From c8c301abeae58ec756b8fcb2178a632bd3c9e284 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 8 Mar 2022 16:30:18 +0100 Subject: x86/ibt: Add ANNOTATE_NOENDBR In order to have objtool warn about code references to !ENDBR instruction, we need an annotation to allow this for non-control-flow instances -- consider text range checks, text patching, or return trampolines etc. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kees Cook Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20220308154317.578968224@infradead.org --- include/linux/objtool.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux/objtool.h') diff --git a/include/linux/objtool.h b/include/linux/objtool.h index aca52db2f3f3..f797368820c8 100644 --- a/include/linux/objtool.h +++ b/include/linux/objtool.h @@ -77,6 +77,12 @@ struct unwind_hint { #define STACK_FRAME_NON_STANDARD_FP(func) #endif +#define ANNOTATE_NOENDBR \ + "986: \n\t" \ + ".pushsection .discard.noendbr\n\t" \ + _ASM_PTR " 986b\n\t" \ + ".popsection\n\t" + #else /* __ASSEMBLY__ */ /* @@ -129,6 +135,13 @@ struct unwind_hint { .popsection .endm +.macro ANNOTATE_NOENDBR +.Lhere_\@: + .pushsection .discard.noendbr + .quad .Lhere_\@ + .popsection +.endm + #endif /* __ASSEMBLY__ */ #else /* !CONFIG_STACK_VALIDATION */ @@ -139,12 +152,15 @@ struct unwind_hint { "\n\t" #define STACK_FRAME_NON_STANDARD(func) #define STACK_FRAME_NON_STANDARD_FP(func) +#define ANNOTATE_NOENDBR #else #define ANNOTATE_INTRA_FUNCTION_CALL .macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0 .endm .macro STACK_FRAME_NON_STANDARD func:req .endm +.macro ANNOTATE_NOENDBR +.endm #endif #endif /* CONFIG_STACK_VALIDATION */ -- cgit From dca5da2abe406168b85f97e22109710ebe0bda08 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 14 Mar 2022 18:05:52 +0100 Subject: x86,objtool: Move the ASM_REACHABLE annotation to objtool.h Because we need a variant for .S files too. Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/Yi9gOW9f1GGwwUD6@hirez.programming.kicks-ass.net --- arch/x86/include/asm/bug.h | 1 + arch/x86/include/asm/irq_stack.h | 1 + include/linux/compiler.h | 7 ------- include/linux/objtool.h | 16 ++++++++++++++++ tools/include/linux/objtool.h | 16 ++++++++++++++++ 5 files changed, 34 insertions(+), 7 deletions(-) (limited to 'include/linux/objtool.h') diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index bab883c0b6fe..4d20a293c6fd 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -4,6 +4,7 @@ #include #include +#include /* * Despite that some emulators terminate on UD2, we use it for WARN(). diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h index 05af249d6bec..63f818aedf77 100644 --- a/arch/x86/include/asm/irq_stack.h +++ b/arch/x86/include/asm/irq_stack.h @@ -3,6 +3,7 @@ #define _ASM_X86_IRQ_STACK_H #include +#include #include diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 0f7fd205ab7e..219aa5ddbc73 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -125,18 +125,11 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, }) #define annotate_unreachable() __annotate_unreachable(__COUNTER__) -#define ASM_REACHABLE \ - "998:\n\t" \ - ".pushsection .discard.reachable\n\t" \ - ".long 998b - .\n\t" \ - ".popsection\n\t" - /* Annotate a C jump table to allow objtool to follow the code flow */ #define __annotate_jump_table __section(".rodata..c_jump_table") #else #define annotate_unreachable() -# define ASM_REACHABLE #define __annotate_jump_table #endif diff --git a/include/linux/objtool.h b/include/linux/objtool.h index f797368820c8..586d35720f13 100644 --- a/include/linux/objtool.h +++ b/include/linux/objtool.h @@ -83,6 +83,12 @@ struct unwind_hint { _ASM_PTR " 986b\n\t" \ ".popsection\n\t" +#define ASM_REACHABLE \ + "998:\n\t" \ + ".pushsection .discard.reachable\n\t" \ + ".long 998b - .\n\t" \ + ".popsection\n\t" + #else /* __ASSEMBLY__ */ /* @@ -142,6 +148,13 @@ struct unwind_hint { .popsection .endm +.macro REACHABLE +.Lhere_\@: + .pushsection .discard.reachable + .long .Lhere_\@ - . + .popsection +.endm + #endif /* __ASSEMBLY__ */ #else /* !CONFIG_STACK_VALIDATION */ @@ -153,6 +166,7 @@ struct unwind_hint { #define STACK_FRAME_NON_STANDARD(func) #define STACK_FRAME_NON_STANDARD_FP(func) #define ANNOTATE_NOENDBR +#define ASM_REACHABLE #else #define ANNOTATE_INTRA_FUNCTION_CALL .macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0 @@ -161,6 +175,8 @@ struct unwind_hint { .endm .macro ANNOTATE_NOENDBR .endm +.macro REACHABLE +.endm #endif #endif /* CONFIG_STACK_VALIDATION */ diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h index f797368820c8..586d35720f13 100644 --- a/tools/include/linux/objtool.h +++ b/tools/include/linux/objtool.h @@ -83,6 +83,12 @@ struct unwind_hint { _ASM_PTR " 986b\n\t" \ ".popsection\n\t" +#define ASM_REACHABLE \ + "998:\n\t" \ + ".pushsection .discard.reachable\n\t" \ + ".long 998b - .\n\t" \ + ".popsection\n\t" + #else /* __ASSEMBLY__ */ /* @@ -142,6 +148,13 @@ struct unwind_hint { .popsection .endm +.macro REACHABLE +.Lhere_\@: + .pushsection .discard.reachable + .long .Lhere_\@ - . + .popsection +.endm + #endif /* __ASSEMBLY__ */ #else /* !CONFIG_STACK_VALIDATION */ @@ -153,6 +166,7 @@ struct unwind_hint { #define STACK_FRAME_NON_STANDARD(func) #define STACK_FRAME_NON_STANDARD_FP(func) #define ANNOTATE_NOENDBR +#define ASM_REACHABLE #else #define ANNOTATE_INTRA_FUNCTION_CALL .macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0 @@ -161,6 +175,8 @@ struct unwind_hint { .endm .macro ANNOTATE_NOENDBR .endm +.macro REACHABLE +.endm #endif #endif /* CONFIG_STACK_VALIDATION */ -- cgit From 03f16cd020eb8bb2eb837e2090086f296a9fa91d Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 18 Apr 2022 09:50:36 -0700 Subject: objtool: Add CONFIG_OBJTOOL Now that stack validation is an optional feature of objtool, add CONFIG_OBJTOOL and replace most usages of CONFIG_STACK_VALIDATION with it. CONFIG_STACK_VALIDATION can now be considered to be frame-pointer specific. CONFIG_UNWINDER_ORC is already inherently valid for live patching, so no need to "validate" it. Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Miroslav Benes Link: https://lkml.kernel.org/r/939bf3d85604b2a126412bf11af6e3bd3b872bcb.1650300597.git.jpoimboe@redhat.com --- Makefile | 2 +- arch/Kconfig | 8 ++++++-- arch/x86/Kconfig | 18 +++++++++++------- arch/x86/Kconfig.debug | 2 +- arch/x86/include/asm/jump_label.h | 6 +++--- arch/x86/kernel/alternative.c | 6 +++--- include/linux/compiler.h | 6 +++--- include/linux/instrumentation.h | 6 +++--- include/linux/objtool.h | 6 +++--- kernel/trace/Kconfig | 1 + lib/Kconfig.debug | 20 +++++++++++--------- lib/Kconfig.kcsan | 3 ++- lib/Kconfig.ubsan | 2 +- scripts/Makefile.build | 4 ++-- scripts/link-vmlinux.sh | 32 ++++++++++++++++++-------------- scripts/package/builddeb | 2 +- tools/include/linux/objtool.h | 6 +++--- 17 files changed, 73 insertions(+), 57 deletions(-) (limited to 'include/linux/objtool.h') diff --git a/Makefile b/Makefile index fa5112a0ec1b..250707647359 100644 --- a/Makefile +++ b/Makefile @@ -1302,7 +1302,7 @@ install: sub_make_done := # --------------------------------------------------------------------------- # Tools -ifdef CONFIG_STACK_VALIDATION +ifdef CONFIG_OBJTOOL prepare: tools/objtool endif diff --git a/arch/Kconfig b/arch/Kconfig index 29b0167c088b..04cdef16db24 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1028,11 +1028,14 @@ config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT depends on MMU select ARCH_HAS_ELF_RANDOMIZE +config HAVE_OBJTOOL + 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 @@ -1302,6 +1305,7 @@ config HAVE_STATIC_CALL config HAVE_STATIC_CALL_INLINE bool depends on HAVE_STATIC_CALL + select OBJTOOL config HAVE_PREEMPT_DYNAMIC bool diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 4bed3abf444d..43e26ee1611e 100644 --- a/arch/x86/Kconfig +++ b/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 @@ -231,6 +231,7 @@ config X86 select HAVE_MOVE_PMD select HAVE_MOVE_PUD select HAVE_NMI + select HAVE_OBJTOOL if X86_64 select HAVE_OPTPROBES select HAVE_PCSPKR_PLATFORM select HAVE_PERF_EVENTS @@ -239,17 +240,17 @@ 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 +269,6 @@ 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 +459,7 @@ 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 +473,7 @@ 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 @@ -1819,6 +1821,7 @@ config ARCH_RANDOM config X86_SMAP def_bool y prompt "Supervisor Mode Access Prevention" if EXPERT + select OBJTOOL if HAVE_OBJTOOL help Supervisor Mode Access Prevention (SMAP) is a security feature in newer Intel processors. There is a small @@ -1855,9 +1858,10 @@ 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 diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index d3a6f74a94bd..d872a7522e55 100644 --- a/arch/x86/Kconfig.debug +++ b/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 diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 0449b125d27f..3ce0e67c579c 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/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_OBJTOOL static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { @@ -34,7 +34,7 @@ l_yes: return true; } -#else +#else /* !CONFIG_OBJTOOL */ static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) { @@ -48,7 +48,7 @@ l_yes: return true; } -#endif /* STACK_VALIDATION */ +#endif /* CONFIG_OBJTOOL */ static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch) { diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index d374cb3cf024..3c66073e7645 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -338,7 +338,7 @@ next: } } -#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 diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 219aa5ddbc73..01ce94b58b42 100644 --- a/include/linux/compiler.h +++ b/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 { \ diff --git a/include/linux/instrumentation.h b/include/linux/instrumentation.h index 24359b4a9605..9111a3704072 100644 --- a/include/linux/instrumentation.h +++ b/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_VMLINUX_VALIDATION #include @@ -53,9 +53,9 @@ ".popsection\n\t" : : "i" (c)); \ }) #define instrumentation_end() __instrumentation_end(__COUNTER__) -#else +#else /* !CONFIG_VMLINUX_VALIDATION */ # define instrumentation_begin() do { } while(0) # define instrumentation_end() do { } while(0) -#endif +#endif /* CONFIG_VMLINUX_VALIDATION */ #endif /* __LINUX_INSTRUMENTATION_H */ diff --git a/include/linux/objtool.h b/include/linux/objtool.h index 586d35720f13..977d90ba642d 100644 --- a/include/linux/objtool.h +++ b/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 #ifndef __ASSEMBLY__ @@ -157,7 +157,7 @@ struct unwind_hint { #endif /* __ASSEMBLY__ */ -#else /* !CONFIG_STACK_VALIDATION */ +#else /* !CONFIG_OBJTOOL */ #ifndef __ASSEMBLY__ @@ -179,6 +179,6 @@ struct unwind_hint { .endm #endif -#endif /* CONFIG_STACK_VALIDATION */ +#endif /* CONFIG_OBJTOOL */ #endif /* _LINUX_OBJTOOL_H */ diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 2c43e327a619..2956bc277150 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -728,6 +728,7 @@ 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 diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 075cd25363ac..c0e4e47f3ce3 100644 --- a/lib/Kconfig.debug +++ b/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 bool - depends on STACK_VALIDATION && DEBUG_ENTRY + depends on HAVE_OBJTOOL && 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_OBJTOOL || \ GCC_VERSION >= 120000 || CLANG_VERSION >= 130000 select DEBUG_FS select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC + select OBJTOOL if HAVE_OBJTOOL help KCOV exposes kernel code coverage information in a form suitable for coverage-guided fuzzing (randomized testing). diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index de022445fbba..901c3b509aca 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -187,7 +187,8 @@ 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 HAVE_OBJTOOL || CC_IS_GCC || CLANG_VERSION >= 140000 + select OBJTOOL if HAVE_OBJTOOL help Enable support for modeling a subset of weak memory, which allows detecting a subset of data races due to missing memory barriers. diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index f3c57ed51838..c4fe15d38b60 100644 --- a/lib/Kconfig.ubsan +++ b/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 diff --git a/scripts/Makefile.build b/scripts/Makefile.build index d5e15ae29156..0f73e02b7cf1 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -222,7 +222,7 @@ 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 @@ -241,7 +241,7 @@ objtool_args = \ 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)$(CONFIG_X86_KERNEL_IBT),) diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 0140bfa32c0c..5101a7fbfaaf 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -108,8 +108,11 @@ objtool_link() local objtoolcmd; local objtoolopt; - if is_enabled CONFIG_STACK_VALIDATION && \ - ( is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT ); then + if ! is_enabled CONFIG_OBJTOOL; then + return; + fi + + if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then # Don't perform vmlinux validation unless explicitly requested, # but run objtool on vmlinux.o now that we have an object file. @@ -126,10 +129,23 @@ objtool_link() objtoolopt="${objtoolopt} --orc" fi + if is_enabled CONFIG_RETPOLINE; then + objtoolopt="${objtoolopt} --retpoline" + fi + + if is_enabled CONFIG_SLS; then + objtoolopt="${objtoolopt} --sls" + fi + if is_enabled CONFIG_STACK_VALIDATION; then objtoolopt="${objtoolopt} --stackval" fi + if is_enabled CONFIG_X86_SMAP; then + objtoolopt="${objtoolopt} --uaccess" + fi + + objtoolopt="${objtoolopt} --lto" fi @@ -139,18 +155,6 @@ objtool_link() if [ -n "${objtoolopt}" ]; then - if is_enabled CONFIG_RETPOLINE; then - objtoolopt="${objtoolopt} --retpoline" - fi - - if is_enabled CONFIG_SLS; then - objtoolopt="${objtoolopt} --sls" - fi - - if is_enabled CONFIG_X86_SMAP; then - objtoolopt="${objtoolopt} --uaccess" - fi - if ! is_enabled CONFIG_FRAME_POINTER; then objtoolopt="${objtoolopt} --no-fp" fi diff --git a/scripts/package/builddeb b/scripts/package/builddeb index 91a502bb97e8..67cd420dcf89 100755 --- a/scripts/package/builddeb +++ b/scripts/package/builddeb @@ -67,7 +67,7 @@ deploy_kernel_headers () { ) > debian/hdrsrcfiles { - if is_enabled CONFIG_STACK_VALIDATION; then + if is_enabled CONFIG_OBJTOOL; then echo tools/objtool/objtool fi diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h index 586d35720f13..977d90ba642d 100644 --- a/tools/include/linux/objtool.h +++ b/tools/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 #ifndef __ASSEMBLY__ @@ -157,7 +157,7 @@ struct unwind_hint { #endif /* __ASSEMBLY__ */ -#else /* !CONFIG_STACK_VALIDATION */ +#else /* !CONFIG_OBJTOOL */ #ifndef __ASSEMBLY__ @@ -179,6 +179,6 @@ struct unwind_hint { .endm #endif -#endif /* CONFIG_STACK_VALIDATION */ +#endif /* CONFIG_OBJTOOL */ #endif /* _LINUX_OBJTOOL_H */ -- cgit From e2ef115813c34ea5380ac5b4879f515070150210 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 6 May 2022 14:14:37 +0200 Subject: objtool: Fix STACK_FRAME_NON_STANDARD reloc type STACK_FRAME_NON_STANDARD results in inconsistent relocation types depending on .c or .S usage: Relocation section '.rela.discard.func_stack_frame_non_standard' at offset 0x3c01090 contains 5 entries: Offset Info Type Symbol's Value Symbol's Name + Addend 0000000000000000 00020c2200000002 R_X86_64_PC32 0000000000047b40 do_suspend_lowlevel + 0 0000000000000008 0002461e00000001 R_X86_64_64 00000000000480a0 machine_real_restart + 0 0000000000000010 0000001400000001 R_X86_64_64 0000000000000000 .rodata + b3d4 0000000000000018 0002444600000002 R_X86_64_PC32 00000000000678a0 __efi64_thunk + 0 0000000000000020 0002659d00000001 R_X86_64_64 0000000000113160 __crash_kexec + 0 Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20220506121631.508692613@infradead.org --- include/linux/objtool.h | 4 +++- tools/include/linux/objtool.h | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) (limited to 'include/linux/objtool.h') diff --git a/include/linux/objtool.h b/include/linux/objtool.h index 586d35720f13..b9c1474a571e 100644 --- a/include/linux/objtool.h +++ b/include/linux/objtool.h @@ -40,6 +40,8 @@ struct unwind_hint { #ifdef CONFIG_STACK_VALIDATION +#include + #ifndef __ASSEMBLY__ #define UNWIND_HINT(sp_reg, sp_offset, type, end) \ @@ -137,7 +139,7 @@ struct unwind_hint { .macro STACK_FRAME_NON_STANDARD func:req .pushsection .discard.func_stack_frame_non_standard, "aw" - .long \func - . + _ASM_PTR \func .popsection .endm diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h index 586d35720f13..b9c1474a571e 100644 --- a/tools/include/linux/objtool.h +++ b/tools/include/linux/objtool.h @@ -40,6 +40,8 @@ struct unwind_hint { #ifdef CONFIG_STACK_VALIDATION +#include + #ifndef __ASSEMBLY__ #define UNWIND_HINT(sp_reg, sp_offset, type, end) \ @@ -137,7 +139,7 @@ struct unwind_hint { .macro STACK_FRAME_NON_STANDARD func:req .pushsection .discard.func_stack_frame_non_standard, "aw" - .long \func - . + _ASM_PTR \func .popsection .endm -- cgit From 7b6c7a877cc616bc7dc9cd39646fe454acbed48b Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Fri, 3 Jun 2022 08:04:44 -0700 Subject: x86/ftrace: Remove OBJECT_FILES_NON_STANDARD usage The file-wide OBJECT_FILES_NON_STANDARD annotation is used with CONFIG_FRAME_POINTER to tell objtool to skip the entire file when frame pointers are enabled. However that annotation is now deprecated because it doesn't work with IBT, where objtool runs on vmlinux.o instead of individual translation units. Instead, use more fine-grained function-specific annotations: - The 'save_mcount_regs' macro does funny things with the frame pointer. Use STACK_FRAME_NON_STANDARD_FP to tell objtool to ignore the functions using it. - The return_to_handler() "function" isn't actually a callable function. Instead of being called, it's returned to. The real return address isn't on the stack, so unwinding is already doomed no matter which unwinder is used. So just remove the STT_FUNC annotation, telling objtool to ignore it. That also removes the implicit ANNOTATE_NOENDBR, which now needs to be made explicit. Fixes the following warning: vmlinux.o: warning: objtool: __fentry__+0x16: return with modified stack frame Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls") Reported-by: kernel test robot Signed-off-by: Josh Poimboeuf Link: https://lore.kernel.org/r/b7a7a42fe306aca37826043dac89e113a1acdbac.1654268610.git.jpoimboe@kernel.org --- arch/x86/kernel/Makefile | 4 ---- arch/x86/kernel/ftrace_64.S | 11 ++++++++--- include/linux/objtool.h | 6 ++++++ tools/include/linux/objtool.h | 6 ++++++ 4 files changed, 20 insertions(+), 7 deletions(-) (limited to 'include/linux/objtool.h') diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 03364dc40d8d..4c8b6ae802ac 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -36,10 +36,6 @@ KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD_test_nx.o := y -ifdef CONFIG_FRAME_POINTER -OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o := y -endif - # If instrumentation of this dir is enabled, boot hangs during first second. # Probably could be more selective here, but note that files related to irqs, # boot, dumpstack/stacktrace, etc are either non-interesting or can lead to diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index 4ec13608d3c6..dfeb227de561 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -175,6 +175,7 @@ SYM_INNER_LABEL(ftrace_caller_end, SYM_L_GLOBAL) jmp ftrace_epilogue SYM_FUNC_END(ftrace_caller); +STACK_FRAME_NON_STANDARD_FP(ftrace_caller) SYM_FUNC_START(ftrace_epilogue) /* @@ -282,6 +283,7 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) jmp ftrace_epilogue SYM_FUNC_END(ftrace_regs_caller) +STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller) #else /* ! CONFIG_DYNAMIC_FTRACE */ @@ -311,10 +313,14 @@ trace: jmp ftrace_stub SYM_FUNC_END(__fentry__) EXPORT_SYMBOL(__fentry__) +STACK_FRAME_NON_STANDARD_FP(__fentry__) + #endif /* CONFIG_DYNAMIC_FTRACE */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER -SYM_FUNC_START(return_to_handler) +SYM_CODE_START(return_to_handler) + UNWIND_HINT_EMPTY + ANNOTATE_NOENDBR subq $16, %rsp /* Save the return values */ @@ -339,7 +345,6 @@ SYM_FUNC_START(return_to_handler) int3 .Ldo_rop: mov %rdi, (%rsp) - UNWIND_HINT_FUNC RET -SYM_FUNC_END(return_to_handler) +SYM_CODE_END(return_to_handler) #endif diff --git a/include/linux/objtool.h b/include/linux/objtool.h index 6491fa8fba6d..15b940ec1eac 100644 --- a/include/linux/objtool.h +++ b/include/linux/objtool.h @@ -143,6 +143,12 @@ struct unwind_hint { .popsection .endm +.macro STACK_FRAME_NON_STANDARD_FP func:req +#ifdef CONFIG_FRAME_POINTER + STACK_FRAME_NON_STANDARD \func +#endif +.endm + .macro ANNOTATE_NOENDBR .Lhere_\@: .pushsection .discard.noendbr diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h index 6491fa8fba6d..15b940ec1eac 100644 --- a/tools/include/linux/objtool.h +++ b/tools/include/linux/objtool.h @@ -143,6 +143,12 @@ struct unwind_hint { .popsection .endm +.macro STACK_FRAME_NON_STANDARD_FP func:req +#ifdef CONFIG_FRAME_POINTER + STACK_FRAME_NON_STANDARD \func +#endif +.endm + .macro ANNOTATE_NOENDBR .Lhere_\@: .pushsection .discard.noendbr -- cgit