diff --git a/src/yunohost/vendor/spectre-meltdown-checker/README.md b/src/yunohost/vendor/spectre-meltdown-checker/README.md
index 518b3ec9b..4a9c71828 100644
--- a/src/yunohost/vendor/spectre-meltdown-checker/README.md
+++ b/src/yunohost/vendor/spectre-meltdown-checker/README.md
@@ -1,16 +1,57 @@
 Spectre & Meltdown Checker
 ==========================
 
-A simple shell script to tell if your Linux installation is vulnerable against the 3 "speculative execution" CVEs that were made public early 2018.
+A shell script to tell if your system is vulnerable against the 3 "speculative execution" CVEs that were made public early 2018.
 
-Without options, it'll inspect your currently running kernel. 
-You can also specify a kernel image on the command line, if you'd like to inspect a kernel you're not running.
+Supported operating systems:
+- Linux (all versions, flavors and distros)
+- BSD (FreeBSD, NetBSD, DragonFlyBSD)
 
-The script will do its best to detect mitigations, including backported non-vanilla patches, regardless of the advertised kernel version number.
+Supported architectures:
+- x86 (32 bits)
+- amd64/x86_64 (64 bits)
+- ARM and ARM64
+- other architectures will work, but mitigations (if they exist) might not always be detected
+
+For Linux systems, the script will detect mitigations, including backported non-vanilla patches, regardless of the advertised kernel version number and the distribution (such as Debian, Ubuntu, CentOS, RHEL, Fedora, openSUSE, Arch, ...), it also works if you've compiled your own kernel.
+
+For BSD systems, the detection will work as long as the BSD you're using supports `cpuctl` and `linprocfs` (this is not the case of OpenBSD for example).
+
+## Easy way to run the script
+
+- Get the latest version of the script using `curl` *or* `wget`
+
+```bash
+curl -L https://meltdown.ovh -o spectre-meltdown-checker.sh
+wget https://meltdown.ovh -O spectre-meltdown-checker.sh
+```
+
+- Inspect the script. You never blindly run scripts you downloaded from the Internet, do you?
+
+```bash
+vim spectre-meltdown-checker.sh
+```
+
+- When you're ready, run the script as root
+
+```bash
+chmod +x spectre-meltdown-checker.sh
+sudo ./spectre-meltdown-checker.sh
+```
 
 ## Example of script output
 
-![checker](https://framapic.org/6O4v4AAwMenv/M6J4CFWwsB3z.png)
+- Intel Haswell CPU running under Ubuntu 16.04 LTS
+
+![haswell](https://framapic.org/1kWmNwE6ll0p/ayTRX9JRlHJ7.png)
+
+- AMD Ryzen running under OpenSUSE Tumbleweed
+
+![ryzen](https://framapic.org/TkWbuh421YQR/6MAGUP3lL6Ne.png)
+
+- Batch mode (JSON flavor)
+
+![batch](https://framapic.org/HEcWFPrLewbs/om1LdufspWTJ.png)
 
 ## Quick summary of the CVEs
 
@@ -38,8 +79,10 @@ The script will do its best to detect mitigations, including backported non-vani
 This tool does its best to determine whether your system is immune (or has proper mitigations in place) for the collectively named "speculative execution" vulnerabilities. It doesn't attempt to run any kind of exploit, and can't guarantee that your system is secure, but rather helps you verifying whether your system has the known correct mitigations in place.
 However, some mitigations could also exist in your kernel that this script doesn't know (yet) how to detect, or it might falsely detect mitigations that in the end don't work as expected (for example, on backported or modified kernels).
 
-Your system exposure also depends on your CPU. As of now, AMD and ARM processors are marked as immune to some or all of these vulnerabilities (except some specific ARM models). All Intel processors manufactured since circa 1995 are thought to be vulnerable. Whatever processor one uses, one might seek more information from the manufacturer of that processor and/or of the device in which it runs.
+Your system exposure also depends on your CPU. As of now, AMD and ARM processors are marked as immune to some or all of these vulnerabilities (except some specific ARM models). All Intel processors manufactured since circa 1995 are thought to be vulnerable, except some specific/old models, such as some early Atoms. Whatever processor one uses, one might seek more information from the manufacturer of that processor and/or of the device in which it runs.
 
 The nature of the discovered vulnerabilities being quite new, the landscape of vulnerable processors can be expected to change over time, which is why this script makes the assumption that all CPUs are vulnerable, except if the manufacturer explicitly stated otherwise in a verifiable public announcement.
 
+Please also note that for Spectre vulnerabilities, all software can possibly be exploited, this tool only verifies that the kernel (which is the core of the system) you're using has the proper protections in place. Verifying all the other software is out of the scope of this tool. As a general measure, ensure you always have the most up to date stable versions of all the software you use, especially for those who are exposed to the world, such as network daemons and browsers.
+
 This tool has been released in the hope that it'll be useful, but don't use it to jump to conclusions about your security.
diff --git a/src/yunohost/vendor/spectre-meltdown-checker/spectre-meltdown-checker.sh b/src/yunohost/vendor/spectre-meltdown-checker/spectre-meltdown-checker.sh
index f71deb5bf..0f3c10575 100755
--- a/src/yunohost/vendor/spectre-meltdown-checker/spectre-meltdown-checker.sh
+++ b/src/yunohost/vendor/spectre-meltdown-checker/spectre-meltdown-checker.sh
@@ -4,19 +4,35 @@
 # Check for the latest version at:
 # https://github.com/speed47/spectre-meltdown-checker
 # git clone https://github.com/speed47/spectre-meltdown-checker.git
-# or wget https://raw.githubusercontent.com/speed47/spectre-meltdown-checker/master/spectre-meltdown-checker.sh
+# or wget https://meltdown.ovh -O spectre-meltdown-checker.sh
+# or curl -L https://meltdown.ovh -o spectre-meltdown-checker.sh
 #
 # Stephane Lesimple
 #
-VERSION=0.29
+VERSION='0.37'
+
+trap 'exit_cleanup' EXIT
+trap '_warn "interrupted, cleaning up..."; exit_cleanup; exit 1' INT
+exit_cleanup()
+{
+	# cleanup the temp decompressed config & kernel image
+	[ -n "$dumped_config" ] && [ -f "$dumped_config" ] && rm -f "$dumped_config"
+	[ -n "$kerneltmp"     ] && [ -f "$kerneltmp"     ] && rm -f "$kerneltmp"
+	[ -n "$kerneltmp2"    ] && [ -f "$kerneltmp2"    ] && rm -f "$kerneltmp2"
+	[ "$mounted_debugfs" = 1 ] && umount /sys/kernel/debug 2>/dev/null
+	[ "$mounted_procfs"  = 1 ] && umount "$procfs" 2>/dev/null
+	[ "$insmod_cpuid"    = 1 ] && rmmod cpuid 2>/dev/null
+	[ "$insmod_msr"      = 1 ] && rmmod msr 2>/dev/null
+	[ "$kldload_cpuctl"  = 1 ] && kldunload cpuctl 2>/dev/null
+}
 
-# Script configuration
 show_usage()
 {
+	# shellcheck disable=SC2086
 	cat <<EOF
 	Usage:
-		Live mode:    `basename $0` [options] [--live]
-		Offline mode: `basename $0` [options] [--kernel <vmlinux_file>] [--config <kernel_config>] [--map <kernel_map_file>]
+		Live mode:    $(basename $0) [options] [--live]
+		Offline mode: $(basename $0) [options] [--kernel <kernel_file>] [--config <kernel_config>] [--map <kernel_map_file>]
 
 	Modes:
 		Two modes are available.
@@ -25,22 +41,36 @@ show_usage()
 		To run under this mode, just start the script without any option (you can also use --live explicitly)
 
 		Second mode is the "offline" mode, where you can inspect a non-running kernel.
-		You'll need to specify the location of the vmlinux file, and if possible, the corresponding config and System.map files:
+		You'll need to specify the location of the kernel file, config and System.map files:
 
-		--kernel vmlinux_file		Specify a (possibly compressed) vmlinux file
-		--config kernel_config		Specify a kernel config file
-		--map	 kernel_map_file	Specify a kernel System.map file
+		--kernel kernel_file	specify a (possibly compressed) Linux or BSD kernel file
+		--config kernel_config	specify a kernel config file (Linux only)
+		--map kernel_map_file	specify a kernel System.map file (Linux only)
 
 	Options:
-		--no-color			Don't use color codes
-		--verbose, -v			Increase verbosity level
-		--no-sysfs			Don't use the /sys interface even if present
-		--batch text			Produce machine readable output, this is the default if --batch is specified alone
-		--batch json			Produce JSON output formatted for Puppet, Ansible, Chef...
-		--batch nrpe			Produce machine readable output formatted for NRPE
-		--variant [1,2,3]		Specify which variant you'd like to check, by default all variants are checked
-						Can be specified multiple times (e.g. --variant 2 --variant 3)
+		--no-color		don't use color codes
+		--verbose, -v		increase verbosity level, possibly several times
+		--no-explain		don't produce a human-readable explanation of actions to take to mitigate a vulnerability
+		--paranoid		require IBPB to deem Variant 2 as mitigated
 
+		--no-sysfs		don't use the /sys interface even if present [Linux]
+		--sysfs-only		only use the /sys interface, don't run our own checks [Linux]
+		--coreos		special mode for CoreOS (use an ephemeral toolbox to inspect kernel) [Linux]
+
+		--arch-prefix PREFIX	specify a prefix for cross-inspecting a kernel of a different arch, for example "aarch64-linux-gnu-",
+					so that invoked tools will be prefixed with this (i.e. aarch64-linux-gnu-objdump)
+		--batch text		produce machine readable output, this is the default if --batch is specified alone
+		--batch json		produce JSON output formatted for Puppet, Ansible, Chef...
+		--batch nrpe		produce machine readable output formatted for NRPE
+		--batch prometheus      produce output for consumption by prometheus-node-exporter
+
+		--variant [1,2,3]	specify which variant you'd like to check, by default all variants are checked,
+					can be specified multiple times (e.g. --variant 2 --variant 3)
+		--hw-only		only check for CPU information, don't check for any variant
+		--no-hw			skip CPU information and checks, if you're inspecting a kernel not to be run on this host
+
+	Return codes:
+		0 (not vulnerable), 2 (vulnerable), 3 (unknown), 255 (error)
 
 	IMPORTANT:
 	A false sense of security is worse than no security at all.
@@ -61,19 +91,26 @@ However, some mitigations could also exist in your kernel that this script doesn
 falsely detect mitigations that in the end don't work as expected (for example, on backported or modified kernels).
 
 Your system exposure also depends on your CPU. As of now, AMD and ARM processors are marked as immune to some or all of these
-vulnerabilities (except some specific ARM models). All Intel processors manufactured since circa 1995 are thought to be vulnerable.
-Whatever processor one uses, one might seek more information from the manufacturer of that processor and/or of the device
-in which it runs.
+vulnerabilities (except some specific ARM models). All Intel processors manufactured since circa 1995 are thought to be vulnerable,
+except some specific/old models, such as some early Atoms. Whatever processor one uses, one might seek more information
+from the manufacturer of that processor and/or of the device in which it runs.
 
 The nature of the discovered vulnerabilities being quite new, the landscape of vulnerable processors can be expected
 to change over time, which is why this script makes the assumption that all CPUs are vulnerable, except if the manufacturer
 explicitly stated otherwise in a verifiable public announcement.
 
+Please also note that for Spectre vulnerabilities, all software can possibly be exploited, this tool only verifies that the
+kernel (which is the core of the system) you're using has the proper protections in place. Verifying all the other software
+is out of the scope of this tool. As a general measure, ensure you always have the most up to date stable versions of all
+the software you use, especially for those who are exposed to the world, such as network daemons and browsers.
+
 This tool has been released in the hope that it'll be useful, but don't use it to jump to conclusions about your security.
 
 EOF
 }
 
+os=$(uname -s)
+
 # parse options
 opt_kernel=''
 opt_config=''
@@ -89,63 +126,130 @@ opt_variant2=0
 opt_variant3=0
 opt_allvariants=1
 opt_no_sysfs=0
+opt_sysfs_only=0
+opt_coreos=0
+opt_arch_prefix=''
+opt_hw_only=0
+opt_no_hw=0
+opt_no_explain=0
+opt_paranoid=0
 
-nrpe_critical=0
-nrpe_unknown=0
+global_critical=0
+global_unknown=0
 nrpe_vuln=""
 
+# find a sane command to print colored messages, we prefer `printf` over `echo`
+# because `printf` behavior is more standard across Linux/BSD
+# we'll try to avoid using shell builtins that might not take options
+echo_cmd_type=echo
+if which printf >/dev/null 2>&1; then
+	echo_cmd=$(which printf)
+	echo_cmd_type=printf
+elif which echo >/dev/null 2>&1; then
+	echo_cmd=$(which echo)
+else
+	# which command is broken?
+	[ -x /bin/echo        ] && echo_cmd=/bin/echo
+	# for Android
+	[ -x /system/bin/echo ] && echo_cmd=/system/bin/echo
+fi
+# still empty ? fallback to builtin
+[ -z "$echo_cmd" ] && echo_cmd=echo
 __echo()
 {
 	opt="$1"
 	shift
-	_msg="$@"
+	_msg="$*"
+
 	if [ "$opt_no_color" = 1 ] ; then
 		# strip ANSI color codes
-		_msg=$(/bin/echo -e  "$_msg" | sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g")
+		# some sed versions (i.e. toybox) can't seem to handle
+		# \033 aka \x1B correctly, so do it for them.
+		if [ "$echo_cmd_type" = printf ]; then
+			_interpret_chars=''
+		else
+			_interpret_chars='-e'
+		fi
+		_ctrlchar=$($echo_cmd $_interpret_chars "\033")
+		_msg=$($echo_cmd $_interpret_chars "$_msg" | sed -r "s/$_ctrlchar\[([0-9][0-9]?(;[0-9][0-9]?)?)?m//g")
+	fi
+	if [ "$echo_cmd_type" = printf ]; then
+		if [ "$opt" = "-n" ]; then
+			$echo_cmd "$_msg"
+		else
+			$echo_cmd "$_msg\n"
+		fi
+	else
+		# shellcheck disable=SC2086
+		$echo_cmd $opt -e "$_msg"
 	fi
-	# explicitly call /bin/echo to avoid shell builtins that might not take options
-	/bin/echo $opt -e "$_msg"
 }
 
 _echo()
 {
-	if [ $opt_verbose -ge $1 ]; then
+	if [ "$opt_verbose" -ge "$1" ]; then
 		shift
-		__echo '' "$@"
+		__echo '' "$*"
 	fi
 }
 
 _echo_nol()
 {
-	if [ $opt_verbose -ge $1 ]; then
+	if [ "$opt_verbose" -ge "$1" ]; then
 		shift
-		__echo -n "$@"
+		__echo -n "$*"
 	fi
 }
 
 _warn()
 {
-	_echo 0 "\033[31m${@}\033[0m" >&2
+	_echo 0 "\033[31m$*\033[0m" >&2
 }
 
 _info()
 {
-	_echo 1 "$@"
+	_echo 1 "$*"
 }
 
 _info_nol()
 {
-	_echo_nol 1 "$@"
+	_echo_nol 1 "$*"
 }
 
 _verbose()
 {
-	_echo 2 "$@"
+	_echo 2 "$*"
+}
+
+_verbose_nol()
+{
+	_echo_nol 2 "$*"
 }
 
