
 	select HAVE_BUILDTIME_MCOUNT_SORT
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_CONTIGUOUS
@@ -212,6 +212,7 @@ config X86
 	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
 	select HAVE_IRQ_TIME_ACCOUNTING
+	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
 	select HAVE_KERNEL_BZIP2
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZ4
@@ -230,7 +231,10 @@ config X86
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_MOVE_PMD
 	select HAVE_MOVE_PUD
+	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
 	select HAVE_NMI
+	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
+	select HAVE_OBJTOOL			if X86_64
 	select HAVE_OPTPROBES
 	select HAVE_PCSPKR_PLATFORM
 	select HAVE_PERF_EVENTS
@@ -239,17 +243,17 @@ config X86
 	select HAVE_PCI
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
-	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
+	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
 	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
 	select HAVE_REGS_AND_STACK_ACCESS_API
-	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
+	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_SETUP_PER_CPU_AREA
 	select HAVE_SOFTIRQ_ON_OWN_STACK
 	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
-	select HAVE_STACK_VALIDATION		if X86_64
+	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
 	select HAVE_STATIC_CALL
-	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
+	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
 	select HAVE_PREEMPT_DYNAMIC_CALL
 	select HAVE_RSEQ
 	select HAVE_SYSCALL_TRACEPOINTS
@@ -268,7 +272,6 @@ config X86
 	select RTC_MC146818_LIB
 	select SPARSE_IRQ
 	select SRCU
-	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
 	select SYSCTL_EXCEPTION_TRACE
 	select THREAD_INFO_IN_TASK
 	select TRACE_IRQFLAGS_SUPPORT
@@ -459,6 +462,7 @@ config GOLDFISH
 
 config RETPOLINE
 	bool "Avoid speculative indirect branches in kernel"
+	select OBJTOOL if HAVE_OBJTOOL
 	default y
 	help
 	  Compile kernel with the retpoline compiler options to guard against
@@ -472,6 +476,7 @@ config CC_HAS_SLS
 config SLS
 	bool "Mitigate Straight-Line-Speculation"
 	depends on CC_HAS_SLS && X86_64
+	select OBJTOOL if HAVE_OBJTOOL
 	default n
 	help
 	  Compile the kernel with straight-line-speculation options to guard
@@ -1859,9 +1864,10 @@ config CC_HAS_IBT
 config X86_KERNEL_IBT
 	prompt "Indirect Branch Tracking"
 	bool
-	depends on X86_64 && CC_HAS_IBT && STACK_VALIDATION
+	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
 	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
 	depends on !LD_IS_LLD || LLD_VERSION >= 140000
+	select OBJTOOL
 	help
 	  Build the kernel with support for Indirect Branch Tracking, a
 	  hardware support course-grain forward-edge Control Flow Integrity

arch/x86/Kconfig.debug

@@ -237,7 +237,7 @@ choice
 config UNWINDER_ORC
 	bool "ORC unwinder"
 	depends on X86_64
-	select STACK_VALIDATION
+	select OBJTOOL
 	help
 	  This option enables the ORC (Oops Rewind Capability) unwinder for
 	  unwinding kernel stack traces.  It uses a custom data format which is

arch/x86/include/asm/jump_label.h

@@ -20,7 +20,7 @@
 	_ASM_PTR "%c0 + %c1 - .\n\t"			\
 	".popsection \n\t"
 
-#ifdef CONFIG_STACK_VALIDATION
+#ifdef CONFIG_HAVE_JUMP_LABEL_HACK
 
 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
 {
@@ -34,7 +34,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
 	return true;
 }
 
-#else
+#else /* !CONFIG_HAVE_JUMP_LABEL_HACK */
 
 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
 {
@@ -48,7 +48,7 @@ static __always_inline bool arch_static_branch(struct static_key * const key, co
 	return true;
 }
 
-#endif /* STACK_VALIDATION */
+#endif /* CONFIG_HAVE_JUMP_LABEL_HACK */
 
 static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
 {

arch/x86/kernel/alternative.c

@@ -338,7 +338,7 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
 	}
 }
 
-#if defined(CONFIG_RETPOLINE) && defined(CONFIG_STACK_VALIDATION)
+#if defined(CONFIG_RETPOLINE) && defined(CONFIG_OBJTOOL)
 
