Merge tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar: - Comprehensive interface overhaul: ================================= Objtool's interface has some issues: - Several features are done unconditionally, without any way to turn them off. Some of them might be surprising. This makes objtool tricky to use, and prevents porting individual features to other arches. - The config dependencies are too coarse-grained. Objtool enablement is tied to CONFIG_STACK_VALIDATION, but it has several other features independent of that. - The objtool subcmds ("check" and "orc") are clumsy: "check" is really a subset of "orc", so it has all the same options. The subcmd model has never really worked for objtool, as it only has a single purpose: "do some combination of things on an object file". - The '--lto' and '--vmlinux' options are nonsensical and have surprising behavior. Overhaul the interface: - get rid of subcmds - make all features individually selectable - remove and/or clarify confusing/obsolete options - update the documentation - fix some bugs found along the way - Fix x32 regression - Fix Kbuild cleanup bugs - Add scripts/objdump-func helper script to disassemble a single function from an object file. - Rewrite scripts/faddr2line to be section-aware, by basing it on 'readelf', moving it away from 'nm', which doesn't handle multiple sections well, which can result in decoding failure. - Rewrite & fix symbol handling - which had a number of bugs wrt. object files that don't have global symbols - which is rare but possible. Also fix a bunch of symbol handling bugs found along the way. * tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) objtool: Fix objtool regression on x32 systems objtool: Fix symbol creation scripts/faddr2line: Fix overlapping text section failures scripts: Create objdump-func helper script objtool: Remove libsubcmd.a when make clean objtool: Remove inat-tables.c when make clean objtool: Update documentation objtool: Remove --lto and --vmlinux in favor of --link objtool: Add HAVE_NOINSTR_VALIDATION objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION" objtool: Make noinstr hacks optional objtool: Make jump label hack optional objtool: Make static call annotation optional objtool: Make stack validation frame-pointer-specific objtool: Add CONFIG_OBJTOOL objtool: Extricate sls from stack validation objtool: Rework ibt and extricate from stack validation objtool: Make stack validation optional objtool: Add option to print section addresses objtool: Don't print parentheses in function addresses ...

Linus Torvalds committed 4 years ago

Commit 22922de2 parents 2319be1 22682a034 files · +955 −683Browse files

Showing the changes to scripts (5 of 34 files). Show all

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5 files

scripts/Makefile.build +14 −9
scripts/faddr2line +97 −53
scripts/link-vmlinux.sh +39 −23
scripts/objdump-func +29 −0
scripts/package/builddeb +1 −1

scripts/Makefile.build+14−9

@@ -222,25 +222,29 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), · 221 unmodified lines
222	222	$(sub_cmd_record_mcount))
223	223	endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
224	224
225		−ifdef CONFIG_STACK_VALIDATION
	225	+ifdef CONFIG_OBJTOOL
226	226
227	227	objtool := $(objtree)/tools/objtool/objtool
228	228
229	229	objtool_args = \
230		− $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \
231		− $(if $(part-of-module), --module) \
232		− $(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt) \
233		− $(if $(CONFIG_FRAME_POINTER),, --no-fp) \
234		− $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \
	230	+ $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \
	231	+ $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
	232	+ $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
	233	+ $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
	234	+ $(if $(CONFIG_UNWINDER_ORC), --orc) \
235	235	$(if $(CONFIG_RETPOLINE), --retpoline) \
	236	+ $(if $(CONFIG_SLS), --sls) \
	237	+ $(if $(CONFIG_STACK_VALIDATION), --stackval) \
	238	+ $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \
236	239	--uaccess \
237		− $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
238		− $(if $(CONFIG_SLS), --sls)
	240	+ $(if $(linked-object), --link) \
	241	+ $(if $(part-of-module), --module) \
	242	+ $(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
239	243
240	244	cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
241	245	cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
242	246
243		−endif # CONFIG_STACK_VALIDATION
	247	+endif # CONFIG_OBJTOOL
244	248
245	249	ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
246	250
@@ -303,6 +307,7 @@ quiet_cmd_cc_prelink_modules = LD [M] $@ · 56 unmodified lines
303	307	# modules into native code
304	308	$(obj)/%.prelink.o: objtool-enabled = y
305	309	$(obj)/%.prelink.o: part-of-module := y
	310	+$(obj)/%.prelink.o: linked-object := y
306	311
307	312	$(obj)/%.prelink.o: $(obj)/%.o FORCE
308	313	$(call if_changed,cc_prelink_modules)