 _debug()
 {
-	_echo 3 "\033[34m(debug) $@\033[0m"
+	_echo 3 "\033[34m(debug) $*\033[0m"
+}
+
+explain()
+{
+	if [ "$opt_no_explain" != 1 ] ; then
+		_info ''
+		_info "> \033[41m\033[30mHow to fix:\033[0m $*"
+	fi
+}
+
+is_cpu_vulnerable_cached=0
+_is_cpu_vulnerable_cached()
+{
+	# shellcheck disable=SC2086
+	[ "$1" = 1 ] && return $variant1
+	# shellcheck disable=SC2086
+	[ "$1" = 2 ] && return $variant2
+	# shellcheck disable=SC2086
+	[ "$1" = 3 ] && return $variant3
+	echo "$0: error: invalid variant '$1' passed to is_cpu_vulnerable()" >&2
+	exit 255
 }
 
 is_cpu_vulnerable()
@@ -155,52 +259,140 @@ is_cpu_vulnerable()
 	# (note that in shell, a return of 0 is success)
 	# by default, everything is vulnerable, we work in a "whitelist" logic here.
 	# usage: is_cpu_vulnerable 2 && do something if vulnerable
-	variant1=0
-	variant2=0
-	variant3=0
-
-	if grep -q AMD /proc/cpuinfo; then
-		# AMD revised their statement about variant2 => vulnerable
-		# https://www.amd.com/en/corporate/speculative-execution
-		variant3=1
-	elif grep -qi 'CPU implementer\s*:\s*0x41' /proc/cpuinfo; then
-		# ARM
-		# reference: https://developer.arm.com/support/security-update
-		cpupart=$(awk '/CPU part/         {print $4;exit}' /proc/cpuinfo)
-		cpuarch=$(awk '/CPU architecture/ {print $3;exit}' /proc/cpuinfo)
-		if [ -n "$cpupart" -a -n "$cpuarch" ]; then
-			# Cortex-R7 and Cortex-R8 are real-time and only used in medical devices or such
-			# I can't find their CPU part number, but it's probably not that useful anyway
-			# model R7 R8 A9    A15   A17   A57   A72    A73    A75
-			# part   ?  ? 0xc09 0xc0f 0xc0e 0xd07 0xd08  0xd09  0xd0a
-			# arch  7? 7? 7     7     7     8     8      8      8
-			if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c09|c0f|c0e)$'; then
-				# armv7 vulnerable chips
-				:
-			elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d07|d08|d09|d0a)$'; then
-				# armv8 vulnerable chips
-				:
-			else
-				variant1=1
-				variant2=1
-			fi
-			# for variant3, only A75 is vulnerable
-			if ! [ "$cpuarch" = 8 -a "$cpupart" = 0xd0a ]; then
-				variant3=1
-			fi
-		fi
+	if [ "$is_cpu_vulnerable_cached" = 1 ]; then
+		_is_cpu_vulnerable_cached "$1"
+		return $?
 	fi
 
-	[ "$1" = 1 ] && return $variant1
-	[ "$1" = 2 ] && return $variant2
-	[ "$1" = 3 ] && return $variant3
-	echo "$0: error: invalid variant '$1' passed to is_cpu_vulnerable()" >&2
-	exit 1
+	variant1=''
+	variant2=''
+	variant3=''
+
+	if is_cpu_specex_free; then
+		variant1=immune
+		variant2=immune
+		variant3=immune
+	elif is_intel; then
+		# Intel
+		# https://github.com/crozone/SpectrePoC/issues/1 ^F E5200 => spectre 2 not vulnerable
+		# https://github.com/paboldin/meltdown-exploit/issues/19 ^F E5200 => meltdown vulnerable
+		# model name : Pentium(R) Dual-Core  CPU      E5200  @ 2.50GHz
+		if grep -qE '^model name.+ Pentium\(R\) Dual-Core[[:space:]]+CPU[[:space:]]+E[0-9]{4}K? ' "$procfs/cpuinfo"; then
+			variant1=vuln
+			[ -z "$variant2" ] && variant2=immune
+			variant3=vuln
+		fi
+		if [ "$capabilities_rdcl_no" = 1 ]; then
+			# capability bit for future Intel processor that will explicitly state
+			# that they're not vulnerable to Meltdown
+			# this var is set in check_cpu()
+			variant3=immune
+			_debug "is_cpu_vulnerable: RDCL_NO is set so not vuln to meltdown"
+		fi
+	elif is_amd; then
+		# AMD revised their statement about variant2 => vulnerable
+		# https://www.amd.com/en/corporate/speculative-execution
+		variant1=vuln
+		variant2=vuln
+		[ -z "$variant3" ] && variant3=immune
+	elif [ "$cpu_vendor" = ARM ]; then
+		# ARM
+		# reference: https://developer.arm.com/support/security-update
+		# some devices (phones or other) have several ARMs and as such different part numbers,
+		# an example is "bigLITTLE". we shouldn't rely on the first CPU only, so we check the whole list
+		i=0
+		for cpupart in $cpu_part_list
+		do
+			i=$(( i + 1 ))
+			# do NOT quote $cpu_arch_list below
+			# shellcheck disable=SC2086
+			cpuarch=$(echo $cpu_arch_list | awk '{ print $'$i' }')
+			_debug "checking cpu$i: <$cpupart> <$cpuarch>"
+			# some kernels report AArch64 instead of 8
+			[ "$cpuarch" = "AArch64" ] && cpuarch=8
+			if [ -n "$cpupart" ] && [ -n "$cpuarch" ]; then
+				# Cortex-R7 and Cortex-R8 are real-time and only used in medical devices or such
+				# I can't find their CPU part number, but it's probably not that useful anyway
+				# model R7 R8 A9    A15   A17   A57   A72    A73    A75
+				# part   ?  ? 0xc09 0xc0f 0xc0e 0xd07 0xd08  0xd09  0xd0a
+				# arch  7? 7? 7     7     7     8     8      8      8
+				#
+				# variant 1 & variant 2
+				if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c09|c0f|c0e)$'; then
+					# armv7 vulnerable chips
+					_debug "checking cpu$i: this armv7 vulnerable to spectre 1 & 2"
+					variant1=vuln
+					variant2=vuln
+				elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d07|d08|d09|d0a)$'; then
+					# armv8 vulnerable chips
+					_debug "checking cpu$i: this armv8 vulnerable to spectre 1 & 2"
+					variant1=vuln
+					variant2=vuln
+				else
+					_debug "checking cpu$i: this arm non vulnerable to 1 & 2"
+					# others are not vulnerable
+					[ -z "$variant1" ] && variant1=immune
+					[ -z "$variant2" ] && variant2=immune
+				fi
+
+				# for variant3, only A75 is vulnerable
+				if [ "$cpuarch" = 8 ] && [ "$cpupart" = 0xd0a ]; then
+					_debug "checking cpu$i: arm A75 vulnerable to meltdown"
+					variant3=vuln
+				else
+					_debug "checking cpu$i: this arm non vulnerable to meltdown"
+					[ -z "$variant3" ] && variant3=immune
+				fi
+			fi
+			_debug "is_cpu_vulnerable: for cpu$i and so far, we have <$variant1> <$variant2> <$variant3>"
+		done
+	fi
+	_debug "is_cpu_vulnerable: temp results are <$variant1> <$variant2> <$variant3>"
+	# if at least one of the cpu is vulnerable, then the system is vulnerable
+	[ "$variant1" = "immune" ] && variant1=1 || variant1=0
+	[ "$variant2" = "immune" ] && variant2=1 || variant2=0
+	[ "$variant3" = "immune" ] && variant3=1 || variant3=0
+	_debug "is_cpu_vulnerable: final results are <$variant1> <$variant2> <$variant3>"
+	is_cpu_vulnerable_cached=1
+	_is_cpu_vulnerable_cached "$1"
+	return $?
+}
+
+is_cpu_specex_free()
+{
+	# return true (0) if the CPU doesn't do speculative execution, false (1) if it does.
+	# if it's not in the list we know, return false (1).
+	# source: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/cpu/common.c#n882
+	# { X86_VENDOR_INTEL,     6, INTEL_FAM6_ATOM_CEDARVIEW,   X86_FEATURE_ANY },
+	# { X86_VENDOR_INTEL,     6, INTEL_FAM6_ATOM_CLOVERVIEW,  X86_FEATURE_ANY },
+	# { X86_VENDOR_INTEL,     6, INTEL_FAM6_ATOM_LINCROFT,    X86_FEATURE_ANY },
+	# { X86_VENDOR_INTEL,     6, INTEL_FAM6_ATOM_PENWELL,     X86_FEATURE_ANY },
+	# { X86_VENDOR_INTEL,     6, INTEL_FAM6_ATOM_PINEVIEW,    X86_FEATURE_ANY },
+	# { X86_VENDOR_CENTAUR,   5 },
+	# { X86_VENDOR_INTEL,     5 },
+	# { X86_VENDOR_NSC,       5 },
+	# { X86_VENDOR_ANY,       4 },
+	parse_cpu_details
+	if is_intel; then
+		if [ "$cpu_family" = 6 ]; then
+			if [ "$cpu_model" = "$INTEL_FAM6_ATOM_CEDARVIEW"  ]      || \
+				[ "$cpu_model" = "$INTEL_FAM6_ATOM_CLOVERVIEW" ] || \
+				[ "$cpu_model" = "$INTEL_FAM6_ATOM_LINCROFT"   ] || \
+				[ "$cpu_model" = "$INTEL_FAM6_ATOM_PENWELL"    ] || \
+				[ "$cpu_model" = "$INTEL_FAM6_ATOM_PINEVIEW"   ]; then
+				return 0
+			fi
+		elif [ "$cpu_family" = 5 ]; then
+			return 0
+		fi
+	fi
+	[ "$cpu_family" = 4 ] && return 0
+	return 1
 }
 
 show_header()
 {
-	_info "\033[1;34mSpectre and Meltdown mitigation detection tool v$VERSION\033[0m"
+	_info "Spectre and Meltdown mitigation detection tool v$VERSION"
 	_info
 }
 
@@ -233,20 +425,23 @@ parse_opt_file()
 
 while [ -n "$1" ]; do
 	if [ "$1" = "--kernel" ]; then
-		opt_kernel=$(parse_opt_file kernel "$2")
-		[ $? -ne 0 ] && exit $?
+		opt_kernel=$(parse_opt_file kernel "$2"); ret=$?
+		[ $ret -ne 0 ] && exit 255
 		shift 2
 		opt_live=0
 	elif [ "$1" = "--config" ]; then
-		opt_config=$(parse_opt_file config "$2")
-		[ $? -ne 0 ] && exit $?
+		opt_config=$(parse_opt_file config "$2"); ret=$?
+		[ $ret -ne 0 ] && exit 255
 		shift 2
 		opt_live=0
 	elif [ "$1" = "--map" ]; then
-		opt_map=$(parse_opt_file map "$2")
-		[ $? -ne 0 ] && exit $?
+		opt_map=$(parse_opt_file map "$2"); ret=$?
+		[ $ret -ne 0 ] && exit 255
 		shift 2
 		opt_live=0
+	elif [ "$1" = "--arch-prefix" ]; then
+		opt_arch_prefix="$2"
+		shift 2
 	elif [ "$1" = "--live" ]; then
 		opt_live_explicit=1
 		shift
@@ -256,27 +451,49 @@ while [ -n "$1" ]; do
 	elif [ "$1" = "--no-sysfs" ]; then
 		opt_no_sysfs=1
 		shift
+	elif [ "$1" = "--sysfs-only" ]; then
+		opt_sysfs_only=1
+		shift
+	elif [ "$1" = "--coreos" ]; then
+		opt_coreos=1
+		shift
+	elif [ "$1" = "--coreos-within-toolbox" ]; then
+		# don't use directly: used internally by --coreos
+		opt_coreos=0
+		shift
+	elif [ "$1" = "--paranoid" ]; then
+		opt_paranoid=1
+		shift
+	elif [ "$1" = "--hw-only" ]; then
+		opt_hw_only=1
+		shift
+	elif [ "$1" = "--no-hw" ]; then
+		opt_no_hw=1
+		shift
+	elif [ "$1" = "--no-explain" ]; then
+		opt_no_explain=1
+		shift
 	elif [ "$1" = "--batch" ]; then
 		opt_batch=1
 		opt_verbose=0
 		shift
 		case "$1" in
-			text|nrpe|json) opt_batch_format="$1"; shift;;
+			text|nrpe|json|prometheus) opt_batch_format="$1"; shift;;
 			--*) ;;    # allow subsequent flags
 			'') ;;     # allow nothing at all
 			*)
-				echo "$0: error: unknown batch format '$1'"
-				echo "$0: error: --batch expects a format from: text, nrpe, json"
-				exit 1 >&2
+				echo "$0: error: unknown batch format '$1'" >&2
+				echo "$0: error: --batch expects a format from: text, nrpe, json" >&2
+				exit 255
 				;;
 		esac
-	elif [ "$1" = "-v" -o "$1" = "--verbose" ]; then
-		opt_verbose=$(expr $opt_verbose + 1)
+	elif [ "$1" = "-v" ] || [ "$1" = "--verbose" ]; then
+		opt_verbose=$(( opt_verbose + 1 ))
 		shift
 	elif [ "$1" = "--variant" ]; then
 		if [ -z "$2" ]; then
 			echo "$0: error: option --variant expects a parameter (1, 2 or 3)" >&2
-			exit 1
+			exit 255
 		fi
 		case "$2" in
 			1) opt_variant1=1; opt_allvariants=0;;
@@ -284,17 +501,18 @@ while [ -n "$1" ]; do
 			3) opt_variant3=1; opt_allvariants=0;;
 			*)
 				echo "$0: error: invalid parameter '$2' for --variant, expected either 1, 2 or 3" >&2;
-				exit 1;;
+				exit 255
+				;;
 		esac
 		shift 2
-	elif [ "$1" = "-h" -o "$1" = "--help" ]; then
+	elif [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
 		show_header
 		show_usage
 		exit 0
 	elif [ "$1" = "--version" ]; then
 		opt_no_color=1
 		show_header
-		exit 1
+		exit 0
 	elif [ "$1" = "--disclaimer" ]; then
 		show_header
 		show_disclaimer
@@ -303,12 +521,22 @@ while [ -n "$1" ]; do
 		show_header
 		show_usage
 		echo "$0: error: unknown option '$1'"
-		exit 1
+		exit 255
 	fi
 done
 
 show_header
 
+if [ "$opt_no_sysfs" = 1 ] && [ "$opt_sysfs_only" = 1 ]; then
+	_warn "Incompatible options specified (--no-sysfs and --sysfs-only), aborting"
+	exit 255
+fi
+
+if [ "$opt_no_hw" = 1 ] && [ "$opt_hw_only" = 1 ]; then
+	_warn "Incompatible options specified (--no-hw and --hw-only), aborting"
+	exit 255
+fi
+
 # print status function
 pstatus()
 {
@@ -316,54 +544,63 @@ pstatus()
 		_info_nol "$2"
 	else
 		case "$1" in
-			red)    col="\033[101m\033[30m";;
-			green)  col="\033[102m\033[30m";;
-			yellow) col="\033[103m\033[30m";;
-			blue)   col="\033[104m\033[30m";;
+			red)    col="\033[41m\033[30m";;
+			green)  col="\033[42m\033[30m";;
+			yellow) col="\033[43m\033[30m";;
+			blue)   col="\033[44m\033[30m";;
 			*)      col="";;
 		esac
 		_info_nol "$col $2 \033[0m"
 	fi
 	[ -n "$3" ] && _info_nol " ($3)"
 	_info
+	unset col
 }
 
