Commit 22c8542d authored by Sami Tolvanen's avatar Sami Tolvanen Committed by Kees Cook
Browse files

tracing: add support for objtool mcount 



This change adds build support for using objtool to generate
__mcount_loc sections.

Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
parent 0e731dbc

Makefile

+7 −0
Original line number Diff line number Diff line
@@ -860,6 +860,9 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_CC 
    endif

  endif

endif

ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL

  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT

endif

ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT

  ifdef CONFIG_HAVE_C_RECORDMCOUNT

    BUILD_C_RECORDMCOUNT := y
@@ -1236,6 +1239,10 @@ uapi-asm-generic: 
PHONY += prepare-objtool prepare-resolve_btfids

prepare-objtool: $(objtool_target)

ifeq ($(SKIP_STACK_VALIDATION),1)

ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL

	@echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2

	@false

endif

ifdef CONFIG_UNWINDER_ORC

	@echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2

	@false

kernel/trace/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -60,6 +60,11 @@ config HAVE_NOP_MCOUNT 
	help

	  Arch supports the gcc options -pg with -mrecord-mcount and -nop-mcount



config HAVE_OBJTOOL_MCOUNT

	bool

	help

	  Arch supports objtool --mcount



config HAVE_C_RECORDMCOUNT

	bool

	help
@@ -612,10 +617,18 @@ config FTRACE_MCOUNT_USE_CC 
	depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY

	depends on FTRACE_MCOUNT_RECORD



config FTRACE_MCOUNT_USE_OBJTOOL

	def_bool y

	depends on HAVE_OBJTOOL_MCOUNT

	depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY

	depends on !FTRACE_MCOUNT_USE_CC

	depends on FTRACE_MCOUNT_RECORD



config FTRACE_MCOUNT_USE_RECORDMCOUNT

	def_bool y

	depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY

	depends on !FTRACE_MCOUNT_USE_CC

	depends on !FTRACE_MCOUNT_USE_OBJTOOL

	depends on FTRACE_MCOUNT_RECORD



config TRACING_MAP

scripts/Makefile.build

+3 −0
Original line number Diff line number Diff line
@@ -238,6 +238,9 @@ endif 
ifdef CONFIG_X86_SMAP

  objtool_args += --uaccess

endif

ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL

  objtool_args += --mcount

endif



# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory

# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file