Files
wolfssl/linuxkm/Kbuild

53 lines
2.0 KiB
Plaintext
Raw Normal View History

# libwolfssl Kbuild
SHELL=/bin/bash
ifeq "$(WOLFSSL_OBJ_FILES)" ""
$(error $$WOLFSSL_OBJ_FILES is unset.)
endif
ifeq "$(WOLFSSL_CFLAGS)" ""
$(error $$WOLFSSL_CFLAGS is unset.)
endif
obj-m := libwolfssl.o
WOLFSSL_OBJ_TARGETS=$(patsubst %, $(obj)/%, $(WOLFSSL_OBJ_FILES))
$(obj)/linuxkm/module_exports.o: $(WOLFSSL_OBJ_TARGETS)
# this mechanism only works in kernel 5.x+ (fallback to hardcoded value)
hostprogs := linuxkm/get_thread_size
always-y := $(hostprogs)
HOST_EXTRACFLAGS += $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(KBUILD_CFLAGS) -static
# this rule is needed to get build to succeed in 4.x (get_thread_size still doesn't get built)
$(obj)/linuxkm/get_thread_size: $(src)/linuxkm/get_thread_size.c
$(WOLFSSL_OBJ_TARGETS): | $(obj)/linuxkm/get_thread_size
KERNEL_THREAD_STACK_SIZE=$(shell test -x $(obj)/linuxkm/get_thread_size && $(obj)/linuxkm/get_thread_size || echo 16384)
MAX_STACK_FRAME_SIZE=$(shell echo $$(( $(KERNEL_THREAD_STACK_SIZE) / 4)))
libwolfssl-y := $(WOLFSSL_OBJ_FILES) linuxkm/module_hooks.o linuxkm/module_exports.o
ccflags-y = $(WOLFSSL_CFLAGS) -Wframe-larger-than=$(MAX_STACK_FRAME_SIZE) -mpreferred-stack-boundary=4
%/libwolfssl.mod.o: ccflags-y :=
%/test.o: ccflags-y += -DNO_MAIN_DRIVER
asflags-y := $(WOLFSSL_ASFLAGS)
# these two _asms are kernel-compatible (they don't reference the pic-related _GLOBAL_OFFSET_TABLE_)
# but they still irritate objtool: "unannotated intra-function call" and "BP used as a scratch register"
%/aes_asm.o: OBJECT_FILES_NON_STANDARD := y
%/aes_gcm_asm.o: OBJECT_FILES_NON_STANDARD := y
# auto-generate the exported symbol list, leveraging the WOLFSSL_API visibility tags.
# exclude symbols that don't match wc_* or wolf*.
$(src)/linuxkm/module_exports.c: $(src)/linuxkm/module_exports.c.template $(WOLFSSL_OBJ_TARGETS)
@cp $< $@
@readelf --symbols --wide $(WOLFSSL_OBJ_TARGETS) | awk '/^ *[0-9]+: /{if ($$8 !~ /^(wc_|wolf)/){next;} if (($$4 == "FUNC") && ($$5 == "GLOBAL") && ($$6 == "DEFAULT")) { print "EXPORT_SYMBOL(" $$8 ");"; }}' >> $@
@echo 'EXPORT_SYMBOL(wolfcrypt_test);' >> $@
clean-files := module_exports.c