 # Print the final status of a vulnerability (incl. batch mode)
 # Arguments are: CVE UNK/OK/VULN description
 pvulnstatus()
 {
+	pvulnstatus_last_cve="$1"
 	if [ "$opt_batch" = 1 ]; then
-                case "$opt_batch_format" in
-                        text) _echo 0 "$1: $2 ($3)";;
-                        nrpe)
-                              case "$2" in
-                                       UKN) nrpe_unknown="1";;
-                                       VULN) nrpe_critical="1"; nrpe_vuln="$nrpe_vuln $1";;
-                              esac
-                              ;;
-                        json)
-                              case "$1" in
-                                       CVE-2017-5753) aka="SPECTRE VARIANT 1";;
-                                       CVE-2017-5715) aka="SPECTRE VARIANT 2";;
-                                       CVE-2017-5754) aka="MELTDOWN";;
-                              esac
-                              case "$2" in
-                                       UKN)  is_vuln="unknown";;
-                                       VULN) is_vuln="true";;
-                                       OK)   is_vuln="false";;
-                              esac
-                              json_output="${json_output:-[}{\"NAME\":\""$aka"\",\"CVE\":\""$1"\",\"VULNERABLE\":$is_vuln,\"INFOS\":\""$3"\"},"
-                              ;;
+		case "$1" in
+			CVE-2017-5753) aka="SPECTRE VARIANT 1";;
+			CVE-2017-5715) aka="SPECTRE VARIANT 2";;
+			CVE-2017-5754) aka="MELTDOWN";;
+		esac
+
+		case "$opt_batch_format" in
+			text) _echo 0 "$1: $2 ($3)";;
+			json)
+				case "$2" in
+					UNK)  is_vuln="null";;
+					VULN) is_vuln="true";;
+					OK)   is_vuln="false";;
+				esac
+				json_output="${json_output:-[}{\"NAME\":\"$aka\",\"CVE\":\"$1\",\"VULNERABLE\":$is_vuln,\"INFOS\":\"$3\"},"
+				;;
+
+			nrpe)	[ "$2" = VULN ] && nrpe_vuln="$nrpe_vuln $1";;
+			prometheus)
+				prometheus_output="${prometheus_output:+$prometheus_output\n}specex_vuln_status{name=\"$aka\",cve=\"$1\",status=\"$2\",info=\"$3\"} 1"
+				;;
 		esac
 	fi
 
-	_info_nol "> \033[46m\033[30mSTATUS:\033[0m "
+	# always fill global_* vars because we use that do decide the program exit code
+	case "$2" in
+		UNK)  global_unknown="1";;
+		VULN) global_critical="1";;
+	esac
+
+	# display info if we're not in quiet/batch mode
 	vulnstatus="$2"
 	shift 2
+	_info_nol "> \033[46m\033[30mSTATUS:\033[0m "
 	case "$vulnstatus" in
-		UNK) pstatus yellow UNKNOWN "$@";;
-		VULN) pstatus red 'VULNERABLE' "$@";;
-		OK) pstatus green 'NOT VULNERABLE' "$@";;
+		UNK)  pstatus yellow 'UNKNOWN'        "$@";;
+		VULN) pstatus red    'VULNERABLE'     "$@";;
+		OK)   pstatus green  'NOT VULNERABLE' "$@";;
 	esac
 }
 
@@ -384,12 +621,38 @@ pvulnstatus()
 # Licensed under the GNU General Public License, version 2 (GPLv2).
 # ----------------------------------------------------------------------
 
-vmlinux=''
-vmlinux_err=''
-check_vmlinux()
+kernel=''
+kernel_err=''
+check_kernel()
 {
-	readelf -h "$1" > /dev/null 2>&1 || return 1
-	return 0
+	_file="$1"
+	_desperate_mode="$2"
+	# checking the return code of readelf -h is not enough, we could get
+	# a damaged ELF file and validate it, check for stderr warnings too
+	_readelf_warnings=$("${opt_arch_prefix}readelf" -S "$_file" 2>&1 >/dev/null | tr "\n" "/"); ret=$?
+	_readelf_sections=$("${opt_arch_prefix}readelf" -S "$_file" 2>/dev/null | grep -c -e data -e text -e init)
+	_kernel_size=$(stat -c %s "$_file" 2>/dev/null || stat -f %z "$_file" 2>/dev/null || echo 10000)
+	_debug "check_kernel: ret=$? size=$_kernel_size sections=$_readelf_sections warnings=$_readelf_warnings"
+	if [ -n "$_desperate_mode" ]; then
+		if "${opt_arch_prefix}strings" "$_file" | grep -Eq '^Linux version '; then
+			_debug "check_kernel (desperate): ... matched!"
+			return 0
+		else
+			_debug "check_kernel (desperate): ... invalid"
+		fi
+	else
+		if [ $ret -eq 0 ] && [ -z "$_readelf_warnings" ] && [ "$_readelf_sections" -gt 0 ]; then
+			if [ "$_kernel_size" -ge 100000 ]; then
+				_debug "check_kernel: ... file is valid"
+				return 0
+			else
+				_debug "check_kernel: ... file seems valid but is too small, ignoring"
+			fi
+		else
+			_debug "check_kernel: ... file is invalid"
+		fi
+	fi
+	return 1
 }
 
 try_decompress()
@@ -398,159 +661,66 @@ try_decompress()
 	# "grep" that report the byte offset of the line instead of the pattern.
 
 	# Try to find the header ($1) and decompress from here
-	for     pos in `tr "$1\n$2" "\n$2=" < "$6" | grep -abo "^$2"`
+	_debug "try_decompress: looking for $3 magic in $6"
+	for     pos in $(tr "$1\n$2" "\n$2=" < "$6" | grep -abo "^$2")
 	do
 		_debug "try_decompress: magic for $3 found at offset $pos"
 		if ! which "$3" >/dev/null 2>&1; then
-			vmlinux_err="missing '$3' tool, please install it, usually it's in the '$5' package"
+			kernel_err="missing '$3' tool, please install it, usually it's in the '$5' package"
 			return 0
 		fi
 		pos=${pos%%:*}
-		tail -c+$pos "$6" 2>/dev/null | $3 $4 > $vmlinuxtmp 2>/dev/null
-		if check_vmlinux "$vmlinuxtmp"; then
-			vmlinux="$vmlinuxtmp"
+		# shellcheck disable=SC2086
+		tail -c+$pos "$6" 2>/dev/null | $3 $4 > "$kerneltmp" 2>/dev/null; ret=$?
+		if [ ! -s "$kerneltmp" ]; then
+			# don't rely on $ret, sometimes it's != 0 but worked
+			# (e.g. gunzip ret=2 just means there was trailing garbage)
+			_debug "try_decompress: decompression with $3 failed (err=$ret)"
+		elif check_kernel "$kerneltmp" "$7"; then
+			kernel="$kerneltmp"
 			_debug "try_decompress: decompressed with $3 successfully!"
 			return 0
+		elif [ "$3" != "cat" ]; then
+			_debug "try_decompress: decompression with $3 worked but result is not a kernel, trying with an offset"
+			[ -z "$kerneltmp2" ] && kerneltmp2=$(mktemp /tmp/kernel-XXXXXX)
+			cat "$kerneltmp" > "$kerneltmp2"
+			try_decompress '\177ELF' xxy 'cat' '' cat "$kerneltmp2" && return 0
 		else
-			_debug "try_decompress: decompression with $3 did not work"
+			_debug "try_decompress: decompression with $3 worked but result is not a kernel"
 		fi
 	done
 	return 1
 }
 
-extract_vmlinux()
+extract_kernel()
 {
 	[ -n "$1" ] || return 1
 	# Prepare temp files:
-	vmlinuxtmp="$(mktemp /tmp/vmlinux-XXXXXX)"
-	trap "rm -f $vmlinuxtmp" EXIT
+	kerneltmp="$(mktemp /tmp/kernel-XXXXXX)"
 
 	# Initial attempt for uncompressed images or objects:
-	if check_vmlinux "$1"; then
-		cat "$1" > "$vmlinuxtmp"
-		vmlinux=$vmlinuxtmp
+	if check_kernel "$1"; then
+		cat "$1" > "$kerneltmp"
+		kernel=$kerneltmp
 		return 0
 	fi
 
 	# That didn't work, so retry after decompression.
-	try_decompress '\037\213\010'     xy    gunzip  ''      gunzip      "$1" && return 0
-	try_decompress '\3757zXZ\000'     abcde unxz    ''      xz-utils    "$1" && return 0
-	try_decompress 'BZh'              xy    bunzip2 ''      bzip2       "$1" && return 0
-	try_decompress '\135\0\0\0'       xxx   unlzma  ''      xz-utils    "$1" && return 0
-	try_decompress '\211\114\132'     xy    'lzop'  '-d'    lzop        "$1" && return 0
-	try_decompress '\002\041\114\030' xyy   'lz4'   '-d -l' liblz4-tool "$1" && return 0
+	for mode in '' 'desperate'; do
+		try_decompress '\037\213\010'     xy    gunzip  ''      gunzip      "$1" "$mode" && return 0
+		try_decompress '\3757zXZ\000'     abcde unxz    ''      xz-utils    "$1" "$mode" && return 0
+		try_decompress 'BZh'              xy    bunzip2 ''      bzip2       "$1" "$mode" && return 0
+		try_decompress '\135\0\0\0'       xxx   unlzma  ''      xz-utils    "$1" "$mode" && return 0
+		try_decompress '\211\114\132'     xy    'lzop'  '-d'    lzop        "$1" "$mode" && return 0
+		try_decompress '\002\041\114\030' xyy   'lz4'   '-d -l' liblz4-tool "$1" "$mode" && return 0
+		try_decompress '\177ELF'          xxy   'cat'   ''      cat         "$1" "$mode" && return 0
+	done
+	_verbose "Couldn't extract the kernel image, accuracy might be reduced"
 	return 1
 }
 
 # end of extract-vmlinux functions
 
-# check for mode selection inconsistency
-if [ "$opt_live_explicit" = 1 ]; then
-	if [ -n "$opt_kernel" -o -n "$opt_config" -o -n "$opt_map" ]; then
-		show_usage
-		echo "$0: error: incompatible modes specified, use either --live or --kernel/--config/--map"
-		exit 1
-	fi
-fi
-
-# root check (only for live mode, for offline mode, we already checked if we could read the files)
-
-if [ "$opt_live" = 1 ]; then
-	if [ "$(id -u)" -ne 0 ]; then
-		_warn "Note that you should launch this script with root privileges to get accurate information."
-		_warn "We'll proceed but you might see permission denied errors."
-		_warn "To run it as root, you can try the following command: sudo $0"
-		_warn
-	fi
-	_info "Checking for vulnerabilities against running kernel \033[35m"$(uname -s) $(uname -r) $(uname -v) $(uname -m)"\033[0m"
-	_info "CPU is\033[35m"$(grep '^model name' /proc/cpuinfo | cut -d: -f2 | head -1)"\033[0m"
-
-	# try to find the image of the current running kernel
-	# first, look for the BOOT_IMAGE hint in the kernel cmdline
-	if [ -r /proc/cmdline ] && grep -q 'BOOT_IMAGE=' /proc/cmdline; then
-		opt_kernel=$(grep -Eo 'BOOT_IMAGE=[^ ]+' /proc/cmdline | cut -d= -f2)
-		_debug "found opt_kernel=$opt_kernel in /proc/cmdline"
-		# if we have a dedicated /boot partition, our bootloader might have just called it /
-		# so try to prepend /boot and see if we find anything
-		[ -e "/boot/$opt_kernel" ] && opt_kernel="/boot/$opt_kernel"
-		_debug "opt_kernel is now $opt_kernel"
-		# else, the full path is already there (most probably /boot/something)
-	fi
-	# if we didn't find a kernel, default to guessing
-	if [ ! -e "$opt_kernel" ]; then
-		[ -e /boot/vmlinuz-linux       ] && opt_kernel=/boot/vmlinuz-linux
-		[ -e /boot/vmlinuz-linux-libre ] && opt_kernel=/boot/vmlinuz-linux-libre
-		[ -e /boot/vmlinuz-$(uname -r) ] && opt_kernel=/boot/vmlinuz-$(uname -r)
-		[ -e /boot/kernel-$( uname -r) ] && opt_kernel=/boot/kernel-$( uname -r)
-		[ -e /boot/bzImage-$(uname -r) ] && opt_kernel=/boot/bzImage-$(uname -r)
-		[ -e /boot/kernel-genkernel-$(uname -m)-$(uname -r) ] && opt_kernel=/boot/kernel-genkernel-$(uname -m)-$(uname -r)
-	fi
-
-	# system.map
-	if [ -e /proc/kallsyms ] ; then
-		opt_map="/proc/kallsyms"
-	elif [ -e /boot/System.map-$(uname -r) ] ; then
-		opt_map=/boot/System.map-$(uname -r)
-	fi
-
-	# config
-	if [ -e /proc/config.gz ] ; then
-		dumped_config="$(mktemp /tmp/config-XXXXXX)"
-		gunzip -c /proc/config.gz > $dumped_config
-		# dumped_config will be deleted at the end of the script
-		opt_config=$dumped_config
-	elif [ -e /boot/config-$(uname -r) ]; then
-		opt_config=/boot/config-$(uname -r)
-	fi
-else
-	_info "Checking for vulnerabilities against specified kernel"
-fi
-
-if [ -n "$opt_kernel" ]; then
-	_verbose "Will use vmlinux image \033[35m$opt_kernel\033[0m"
-else
-	_verbose "Will use no vmlinux image (accuracy might be reduced)"
-	bad_accuracy=1
-fi
-if [ -n "$dumped_config" ]; then
-	_verbose "Will use kconfig \033[35m/proc/config.gz\033[0m"
-elif [ -n "$opt_config" ]; then
-	_verbose "Will use kconfig \033[35m$opt_config\033[0m"
-else
-	_verbose "Will use no kconfig (accuracy might be reduced)"
-	bad_accuracy=1
-fi
-if [ -n "$opt_map" ]; then
-	_verbose "Will use System.map file \033[35m$opt_map\033[0m"
-else
-	_verbose "Will use no System.map file (accuracy might be reduced)"
-	bad_accuracy=1
-fi
-
-if [ "$bad_accuracy" = 1 ]; then
-	_info "We're missing some kernel info (see -v), accuracy might be reduced"
-fi
-
-if [ -e "$opt_kernel" ]; then
-	if ! which readelf >/dev/null 2>&1; then
-		vmlinux_err="missing 'readelf' tool, please install it, usually it's in the 'binutils' package"
-	else
-		extract_vmlinux "$opt_kernel"
-	fi
-else
-	vmlinux_err="couldn't find your kernel image in /boot, if you used netboot, this is normal"
-fi
-if [ -z "$vmlinux" -o ! -r "$vmlinux" ]; then
-	[ -z "$vmlinux_err" ] && vmlinux_err="couldn't extract your kernel from $opt_kernel"
-fi
-
-_info
-
-# end of header stuff
-
-# now we define some util functions and the check_*() funcs, as
-# the user can choose to execute only some of those
-
 mount_debugfs()
 {
 	if [ ! -e /sys/kernel/debug/sched_features ]; then
@@ -559,188 +729,1444 @@ mount_debugfs()
 	fi
 }
 