scripts/faddr2line+97−53

@@ -44,17 +44,6 @@ · 43 unmodified lines
44	44	set -o errexit
45	45	set -o nounset
46	46
47		−READELF="${CROSS_COMPILE:-}readelf"
48		−ADDR2LINE="${CROSS_COMPILE:-}addr2line"
49		−SIZE="${CROSS_COMPILE:-}size"
50		−NM="${CROSS_COMPILE:-}nm"
51		−
52		−command -v awk >/dev/null 2>&1 \|\| die "awk isn't installed"
53		−command -v ${READELF} >/dev/null 2>&1 \|\| die "readelf isn't installed"
54		−command -v ${ADDR2LINE} >/dev/null 2>&1 \|\| die "addr2line isn't installed"
55		−command -v ${SIZE} >/dev/null 2>&1 \|\| die "size isn't installed"
56		−command -v ${NM} >/dev/null 2>&1 \|\| die "nm isn't installed"
57		−
58	47	usage() {
59	48	echo "usage: faddr2line [--list] <object file> <func+offset> <func+offset>..." >&2
60	49	exit 1
@@ -69,6 +58,14 @@ die() { · 8 unmodified lines
69	58	exit 1
70	59	}
71	60
	61	+READELF="${CROSS_COMPILE:-}readelf"
	62	+ADDR2LINE="${CROSS_COMPILE:-}addr2line"
	63	+AWK="awk"
	64	+
	65	+command -v ${AWK} >/dev/null 2>&1 \|\| die "${AWK} isn't installed"
	66	+command -v ${READELF} >/dev/null 2>&1 \|\| die "${READELF} isn't installed"
	67	+command -v ${ADDR2LINE} >/dev/null 2>&1 \|\| die "${ADDR2LINE} isn't installed"
	68	+
72	69	# Try to figure out the source directory prefix so we can remove it from the
73	70	# addr2line output. HACK ALERT: This assumes that start_kernel() is in
74	71	# init/main.c! This only works for vmlinux. Otherwise it falls back to
@@ -76,7 +73,7 @@ die() { · 1 unmodified line
76	73	find_dir_prefix() {
77	74	local objfile=$1
78	75
79		− local start_kernel_addr=$(${READELF} -sW $objfile \| awk '$8 == "start_kernel" {printf "0x%s", $2}')
	76	+ local start_kernel_addr=$(${READELF} --symbols --wide $objfile \| ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
80	77	[[ -z $start_kernel_addr ]] && return
81	78
82	79	local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
@@ -97,86 +94,133 @@ __faddr2line() { · 14 unmodified lines
97	94	local dir_prefix=$3
98	95	local print_warnings=$4
99	96
100		− local func=${func_addr%+*}
	97	+ local sym_name=${func_addr%+*}
101	98	local offset=${func_addr#*+}
102	99	offset=${offset%/*}
103		− local size=
104		− [[ $func_addr =~ "/" ]] && size=${func_addr#*/}
	100	+ local user_size=
	101	+ [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/}
105	102
106		− if [[ -z $func ]] \|\| [[ -z $offset ]] \|\| [[ $func = $func_addr ]]; then
	103	+ if [[ -z $sym_name ]] \|\| [[ -z $offset ]] \|\| [[ $sym_name = $func_addr ]]; then
107	104	warn "bad func+offset $func_addr"
108	105	DONE=1
109	106	return
110	107	fi
111	108
112	109	# Go through each of the object's symbols which match the func name.
113		− # In rare cases there might be duplicates.
114		− file_end=$(${SIZE} -Ax $objfile \| awk '$1 == ".text" {print $2}')
115		− while read symbol; do
116		− local fields=($symbol)
117		− local sym_base=0x${fields[0]}
118		− local sym_type=${fields[1]}
119		− local sym_end=${fields[3]}
