arch/x86/purgatory/Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 OBJECT_FILES_NON_STANDARD := y
   3
   4 purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string.o
   5
   6 targets += $(purgatory-y)
   7 PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
   8
   9 $(obj)/string.o: $(srctree)/arch/x86/boot/compressed/string.c FORCE
  10         $(call if_changed_rule,cc_o_c)
  11
  12 $(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE
  13         $(call if_changed_rule,cc_o_c)
  14
  15 CFLAGS_sha256.o := -D__DISABLE_EXPORTS -D__NO_FORTIFY
  16
  17 # When profile-guided optimization is enabled, llvm emits two different
  18 # overlapping text sections, which is not supported by kexec. Remove profile
  19 # optimization flags.
  20 KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%,$(KBUILD_CFLAGS))
  21
  22 # When LTO is enabled, llvm emits many text sections, which is not supported
  23 # by kexec. Remove -flto=* flags.
  24 KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS))
  25
  26 # When linking purgatory.ro with -r unresolved symbols are not checked,
  27 # also link a purgatory.chk binary without -r to check for unresolved symbols.
  28 PURGATORY_LDFLAGS := -e purgatory_start -z nodefaultlib
  29 LDFLAGS_purgatory.ro := -r $(PURGATORY_LDFLAGS)
  30 LDFLAGS_purgatory.chk := $(PURGATORY_LDFLAGS)
  31 targets += purgatory.ro purgatory.chk
  32
  33 # Sanitizer, etc. runtimes are unavailable and cannot be linked here.
  34 GCOV_PROFILE    := n
  35 KASAN_SANITIZE  := n
  36 UBSAN_SANITIZE  := n
  37 KCSAN_SANITIZE  := n
  38 KMSAN_SANITIZE  := n
  39 KCOV_INSTRUMENT := n
  40
  41 # These are adjustments to the compiler flags used for objects that
  42 # make up the standalone purgatory.ro
  43
  44 PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel
  45 PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss -g0
  46 PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING
  47 PURGATORY_CFLAGS += -fno-stack-protector
  48
  49 # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
  50 # in turn leaves some undefined symbols like __fentry__ in purgatory and not
  51 # sure how to relocate those.
  52 ifdef CONFIG_FUNCTION_TRACER
  53 PURGATORY_CFLAGS_REMOVE         += $(CC_FLAGS_FTRACE)
  54 endif
  55
  56 ifdef CONFIG_STACKPROTECTOR
  57 PURGATORY_CFLAGS_REMOVE         += -fstack-protector
  58 endif
  59
  60 ifdef CONFIG_STACKPROTECTOR_STRONG
  61 PURGATORY_CFLAGS_REMOVE         += -fstack-protector-strong
  62 endif
  63
  64 ifdef CONFIG_RETPOLINE
  65 PURGATORY_CFLAGS_REMOVE         += $(RETPOLINE_CFLAGS)
  66 endif
  67
  68 ifdef CONFIG_CFI_CLANG
  69 PURGATORY_CFLAGS_REMOVE         += $(CC_FLAGS_CFI)
  70 endif
  71
  72 CFLAGS_REMOVE_purgatory.o       += $(PURGATORY_CFLAGS_REMOVE)
  73 CFLAGS_purgatory.o              += $(PURGATORY_CFLAGS)
  74
  75 CFLAGS_REMOVE_sha256.o          += $(PURGATORY_CFLAGS_REMOVE)
  76 CFLAGS_sha256.o                 += $(PURGATORY_CFLAGS)
  77
  78 CFLAGS_REMOVE_string.o          += $(PURGATORY_CFLAGS_REMOVE)
  79 CFLAGS_string.o                 += $(PURGATORY_CFLAGS)
  80
  81 asflags-remove-y                += $(foreach x, -g -gdwarf-4 -gdwarf-5, $(x) -Wa,$(x))
  82
  83 $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
  84                 $(call if_changed,ld)
  85
  86 $(obj)/purgatory.chk: $(obj)/purgatory.ro FORCE
  87                 $(call if_changed,ld)
  88
  89 $(obj)/kexec-purgatory.o: $(obj)/purgatory.ro $(obj)/purgatory.chk
  90
  91 obj-y += kexec-purgatory.o