-umount_debugfs()
+load_msr()
 {
-	if [ "$mounted_debugfs" = 1 ]; then
-		# umount debugfs if we did mount it ourselves
-		umount /sys/kernel/debug
+	if [ "$os" = Linux ]; then
+		modprobe msr 2>/dev/null && insmod_msr=1
+		_debug "attempted to load module msr, insmod_msr=$insmod_msr"
+	else
+		if ! kldstat -q -m cpuctl; then
+			kldload cpuctl 2>/dev/null && kldload_cpuctl=1
+			_debug "attempted to load module cpuctl, kldload_cpuctl=$kldload_cpuctl"
+		else
+			_debug "cpuctl module already loaded"
+		fi
 	fi
 }
 
+load_cpuid()
+{
+	if [ "$os" = Linux ]; then
+		modprobe cpuid 2>/dev/null && insmod_cpuid=1
+		_debug "attempted to load module cpuid, insmod_cpuid=$insmod_cpuid"
+	else
+		if ! kldstat -q -m cpuctl; then
+			kldload cpuctl 2>/dev/null && kldload_cpuctl=1
+			_debug "attempted to load module cpuctl, kldload_cpuctl=$kldload_cpuctl"
+		else
+			_debug "cpuctl module already loaded"
+		fi
+	fi
+}
+
+# shellcheck disable=SC2034
+{
+EAX=1; EBX=2; ECX=3; EDX=4;
+}
+read_cpuid()
+{
+	# leaf is the value of the eax register when calling the cpuid instruction:
+	_leaf="$1"
+	# eax=1 ebx=2 ecx=3 edx=4:
+	_register="$2"
+	# number of bits to shift the register right to:
+	_shift="$3"
+	# mask to apply as an AND operand to the shifted register value
+	_mask="$4"
+	# wanted value (optional), if present we return 0(true) if the obtained value is equal, 1 otherwise:
+	_wanted="$5"
+	# in any case, the read value is globally available in $read_cpuid_value
+
+	read_cpuid_value=''
+	if [ ! -e /dev/cpu/0/cpuid ] && [ ! -e /dev/cpuctl0 ]; then
+		# try to load the module ourselves (and remember it so we can rmmod it afterwards)
+		load_cpuid
+	fi
+
+	if [ -e /dev/cpu/0/cpuid ]; then
+		# Linux
+		# we need _leaf to be converted to decimal for dd
+		_leaf=$(( _leaf ))
+		_cpuid=$(dd if=/dev/cpu/0/cpuid bs=16 skip="$_leaf" iflag=skip_bytes count=1 2>/dev/null | od -A n -t u4)
+	elif [ -e /dev/cpuctl0 ]; then
+		# BSD
+		_cpuid=$(cpucontrol -i "$_leaf" /dev/cpuctl0 2>/dev/null | awk '{print $4,$5,$6,$7}')
+		# cpuid level 0x1: 0x000306d4 0x00100800 0x4dfaebbf 0xbfebfbff
+	else
+		return 2
+	fi
+
+	_debug "cpuid: leaf$_leaf on cpu0, eax-ebx-ecx-edx: $_cpuid"
+	[ -z "$_cpuid" ] && return 2
+	# get the value of the register we want
+	_reg=$(echo "$_cpuid" | awk '{print $'"$_register"'}')
+	# Linux returns it as decimal, BSD as hex, normalize to decimal
+	_reg=$(( _reg ))
+	# shellcheck disable=SC2046
+	_debug "cpuid: wanted register ($_register) has value $_reg aka "$(printf "%08x" "$_reg")
+	_reg_shifted=$(( _reg >> _shift ))
+	# shellcheck disable=SC2046
+	_debug "cpuid: shifted value by $_shift is $_reg_shifted aka "$(printf "%x" "$_reg_shifted")
+	read_cpuid_value=$(( _reg_shifted & _mask ))
+	# shellcheck disable=SC2046
+	_debug "cpuid: after AND $_mask, final value is $read_cpuid_value aka "$(printf "%x" "$read_cpuid_value")
+	if [ -n "$_wanted" ]; then
+		_debug "cpuid: wanted $_wanted and got $read_cpuid_value"
+		if [ "$read_cpuid_value" = "$_wanted" ]; then
+			return 0
+		else
+			return 1
+		fi
+	fi
+
+	return 0
+}
+
+dmesg_grep()
+{
+	# grep for something in dmesg, ensuring that the dmesg buffer
+	# has not been truncated
+	dmesg_grepped=''
+	if ! dmesg | grep -qE -e '(^|\] )Linux version [0-9]' -e '^FreeBSD is a registered' ; then
+		# dmesg truncated
+		return 2
+	fi
+	dmesg_grepped=$(dmesg | grep -E "$1" | head -1)
+	# not found:
+	[ -z "$dmesg_grepped" ] && return 1
+	# found, output is in $dmesg_grepped
+	return 0
+}
+
+is_coreos()
+{
+	which coreos-install >/dev/null 2>&1 && which toolbox >/dev/null 2>&1 && return 0
+	return 1
+}
+
+parse_cpu_details()
+{
+	[ "$parse_cpu_details_done" = 1 ] && return 0
+
+	if [ -e "$procfs/cpuinfo" ]; then
+		cpu_vendor=$(  grep '^vendor_id'  "$procfs/cpuinfo" | awk '{print $3}' | head -1)
+		cpu_friendly_name=$(grep '^model name' "$procfs/cpuinfo" | cut -d: -f2- | head -1 | sed -e 's/^ *//')
+		# special case for ARM follows
+		if grep -qi 'CPU implementer[[:space:]]*:[[:space:]]*0x41' "$procfs/cpuinfo"; then
+			cpu_vendor='ARM'
+			# some devices (phones or other) have several ARMs and as such different part numbers,
+			# an example is "bigLITTLE", so we need to store the whole list, this is needed for is_cpu_vulnerable
+			cpu_part_list=$(awk '/CPU part/         {print $4}' "$procfs/cpuinfo")
+			cpu_arch_list=$(awk '/CPU architecture/ {print $3}' "$procfs/cpuinfo")
+			# take the first one to fill the friendly name, do NOT quote the vars below
+			# shellcheck disable=SC2086
+			cpu_arch=$(echo $cpu_arch_list | awk '{ print $1 }')
+			# shellcheck disable=SC2086
+			cpu_part=$(echo $cpu_part_list | awk '{ print $1 }')
+			[ "$cpu_arch" = "AArch64" ] && cpu_arch=8
+			cpu_friendly_name="ARM"
+			[ -n "$cpu_arch" ] && cpu_friendly_name="$cpu_friendly_name v$cpu_arch"
+			[ -n "$cpu_part" ] && cpu_friendly_name="$cpu_friendly_name model $cpu_part"
+		fi
+
+		cpu_family=$(  grep '^cpu family' "$procfs/cpuinfo" | awk '{print $4}' | grep -E '^[0-9]+$' | head -1)
+		cpu_model=$(   grep '^model'      "$procfs/cpuinfo" | awk '{print $3}' | grep -E '^[0-9]+$' | head -1)
+		cpu_stepping=$(grep '^stepping'   "$procfs/cpuinfo" | awk '{print $3}' | grep -E '^[0-9]+$' | head -1)
+		cpu_ucode=$(  grep '^microcode'   "$procfs/cpuinfo" | awk '{print $3}' | head -1)
+	else
+		cpu_friendly_name=$(sysctl -n hw.model)
+	fi
+
+	# get raw cpuid, it's always useful (referenced in the Intel doc for firmware updates for example)
+	if read_cpuid 0x1 $EAX 0 0xFFFFFFFF; then
+		cpuid="$read_cpuid_value"
+	fi
+
+	# under BSD, linprocfs often doesn't export ucode information, so fetch it ourselves the good old way
+	if [ -z "$cpu_ucode" ] && [ "$os" != Linux ]; then
+		load_cpuid
+		if [ -e /dev/cpuctl0 ]; then
+			# init MSR with NULLs
+			cpucontrol -m 0x8b=0 /dev/cpuctl0
+			# call CPUID
+			cpucontrol -i 1 /dev/cpuctl0 >/dev/null
+			# read MSR
+			cpu_ucode=$(cpucontrol -m 0x8b /dev/cpuctl0 | awk '{print $3}')
+			# convert to decimal
+			cpu_ucode=$(( cpu_ucode ))
+			# convert back to hex
+			cpu_ucode=$(printf "0x%x" "$cpu_ucode")
+		fi
+	fi
+
+	echo "$cpu_ucode" | grep -q ^0x && cpu_ucode_decimal=$(( cpu_ucode ))
+	ucode_found="model $cpu_model stepping $cpu_stepping ucode $cpu_ucode cpuid "$(printf "0x%x" "$cpuid")
+
+	# also define those that we will need in other funcs
+	# taken from ttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/include/asm/intel-family.h
+	# shellcheck disable=SC2034
+	{
+	INTEL_FAM6_CORE_YONAH=$(( 0x0E ))
+
+	INTEL_FAM6_CORE2_MEROM=$(( 0x0F ))
+	INTEL_FAM6_CORE2_MEROM_L=$(( 0x16 ))
+	INTEL_FAM6_CORE2_PENRYN=$(( 0x17 ))
+	INTEL_FAM6_CORE2_DUNNINGTON=$(( 0x1D ))
+
+	INTEL_FAM6_NEHALEM=$(( 0x1E ))
+	INTEL_FAM6_NEHALEM_G=$(( 0x1F ))
+	INTEL_FAM6_NEHALEM_EP=$(( 0x1A ))
+	INTEL_FAM6_NEHALEM_EX=$(( 0x2E ))
+
+	INTEL_FAM6_WESTMERE=$(( 0x25 ))
+	INTEL_FAM6_WESTMERE_EP=$(( 0x2C ))
+	INTEL_FAM6_WESTMERE_EX=$(( 0x2F ))
+
+	INTEL_FAM6_SANDYBRIDGE=$(( 0x2A ))
+	INTEL_FAM6_SANDYBRIDGE_X=$(( 0x2D ))
+	INTEL_FAM6_IVYBRIDGE=$(( 0x3A ))
+	INTEL_FAM6_IVYBRIDGE_X=$(( 0x3E ))
+
+	INTEL_FAM6_HASWELL_CORE=$(( 0x3C ))
+	INTEL_FAM6_HASWELL_X=$(( 0x3F ))
+	INTEL_FAM6_HASWELL_ULT=$(( 0x45 ))
+	INTEL_FAM6_HASWELL_GT3E=$(( 0x46 ))
+
+	INTEL_FAM6_BROADWELL_CORE=$(( 0x3D ))
+	INTEL_FAM6_BROADWELL_GT3E=$(( 0x47 ))
+	INTEL_FAM6_BROADWELL_X=$(( 0x4F ))
+	INTEL_FAM6_BROADWELL_XEON_D=$(( 0x56 ))
+
+	INTEL_FAM6_SKYLAKE_MOBILE=$(( 0x4E ))
+	INTEL_FAM6_SKYLAKE_DESKTOP=$(( 0x5E ))
+	INTEL_FAM6_SKYLAKE_X=$(( 0x55 ))
+	INTEL_FAM6_KABYLAKE_MOBILE=$(( 0x8E ))
+	INTEL_FAM6_KABYLAKE_DESKTOP=$(( 0x9E ))
+
+	# /* "Small Core" Processors (Atom) */
+
+	INTEL_FAM6_ATOM_PINEVIEW=$(( 0x1C ))
+	INTEL_FAM6_ATOM_LINCROFT=$(( 0x26 ))
+	INTEL_FAM6_ATOM_PENWELL=$(( 0x27 ))
+	INTEL_FAM6_ATOM_CLOVERVIEW=$(( 0x35 ))
+	INTEL_FAM6_ATOM_CEDARVIEW=$(( 0x36 ))
+	INTEL_FAM6_ATOM_SILVERMONT1=$(( 0x37 ))
+	INTEL_FAM6_ATOM_SILVERMONT2=$(( 0x4D ))
+	INTEL_FAM6_ATOM_AIRMONT=$(( 0x4C ))
+	INTEL_FAM6_ATOM_MERRIFIELD=$(( 0x4A ))
+	INTEL_FAM6_ATOM_MOOREFIELD=$(( 0x5A ))
+	INTEL_FAM6_ATOM_GOLDMONT=$(( 0x5C ))
+	INTEL_FAM6_ATOM_DENVERTON=$(( 0x5F ))
+	INTEL_FAM6_ATOM_GEMINI_LAKE=$(( 0x7A ))
+
+	# /* Xeon Phi */
+
+	INTEL_FAM6_XEON_PHI_KNL=$(( 0x57 ))
+	INTEL_FAM6_XEON_PHI_KNM=$(( 0x85 ))
+	}
+	parse_cpu_details_done=1
+}
+
+is_amd()
+{
+	[ "$cpu_vendor" = AuthenticAMD ] && return 0
+	return 1
+}
+
+is_intel()
+{
+	[ "$cpu_vendor" = GenuineIntel ] && return 0
+	return 1
+}
+
+is_cpu_smt_enabled()
+{
+	# SMT / HyperThreading is enabled if siblings != cpucores
+	if [ -e "$procfs/cpuinfo" ]; then
+		_siblings=$(awk '/^siblings/  {print $3;exit}' "$procfs/cpuinfo")
+		_cpucores=$(awk '/^cpu cores/ {print $4;exit}' "$procfs/cpuinfo")
+		if [ -n "$_siblings" ] && [ -n "$_cpucores" ]; then
+			if [ "$_siblings" = "$_cpucores" ]; then
+				return 1
+			else
+				return 0
+			fi
+		fi
+	fi
+	# we can't tell
+	return 2
+}
+
+is_ucode_blacklisted()
+{
+	parse_cpu_details
+	# if it's not an Intel, don't bother: it's not blacklisted
+	is_intel || return 1
+	# it also needs to be family=6
+	[ "$cpu_family" = 6 ] || return 1
+	# now, check each known bad microcode
+	# source: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/cpu/intel.c#n105
+	# 2018-02-08 update: https://newsroom.intel.com/wp-content/uploads/sites/11/2018/02/microcode-update-guidance.pdf
+	# model,stepping,microcode
+	for tuple in \
+		$INTEL_FAM6_KABYLAKE_DESKTOP,0x0B,0x80 \
+		$INTEL_FAM6_KABYLAKE_DESKTOP,0x0A,0x80 \
+		$INTEL_FAM6_KABYLAKE_DESKTOP,0x09,0x80 \
+		$INTEL_FAM6_KABYLAKE_MOBILE,0x0A,0x80  \
+		$INTEL_FAM6_KABYLAKE_MOBILE,0x09,0x80  \
+		$INTEL_FAM6_SKYLAKE_X,0x03,0x0100013e  \
+		$INTEL_FAM6_SKYLAKE_X,0x04,0x02000036  \
+		$INTEL_FAM6_SKYLAKE_X,0x04,0x0200003a  \
+		$INTEL_FAM6_SKYLAKE_X,0x04,0x0200003c  \
+		$INTEL_FAM6_BROADWELL_CORE,0x04,0x28   \
+		$INTEL_FAM6_BROADWELL_GT3E,0x01,0x1b   \
+		$INTEL_FAM6_BROADWELL_XEON_D,0x02,0x14 \
+		$INTEL_FAM6_BROADWELL_XEON_D,0x03,0x07000011 \
+		$INTEL_FAM6_BROADWELL_X,0x01,0x0b000023 \
+		$INTEL_FAM6_BROADWELL_X,0x01,0x0b000025 \
+		$INTEL_FAM6_HASWELL_ULT,0x01,0x21      \
+		$INTEL_FAM6_HASWELL_GT3E,0x01,0x18     \
+		$INTEL_FAM6_HASWELL_CORE,0x03,0x23     \
+		$INTEL_FAM6_HASWELL_X,0x02,0x3b        \
+		$INTEL_FAM6_HASWELL_X,0x04,0x10        \
+		$INTEL_FAM6_IVYBRIDGE_X,0x04,0x42a     \
+		$INTEL_FAM6_SANDYBRIDGE_X,0x06,0x61b   \
+		$INTEL_FAM6_SANDYBRIDGE_X,0x07,0x712
+	do
+		model=$(echo $tuple | cut -d, -f1)
+		stepping=$(( $(echo $tuple | cut -d, -f2) ))
+		ucode=$(echo $tuple | cut -d, -f3)
+		echo "$ucode" | grep -q ^0x && ucode_decimal=$(( ucode ))
+		if [ "$cpu_model" = "$model" ] && [ "$cpu_stepping" = "$stepping" ]; then
+			if [ "$cpu_ucode_decimal" = "$ucode_decimal" ] || [ "$cpu_ucode" = "$ucode" ]; then
+				_debug "is_ucode_blacklisted: we have a match! ($cpu_model/$cpu_stepping/$cpu_ucode)"
+				return 0