120		−
121		− # calculate the size
122		− local sym_size=$(($sym_end - $sym_base))
	110	+ # In rare cases there might be duplicates, in which case we print all
	111	+ # matches.
	112	+ while read line; do
	113	+ local fields=($line)
	114	+ local sym_addr=0x${fields[1]}
	115	+ local sym_elf_size=${fields[2]}
	116	+ local sym_sec=${fields[6]}
	117	+
	118	+ # Get the section size:
	119	+ local sec_size=$(${READELF} --section-headers --wide $objfile \|
	120	+ sed 's/\[ /\[/' \|
	121	+ ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }')
	122	+
	123	+ if [[ -z $sec_size ]]; then
	124	+ warn "bad section size: section: $sym_sec"
	125	+ DONE=1
	126	+ return
	127	+ fi
	128	+
	129	+ # Calculate the symbol size.
	130	+ #
	131	+ # Unfortunately we can't use the ELF size, because kallsyms
	132	+ # also includes the padding bytes in its size calculation. For
	133	+ # kallsyms, the size calculation is the distance between the
	134	+ # symbol and the next symbol in a sorted list.
	135	+ local sym_size
	136	+ local cur_sym_addr
	137	+ local found=0
	138	+ while read line; do
	139	+ local fields=($line)
	140	+ cur_sym_addr=0x${fields[1]}
	141	+ local cur_sym_elf_size=${fields[2]}
	142	+ local cur_sym_name=${fields[7]:-}
	143	+
	144	+ if [[ $cur_sym_addr = $sym_addr ]] &&
	145	+ [[ $cur_sym_elf_size = $sym_elf_size ]] &&
	146	+ [[ $cur_sym_name = $sym_name ]]; then
	147	+ found=1
	148	+ continue
	149	+ fi
	150	+
	151	+ if [[ $found = 1 ]]; then
	152	+ sym_size=$(($cur_sym_addr - $sym_addr))
	153	+ [[ $sym_size -lt $sym_elf_size ]] && continue;
	154	+ found=2
	155	+ break
	156	+ fi
	157	+ done < <(${READELF} --symbols --wide $objfile \| ${AWK} -v sec=$sym_sec '$7 == sec' \| sort --key=2)
	158	+
	159	+ if [[ $found = 0 ]]; then
	160	+ warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
	161	+ DONE=1
	162	+ return
	163	+ fi
	164	+
	165	+ # If nothing was found after the symbol, assume it's the last
	166	+ # symbol in the section.
	167	+ [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr))
	168	+
123	169	if [[ -z $sym_size ]] \|\| [[ $sym_size -le 0 ]]; then
124		− warn "bad symbol size: base: $sym_base end: $sym_end"
	170	+ warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr"
125	171	DONE=1
126	172	return
127	173	fi
	174	+
128	175	sym_size=0x$(printf %x $sym_size)
129	176
130		− # calculate the address
131		− local addr=$(($sym_base + $offset))
	177	+ # Calculate the section address from user-supplied offset:
	178	+ local addr=$(($sym_addr + $offset))
132	179	if [[ -z $addr ]] \|\| [[ $addr = 0 ]]; then
133		− warn "bad address: $sym_base + $offset"
	180	+ warn "bad address: $sym_addr + $offset"
134	181	DONE=1
135	182	return
136	183	fi
137	184	addr=0x$(printf %x $addr)
138	185
139		− # weed out non-function symbols
140		− if [[ $sym_type != t ]] && [[ $sym_type != T ]]; then
141		− [[ $print_warnings = 1 ]] &&
142		− echo "skipping $func address at $addr due to non-function symbol of type '$sym_type'"