 /*
  * CALL/JMP *%\reg
@@ -507,11 +507,11 @@ void __init_or_module noinline apply_retpolines(s32 *start, s32 *end)
 	}
 }
 
-#else /* !RETPOLINES || !CONFIG_STACK_VALIDATION */
+#else /* !CONFIG_RETPOLINE || !CONFIG_OBJTOOL */
 
 void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) { }
 
-#endif /* CONFIG_RETPOLINE && CONFIG_STACK_VALIDATION */
+#endif /* CONFIG_RETPOLINE && CONFIG_OBJTOOL */
 
 #ifdef CONFIG_X86_KERNEL_IBT
 

include/linux/compiler.h

@@ -109,7 +109,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 #endif
 
 /* Unreachable code */
-#ifdef CONFIG_STACK_VALIDATION
+#ifdef CONFIG_OBJTOOL
 /*
  * These macros help objtool understand GCC code flow for unreachable code.
  * The __COUNTER__ based labels are a hack to make each instance of the macros
@@ -128,10 +128,10 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 /* Annotate a C jump table to allow objtool to follow the code flow */
 #define __annotate_jump_table __section(".rodata..c_jump_table")
 
-#else
+#else /* !CONFIG_OBJTOOL */
 #define annotate_unreachable()
 #define __annotate_jump_table
-#endif
+#endif /* CONFIG_OBJTOOL */
 
 #ifndef unreachable
 # define unreachable() do {		\

include/linux/instrumentation.h

@@ -2,7 +2,7 @@
 #ifndef __LINUX_INSTRUMENTATION_H
 #define __LINUX_INSTRUMENTATION_H
 
-#if defined(CONFIG_DEBUG_ENTRY) && defined(CONFIG_STACK_VALIDATION)
+#ifdef CONFIG_NOINSTR_VALIDATION
 
 #include <linux/stringify.h>
 
@@ -53,9 +53,9 @@
 		     ".popsection\n\t" : : "i" (c));			\
 })
 #define instrumentation_end() __instrumentation_end(__COUNTER__)
-#else
+#else /* !CONFIG_NOINSTR_VALIDATION */
 # define instrumentation_begin()	do { } while(0)
 # define instrumentation_end()		do { } while(0)
-#endif
+#endif /* CONFIG_NOINSTR_VALIDATION */
 
 #endif /* __LINUX_INSTRUMENTATION_H */

include/linux/objtool.h

@@ -38,7 +38,7 @@ struct unwind_hint {
 #define UNWIND_HINT_TYPE_REGS_PARTIAL	2
 #define UNWIND_HINT_TYPE_FUNC		3
 
-#ifdef CONFIG_STACK_VALIDATION
+#ifdef CONFIG_OBJTOOL
 
 #include <asm/asm.h>
 
@@ -159,7 +159,7 @@ struct unwind_hint {
 
 #endif /* __ASSEMBLY__ */
 
-#else /* !CONFIG_STACK_VALIDATION */
+#else /* !CONFIG_OBJTOOL */
 
 #ifndef __ASSEMBLY__
 
@@ -181,6 +181,6 @@ struct unwind_hint {
 .endm
 #endif
 
-#endif /* CONFIG_STACK_VALIDATION */
+#endif /* CONFIG_OBJTOOL */
 
 #endif /* _LINUX_OBJTOOL_H */

kernel/trace/Kconfig

@@ -729,6 +729,7 @@ config FTRACE_MCOUNT_USE_OBJTOOL
 	depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
 	depends on !FTRACE_MCOUNT_USE_CC
 	depends on FTRACE_MCOUNT_RECORD
+	select OBJTOOL
 
 config FTRACE_MCOUNT_USE_RECORDMCOUNT
 	def_bool y

lib/Kconfig.debug

@@ -485,24 +485,25 @@ config FRAME_POINTER
 	  larger and slower, but it gives very useful debugging information
 	  in case of kernel bugs. (precise oopses/stacktraces/warnings)
 
+config OBJTOOL
+	bool
+
 config STACK_VALIDATION
 	bool "Compile-time stack metadata validation"
-	depends on HAVE_STACK_VALIDATION
+	depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
+	select OBJTOOL
 	default n
 	help
-	  Add compile-time checks to validate stack metadata, including frame
-	  pointers (if CONFIG_FRAME_POINTER is enabled).  This helps ensure
-	  that runtime stack traces are more reliable.
-
-	  This is also a prerequisite for generation of ORC unwind data, which
-	  is needed for CONFIG_UNWINDER_ORC.
+	  Validate frame pointer rules at compile-time.  This helps ensure that
+	  runtime stack traces are more reliable.
 