+			fi
+		fi
+	done
+	_debug "is_ucode_blacklisted: no ($cpu_model/$cpu_stepping/$cpu_ucode)"
+	return 1
+}
+
+is_skylake_cpu()
+{
+	# is this a skylake cpu?
+	# return 0 if yes, 1 otherwise
+	#if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+	#	    boot_cpu_data.x86 == 6) {
+	#		switch (boot_cpu_data.x86_model) {
+	#		case INTEL_FAM6_SKYLAKE_MOBILE:
+	#		case INTEL_FAM6_SKYLAKE_DESKTOP:
+	#		case INTEL_FAM6_SKYLAKE_X:
+	#		case INTEL_FAM6_KABYLAKE_MOBILE:
+	#		case INTEL_FAM6_KABYLAKE_DESKTOP:
+	#			return true;
+	parse_cpu_details
+	is_intel || return 1
+	[ "$cpu_family" = 6 ] || return 1
+	if [ "$cpu_model" = $INTEL_FAM6_SKYLAKE_MOBILE        ] || \
+		[ "$cpu_model" = $INTEL_FAM6_SKYLAKE_DESKTOP  ] || \
+		[ "$cpu_model" = $INTEL_FAM6_SKYLAKE_X        ] || \
+		[ "$cpu_model" = $INTEL_FAM6_KABYLAKE_MOBILE  ] || \
+		[ "$cpu_model" = $INTEL_FAM6_KABYLAKE_DESKTOP ]; then
+		return 0
+	fi
+	return 1
+}
+
+is_zen_cpu()
+{
+	# is this CPU from the AMD ZEN family ? (ryzen, epyc, ...)
+	parse_cpu_details
+	is_amd || return 1
+	[ "$cpu_family" = 23 ] && return 0
+	return 1
+}
+
+# ENTRYPOINT
+
+# we can't do anything useful under WSL
+if uname -a | grep -qE -- '-Microsoft #[0-9]+-Microsoft '; then
+	_warn "This script doesn't work under Windows Subsystem for Linux"
+	_warn "You should use the official Microsoft tool instead."
+	_warn "It can be found under https://aka.ms/SpeculationControlPS"
+	exit 1
+fi
+
+# check for mode selection inconsistency
+if [ "$opt_live_explicit" = 1 ]; then
+	if [ -n "$opt_kernel" ] || [ -n "$opt_config" ] || [ -n "$opt_map" ]; then
+		show_usage
+		echo "$0: error: incompatible modes specified, use either --live or --kernel/--config/--map" >&2
+		exit 255
+	fi
+fi
+if [ "$opt_hw_only" = 1 ]; then
+	if [ "$opt_allvariants" = 0 ]; then
+		show_usage
+		echo "$0: error: incompatible modes specified, --hw-only vs --variant" >&2
+		exit 255
+	else
+		opt_allvariants=0
+		opt_variant1=0
+		opt_variant2=0
+		opt_variant3=0
+	fi
+fi
+
+# coreos mode
+if [ "$opt_coreos" = 1 ]; then
+	if ! is_coreos; then
+		_warn "CoreOS mode asked, but we're not under CoreOS!"
+		exit 255
+	fi
+	_warn "CoreOS mode, starting an ephemeral toolbox to launch the script"
+	load_msr
+	load_cpuid
+	mount_debugfs
+	toolbox --ephemeral --bind-ro /dev/cpu:/dev/cpu -- sh -c "dnf install -y binutils which && /media/root$PWD/$0 $* --coreos-within-toolbox"
+	exitcode=$?
+	exit $exitcode
+else
+	if is_coreos; then
+		_warn "You seem to be running CoreOS, you might want to use the --coreos option for better results"
+		_warn
+	fi
+fi
+
+# if we're under a BSD, try to mount linprocfs for "$procfs/cpuinfo"
+procfs=/proc
+if echo "$os" | grep -q BSD; then
+	_debug "We're under BSD, check if we have procfs"
+	procfs=$(mount | awk '/^linprocfs/ { print $3; exit; }')
+	if [ -z "$procfs" ]; then
+		_debug "we don't, try to mount it"
+		procfs=/proc
+		[ -d /compat/linux/proc ] && procfs=/compat/linux/proc
+		test -d $procfs || mkdir $procfs
+		if mount -t linprocfs linprocfs $procfs 2>/dev/null; then
+			mounted_procfs=1
+			_debug "procfs just mounted at $procfs"
+		else
+			procfs=''
+		fi
+	else
+		_debug "We do: $procfs"
+	fi
+fi
+
+parse_cpu_details
+if [ "$opt_live" = 1 ]; then
+	# root check (only for live mode, for offline mode, we already checked if we could read the files)
+	if [ "$(id -u)" -ne 0 ]; then
+		_warn "Note that you should launch this script with root privileges to get accurate information."
+		_warn "We'll proceed but you might see permission denied errors."
+		_warn "To run it as root, you can try the following command: sudo $0"
+		_warn
+	fi
+	_info "Checking for vulnerabilities on current system"
+	_info "Kernel is \033[35m$(uname -s) $(uname -r) $(uname -v) $(uname -m)\033[0m"
+	_info "CPU is \033[35m$cpu_friendly_name\033[0m"
+
+	# try to find the image of the current running kernel
+	# first, look for the BOOT_IMAGE hint in the kernel cmdline
+	if [ -r /proc/cmdline ] && grep -q 'BOOT_IMAGE=' /proc/cmdline; then
+		opt_kernel=$(grep -Eo 'BOOT_IMAGE=[^ ]+' /proc/cmdline | cut -d= -f2)
+		_debug "found opt_kernel=$opt_kernel in /proc/cmdline"
+		# if we have a dedicated /boot partition, our bootloader might have just called it /
+		# so try to prepend /boot and see if we find anything
+		[ -e "/boot/$opt_kernel" ] && opt_kernel="/boot/$opt_kernel"
+		# special case for CoreOS if we're inside the toolbox
+		[ -e "/media/root/boot/$opt_kernel" ] && opt_kernel="/media/root/boot/$opt_kernel"
+		_debug "opt_kernel is now $opt_kernel"
+		# else, the full path is already there (most probably /boot/something)
+	fi
+	# if we didn't find a kernel, default to guessing
+	if [ ! -e "$opt_kernel" ]; then
+		# Fedora:
+		[ -e "/lib/modules/$(uname -r)/vmlinuz" ] && opt_kernel="/lib/modules/$(uname -r)/vmlinuz"
+		# Slackare:
+		[ -e "/boot/vmlinuz"             ] && opt_kernel="/boot/vmlinuz"
+		# Arch:
+		[ -e "/boot/vmlinuz-linux"       ] && opt_kernel="/boot/vmlinuz-linux"
+		# Linux-Libre:
+		[ -e "/boot/vmlinuz-linux-libre" ] && opt_kernel="/boot/vmlinuz-linux-libre"
+		# pine64
+		[ -e "/boot/pine64/Image"        ] && opt_kernel="/boot/pine64/Image"
+		# generic:
+		[ -e "/boot/vmlinuz-$(uname -r)" ] && opt_kernel="/boot/vmlinuz-$(uname -r)"
+		[ -e "/boot/kernel-$( uname -r)" ] && opt_kernel="/boot/kernel-$( uname -r)"
+		[ -e "/boot/bzImage-$(uname -r)" ] && opt_kernel="/boot/bzImage-$(uname -r)"
+		# Gentoo:
+		[ -e "/boot/kernel-genkernel-$(uname -m)-$(uname -r)" ] && opt_kernel="/boot/kernel-genkernel-$(uname -m)-$(uname -r)"
+		# NixOS:
+		[ -e "/run/booted-system/kernel" ] && opt_kernel="/run/booted-system/kernel"
+		# systemd kernel-install:
+		[ -e "/etc/machine-id" ] && [ -e "/boot/$(cat /etc/machine-id)/$(uname -r)/linux" ] && opt_kernel="/boot/$(cat /etc/machine-id)/$(uname -r)/linux"
+	fi
+
+	# system.map
+	if [ -e /proc/kallsyms ] ; then
+		opt_map=/proc/kallsyms
+	elif [ -e "/lib/modules/$(uname -r)/System.map" ] ; then
+		opt_map="/lib/modules/$(uname -r)/System.map"
+	elif [ -e "/boot/System.map-$(uname -r)" ] ; then
+		opt_map="/boot/System.map-$(uname -r)"
+	fi
+
+	# config
+	if [ -e /proc/config.gz ] ; then
+		dumped_config="$(mktemp /tmp/config-XXXXXX)"
+		gunzip -c /proc/config.gz > "$dumped_config"
+		# dumped_config will be deleted at the end of the script
+		opt_config="$dumped_config"
+	elif [ -e "/lib/modules/$(uname -r)/config" ]; then
+		opt_config="/lib/modules/$(uname -r)/config"
+	elif [ -e "/boot/config-$(uname -r)" ]; then
+		opt_config="/boot/config-$(uname -r)"
+	fi
+else
+	_info "Checking for vulnerabilities against specified kernel"
+	_info "CPU is \033[35m$cpu_friendly_name\033[0m"
+fi
+
+if [ -n "$opt_kernel" ]; then
+	_verbose "Will use kernel image \033[35m$opt_kernel\033[0m"
+else
+	_verbose "Will use no kernel image (accuracy might be reduced)"
+	bad_accuracy=1
+fi
+
+if [ "$os" = Linux ]; then
+	if [ -n "$opt_config" ] && ! grep -q '^CONFIG_' "$opt_config"; then
+		# given file is invalid!
+		_warn "The kernel config file seems invalid, was expecting a plain-text file, ignoring it!"
+		opt_config=''
+	fi
+
+	if [ -n "$dumped_config" ] && [ -n "$opt_config" ]; then
+		_verbose "Will use kconfig \033[35m/proc/config.gz (decompressed)\033[0m"
+	elif [ -n "$opt_config" ]; then
+		_verbose "Will use kconfig \033[35m$opt_config\033[0m"
+	else
+		_verbose "Will use no kconfig (accuracy might be reduced)"
+		bad_accuracy=1
+	fi
+
+	if [ -n "$opt_map" ]; then
+		_verbose "Will use System.map file \033[35m$opt_map\033[0m"
+	else
+		_verbose "Will use no System.map file (accuracy might be reduced)"
+		bad_accuracy=1
+	fi
+
+	if [ "$bad_accuracy" = 1 ]; then
+		_info "We're missing some kernel info (see -v), accuracy might be reduced"
+	fi
+fi
+
+if [ -e "$opt_kernel" ]; then
+	if ! which "${opt_arch_prefix}readelf" >/dev/null 2>&1; then
+		_debug "readelf not found"
+		kernel_err="missing '${opt_arch_prefix}readelf' tool, please install it, usually it's in the 'binutils' package"
+	elif [ "$opt_sysfs_only" = 1 ]; then
+		kernel_err='kernel image decompression skipped'
+	else
+		extract_kernel "$opt_kernel"
+	fi
+else
+	_debug "no opt_kernel defined"
+	kernel_err="couldn't find your kernel image in /boot, if you used netboot, this is normal"
+fi
+if [ -z "$kernel" ] || [ ! -r "$kernel" ]; then
+	[ -z "$kernel_err" ] && kernel_err="couldn't extract your kernel from $opt_kernel"
+else
+	# vanilla kernels have with ^Linux version
+	# also try harder with some kernels (such as Red Hat) that don't have ^Linux version before their version string
+	# and check for FreeBSD
+	kernel_version=$("${opt_arch_prefix}strings" "$kernel" 2>/dev/null | grep -E \
+		-e '^Linux version ' \
+		-e '^[[:alnum:]][^[:space:]]+ \([^[:space:]]+\) #[0-9]+ .+ (19|20)[0-9][0-9]$' \
+		-e '^FreeBSD [0-9]' | head -1)
+	if [ -z "$kernel_version" ]; then
+		# try even harder with some kernels (such as ARM) that split the release (uname -r) and version (uname -v) in 2 adjacent strings
+		kernel_version=$("${opt_arch_prefix}strings" "$kernel" 2>/dev/null | grep -E -B1 '^#[0-9]+ .+ (19|20)[0-9][0-9]$' | tr "\n" " ")
+	fi
+	if [ -n "$kernel_version" ]; then
+		# in live mode, check if the img we found is the correct one
+		if [ "$opt_live" = 1 ]; then
+			_verbose "Kernel image is \033[35m$kernel_version"
+			if ! echo "$kernel_version" | grep -qF "$(uname -r)"; then
+				_warn "Possible disrepancy between your running kernel '$(uname -r)' and the image '$kernel_version' we found ($opt_kernel), results might be incorrect"
+			fi
+		else
+			_info "Kernel image is \033[35m$kernel_version"
+		fi
+	else
+		_verbose "Kernel image version is unknown"
+	fi
+fi
+
+_info
+
+# end of header stuff
+
+# now we define some util functions and the check_*() funcs, as
+# the user can choose to execute only some of those
+
 sys_interface_check()
 {
-	[ "$opt_live" = 1 -a "$opt_no_sysfs" = 0 -a -r "$1" ] || return 1
-	_info_nol "* Checking whether we're safe according to the /sys interface: "
+	[ "$opt_live" = 1 ] && [ "$opt_no_sysfs" = 0 ] && [ -r "$1" ] || return 1
+	_info_nol "* Mitigated according to the /sys interface: "
+	msg=$(cat "$1")
 	if grep -qi '^not affected' "$1"; then
 		# Not affected
 		status=OK
-		pstatus green YES "kernel confirms that your CPU is unaffected"
+		pstatus green YES "$msg"
 	elif grep -qi '^mitigation' "$1"; then
 		# Mitigation: PTI
 		status=OK
-		pstatus green YES "kernel confirms that the mitigation is active"
+		pstatus green YES "$msg"
 	elif grep -qi '^vulnerable' "$1"; then
 		# Vulnerable
 		status=VULN
-		pstatus red NO "kernel confirms your system is vulnerable"
+		pstatus yellow NO "$msg"
 	else
 		status=UNK
-		pstatus yellow UNKNOWN "unknown value reported by kernel"
+		pstatus yellow UNKNOWN "$msg"
 	fi
-	msg=$(cat "$1")
 	_debug "sys_interface_check: $1=$msg"
 	return 0
 }
 