143		− continue
144		− fi
145		−
146		− # if the user provided a size, make sure it matches the symbol's size
147		− if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then
	186	+ # If the user provided a size, make sure it matches the symbol's size:
	187	+ if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then
148	188	[[ $print_warnings = 1 ]] &&
149		− echo "skipping $func address at $addr due to size mismatch ($size != $sym_size)"
	189	+ echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)"
150	190	continue;
151	191	fi
152	192
153		− # make sure the provided offset is within the symbol's range
	193	+ # Make sure the provided offset is within the symbol's range:
154	194	if [[ $offset -gt $sym_size ]]; then
155	195	[[ $print_warnings = 1 ]] &&
156		− echo "skipping $func address at $addr due to size mismatch ($offset > $sym_size)"
	196	+ echo "skipping $sym_name address at $addr due to size mismatch ($offset > $sym_size)"
157	197	continue
158	198	fi
159	199
160		− # separate multiple entries with a blank line
	200	+ # In case of duplicates or multiple addresses specified on the
	201	+ # cmdline, separate multiple entries with a blank line:
161	202	[[ $FIRST = 0 ]] && echo
162	203	FIRST=0
163	204
164		− # pass real address to addr2line
165		− echo "$func+$offset/$sym_size:"
166		− local file_lines=$(${ADDR2LINE} -fpie $objfile $addr \| sed "s; $dir_prefix$\./$*; ;")
167		− [[ -z $file_lines ]] && return
	205	+ echo "$sym_name+$offset/$sym_size:"
168	206
	207	+ # Pass section address to addr2line and strip absolute paths
	208	+ # from the output:
	209	+ local output=$(${ADDR2LINE} -fpie $objfile $addr \| sed "s; $dir_prefix$\./$*; ;")
	210	+ [[ -z $output ]] && continue
	211	+
	212	+ # Default output (non --list):
169	213	if [[ $LIST = 0 ]]; then
170		− echo "$file_lines" \| while read -r line
	214	+ echo "$output" \| while read -r line
171	215	do
172	216	echo $line
173	217	done
174	218	DONE=1;
175		− return
	219	+ continue
176	220	fi
177	221
178		− # show each line with context
179		− echo "$file_lines" \| while read -r line
	222	+ # For --list, show each line with its corresponding source code:
	223	+ echo "$output" \| while read -r line
180	224	do
181	225	echo
182	226	echo $line
@@ -184,12 +228,12 @@ __faddr2line() { · 1 unmodified line
184	228	n1=$[$n-5]
185	229	n2=$[$n+5]
186	230	f=$(echo $line \| sed 's/.at $.\+$:./\1/g')
187		− awk 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f
	231	+ ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f
188	232	done
189	233
190	234	DONE=1
191	235
192		− done < <(${NM} -n $objfile \| awk -v fn=$func -v end=$file_end '$3 == fn { found=1; line=$0; start=$1; next } found == 1 { found=0; print line, "0x"$1 } END {if (found == 1) print line, end; }')
	236	+ done < <(${READELF} --symbols --wide $objfile \| ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
193	237	}
194	238
195	239	[[ $# -lt 2 ]] && usage

