Commit 3b15cdc1 authored by Sami Tolvanen's avatar Sami Tolvanen Committed by Kees Cook
Browse files

tracing: move function tracer options to Kconfig 



Move function tracer options to Kconfig to make it easier to add
new methods for generating __mcount_loc, and to make the options
available also when building kernel modules.

Note that FTRACE_MCOUNT_USE_* options are updated on rebuild and
therefore, work even if the .config was generated in a different
environment.

Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
Acked-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-2-samitolvanen@google.com
parent e71ba945

Makefile

+8 −12
Original line number Diff line number Diff line
@@ -851,12 +851,8 @@ KBUILD_CFLAGS += $(DEBUG_CFLAGS) 
export DEBUG_CFLAGS



ifdef CONFIG_FUNCTION_TRACER

ifdef CONFIG_FTRACE_MCOUNT_RECORD

  # gcc 5 supports generating the mcount tables directly

  ifeq ($(call cc-option-yn,-mrecord-mcount),y)

ifdef CONFIG_FTRACE_MCOUNT_USE_CC

  CC_FLAGS_FTRACE	+= -mrecord-mcount

    export CC_USING_RECORD_MCOUNT := 1

  endif

  ifdef CONFIG_HAVE_NOP_MCOUNT

    ifeq ($(call cc-option-yn, -mnop-mcount),y)

      CC_FLAGS_FTRACE	+= -mnop-mcount
@@ -864,6 +860,12 @@ ifdef CONFIG_FTRACE_MCOUNT_RECORD 
    endif

  endif

endif

ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT

  ifdef CONFIG_HAVE_C_RECORDMCOUNT

    BUILD_C_RECORDMCOUNT := y

    export BUILD_C_RECORDMCOUNT

  endif

endif

ifdef CONFIG_HAVE_FENTRY

  ifeq ($(call cc-option-yn, -mfentry),y)

    CC_FLAGS_FTRACE	+= -mfentry
@@ -873,12 +875,6 @@ endif 
export CC_FLAGS_FTRACE

KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)

KBUILD_AFLAGS	+= $(CC_FLAGS_USING)

ifdef CONFIG_DYNAMIC_FTRACE

	ifdef CONFIG_HAVE_C_RECORDMCOUNT

		BUILD_C_RECORDMCOUNT := y

		export BUILD_C_RECORDMCOUNT

	endif

endif

endif



# We trigger additional mismatches with less inlining

kernel/trace/Kconfig

+16 −0
Original line number Diff line number Diff line
@@ -602,6 +602,22 @@ config FTRACE_MCOUNT_RECORD 
	depends on DYNAMIC_FTRACE

	depends on HAVE_FTRACE_MCOUNT_RECORD



config FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY

	bool

	depends on FTRACE_MCOUNT_RECORD



config FTRACE_MCOUNT_USE_CC

	def_bool y

	depends on $(cc-option,-mrecord-mcount)

	depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY

	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_RECORD



config TRACING_MAP

	bool

	depends on ARCH_HAVE_NMI_SAFE_CMPXCHG

scripts/Makefile.build

+2 −4
Original line number Diff line number Diff line
@@ -178,8 +178,7 @@ cmd_modversions_c = \ 
	fi

endif



ifdef CONFIG_FTRACE_MCOUNT_RECORD

ifndef CC_USING_RECORD_MCOUNT

ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT

# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl

ifdef BUILD_C_RECORDMCOUNT

ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
@@ -206,8 +205,7 @@ recordmcount_source := $(srctree)/scripts/recordmcount.pl 
endif # BUILD_C_RECORDMCOUNT

cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),	\

	$(sub_cmd_record_mcount))

endif # CC_USING_RECORD_MCOUNT

endif # CONFIG_FTRACE_MCOUNT_RECORD

endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT



ifdef CONFIG_STACK_VALIDATION

ifneq ($(SKIP_STACK_VALIDATION),1)