+number_of_cpus()
+{
+	if echo "$os" | grep -q BSD; then
+		n=$(sysctl -n hw.ncpu 2>/dev/null || echo 1)
+	elif [ -e "$procfs/cpuinfo" ]; then
+		n=$(grep -c ^processor "$procfs/cpuinfo" 2>/dev/null || echo 1)
+	else
+		# if we don't know, default to 1 CPU
+		n=1
+	fi
+	return "$n"
+}
+
+# $1 - msr number
+# $2 - cpu index
+write_msr()
+{
+	if [ "$os" != Linux ]; then
+		cpucontrol -m "$1=0" "/dev/cpuctl$2" >/dev/null 2>&1; ret=$?
+	else
+		# convert to decimal
+		_msrindex=$(( $1 ))
+		if [ ! -w /dev/cpu/"$2"/msr ]; then
+			ret=200 # permission error
+		else
+			dd if=/dev/zero of=/dev/cpu/"$2"/msr bs=8 count=1 seek="$_msrindex" oflag=seek_bytes 2>/dev/null; ret=$?
+		fi
+	fi
+	_debug "write_msr: for cpu $2 on msr $1 ($_msrindex), ret=$ret"
+	return $ret
+}
+
+read_msr()
+{
+	# _msr must be in hex, in the form 0x1234:
+	_msr="$1"
+	# cpu index, starting from 0:
+	_cpu="$2"
+	read_msr_value=''
+	if [ "$os" != Linux ]; then
+		_msr=$(cpucontrol -m "$_msr" "/dev/cpuctl$_cpu" 2>/dev/null); ret=$?
+		[ $ret -ne 0 ] && return 1
+		# MSR 0x10: 0x000003e1 0xb106dded
+		_msr_h=$(echo "$_msr" | awk '{print $3}');
+		_msr_h="$(( _msr_h >> 24 & 0xFF )) $(( _msr_h >> 16 & 0xFF )) $(( _msr_h >> 8 & 0xFF )) $(( _msr_h & 0xFF ))"
+		_msr_l=$(echo "$_msr" | awk '{print $4}');
+		_msr_l="$(( _msr_l >> 24 & 0xFF )) $(( _msr_l >> 16 & 0xFF )) $(( _msr_l >> 8 & 0xFF )) $(( _msr_l & 0xFF ))"
+		read_msr_value="$_msr_h $_msr_l"
+	else
+		# convert to decimal
+		_msr=$(( _msr ))
+		if [ ! -r /dev/cpu/"$_cpu"/msr ]; then
+			return 200 # permission error
+		fi
+		read_msr_value=$(dd if=/dev/cpu/"$_cpu"/msr bs=8 count=1 skip="$_msr" iflag=skip_bytes 2>/dev/null | od -t u1 -A n)
+		if [ -z "$read_msr_value" ]; then
+			# MSR doesn't exist, don't check for $? because some versions of dd still return 0!
+			return 1
+		fi
+	fi
+	_debug "read_msr: MSR=$1 value is $read_msr_value"
+	return 0
+}
+
+
+check_cpu()
+{
+	_info "\033[1;34mHardware check\033[0m"
+
+	if ! uname -m | grep -qwE 'x86_64|i[3-6]86|amd64'; then
+		return
+	fi
+
+	_info     "* Hardware support (CPU microcode) for mitigation techniques"
+	_info     "  * Indirect Branch Restricted Speculation (IBRS)"
+	_info_nol "    * SPEC_CTRL MSR is available: "
+	number_of_cpus
+	ncpus=$?
+	idx_max_cpu=$((ncpus-1))
+	if [ ! -e /dev/cpu/0/msr ] && [ ! -e /dev/cpuctl0 ]; then
+		# try to load the module ourselves (and remember it so we can rmmod it afterwards)
+		load_msr
+	fi
+	if [ ! -e /dev/cpu/0/msr ] && [ ! -e /dev/cpuctl0 ]; then
+		spec_ctrl_msr=-1
+		pstatus yellow UNKNOWN "is msr kernel module available?"
+	else
+		# the new MSR 'SPEC_CTRL' is at offset 0x48
+		# here we use dd, it's the same as using 'rdmsr 0x48' but without needing the rdmsr tool
+		# if we get a read error, the MSR is not there. bs has to be 8 for msr
+		# skip=9 because 8*9=72=0x48
+		val=0
+		cpu_mismatch=0
+		for i in $(seq 0 "$idx_max_cpu")
+		do
+			read_msr 0x48 "$i"; ret=$?
+			if [ "$i" -eq 0 ]; then
+				val=$ret
+			else
+				if [ "$ret" -eq $val ]; then
+					continue
+				else
+					cpu_mismatch=1
+				fi
+			fi
+		done
+		if [ $val -eq 0 ]; then
+			if [ $cpu_mismatch -eq 0 ]; then
+				spec_ctrl_msr=1
+				pstatus green YES
+			else
+				spec_ctrl_msr=1
+				pstatus green YES "But not in all CPUs"
+			fi
+		elif [ $val -eq 200 ]; then
+			pstatus yellow UNKNOWN "is msr kernel module available?"
+			spec_ctrl_msr=-1
+		else
+			spec_ctrl_msr=0
+			pstatus yellow NO
+		fi
+	fi
+
+	_info_nol "    * CPU indicates IBRS capability: "
+	# from kernel src: { X86_FEATURE_SPEC_CTRL,        CPUID_EDX,26, 0x00000007, 0 },
+	# amd: https://developer.amd.com/wp-content/resources/Architecture_Guidelines_Update_Indirect_Branch_Control.pdf
+	# amd: 8000_0008 EBX[14]=1
+	if is_intel; then
+		read_cpuid 0x7 $EDX 26 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			pstatus green YES "SPEC_CTRL feature bit"
+			cpuid_spec_ctrl=1
+			cpuid_ibrs='SPEC_CTRL'
+		fi
+	elif is_amd; then
+		read_cpuid 0x80000008 $EBX 14 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			pstatus green YES "IBRS_SUPPORT feature bit"
+			cpuid_ibrs='IBRS_SUPPORT'
+		fi
+	else
+		ret=-1
+		pstatus yellow UNKNOWN "unknown CPU"
+	fi
+	if [ $ret -eq 1 ]; then
+		pstatus yellow NO
+	elif [ $ret -eq 2 ]; then
+		pstatus yellow UNKNOWN "is cpuid kernel module available?"
+		cpuid_spec_ctrl=-1
+	fi
+
+	if is_amd; then
+		_info_nol "    * CPU indicates preferring IBRS always-on: "
+		# amd
+		read_cpuid 0x80000008 $EBX 16 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			pstatus green YES
+		else
+			pstatus yellow NO
+		fi
+
+		_info_nol "    * CPU indicates preferring IBRS over retpoline: "
+		# amd
+		read_cpuid 0x80000008 $EBX 18 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			pstatus green YES
+		else
+			pstatus yellow NO
+		fi
+	fi
+
+	# IBPB
+	_info     "  * Indirect Branch Prediction Barrier (IBPB)"
+	_info_nol "    * PRED_CMD MSR is available: "
+	if [ ! -e /dev/cpu/0/msr ] && [ ! -e /dev/cpuctl0 ]; then
+		pstatus yellow UNKNOWN "is msr kernel module available?"
+	else
+		# the new MSR 'PRED_CTRL' is at offset 0x49, write-only
+		# here we use dd, it's the same as using 'wrmsr 0x49 0' but without needing the wrmsr tool
+		# if we get a write error, the MSR is not there
+		val=0
+		cpu_mismatch=0
+		for i in $(seq 0 "$idx_max_cpu")
+		do
+			write_msr 0x49 "$i"; ret=$?
+			if [ "$i" -eq 0 ]; then
+				val=$ret
+			else
+				if [ "$ret" -eq $val ]; then
+					continue
+				else
+					cpu_mismatch=1
+				fi
+			fi
+		done
+
+		if [ $val -eq 0 ]; then
+			if [ $cpu_mismatch -eq 0 ]; then
+				pstatus green YES
+			else
+				pstatus green YES "But not in all CPUs"
+			fi
+		elif [ $val -eq 200 ]; then
+			pstatus yellow UNKNOWN "is msr kernel module available?"
+		else
+			pstatus yellow NO
+		fi
+	fi
+
+	_info_nol "    * CPU indicates IBPB capability: "
+	# CPUID EAX=0x80000008, ECX=0x00 return EBX[12] indicates support for just IBPB.
+	if [ "$cpuid_spec_ctrl" = 1 ]; then
+		# spec_ctrl implies ibpb
+		cpuid_ibpb='SPEC_CTRL'
+		pstatus green YES "SPEC_CTRL feature bit"
+	elif is_intel; then
+		if [ "$cpuid_spec_ctrl" = -1 ]; then
+			pstatus yellow UNKNOWN "is cpuid kernel module available?"
+		else
+			pstatus yellow NO
+		fi
+	elif is_amd; then
+		read_cpuid 0x80000008 $EBX 12 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			cpuid_ibpb='IBPB_SUPPORT'
+			pstatus green YES "IBPB_SUPPORT feature bit"
+		elif [ $ret -eq 1 ]; then
+			pstatus yellow NO
+		else
+			pstatus yellow UNKNOWN "is cpuid kernel module available?"
+		fi
+	fi
+
+	# STIBP
+	_info     "  * Single Thread Indirect Branch Predictors (STIBP)"
+	_info_nol "    * SPEC_CTRL MSR is available: "
+	if [ "$spec_ctrl_msr" = 1 ]; then
+		pstatus green YES
+	elif [ "$spec_ctrl_msr" = 0 ]; then
+		pstatus yellow NO
+	else
+		pstatus yellow UNKNOWN "is msr kernel module available?"
+	fi
+
+	_info_nol "    * CPU indicates STIBP capability: "
+	# intel: A processor supports STIBP if it enumerates CPUID (EAX=7H,ECX=0):EDX[27] as 1
+	# amd: 8000_0008 EBX[15]=1
+	if is_intel; then
+		read_cpuid 0x7 $EDX 27 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			pstatus green YES "Intel STIBP feature bit"
+			#cpuid_stibp='Intel STIBP'
+		fi
+	elif is_amd; then
+		read_cpuid 0x80000008 $EBX 15 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			pstatus green YES "AMD STIBP feature bit"
+			#cpuid_stibp='AMD STIBP'
+		fi
+	else
+		ret=-1
+		pstatus yellow UNKNOWN "unknown CPU"
+	fi
+	if [ $ret -eq 1 ]; then
+		pstatus yellow NO
+	elif [ $ret -eq 2 ]; then
+		pstatus yellow UNKNOWN "is cpuid kernel module available?"
+	fi
+
+
+	if is_amd; then
+		_info_nol "    * CPU indicates preferring STIBP always-on: "
+		read_cpuid 0x80000008 $EBX 17 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			pstatus green YES
+		else
+			pstatus yellow NO
+		fi
+	fi
+
+	if is_intel; then
+		_info     "  * Enhanced IBRS (IBRS_ALL)"
+		_info_nol "    * CPU indicates ARCH_CAPABILITIES MSR availability: "
+		cpuid_arch_capabilities=-1
+		# A processor supports the ARCH_CAPABILITIES MSR if it enumerates CPUID (EAX=7H,ECX=0):EDX[29] as 1
+		read_cpuid 0x7 $EDX 29 1 1; ret=$?
+		if [ $ret -eq 0 ]; then
+			pstatus green YES
+			cpuid_arch_capabilities=1
+		elif [ $ret -eq 2 ]; then
+			pstatus yellow UNKNOWN "is cpuid kernel module available?"
+		else
+			pstatus yellow NO
+			cpuid_arch_capabilities=0
+		fi
+
+		_info_nol "    * ARCH_CAPABILITIES MSR advertises IBRS_ALL capability: "
+		capabilities_rdcl_no=-1
+		capabilities_ibrs_all=-1
+		if [ "$cpuid_arch_capabilities" = -1 ]; then
+			pstatus yellow UNKNOWN
+		elif [ "$cpuid_arch_capabilities" != 1 ]; then
+			capabilities_rdcl_no=0
+			capabilities_ibrs_all=0
+			pstatus yellow NO
+		elif [ ! -e /dev/cpu/0/msr ] && [ ! -e /dev/cpuctl0 ]; then
+			spec_ctrl_msr=-1
+			pstatus yellow UNKNOWN "is msr kernel module available?"
+		else
+			# the new MSR 'ARCH_CAPABILITIES' is at offset 0x10a
+			# here we use dd, it's the same as using 'rdmsr 0x10a' but without needing the rdmsr tool
+			# if we get a read error, the MSR is not there. bs has to be 8 for msr
+			val=0
+			val_cap_msr=0
+			cpu_mismatch=0
+			for i in $(seq 0 "$idx_max_cpu")
+			do
+				read_msr 0x10a "$i"; ret=$?
+				capabilities=$(echo "$read_msr_value" | awk '{print $8}')
+				if [ "$i" -eq 0 ]; then
+					val=$ret
+					val_cap_msr=$capabilities
+				else
+					if [ "$ret" -eq "$val" ] && [ "$capabilities" -eq "$val_cap_msr" ]; then
+						continue
+					else
+						cpu_mismatch=1
+					fi
+				fi
+			done
+			capabilities=$val_cap_msr
+			capabilities_rdcl_no=0
+			capabilities_ibrs_all=0
+			if [ $val -eq 0 ]; then
+				_debug "capabilities MSR lower byte is $capabilities (decimal)"
+				[ $(( capabilities & 1 )) -eq 1 ] && capabilities_rdcl_no=1
+				[ $(( capabilities & 2 )) -eq 2 ] && capabilities_ibrs_all=1
+				_debug "capabilities says rdcl_no=$capabilities_rdcl_no ibrs_all=$capabilities_ibrs_all"
+				if [ "$capabilities_ibrs_all" = 1 ]; then
+					if [ $cpu_mismatch -eq 0 ]; then
+						pstatus green YES
+					else:
+						pstatus green YES "But not in all CPUs"
+					fi
+				else
+					pstatus yellow NO
+				fi
+			elif [ $val -eq 200 ]; then
+				pstatus yellow UNKNOWN "is msr kernel module available?"
+			else
+				pstatus yellow NO
+			fi
+		fi
+
+		_info_nol "  * CPU explicitly indicates not being vulnerable to Meltdown (RDCL_NO): "
+		if [ "$capabilities_rdcl_no" = -1 ]; then
+			pstatus yellow UNKNOWN
+		elif [ "$capabilities_rdcl_no" = 1 ]; then
+			pstatus green YES
+		else
+			pstatus yellow NO
+		fi
+	fi
+
+	_info_nol "  * CPU microcode is known to cause stability problems: "
+	if is_ucode_blacklisted; then
+		pstatus red YES "$ucode_found"
+		_warn
+		_warn "The microcode your CPU is running on is known to cause instability problems,"
+		_warn "such as intempestive reboots or random crashes."
+		_warn "You are advised to either revert to a previous microcode version (that might not have"
+		_warn "the mitigations for Spectre), or upgrade to a newer one if available."
+		_warn
+	else
+		pstatus blue NO "$ucode_found"
+	fi
+}
+
+check_cpu_vulnerabilities()
+{
+	_info     "* CPU vulnerability to the three speculative execution attack variants"
+	for v in 1 2 3; do
+		_info_nol "  * Vulnerable to Variant $v: "
+		if is_cpu_vulnerable $v; then
+			pstatus yellow YES
+		else
+			pstatus green NO
+		fi
+	done
+}
+
+check_redhat_canonical_spectre()
+{
+	# if we were already called, don't do it again
+	[ -n "$redhat_canonical_spectre" ] && return
+
+	if ! which "${opt_arch_prefix}strings" >/dev/null 2>&1; then
+		redhat_canonical_spectre=-1
+	elif [ -n "$kernel_err" ]; then
+		redhat_canonical_spectre=-2
+	else
+		# Red Hat / Ubuntu specific variant1 patch is difficult to detect,
+		# let's use the two same tricks than the official Red Hat detection script uses:
+		if "${opt_arch_prefix}strings" "$kernel" | grep -qw noibrs && "${opt_arch_prefix}strings" "$kernel" | grep -qw noibpb; then
+			# 1) detect their specific variant2 patch. If it's present, it means
+			# that the variant1 patch is also present (both were merged at the same time)
+			_debug "found redhat/canonical version of the variant2 patch (implies variant1)"
+			redhat_canonical_spectre=1
+		elif "${opt_arch_prefix}strings" "$kernel" | grep -q 'x86/pti:'; then
+			# 2) detect their specific variant3 patch. If it's present, but the variant2
+			# is not, it means that only variant1 is present in addition to variant3
+			_debug "found redhat/canonical version of the variant3 patch (implies variant1 but not variant2)"
+			redhat_canonical_spectre=2
+		else
+			redhat_canonical_spectre=0
+		fi
+	fi
+}
+
+
 ###################
 # SPECTRE VARIANT 1
 check_variant1()
 {
 	_info "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m"
+	if [ "$os" = Linux ]; then
+		check_variant1_linux
+	elif echo "$os" | grep -q BSD; then
+		check_variant1_bsd
+	else
+		_warn "Unsupported OS ($os)"
+	fi
+}
 
