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authorLinus Torvalds2022-05-24 10:36:38 -0700
committerLinus Torvalds2022-05-24 10:36:38 -0700
commit22922deae13fc8d3769790c2eb388e9afce9771d (patch)
treefb6c5433983790fa38c3ef210ace00b2bd77649e /scripts
parent2319be135672f6e45aa937bceaae6c2668c7867c (diff)
parent22682a07acc308ef78681572e19502ce8893c4d4 (diff)
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 ...
Diffstat (limited to 'scripts')
-rw-r--r--scripts/Makefile.build23
-rwxr-xr-xscripts/faddr2line150
-rwxr-xr-xscripts/link-vmlinux.sh62
-rwxr-xr-xscripts/objdump-func29
-rwxr-xr-xscripts/package/builddeb2
5 files changed, 180 insertions, 86 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 3911bfc21702..f89d3fcff39f 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -222,25 +222,29 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),
$(sub_cmd_record_mcount))
endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
-ifdef CONFIG_STACK_VALIDATION
+ifdef CONFIG_OBJTOOL
objtool := $(objtree)/tools/objtool/objtool
objtool_args = \
- $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \
- $(if $(part-of-module), --module) \
- $(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt) \
- $(if $(CONFIG_FRAME_POINTER),, --no-fp) \
- $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \
+ $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \
+ $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
+ $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
+ $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
+ $(if $(CONFIG_UNWINDER_ORC), --orc) \
$(if $(CONFIG_RETPOLINE), --retpoline) \
+ $(if $(CONFIG_SLS), --sls) \
+ $(if $(CONFIG_STACK_VALIDATION), --stackval) \
+ $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \
--uaccess \
- $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
- $(if $(CONFIG_SLS), --sls)
+ $(if $(linked-object), --link) \
+ $(if $(part-of-module), --module) \
+ $(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
-endif # CONFIG_STACK_VALIDATION
+endif # CONFIG_OBJTOOL
ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
@@ -303,6 +307,7 @@ quiet_cmd_cc_prelink_modules = LD [M] $@
# modules into native code
$(obj)/%.prelink.o: objtool-enabled = y
$(obj)/%.prelink.o: part-of-module := y
+$(obj)/%.prelink.o: linked-object := y
$(obj)/%.prelink.o: $(obj)/%.o FORCE
$(call if_changed,cc_prelink_modules)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 6c6439f69a72..0e6268d59883 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -44,17 +44,6 @@
set -o errexit
set -o nounset
-READELF="${CROSS_COMPILE:-}readelf"
-ADDR2LINE="${CROSS_COMPILE:-}addr2line"
-SIZE="${CROSS_COMPILE:-}size"
-NM="${CROSS_COMPILE:-}nm"
-
-command -v awk >/dev/null 2>&1 || die "awk isn't installed"
-command -v ${READELF} >/dev/null 2>&1 || die "readelf isn't installed"
-command -v ${ADDR2LINE} >/dev/null 2>&1 || die "addr2line isn't installed"
-command -v ${SIZE} >/dev/null 2>&1 || die "size isn't installed"
-command -v ${NM} >/dev/null 2>&1 || die "nm isn't installed"
-
usage() {
echo "usage: faddr2line [--list] <object file> <func+offset> <func+offset>..." >&2
exit 1
@@ -69,6 +58,14 @@ die() {
exit 1
}
+READELF="${CROSS_COMPILE:-}readelf"
+ADDR2LINE="${CROSS_COMPILE:-}addr2line"
+AWK="awk"
+
+command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed"
+command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed"
+command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed"
+
# Try to figure out the source directory prefix so we can remove it from the
# addr2line output. HACK ALERT: This assumes that start_kernel() is in
# init/main.c! This only works for vmlinux. Otherwise it falls back to
@@ -76,7 +73,7 @@ die() {
find_dir_prefix() {
local objfile=$1
- local start_kernel_addr=$(${READELF} -sW $objfile | awk '$8 == "start_kernel" {printf "0x%s", $2}')
+ local start_kernel_addr=$(${READELF} --symbols --wide $objfile | ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
[[ -z $start_kernel_addr ]] && return
local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
@@ -97,86 +94,133 @@ __faddr2line() {
local dir_prefix=$3
local print_warnings=$4
- local func=${func_addr%+*}
+ local sym_name=${func_addr%+*}
local offset=${func_addr#*+}
offset=${offset%/*}
- local size=
- [[ $func_addr =~ "/" ]] && size=${func_addr#*/}
+ local user_size=
+ [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/}
- if [[ -z $func ]] || [[ -z $offset ]] || [[ $func = $func_addr ]]; then
+ if [[ -z $sym_name ]] || [[ -z $offset ]] || [[ $sym_name = $func_addr ]]; then
warn "bad func+offset $func_addr"
DONE=1
return
fi
# Go through each of the object's symbols which match the func name.
- # In rare cases there might be duplicates.
- file_end=$(${SIZE} -Ax $objfile | awk '$1 == ".text" {print $2}')
- while read symbol; do
- local fields=($symbol)
- local sym_base=0x${fields[0]}
- local sym_type=${fields[1]}
- local sym_end=${fields[3]}
-
- # calculate the size
- local sym_size=$(($sym_end - $sym_base))
+ # In rare cases there might be duplicates, in which case we print all
+ # matches.
+ while read line; do
+ local fields=($line)
+ local sym_addr=0x${fields[1]}
+ local sym_elf_size=${fields[2]}
+ local sym_sec=${fields[6]}
+
+ # Get the section size:
+ local sec_size=$(${READELF} --section-headers --wide $objfile |
+ sed 's/\[ /\[/' |
+ ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }')
+
+ if [[ -z $sec_size ]]; then
+ warn "bad section size: section: $sym_sec"
+ DONE=1
+ return
+ fi
+
+ # Calculate the symbol size.
+ #
+ # Unfortunately we can't use the ELF size, because kallsyms
+ # also includes the padding bytes in its size calculation. For
+ # kallsyms, the size calculation is the distance between the
+ # symbol and the next symbol in a sorted list.
+ local sym_size
+ local cur_sym_addr
+ local found=0
+ while read line; do
+ local fields=($line)
+ cur_sym_addr=0x${fields[1]}
+ local cur_sym_elf_size=${fields[2]}
+ local cur_sym_name=${fields[7]:-}
+
+ if [[ $cur_sym_addr = $sym_addr ]] &&
+ [[ $cur_sym_elf_size = $sym_elf_size ]] &&
+ [[ $cur_sym_name = $sym_name ]]; then
+ found=1
+ continue
+ fi
+
+ if [[ $found = 1 ]]; then
+ sym_size=$(($cur_sym_addr - $sym_addr))
+ [[ $sym_size -lt $sym_elf_size ]] && continue;
+ found=2
+ break
+ fi
+ done < <(${READELF} --symbols --wide $objfile | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
+
+ if [[ $found = 0 ]]; then
+ warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
+ DONE=1
+ return
+ fi
+
+ # If nothing was found after the symbol, assume it's the last
+ # symbol in the section.
+ [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr))
+
if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then
- warn "bad symbol size: base: $sym_base end: $sym_end"
+ warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr"
DONE=1
return
fi
+
sym_size=0x$(printf %x $sym_size)
- # calculate the address
- local addr=$(($sym_base + $offset))
+ # Calculate the section address from user-supplied offset:
+ local addr=$(($sym_addr + $offset))
if [[ -z $addr ]] || [[ $addr = 0 ]]; then
- warn "bad address: $sym_base + $offset"
+ warn "bad address: $sym_addr + $offset"
DONE=1
return
fi
addr=0x$(printf %x $addr)
- # weed out non-function symbols
- if [[ $sym_type != t ]] && [[ $sym_type != T ]]; then
- [[ $print_warnings = 1 ]] &&
- echo "skipping $func address at $addr due to non-function symbol of type '$sym_type'"
- continue
- fi
-
- # if the user provided a size, make sure it matches the symbol's size
- if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then
+ # If the user provided a size, make sure it matches the symbol's size:
+ if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then
[[ $print_warnings = 1 ]] &&
- echo "skipping $func address at $addr due to size mismatch ($size != $sym_size)"
+ echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)"
continue;
fi
- # make sure the provided offset is within the symbol's range
+ # Make sure the provided offset is within the symbol's range:
if [[ $offset -gt $sym_size ]]; then
[[ $print_warnings = 1 ]] &&
- echo "skipping $func address at $addr due to size mismatch ($offset > $sym_size)"
+ echo "skipping $sym_name address at $addr due to size mismatch ($offset > $sym_size)"
continue
fi
- # separate multiple entries with a blank line
+ # In case of duplicates or multiple addresses specified on the
+ # cmdline, separate multiple entries with a blank line:
[[ $FIRST = 0 ]] && echo
FIRST=0
- # pass real address to addr2line
- echo "$func+$offset/$sym_size:"
- local file_lines=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;")
- [[ -z $file_lines ]] && return
+ echo "$sym_name+$offset/$sym_size:"
+ # Pass section address to addr2line and strip absolute paths
+ # from the output:
+ local output=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;")
+ [[ -z $output ]] && continue
+
+ # Default output (non --list):
if [[ $LIST = 0 ]]; then
- echo "$file_lines" | while read -r line
+ echo "$output" | while read -r line
do
echo $line
done
DONE=1;
- return
+ continue
fi
- # show each line with context
- echo "$file_lines" | while read -r line
+ # For --list, show each line with its corresponding source code:
+ echo "$output" | while read -r line
do
echo
echo $line
@@ -184,12 +228,12 @@ __faddr2line() {
n1=$[$n-5]
n2=$[$n+5]
f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g')
- awk 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f
+ ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f
done
DONE=1
- done < <(${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"$1 } END {if (found == 1) print line, end; }')
+ done < <(${READELF} --symbols --wide $objfile | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
}
[[ $# -lt 2 ]] && usage
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index e036b0bbb42c..d7f26f02f142 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -108,16 +108,22 @@ objtool_link()
local objtoolcmd;
local objtoolopt;
- if is_enabled CONFIG_STACK_VALIDATION && \
- ( is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT ); then
+ if ! is_enabled CONFIG_OBJTOOL; then
+ return;
+ fi
- # Don't perform vmlinux validation unless explicitly requested,
- # but run objtool on vmlinux.o now that we have an object file.