scripts/link-vmlinux.sh+39−23

@@ -108,16 +108,22 @@ objtool_link() · 107 unmodified lines
108	108	local objtoolcmd;
109	109	local objtoolopt;
110	110
111		− if is_enabled CONFIG_STACK_VALIDATION && \
112		− ( is_enabled CONFIG_LTO_CLANG \|\| is_enabled CONFIG_X86_KERNEL_IBT ); then
	111	+ if ! is_enabled CONFIG_OBJTOOL; then
	112	+ return;
	113	+ fi
113	114
114		− # Don't perform vmlinux validation unless explicitly requested,
115		− # but run objtool on vmlinux.o now that we have an object file.
116		− if is_enabled CONFIG_UNWINDER_ORC; then
117		− objtoolcmd="orc generate"
	115	+ if is_enabled CONFIG_LTO_CLANG \|\| is_enabled CONFIG_X86_KERNEL_IBT; then
	116	+
	117	+ # For LTO and IBT, objtool doesn't run on individual
	118	+ # translation units. Run everything on vmlinux instead.
	119	+
	120	+ if is_enabled CONFIG_HAVE_JUMP_LABEL_HACK; then
	121	+ objtoolopt="${objtoolopt} --hacks=jump_label"
118	122	fi
119	123
120		− objtoolopt="${objtoolopt} --lto"
	124	+ if is_enabled CONFIG_HAVE_NOINSTR_HACK; then
	125	+ objtoolopt="${objtoolopt} --hacks=noinstr"
	126	+ fi
121	127
122	128	if is_enabled CONFIG_X86_KERNEL_IBT; then
123	129	objtoolopt="${objtoolopt} --ibt"
@@ -126,34 +132,44 @@ objtool_link() · 2 unmodified lines
126	132	if is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL; then
127	133	objtoolopt="${objtoolopt} --mcount"
128	134	fi
	135	+
	136	+ if is_enabled CONFIG_UNWINDER_ORC; then
	137	+ objtoolopt="${objtoolopt} --orc"
	138	+ fi
	139	+
	140	+ if is_enabled CONFIG_RETPOLINE; then
	141	+ objtoolopt="${objtoolopt} --retpoline"
	142	+ fi
	143	+
	144	+ if is_enabled CONFIG_SLS; then
	145	+ objtoolopt="${objtoolopt} --sls"
	146	+ fi
	147	+
	148	+ if is_enabled CONFIG_STACK_VALIDATION; then
	149	+ objtoolopt="${objtoolopt} --stackval"
	150	+ fi
	151	+
	152	+ if is_enabled CONFIG_HAVE_STATIC_CALL_INLINE; then
	153	+ objtoolopt="${objtoolopt} --static-call"
	154	+ fi
	155	+
	156	+ objtoolopt="${objtoolopt} --uaccess"
129	157	fi
130	158
131		− if is_enabled CONFIG_VMLINUX_VALIDATION; then
	159	+ if is_enabled CONFIG_NOINSTR_VALIDATION; then
132	160	objtoolopt="${objtoolopt} --noinstr"
133	161	fi
134	162
135	163	if [ -n "${objtoolopt}" ]; then
136		− if [ -z "${objtoolcmd}" ]; then
137		− objtoolcmd="check"
138		− fi
139		− objtoolopt="${objtoolopt} --vmlinux"
140		− if ! is_enabled CONFIG_FRAME_POINTER; then
141		− objtoolopt="${objtoolopt} --no-fp"
142		− fi
	164	+
143	165	if is_enabled CONFIG_GCOV_KERNEL; then
144	166	objtoolopt="${objtoolopt} --no-unreachable"
145	167	fi
146		− if is_enabled CONFIG_RETPOLINE; then
147		− objtoolopt="${objtoolopt} --retpoline"
148		− fi
149	168
150		− objtoolopt="${objtoolopt} --uaccess"
	169	+ objtoolopt="${objtoolopt} --link"
151	170
152		− if is_enabled CONFIG_SLS; then
153		− objtoolopt="${objtoolopt} --sls"
154		− fi
155	171	info OBJTOOL ${1}
156		− tools/objtool/objtool ${objtoolcmd} ${objtoolopt} ${1}
	172	+ tools/objtool/objtool ${objtoolopt} ${1}
157	173	fi
158	174	}
159	175

scripts/objdump-func+29−0

@@ -0,0 +1,29 @@
	1	+#!/bin/bash
	2	+# SPDX-License-Identifier: GPL-2.0
	3	+#
	4	+# Disassemble a single function.
	5	+#
	6	+# usage: objdump-func <file> <func>
	7	+
	8	+set -o errexit
	9	+set -o nounset
	10	+
	11	+OBJDUMP="${CROSS_COMPILE:-}objdump"
	12	+
	13	+command -v gawk >/dev/null 2>&1 \|\| die "gawk isn't installed"
	14	+
	15	+usage() {
	16	+ echo "usage: objdump-func <file> <func>" >&2
	17	+ exit 1
	18	+}
	19	+
	20	+[[ $# -lt 2 ]] && usage
	21	+
	22	+OBJ=$1; shift
	23	+FUNC=$1; shift
	24	+
	25	+# Secret feature to allow adding extra objdump args at the end
	26	+EXTRA_ARGS=$@
	27	+
	28	+# Note this also matches compiler-added suffixes like ".cold", etc
	29	+${OBJDUMP} -wdr $EXTRA_ARGS $OBJ \| gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f "(\\..*)?>:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }'

scripts/package/builddeb+1−1

@@ -67,7 +67,7 @@ deploy_kernel_headers () { · 66 unmodified lines
67	67	) > debian/hdrsrcfiles
68	68
69	69	{
70		− if is_enabled CONFIG_STACK_VALIDATION; then
	70	+ if is_enabled CONFIG_OBJTOOL; then
71	71	echo tools/objtool/objtool
72	72	fi
73	73