+check_variant1_linux()
+{
 	status=UNK
 	sys_interface_available=0
 	msg=''
 	if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/spectre_v1"; then
 		# this kernel has the /sys interface, trust it over everything
+		# v0.33+: don't. some kernels have backported the array_index_mask_nospec() workaround without
+		# modifying the vulnerabilities/spectre_v1 file. that's bad. we can't trust it when it says Vulnerable :(
+		# see "silent backport" detection at the bottom of this func
 		sys_interface_available=1
-	else
+	fi
+	if [ "$opt_sysfs_only" != 1 ]; then
 		# no /sys interface (or offline mode), fallback to our own ways
-		_info_nol "* Checking count of LFENCE opcodes in kernel: "
-		if [ -n "$vmlinux_err" ]; then
-			msg="couldn't check ($vmlinux_err)"
-			status=UNK
-			pstatus yellow UNKNOWN
+		_info_nol "* Kernel has array_index_mask_nospec (x86): "
+		# vanilla: look for the Linus' mask aka array_index_mask_nospec()
+		# that is inlined at least in raw_copy_from_user (__get_user_X symbols)
+		#mov PER_CPU_VAR(current_task), %_ASM_DX
+		#cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
+		#jae bad_get_user
+		# /* array_index_mask_nospec() are the 2 opcodes that follow */
+		#+sbb %_ASM_DX, %_ASM_DX
+		#+and %_ASM_DX, %_ASM_AX
+		#ASM_STAC
+		# x86 64bits: jae(0x0f 0x83 0x?? 0x?? 0x?? 0x??) sbb(0x48 0x19 0xd2) and(0x48 0x21 0xd0)
+		# x86 32bits: cmp(0x3b 0x82 0x?? 0x?? 0x00 0x00) jae(0x73 0x??) sbb(0x19 0xd2) and(0x21 0xd0)
+		if [ -n "$kernel_err" ]; then
+			pstatus yellow UNKNOWN "couldn't check ($kernel_err)"
+		elif ! which perl >/dev/null 2>&1; then
+			pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
 		else
-			if ! which objdump >/dev/null 2>&1; then
-				msg="missing 'objdump' tool, please install it, usually it's in the binutils package"
-				status=UNK
-				pstatus yellow UNKNOWN
+			perl -ne '/\x0f\x83....\x48\x19\xd2\x48\x21\xd0/ and $found++; END { exit($found) }' "$kernel"; ret=$?
+			if [ $ret -gt 0 ]; then
+				pstatus green YES "$ret occurrence(s) found of 64 bits array_index_mask_nospec()"
+				v1_mask_nospec="64 bits array_index_mask_nospec"
 			else
-				# here we disassemble the kernel and count the number of occurrences of the LFENCE opcode
-				# in non-patched kernels, this has been empirically determined as being around 40-50
-				# in patched kernels, this is more around 70-80, sometimes way higher (100+)
-				# v0.13: 68 found in a 3.10.23-xxxx-std-ipv6-64 (with lots of modules compiled-in directly), which doesn't have the LFENCE patches,
-				# so let's push the threshold to 70.
-				nb_lfence=$(objdump -d "$vmlinux" | grep -wc lfence)
-				if [ "$nb_lfence" -lt 70 ]; then
-					msg="only $nb_lfence opcodes found, should be >= 70, heuristic to be improved when official patches become available"
-					status=VULN
-					pstatus red NO
+				perl -ne '/\x3b\x82..\x00\x00\x73.\x19\xd2\x21\xd0/ and $found++; END { exit($found) }' "$kernel"; ret=$?
+				if [ $ret -gt 0 ]; then
+					pstatus green YES "$ret occurrence(s) found of 32 bits array_index_mask_nospec()"
+					v1_mask_nospec="32 bits array_index_mask_nospec"
 				else
-					msg="$nb_lfence opcodes found, which is >= 70, heuristic to be improved when official patches become available"
-					status=OK
-					pstatus green YES
+					pstatus yellow NO
 				fi
 			fi
 		fi
-	fi
 
-	# if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it
-	if [ "$sys_interface_available" = 0 ] && ! is_cpu_vulnerable 1; then
-		# override status & msg in case CPU is not vulnerable after all
-		msg="your CPU vendor reported your CPU model as not vulnerable"
-		status=OK
+		_info_nol "* Kernel has the Red Hat/Ubuntu patch: "
+		check_redhat_canonical_spectre
+		if [ "$redhat_canonical_spectre" = -1 ]; then
+			pstatus yellow UNKNOWN "missing '${opt_arch_prefix}strings' tool, please install it, usually it's in the binutils package"
+		elif [ "$redhat_canonical_spectre" = -2 ]; then
+			pstatus yellow UNKNOWN "couldn't check ($kernel_err)"
+		elif [ "$redhat_canonical_spectre" = 1 ]; then
+			pstatus green YES
+		elif [ "$redhat_canonical_spectre" = 2 ]; then
+			pstatus green YES "but without IBRS"
+		else
+			pstatus yellow NO
+		fi
+
+		_info_nol "* Kernel has mask_nospec64 (arm): "
+		#.macro	mask_nospec64, idx, limit, tmp
+		#sub	\tmp, \idx, \limit
+		#bic	\tmp, \tmp, \idx
+		#and	\idx, \idx, \tmp, asr #63
+		#csdb
+		#.endm
+		#$ aarch64-linux-gnu-objdump -d vmlinux | grep -w bic -A1 -B1 | grep -w sub -A2 | grep -w and -B2
+		#ffffff8008082e44:       cb190353        sub     x19, x26, x25
+		#ffffff8008082e48:       8a3a0273        bic     x19, x19, x26
+		#ffffff8008082e4c:       8a93ff5a        and     x26, x26, x19, asr #63
+		#ffffff8008082e50:       d503229f        hint    #0x14
+		# /!\ can also just be "csdb" instead of "hint #0x14" for native objdump
+		#
+		# if we have v1_mask_nospec or redhat_canonical_spectre>0, don't bother disassembling the kernel, the answer is no.
+		if [ -n "$v1_mask_nospec" ] || [ "$redhat_canonical_spectre" -gt 0 ]; then
+			pstatus yellow NO
+		elif [ -n "$kernel_err" ]; then
+			pstatus yellow UNKNOWN "couldn't check ($kernel_err)"
+		elif ! which perl >/dev/null 2>&1; then
+			pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
+		elif ! which "${opt_arch_prefix}objdump" >/dev/null 2>&1; then
+			pstatus yellow UNKNOWN "missing '${opt_arch_prefix}objdump' tool, please install it, usually it's in the binutils package"
+		else
+			"${opt_arch_prefix}objdump" -d "$kernel" | perl -ne 'push @r, $_; /\s(hint|csdb)\s/ && $r[0]=~/\ssub\s+(x\d+)/ && $r[1]=~/\sbic\s+$1,\s+$1,/ && $r[2]=~/\sand\s/ && exit(9); shift @r if @r>3'; ret=$?
+			if [ "$ret" -eq 9 ]; then
+				pstatus green YES "mask_nospec64 macro is present and used"
+				v1_mask_nospec="arm mask_nospec64"
+			else
+				pstatus yellow NO
+			fi
+		fi
+
+
+		if [ "$opt_verbose" -ge 2 ] || ( [ -z "$v1_mask_nospec" ] && [ "$redhat_canonical_spectre" != 1 ] && [ "$redhat_canonical_spectre" != 2 ] ); then
+			# this is a slow heuristic and we don't need it if we already know the kernel is patched
+			# but still show it in verbose mode
+			_info_nol "* Checking count of LFENCE instructions following a jump in kernel... "
+			if [ -n "$kernel_err" ]; then
+				pstatus yellow UNKNOWN "couldn't check ($kernel_err)"
+			else
+				if ! which "${opt_arch_prefix}objdump" >/dev/null 2>&1; then
+					pstatus yellow UNKNOWN "missing '${opt_arch_prefix}objdump' tool, please install it, usually it's in the binutils package"
+				else
+					# here we disassemble the kernel and count the number of occurrences of the LFENCE opcode
+					# in non-patched kernels, this has been empirically determined as being around 40-50
+					# in patched kernels, this is more around 70-80, sometimes way higher (100+)
+					# v0.13: 68 found in a 3.10.23-xxxx-std-ipv6-64 (with lots of modules compiled-in directly), which doesn't have the LFENCE patches,
+					# so let's push the threshold to 70.
+					# v0.33+: now only count lfence opcodes after a jump, way less error-prone
+					# non patched kernel have between 0 and 20 matches, patched ones have at least 40-45
+					nb_lfence=$("${opt_arch_prefix}objdump" -d "$kernel" 2>/dev/null | grep -w -B1 lfence | grep -Ewc 'jmp|jne|je')
+					if [ "$nb_lfence" -lt 30 ]; then
+						pstatus yellow NO "only $nb_lfence jump-then-lfence instructions found, should be >= 30 (heuristic)"
+					else
+						v1_lfence=1
+						pstatus green YES "$nb_lfence jump-then-lfence instructions found, which is >= 30 (heuristic)"
+					fi
+				fi
+			fi
+		fi
+
+	else
+		# we have no sysfs but were asked to use it only!
+		msg="/sys vulnerability interface use forced, but it's not available!"
+		status=UNK
 	fi
 
 	# report status
-	pvulnstatus CVE-2017-5753 "$status" "$msg"
+	cve='CVE-2017-5753'
+
+	if ! is_cpu_vulnerable 1; then
+		# override status & msg in case CPU is not vulnerable after all
+		pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
+	elif [ -z "$msg" ]; then
+		# if msg is empty, sysfs check didn't fill it, rely on our own test
+		if [ -n "$v1_mask_nospec" ]; then
+			pvulnstatus $cve OK "Kernel source has been patched to mitigate the vulnerability ($v1_mask_nospec)"
+		elif [ "$redhat_canonical_spectre" = 1 ] || [ "$redhat_canonical_spectre" = 2 ]; then
+			pvulnstatus $cve OK "Kernel source has been patched to mitigate the vulnerability (Red Hat/Ubuntu patch)"
+		elif [ "$v1_lfence" = 1 ]; then
+			pvulnstatus $cve OK "Kernel source has PROBABLY been patched to mitigate the vulnerability (jump-then-lfence instructions heuristic)"
+		elif [ "$kernel_err" ]; then
+			pvulnstatus $cve UNK "Couldn't find kernel image or tools missing to execute the checks"
+			explain "Re-run this script with root privileges, after installing the missing tools indicated above"
+		else
+			pvulnstatus $cve VULN "Kernel source needs to be patched to mitigate the vulnerability"
+			explain "Your kernel is too old to have the mitigation for Variant 1, you should upgrade to a newer kernel. If you're using a Linux distro and didn't compile the kernel yourself, you should upgrade your distro to get a newer kernel."
+		fi
+	else
+		if [ "$msg" = "Vulnerable" ] && [ -n "$v1_mask_nospec" ]; then
+			pvulnstatus $cve OK "Kernel source has been patched to mitigate the vulnerability (silent backport of array_index_mask_nospec)"
+		else
+			if [ "$msg" = "Vulnerable" ]; then
+				msg="Kernel source needs to be patched to mitigate the vulnerability"
+				_explain="Your kernel is too old to have the mitigation for Variant 1, you should upgrade to a newer kernel. If you're using a Linux distro and didn't compile the kernel yourself, you should upgrade your distro to get a newer kernel."
+			fi
+			pvulnstatus $cve "$status" "$msg"
+			[ -n "$_explain" ] && explain "$_explain"
+			unset _explain
+		fi
+	fi
 }
 
+check_variant1_bsd()
+{
+	cve='CVE-2017-5753'
+	if ! is_cpu_vulnerable 1; then
+		# override status & msg in case CPU is not vulnerable after all
+		pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
+	else
+		pvulnstatus $cve VULN "no mitigation for BSD yet"
+	fi
+}
+
+
 ###################
 # SPECTRE VARIANT 2
 check_variant2()
 {
 	_info "\033[1;34mCVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'\033[0m"
+	if [ "$os" = Linux ]; then
+		check_variant2_linux
+	elif echo "$os" | grep -q BSD; then
+		check_variant2_bsd
+	else
+		_warn "Unsupported OS ($os)"
+	fi
+}
 
