aboutsummaryrefslogtreecommitdiff
path: root/scripts/Makefile.modpost
blob: 066beffca09af0d753ba8ba976ec047a68f9dd85 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
# SPDX-License-Identifier: GPL-2.0
# ===========================================================================
# Module versions
# ===========================================================================
#
# Stage one of module building created the following:
# a) The individual .o files used for the module
# b) A <module>.o file which is the .o files above linked together
# c) A <module>.mod file, listing the name of the preliminary <module>.o file,
#    plus all .o files
# d) modules.order, which lists all the modules

# Stage 2 is handled by this file and does the following
# 1) Find all modules listed in modules.order
# 2) modpost is then used to
# 3)  create one <module>.mod.c file pr. module
# 4)  create one Module.symvers file with CRC for all exported symbols

# Step 3 is used to place certain information in the module's ELF
# section, including information such as:
#   Version magic (see include/linux/vermagic.h for full details)
#     - Kernel release
#     - SMP is CONFIG_SMP
#     - PREEMPT is CONFIG_PREEMPT[_RT]
#     - GCC Version
#   Module info
#     - Module version (MODULE_VERSION)
#     - Module alias'es (MODULE_ALIAS)
#     - Module license (MODULE_LICENSE)
#     - See include/linux/module.h for more details

# Step 4 is solely used to allow module versioning in external modules,
# where the CRC of each module is retrieved from the Module.symvers file.

# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
# symbols in the final module linking stage
# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
# This is solely useful to speed up test compiles

PHONY := __modpost
__modpost:

include include/config/auto.conf
include scripts/Kbuild.include

# for ld_flags
include scripts/Makefile.lib

MODPOST = scripts/mod/modpost								\
	$(if $(CONFIG_MODVERSIONS),-m)							\
	$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a)					\
	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)					\
	$(if $(KBUILD_MODPOST_WARN),-w) \
	-o $@

ifdef MODPOST_VMLINUX

quiet_cmd_modpost = MODPOST $@
      cmd_modpost = $(MODPOST) $<

vmlinux.symvers: vmlinux.o
	$(call cmd,modpost)

__modpost: vmlinux.symvers

else

ifeq ($(KBUILD_EXTMOD),)

input-symdump := vmlinux.symvers
output-symdump := Module.symvers

else

# set src + obj - they may be used in the modules's Makefile
obj := $(KBUILD_EXTMOD)
src := $(obj)

# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
             $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)

# modpost option for external modules
MODPOST += -e

input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS)
output-symdump := $(KBUILD_EXTMOD)/Module.symvers

endif

# modpost options for modules (both in-kernel and external)
MODPOST += \
	$(addprefix -i ,$(wildcard $(input-symdump))) \
	$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
	$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N)

# 'make -i -k' ignores compile errors, and builds as many modules as possible.
ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
MODPOST += -n
endif

# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree).
VPATH :=
$(input-symdump):
	@echo >&2 'WARNING: Symbol version dump "$@" is missing.'
	@echo >&2 '         Modules may not have dependencies or modversions.'

ifdef CONFIG_LTO_CLANG
# With CONFIG_LTO_CLANG, .o files might be LLVM bitcode, so we need to run
# LTO to compile them into native code before running modpost
prelink-ext := .lto

quiet_cmd_cc_lto_link_modules = LTO [M] $@
cmd_cc_lto_link_modules =						\
	$(LD) $(ld_flags) -r -o $@					\
		$(shell [ -s $(@:.lto.o=.o.symversions) ] &&		\
			echo -T $(@:.lto.o=.o.symversions))		\
		--whole-archive $^

%.lto.o: %.o
	$(call if_changed,cc_lto_link_modules)
endif

modules := $(sort $(shell cat $(MODORDER)))

# Read out modules.order to pass in modpost.
# Otherwise, allmodconfig would fail with "Argument list too long".
quiet_cmd_modpost = MODPOST $@
      cmd_modpost = sed 's/\.ko$$/$(prelink-ext)\.o/' $< | $(MODPOST) -T -

$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(prelink-ext).o) FORCE
	$(call if_changed,modpost)

targets += $(output-symdump)

__modpost: $(output-symdump)
ifneq ($(KBUILD_MODPOST_NOFINAL),1)
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
endif

PHONY += FORCE
FORCE:

existing-targets := $(wildcard $(sort $(targets)))

-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)

endif

.PHONY: $(PHONY)