- if is_enabled CONFIG_UNWINDER_ORC; then
- objtoolcmd="orc generate"
+ if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then
+
+ # For LTO and IBT, objtool doesn't run on individual
+ # translation units. Run everything on vmlinux instead.
+
+ if is_enabled CONFIG_HAVE_JUMP_LABEL_HACK; then
+ objtoolopt="${objtoolopt} --hacks=jump_label"
fi
- objtoolopt="${objtoolopt} --lto"
+ if is_enabled CONFIG_HAVE_NOINSTR_HACK; then
+ objtoolopt="${objtoolopt} --hacks=noinstr"
+ fi
if is_enabled CONFIG_X86_KERNEL_IBT; then
objtoolopt="${objtoolopt} --ibt"
@@ -126,34 +132,44 @@ objtool_link()
if is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL; then
objtoolopt="${objtoolopt} --mcount"
fi
+
+ if is_enabled CONFIG_UNWINDER_ORC; then
+ objtoolopt="${objtoolopt} --orc"
+ fi
+
+ if is_enabled CONFIG_RETPOLINE; then
+ objtoolopt="${objtoolopt} --retpoline"
+ fi
+
+ if is_enabled CONFIG_SLS; then
+ objtoolopt="${objtoolopt} --sls"
+ fi
+
+ if is_enabled CONFIG_STACK_VALIDATION; then
+ objtoolopt="${objtoolopt} --stackval"
+ fi
+
+ if is_enabled CONFIG_HAVE_STATIC_CALL_INLINE; then
+ objtoolopt="${objtoolopt} --static-call"
+ fi
+
+ objtoolopt="${objtoolopt} --uaccess"
fi
- if is_enabled CONFIG_VMLINUX_VALIDATION; then
+ if is_enabled CONFIG_NOINSTR_VALIDATION; then
objtoolopt="${objtoolopt} --noinstr"
fi
if [ -n "${objtoolopt}" ]; then
- if [ -z "${objtoolcmd}" ]; then
- objtoolcmd="check"
- fi
- objtoolopt="${objtoolopt} --vmlinux"
- if ! is_enabled CONFIG_FRAME_POINTER; then
- objtoolopt="${objtoolopt} --no-fp"
- fi
+
if is_enabled CONFIG_GCOV_KERNEL; then
objtoolopt="${objtoolopt} --no-unreachable"
fi
- if is_enabled CONFIG_RETPOLINE; then
- objtoolopt="${objtoolopt} --retpoline"
- fi
- objtoolopt="${objtoolopt} --uaccess"
+ objtoolopt="${objtoolopt} --link"
- if is_enabled CONFIG_SLS; then
- objtoolopt="${objtoolopt} --sls"
- fi
info OBJTOOL ${1}
- tools/objtool/objtool ${objtoolcmd} ${objtoolopt} ${1}
+ tools/objtool/objtool ${objtoolopt} ${1}
fi
}
diff --git a/scripts/objdump-func b/scripts/objdump-func
new file mode 100755
index 000000000000..4eb463dd9f52
--- /dev/null
+++ b/scripts/objdump-func
@@ -0,0 +1,29 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Disassemble a single function.
+#
+# usage: objdump-func <file> <func>
+
+set -o errexit
+set -o nounset
+
+OBJDUMP="${CROSS_COMPILE:-}objdump"
+
+command -v gawk >/dev/null 2>&1 || die "gawk isn't installed"
+
+usage() {
+ echo "usage: objdump-func <file> <func>" >&2
+ exit 1
+}
+
+[[ $# -lt 2 ]] && usage
+
+OBJ=$1; shift
+FUNC=$1; shift
+
+# Secret feature to allow adding extra objdump args at the end
+EXTRA_ARGS=$@
+
+# Note this also matches compiler-added suffixes like ".cold", etc
+${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; } }'
diff --git a/scripts/package/builddeb b/scripts/package/builddeb
index 91a502bb97e8..67cd420dcf89 100755
--- a/scripts/package/builddeb
+++ b/scripts/package/builddeb
@@ -67,7 +67,7 @@ deploy_kernel_headers () {
) > debian/hdrsrcfiles
{
- if is_enabled CONFIG_STACK_VALIDATION; then
+ if is_enabled CONFIG_OBJTOOL; then
echo tools/objtool/objtool
fi