summaryrefslogtreecommitdiff
path: root/scripts/link-vmlinux.sh
blob: 1f4c27bd5d2af1c04408ab638d87807e0d78c87b (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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
#!/bin/sh
#
# link vmlinux
#
# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and
# $(KBUILD_VMLINUX_MAIN). Most are built-in.o files from top-level directories
# in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
# Ordering when linking is important, and $(KBUILD_VMLINUX_INIT) must be first.
#
# vmlinux
#   ^
#   |
#   +-< $(KBUILD_VMLINUX_INIT)
#   |   +--< init/version.o + more
#   |
#   +--< $(KBUILD_VMLINUX_MAIN)
#   |    +--< drivers/built-in.o mm/built-in.o + more
#   |
#   +-< ${kallsymso} (see description in KALLSYMS section)
#
# vmlinux version (uname -v) cannot be updated during normal
# descending-into-subdirs phase since we do not yet know if we need to
# update vmlinux.
# Therefore this step is delayed until just before final link of vmlinux.
#
# System.map is generated to document addresses of all kernel symbols

# Error out on error
set -e

# Nice output in kbuild format
# Will be supressed by "make -s"
info()
{
	if [ "${quiet}" != "silent_" ]; then
		printf "  %-7s %s\n" ${1} ${2}
	fi
}

# Link of vmlinux.o used for section mismatch analysis
# ${1} output file
modpost_link()
{
	${LD} ${LDFLAGS} -r -o ${1} ${KBUILD_VMLINUX_INIT}                   \
		--start-group ${KBUILD_VMLINUX_MAIN} --end-group
}

# Link of vmlinux
# ${1} - optional extra .o files
# ${2} - output file
vmlinux_link()
{
	local lds="${objtree}/${KBUILD_LDS}"

	if [ "${SRCARCH}" != "um" ]; then
		${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2}                  \
			-T ${lds} ${KBUILD_VMLINUX_INIT}                     \
			--start-group ${KBUILD_VMLINUX_MAIN} --end-group ${1}
	else
		${CC} ${CFLAGS_vmlinux} -o ${2}                              \
			-Wl,-T,${lds} ${KBUILD_VMLINUX_INIT}                 \
			-Wl,--start-group                                    \
				 ${KBUILD_VMLINUX_MAIN}                      \
			-Wl,--end-group                                      \
			-lutil ${1}
		rm -f linux
	fi
}


# Create ${2} .o file with all symbols from the ${1} object file
kallsyms()
{
	info KSYM ${2}
	local kallsymopt;

	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
		kallsymopt=--all-symbols
	fi

	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
		      ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"

	${NM} -n ${1} | \
		scripts/kallsyms ${kallsymopt} | \
		${CC} ${aflags} -c -o ${2} -x assembler-with-cpp -
}

# Create map file with all symbols from ${1}
# See mksymap for additional details
mksysmap()
{
	${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
}

# Delete output files in case of error
trap cleanup SIGHUP SIGINT SIGQUIT SIGTERM ERR
cleanup()
{
	rm -f .old_version
	rm -f .tmp_System.map
	rm -f .tmp_kallsyms*
	rm -f .tmp_version
	rm -f .tmp_vmlinux*
	rm -f System.map
	rm -f vmlinux
	rm -f vmlinux.o
}

#
#
# Use "make V=1" to debug this script
case "${KBUILD_VERBOSE}" in
*1*)
	set -x
	;;
esac

if [ "$1" = "clean" ]; then
	cleanup
	exit 0
fi

# We need access to CONFIG_ symbols
. ./.config

#link vmlinux.o
info LD vmlinux.o
modpost_link vmlinux.o

# modpost vmlinux.o to check for section mismatches
${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o

# Update version
info GEN .version
if [ ! -r .version ]; then
	rm -f .version;
	echo 1 >.version;
else
	mv .version .old_version;
	expr 0$(cat .old_version) + 1 >.version;
fi;

# final build of init/
${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init

kallsymso=""
kallsyms_vmlinux=""
if [ -n "${CONFIG_KALLSYMS}" ]; then

	# kallsyms support
	# Generate section listing all symbols and add it into vmlinux
	# It's a three step process:
	# 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
	#     but __kallsyms is empty.
	#     Running kallsyms on that gives us .tmp_kallsyms1.o with
	#     the right size
	# 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
	#     the right size, but due to the added section, some
	#     addresses have shifted.
	#     From here, we generate a correct .tmp_kallsyms2.o
	# 2a) We may use an extra pass as this has been necessary to
	#     woraround some alignment related bugs.
	#     KALLSYMS_EXTRA_PASS=1 is used to trigger this.
	# 3)  The correct ${kallsymso} is linked into the final vmlinux.
	#
	# a)  Verify that the System.map from vmlinux matches the map from
	#     ${kallsymso}.

	kallsymso=.tmp_kallsyms2.o
	kallsyms_vmlinux=.tmp_vmlinux2

	# step 1
	vmlinux_link "" .tmp_vmlinux1
	kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o

	# step 2
	vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
	kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o

	# step 2a
	if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
		kallsymso=.tmp_kallsyms3.o
		kallsyms_vmlinux=.tmp_vmlinux3

		vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3

		kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
	fi
fi

info LD vmlinux
vmlinux_link "${kallsymso}" vmlinux

info SYSMAP System.map
mksysmap vmlinux System.map

# step a (see comment above)
if [ -n "${CONFIG_KALLSYMS}" ]; then
	mksysmap ${kallsyms_vmlinux} .tmp_System.map

	if ! cmp -s System.map .tmp_System.map; then
		echo Inconsistent kallsyms data
		echo echo Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
		cleanup
		exit 1
	fi
fi

# We made a new kernel - delete old version file
rm -f .old_version