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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/firmware/efi/libstub/Makefile
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/libstub/Makefile')
-rw-r--r--drivers/firmware/efi/libstub/Makefile103
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
new file mode 100644
index 000000000..d3777d754
--- /dev/null
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# The stub may be linked into the kernel proper or into a separate boot binary,
+# but in either case, it executes before the kernel does (with MMU disabled) so
+# things like ftrace and stack-protector are likely to cause trouble if left
+# enabled, even if doing so doesn't break the build.
+#
+cflags-$(CONFIG_X86_32) := -march=i386
+cflags-$(CONFIG_X86_64) := -mcmodel=small
+cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \
+ -fPIC -fno-strict-aliasing -mno-red-zone \
+ -mno-mmx -mno-sse -fshort-wchar \
+ -Wno-pointer-sign \
+ $(call cc-disable-warning, address-of-packed-member) \
+ $(call cc-disable-warning, gnu)
+
+# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
+# disable the stackleak plugin
+cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie \
+ $(DISABLE_STACKLEAK_PLUGIN)
+cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \
+ -fno-builtin -fpic \
+ $(call cc-option,-mno-single-pic-base)
+
+cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt
+
+KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
+ -D__NO_FORTIFY \
+ $(call cc-option,-ffreestanding) \
+ $(call cc-option,-fno-stack-protector) \
+ $(call cc-option,-fno-addrsig) \
+ -D__DISABLE_EXPORTS
+
+GCOV_PROFILE := n
+KASAN_SANITIZE := n
+UBSAN_SANITIZE := n
+OBJECT_FILES_NON_STANDARD := y
+
+# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
+KCOV_INSTRUMENT := n
+
+lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o
+
+# include the stub's generic dependencies from lib/ when building for ARM/arm64
+arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
+arm-deps-$(CONFIG_ARM64) += sort.c
+
+$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
+ $(call if_changed_rule,cc_o_c)
+
+lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o random.o \
+ $(patsubst %.c,lib-%.o,$(arm-deps-y))
+
+lib-$(CONFIG_ARM) += arm32-stub.o
+lib-$(CONFIG_ARM64) += arm64-stub.o
+CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
+
+#
+# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
+# code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
+# So let's apply the __init annotations at the section level, by prefixing
+# the section names directly. This will ensure that even all the inline string
+# literals are covered.
+# The fact that the stub and the kernel proper are essentially the same binary
+# also means that we need to be extra careful to make sure that the stub does
+# not rely on any absolute symbol references, considering that the virtual
+# kernel mapping that the linker uses is not active yet when the stub is
+# executing. So build all C dependencies of the EFI stub into libstub, and do
+# a verification pass to see if any absolute relocations exist in any of the
+# object files.
+#
+extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y)
+lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y))
+
+STUBCOPY_RM-y := -R *ksymtab* -R *kcrctab*
+STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \
+ --prefix-symbols=__efistub_
+STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS
+
+$(obj)/%.stub.o: $(obj)/%.o FORCE
+ $(call if_changed,stubcopy)
+
+#
+# Strip debug sections and some other sections that may legally contain
+# absolute relocations, so that we can inspect the remaining sections for
+# such relocations. If none are found, regenerate the output object, but
+# this time, use objcopy and leave all sections in place.
+#
+quiet_cmd_stubcopy = STUBCPY $@
+ cmd_stubcopy = if $(STRIP) --strip-debug $(STUBCOPY_RM-y) -o $@ $<; \
+ then if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); \
+ then (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \
+ rm -f $@; /bin/false); \
+ else $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; fi \
+ else /bin/false; fi
+
+#
+# ARM discards the .data section because it disallows r/w data in the
+# decompressor. So move our .data to .data.efistub, which is preserved
+# explicitly by the decompressor linker script.
+#
+STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub
+STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS