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Commit | Line | Data |
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b2441318 | 1 | # SPDX-License-Identifier: GPL-2.0 |
f4f75ad5 AB |
2 | # |
3 | # The stub may be linked into the kernel proper or into a separate boot binary, | |
4 | # but in either case, it executes before the kernel does (with MMU disabled) so | |
5 | # things like ftrace and stack-protector are likely to cause trouble if left | |
6 | # enabled, even if doing so doesn't break the build. | |
7 | # | |
8 | cflags-$(CONFIG_X86_32) := -march=i386 | |
9 | cflags-$(CONFIG_X86_64) := -mcmodel=small | |
846221cf | 10 | cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \ |
f4f75ad5 | 11 | -fPIC -fno-strict-aliasing -mno-red-zone \ |
3db5e0ba NC |
12 | -mno-mmx -mno-sse -fshort-wchar \ |
13 | -Wno-pointer-sign \ | |
14 | $(call cc-disable-warning, address-of-packed-member) \ | |
15 | $(call cc-disable-warning, gnu) | |
f4f75ad5 | 16 | |
ce279d37 LA |
17 | # arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly |
18 | # disable the stackleak plugin | |
19 | cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie \ | |
20 | $(DISABLE_STACKLEAK_PLUGIN) | |
696204fa | 21 | cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \ |
41f1c484 AS |
22 | -fno-builtin -fpic \ |
23 | $(call cc-option,-mno-single-pic-base) | |
f4f75ad5 | 24 | |
e8f3010f AB |
25 | cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt |
26 | ||
b523e185 | 27 | KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ |
3e2c044a | 28 | -D__NO_FORTIFY \ |
f4f75ad5 | 29 | $(call cc-option,-ffreestanding) \ |
0b3e3366 | 30 | $(call cc-option,-fno-stack-protector) \ |
f922c4ab | 31 | -D__DISABLE_EXPORTS |
f4f75ad5 AB |
32 | |
33 | GCOV_PROFILE := n | |
0b24becc | 34 | KASAN_SANITIZE := n |
c6d30853 | 35 | UBSAN_SANITIZE := n |
c0dd6716 | 36 | OBJECT_FILES_NON_STANDARD := y |
f4f75ad5 | 37 | |
5c9a8750 DV |
38 | # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. |
39 | KCOV_INSTRUMENT := n | |
40 | ||
33b6d034 | 41 | lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o |
e8f3010f AB |
42 | |
43 | # include the stub's generic dependencies from lib/ when building for ARM/arm64 | |
29f9007b AB |
44 | arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c |
45 | arm-deps-$(CONFIG_ARM64) += sort.c | |
e8f3010f AB |
46 | |
47 | $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE | |
48 | $(call if_changed_rule,cc_o_c) | |
49 | ||
a6a14469 | 50 | lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o random.o \ |
29f9007b | 51 | $(patsubst %.c,lib-%.o,$(arm-deps-y)) |
f4f75ad5 | 52 | |
81a0bc39 | 53 | lib-$(CONFIG_ARM) += arm32-stub.o |
a6a14469 | 54 | lib-$(CONFIG_ARM64) += arm64-stub.o |
bf457786 AB |
55 | CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) |
56 | ||
ddeeefe2 AB |
57 | # |
58 | # arm64 puts the stub in the kernel proper, which will unnecessarily retain all | |
59 | # code indefinitely unless it is annotated as __init/__initdata/__initconst etc. | |
60 | # So let's apply the __init annotations at the section level, by prefixing | |
61 | # the section names directly. This will ensure that even all the inline string | |
62 | # literals are covered. | |
e8f3010f AB |
63 | # The fact that the stub and the kernel proper are essentially the same binary |
64 | # also means that we need to be extra careful to make sure that the stub does | |
65 | # not rely on any absolute symbol references, considering that the virtual | |
66 | # kernel mapping that the linker uses is not active yet when the stub is | |
67 | # executing. So build all C dependencies of the EFI stub into libstub, and do | |
68 | # a verification pass to see if any absolute relocations exist in any of the | |
69 | # object files. | |
ddeeefe2 | 70 | # |
e8f3010f AB |
71 | extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y) |
72 | lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y)) | |
73 | ||
696204fa | 74 | STUBCOPY_RM-y := -R *ksymtab* -R *kcrctab* |
e8f3010f AB |
75 | STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ |
76 | --prefix-symbols=__efistub_ | |
77 | STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS | |
78 | ||
79 | $(obj)/%.stub.o: $(obj)/%.o FORCE | |
80 | $(call if_changed,stubcopy) | |
ddeeefe2 | 81 | |
696204fa AB |
82 | # |
83 | # Strip debug sections and some other sections that may legally contain | |
84 | # absolute relocations, so that we can inspect the remaining sections for | |
85 | # such relocations. If none are found, regenerate the output object, but | |
86 | # this time, use objcopy and leave all sections in place. | |
87 | # | |
e8f3010f | 88 | quiet_cmd_stubcopy = STUBCPY $@ |
696204fa AB |
89 | cmd_stubcopy = if $(STRIP) --strip-debug $(STUBCOPY_RM-y) -o $@ $<; \ |
90 | then if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); \ | |
91 | then (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \ | |
92 | rm -f $@; /bin/false); \ | |
93 | else $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; fi \ | |
94 | else /bin/false; fi | |
81a0bc39 RF |
95 | |
96 | # | |
97 | # ARM discards the .data section because it disallows r/w data in the | |
98 | # decompressor. So move our .data to .data.efistub, which is preserved | |
99 | # explicitly by the decompressor linker script. | |
100 | # | |
696204fa | 101 | STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub |
81a0bc39 | 102 | STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS |