summaryrefslogtreecommitdiffstats
path: root/scripts/Makefile.modpost
blob: 44936ebad161e914cbcc40ac74a2d651596d7b07 (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
151
152
153
154
155
# 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 per 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.

PHONY := __modpost
__modpost:

include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include

MODPOST = scripts/mod/modpost

modpost-args =										\
	$(if $(CONFIG_MODULES),-M)							\
	$(if $(CONFIG_MODVERSIONS),-m)							\
	$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a)					\
	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)					\
	$(if $(KBUILD_MODPOST_WARN),-w)							\
	$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS))					\
	$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N)	\
	$(if $(findstring 1, $(KBUILD_EXTRA_WARN)),-W)					\
	-o $@

modpost-deps := $(MODPOST)

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

# Read out modules.order to pass in modpost.
# Otherwise, allmodconfig would fail with "Argument list too long".
ifdef KBUILD_MODULES
modpost-args += -T $(MODORDER)
modpost-deps += $(MODORDER)
endif

ifeq ($(KBUILD_EXTMOD),)

# Generate the list of in-tree objects in vmlinux
# ---------------------------------------------------------------------------

# This is used to retrieve symbol versions generated by genksyms.
ifdef CONFIG_MODVERSIONS
vmlinux.symvers Module.symvers: .vmlinux.objs
endif

# Ignore libgcc.a
# Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a
# from the toolchain, but there is no EXPORT_SYMBOL in it.

quiet_cmd_vmlinux_objs = GEN     $@
      cmd_vmlinux_objs =		\
	for f in $(real-prereqs); do	\
		case $${f} in		\
		*libgcc.a) ;;		\
		*) $(AR) t $${f} ;;	\
		esac			\
	done > $@

targets += .vmlinux.objs
.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
	$(call if_changed,vmlinux_objs)

ifdef CONFIG_TRIM_UNUSED_KSYMS
ksym-wl := $(CONFIG_UNUSED_KSYMS_WHITELIST)
ksym-wl := $(if $(filter-out /%, $(ksym-wl)),$(if $(wildcard $(ksym-wl)),,$(srctree)/))$(ksym-wl)
modpost-args += -t $(addprefix -u , $(ksym-wl))
modpost-deps += $(ksym-wl)
endif

ifeq ($(wildcard vmlinux.o),)
missing-input := vmlinux.o
output-symdump := modules-only.symvers
else
modpost-args += vmlinux.o
modpost-deps += vmlinux.o
output-symdump := $(if $(KBUILD_MODULES), Module.symvers, vmlinux.symvers)
endif

else

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

# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
include $(kbuild-file)

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

ifeq ($(wildcard Module.symvers),)
missing-input := Module.symvers
else
modpost-args += -i Module.symvers
modpost-deps += Module.symvers
endif

modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS))

endif # ($(KBUILD_EXTMOD),)

quiet_cmd_modpost = MODPOST $@
      cmd_modpost = \
	$(if $(missing-input), \
		echo >&2 "WARNING: $(missing-input) is missing."; \
		echo >&2 "         Modules may not have dependencies or modversions."; \
		echo >&2 "         You may get many unresolved symbol errors."; \
		echo >&2 "         You can set KBUILD_MODPOST_WARN=1 to turn errors into warning"; \
		echo >&2 "         if you want to proceed at your own risk.";) \
	$(MODPOST) $(modpost-args)

targets += $(output-symdump)
$(output-symdump): $(modpost-deps) FORCE
	$(call if_changed,modpost)

__modpost: $(output-symdump)
PHONY += FORCE
FORCE:

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

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

.PHONY: $(PHONY)