 	  For more information, see
 	  tools/objtool/Documentation/stack-validation.txt.
 
-config VMLINUX_VALIDATION
+config NOINSTR_VALIDATION
 	bool
-	depends on STACK_VALIDATION && DEBUG_ENTRY
+	depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
+	select OBJTOOL
 	default y
 
 config VMLINUX_MAP
@@ -2035,10 +2036,11 @@ 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 || STACK_VALIDATION || \
+	depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
 		   GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
 	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
 	  for coverage-guided fuzzing (randomized testing).

lib/Kconfig.kcsan

@@ -187,7 +187,9 @@ config KCSAN_WEAK_MEMORY
 	# We can either let objtool nop __tsan_func_{entry,exit}() and builtin
 	# atomics instrumentation in .noinstr.text, or use a compiler that can
 	# implement __no_kcsan to really remove all instrumentation.
-	depends on STACK_VALIDATION || CC_IS_GCC || CLANG_VERSION >= 140000
+	depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
+		   CC_IS_GCC || CLANG_VERSION >= 140000
+	select OBJTOOL if HAVE_NOINSTR_HACK
 	help
 	  Enable support for modeling a subset of weak memory, which allows
 	  detecting a subset of data races due to missing memory barriers.

lib/Kconfig.ubsan

@@ -94,7 +94,7 @@ config UBSAN_UNREACHABLE
 	bool "Perform checking for unreachable code"
 	# objtool already handles unreachable checking and gets angry about
 	# seeing UBSan instrumentation located in unreachable places.
-	depends on !STACK_VALIDATION
+	depends on !(OBJTOOL && (STACK_VALIDATION || UNWINDER_ORC || X86_SMAP))
 	depends on $(cc-option,-fsanitize=unreachable)
 	help
 	  This option enables -fsanitize=unreachable which checks for control

scripts/Makefile.build

@@ -222,25 +222,29 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),
 	$(sub_cmd_record_mcount))
 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 
-ifdef CONFIG_STACK_VALIDATION
+ifdef CONFIG_OBJTOOL
 
 objtool := $(objtree)/tools/objtool/objtool
 
 objtool_args =								\
-	$(if $(CONFIG_UNWINDER_ORC),orc generate,check)			\
-	$(if $(part-of-module), --module)				\
-	$(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt)			\
-	$(if $(CONFIG_FRAME_POINTER),, --no-fp)				\
-	$(if $(CONFIG_GCOV_KERNEL), --no-unreachable)			\
+	$(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label)	\
+	$(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr)		\
+	$(if $(CONFIG_X86_KERNEL_IBT), --ibt)				\
+	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)		\
+	$(if $(CONFIG_UNWINDER_ORC), --orc)				\
 	$(if $(CONFIG_RETPOLINE), --retpoline)				\
+	$(if $(CONFIG_SLS), --sls)					\
+	$(if $(CONFIG_STACK_VALIDATION), --stackval)			\
+	$(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call)		\
 	--uaccess							\
-	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)		\
-	$(if $(CONFIG_SLS), --sls)
+	$(if $(linked-object), --link)					\
+	$(if $(part-of-module), --module)				\
+	$(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
 
 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
 
-endif # CONFIG_STACK_VALIDATION
+endif # CONFIG_OBJTOOL
 
 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 
@@ -303,6 +307,7 @@ quiet_cmd_cc_prelink_modules = LD [M]  $@
 # modules into native code
 $(obj)/%.prelink.o: objtool-enabled = y
 $(obj)/%.prelink.o: part-of-module := y
+$(obj)/%.prelink.o: linked-object := y
 
 $(obj)/%.prelink.o: $(obj)/%.o FORCE
 	$(call if_changed,cc_prelink_modules)