+check_variant2_linux()
+{
 	status=UNK
 	sys_interface_available=0
 	msg=''
 	if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/spectre_v2"; then
 		# this kernel has the /sys interface, trust it over everything
 		sys_interface_available=1
-	else
+	fi
+	if [ "$opt_sysfs_only" != 1 ]; then
 		_info "* Mitigation 1"
-		_info_nol "*   Hardware (CPU microcode) support for mitigation: "
-		if [ ! -e /dev/cpu/0/msr ]; then
-			# try to load the module ourselves (and remember it so we can rmmod it afterwards)
-			modprobe msr 2>/dev/null && insmod_msr=1
-			_debug "attempted to load module msr, ret=$insmod_msr"
-		fi
-		if [ ! -e /dev/cpu/0/msr ]; then
-			pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
-		else
-			# the new MSR 'SPEC_CTRL' is at offset 0x48
-			# here we use dd, it's the same as using 'rdmsr 0x48' but without needing the rdmsr tool
-			# if we get a read error, the MSR is not there
-			dd if=/dev/cpu/0/msr of=/dev/null bs=8 count=1 skip=9 2>/dev/null
-			if [ $? -eq 0 ]; then
-				pstatus green YES
-			else
-				pstatus red NO
-			fi
-		fi
 
-		if [ "$insmod_msr" = 1 ]; then
-			# if we used modprobe ourselves, rmmod the module
-			rmmod msr 2>/dev/null
-			_debug "attempted to unload module msr, ret=$?"
-		fi
+		ibrs_can_tell=0
+		ibrs_supported=''
+		ibrs_enabled=''
+		ibpb_can_tell=0
+		ibpb_supported=''
+		ibpb_enabled=''
 
-		_info_nol "*   Kernel support for IBRS: "
 		if [ "$opt_live" = 1 ]; then
+			# in live mode, we can check for the ibrs_enabled file in debugfs
+			# all versions of the patches have it (NOT the case of IBPB or KPTI)
+			ibrs_can_tell=1
 			mount_debugfs
-			for ibrs_file in \
-				/sys/kernel/debug/ibrs_enabled \
-				/sys/kernel/debug/x86/ibrs_enabled \
-				/proc/sys/kernel/ibrs_enabled; do
-				if [ -e "$ibrs_file" ]; then
+			for dir in \
+				/sys/kernel/debug \
+				/sys/kernel/debug/x86 \
+				/proc/sys/kernel; do
+				if [ -e "$dir/ibrs_enabled" ]; then
 					# if the file is there, we have IBRS compiled-in
 					# /sys/kernel/debug/ibrs_enabled: vanilla
-					# /sys/kernel/debug/x86/ibrs_enabled: RedHat (see https://access.redhat.com/articles/3311301)
+					# /sys/kernel/debug/x86/ibrs_enabled: Red Hat (see https://access.redhat.com/articles/3311301)
 					# /proc/sys/kernel/ibrs_enabled: OpenSUSE tumbleweed
-					pstatus green YES
-					ibrs_supported=1
-					ibrs_enabled=$(cat "$ibrs_file" 2>/dev/null)
-					_debug "ibrs: found $ibrs_file=$ibrs_enabled"
+					specex_knob_dir=$dir
+					ibrs_supported="$dir/ibrs_enabled exists"
+					ibrs_enabled=$(cat "$dir/ibrs_enabled" 2>/dev/null)
+					_debug "ibrs: found $dir/ibrs_enabled=$ibrs_enabled"
+					# if ibrs_enabled is there, ibpb_enabled will be in the same dir
+					if [ -e "$dir/ibpb_enabled" ]; then
+						# if the file is there, we have IBPB compiled-in (see note above for IBRS)
+						ibpb_supported="$dir/ibpb_enabled exists"
+						ibpb_enabled=$(cat "$dir/ibpb_enabled" 2>/dev/null)
+						_debug "ibpb: found $dir/ibpb_enabled=$ibpb_enabled"
+					else
+						_debug "ibpb: $dir/ibpb_enabled file doesn't exist"
+					fi
 					break
 				else
-					_debug "ibrs: file $ibrs_file doesn't exist"
+					_debug "ibrs: $dir/ibrs_enabled file doesn't exist"
 				fi
 			done
+			# on some newer kernels, the spec_ctrl_ibrs flag in "$procfs/cpuinfo"
+			# is set when ibrs has been administratively enabled (usually from cmdline)
+			# which in that case means ibrs is supported *and* enabled for kernel & user
+			# as per the ibrs patch series v3
+			if [ -z "$ibrs_supported" ]; then
+				if grep ^flags "$procfs/cpuinfo" | grep -qw spec_ctrl_ibrs; then
+					_debug "ibrs: found spec_ctrl_ibrs flag in $procfs/cpuinfo"
+					ibrs_supported="spec_ctrl_ibrs flag in $procfs/cpuinfo"
+					# enabled=2 -> kernel & user
+					ibrs_enabled=2
+					# XXX and what about ibpb ?
+				fi
+			fi
+			if [ -e "/sys/devices/system/cpu/vulnerabilities/spectre_v2" ]; then
+				# when IBPB is enabled on 4.15+, we can see it in sysfs
+				if grep -q ', IBPB' "/sys/devices/system/cpu/vulnerabilities/spectre_v2"; then
+					_debug "ibpb: found enabled in sysfs"
+					[ -z "$ibpb_supported" ] && ibpb_supported='IBPB found enabled in sysfs'
+					[ -z "$ibpb_enabled"   ] && ibpb_enabled=1
+				fi
+				# when IBRS_FW is enabled on 4.15+, we can see it in sysfs
+				if grep -q ', IBRS_FW' "/sys/devices/system/cpu/vulnerabilities/spectre_v2"; then
+					_debug "ibrs: found IBRS_FW in sysfs"
+					[ -z "$ibrs_supported" ] && ibrs_supported='found IBRS_FW in sysfs'
+					ibrs_fw_enabled=1
+				fi
+				# when IBRS is enabled on 4.15+, we can see it in sysfs
+				if grep -q 'Indirect Branch Restricted Speculation' "/sys/devices/system/cpu/vulnerabilities/spectre_v2"; then
+					_debug "ibrs: found IBRS in sysfs"
+					[ -z "$ibrs_supported" ] && ibrs_supported='found IBRS in sysfs'
+					[ -z "$ibrs_enabled"   ] && ibrs_enabled=3
+				fi
+			fi
+			# in live mode, if ibrs or ibpb is supported and we didn't find these are enabled, then they are not
+			[ -n "$ibrs_supported" ] && [ -z "$ibrs_enabled" ] && ibrs_enabled=0
+			[ -n "$ibpb_supported" ] && [ -z "$ibpb_enabled" ] && ibpb_enabled=0
 		fi
-		if [ "$ibrs_supported" != 1 -a -n "$opt_map" ]; then
+		if [ -z "$ibrs_supported" ]; then
+			check_redhat_canonical_spectre
+			if [ "$redhat_canonical_spectre" = 1 ]; then
+				ibrs_supported="Red Hat/Ubuntu variant"
+				ibpb_supported="Red Hat/Ubuntu variant"
+			fi
+		fi
+		if [ -z "$ibrs_supported" ] && [ -n "$kernel" ]; then
+			if ! which "${opt_arch_prefix}strings" >/dev/null 2>&1; then
+				:
+			else
+				ibrs_can_tell=1
+				ibrs_supported=$("${opt_arch_prefix}strings" "$kernel" | grep -Fw -e ', IBRS_FW' | head -1)
+				if [ -n "$ibrs_supported" ]; then
+					_debug "ibrs: found ibrs evidence in kernel image ($ibrs_supported)"
+					ibrs_supported="found '$ibrs_supported' in kernel image"
+				fi
+			fi
+		fi
+		if [ -z "$ibrs_supported" ] && [ -n "$opt_map" ]; then
+			ibrs_can_tell=1
 			if grep -q spec_ctrl "$opt_map"; then
-				pstatus green YES
-				ibrs_supported=1
+				ibrs_supported="found spec_ctrl in symbols file"
 				_debug "ibrs: found '*spec_ctrl*' symbol in $opt_map"
 			fi
 		fi
-		if [ "$ibrs_supported" != 1 ]; then
-			pstatus red NO
+		# recent (4.15) vanilla kernels have IBPB but not IBRS, and without the debugfs tunables of Red Hat
+		# we can detect it directly in the image
+		if [ -z "$ibpb_supported" ] && [ -n "$kernel" ]; then
+			if ! which "${opt_arch_prefix}strings" >/dev/null 2>&1; then
+				:
+			else
+				ibpb_can_tell=1
+				ibpb_supported=$("${opt_arch_prefix}strings" "$kernel" | grep -Fw -e 'ibpb' -e ', IBPB' | head -1)
+				if [ -n "$ibpb_supported" ]; then
+					_debug "ibpb: found ibpb evidence in kernel image ($ibpb_supported)"
+					ibpb_supported="found '$ibpb_supported' in kernel image"
+				fi
+			fi
 		fi
 
-		_info_nol "*   IBRS enabled for Kernel space: "
+		_info_nol "  * Kernel is compiled with IBRS support: "
+		if [ -z "$ibrs_supported" ]; then
+			if [ "$ibrs_can_tell" = 1 ]; then
+				pstatus yellow NO
+			else
+				# if we're in offline mode without System.map, we can't really know
+				pstatus yellow UNKNOWN "in offline mode, we need the kernel image and System.map to be able to tell"
+			fi
+		else
+			if [ "$opt_verbose" -ge 2 ]; then
+				pstatus green YES "$ibrs_supported"
+			else
+				pstatus green YES
+			fi
+		fi
+
+		_info_nol "    * IBRS enabled and active: "
 		if [ "$opt_live" = 1 ]; then
-			# 0 means disabled
-			# 1 is enabled only for kernel space
-			# 2 is enabled for kernel and user space
-			case "$ibrs_enabled" in
-				"") [ "$ibrs_supported" = 1 ] && pstatus yellow UNKNOWN || pstatus red NO;;
-				0)     pstatus red NO;;
-				1 | 2) pstatus green YES;;
-				*)     pstatus yellow UNKNOWN;;
-			esac
+			if [ "$ibpb_enabled" = 2 ]; then
+				# if ibpb=2, ibrs is forcefully=0
+				pstatus blue NO "IBPB used instead of IBRS in all kernel entrypoints"
+			else
+				# 0 means disabled
+				# 1 is enabled only for kernel space
+				# 2 is enabled for kernel and user space
+				# 3 is enabled
+				case "$ibrs_enabled" in
+					0)
+						if [ "$ibrs_fw_enabled" = 1 ]; then
+							pstatus blue YES "for firmware code only"
+						else
+							pstatus yellow NO
+						fi
+						;;
+					1)	if [ "$ibrs_fw_enabled" = 1 ]; then pstatus green YES "for kernel space and firmware code"; else pstatus green YES "for kernel space"; fi;;
+					2)	if [ "$ibrs_fw_enabled" = 1 ]; then pstatus green YES "for kernel, user space, and firmware code" ; else pstatus green YES "for both kernel and user space"; fi;;
+					3)	if [ "$ibrs_fw_enabled" = 1 ]; then pstatus green YES "for kernel and firmware code"; else pstatus green YES; fi;;
+					*)	pstatus yellow UNKNOWN;;
+				esac
+			fi
 		else
 			pstatus blue N/A "not testable in offline mode"
 		fi
 
-		_info_nol "*   IBRS enabled for User space: "
+		_info_nol "  * Kernel is compiled with IBPB support: "
+		if [ -z "$ibpb_supported" ]; then
+			if [ "$ibpb_can_tell" = 1 ]; then
+				pstatus yellow NO
+			else
+				# if we're in offline mode without System.map, we can't really know
+				pstatus yellow UNKNOWN "in offline mode, we need the kernel image to be able to tell"
+			fi
+		else
+			if [ "$opt_verbose" -ge 2 ]; then
+				pstatus green YES "$ibpb_supported"
+			else
+				pstatus green YES
+			fi
+		fi
+
+		_info_nol "    * IBPB enabled and active: "
 		if [ "$opt_live" = 1 ]; then
-			case "$ibrs_enabled" in
-				"") [ "$ibrs_supported" = 1 ] && pstatus yellow UNKNOWN || pstatus red NO;;
-				0 | 1) pstatus red NO;;
-				2) pstatus green YES;;
+			case "$ibpb_enabled" in
+				"")
+					if [ "$ibrs_supported" = 1 ]; then
+						pstatus yellow UNKNOWN
+					else
+						pstatus yellow NO
+					fi
+					;;
+				0)
+					pstatus yellow NO
+					;;
+				1) pstatus green YES;;
+				2) pstatus green YES "IBPB used instead of IBRS in all kernel entrypoints";;
 				*) pstatus yellow UNKNOWN;;
 			esac
 		else
@@ -748,180 +2174,539 @@ check_variant2()
 		fi
 
 		_info "* Mitigation 2"
-		_info_nol "*   Kernel compiled with retpoline option: "
+		_info_nol "  * Kernel has branch predictor hardening (arm): "
+		if [ -r "$opt_config" ]; then
+			bp_harden_can_tell=1
+			bp_harden=$(grep -w 'CONFIG_HARDEN_BRANCH_PREDICTOR=y' "$opt_config")
+			if [ -n "$bp_harden" ]; then
+				pstatus green YES
+				_debug "bp_harden: found '$bp_harden' in $opt_config"
+			fi
+		fi
+		if [ -z "$bp_harden" ] && [ -n "$opt_map" ]; then
+			bp_harden_can_tell=1
+			bp_harden=$(grep -w bp_hardening_data "$opt_map")
+			if [ -n "$bp_harden" ]; then
+				pstatus green YES
+				_debug "bp_harden: found '$bp_harden' in $opt_map"
+			fi
+		fi
+		if [ -z "$bp_harden" ]; then
+			if [ "$bp_harden_can_tell" = 1 ]; then
+				pstatus yellow NO
+			else
+				pstatus yellow UNKNOWN
+			fi
+		fi
+
+		_info_nol "  * Kernel compiled with retpoline option: "
 		# We check the RETPOLINE kernel options
 		if [ -r "$opt_config" ]; then
 			if grep -q '^CONFIG_RETPOLINE=y' "$opt_config"; then
 				pstatus green YES
 				retpoline=1
-				_debug "retpoline: found "$(grep '^CONFIG_RETPOLINE' "$opt_config")" in $opt_config"
+				# shellcheck disable=SC2046
+				_debug 'retpoline: found '$(grep '^CONFIG_RETPOLINE' "$opt_config")" in $opt_config"
 			else
-				pstatus red NO
+				pstatus yellow NO
 			fi
 		else
 			pstatus yellow UNKNOWN "couldn't read your kernel configuration"
 		fi
 
-		_info_nol "*   Kernel compiled with a retpoline-aware compiler: "
-		# Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm
-		# For gcc, this is -mindirect-branch=thunk-extern (detected by the kernel makefiles)
-		# See gcc commit https://github.com/hjl-tools/gcc/commit/23b517d4a67c02d3ef80b6109218f2aadad7bd79
-		# In latest retpoline LKML patches, the noretpoline_setup symbol exists only if CONFIG_RETPOLINE is set
-		# *AND* if the compiler is retpoline-compliant, so look for that symbol
-		if [ -n "$opt_map" ]; then
-			# look for the symbol
-			if grep -qw noretpoline_setup "$opt_map"; then
-				retpoline_compiler=1
-				pstatus green YES "noretpoline_setup symbol found in System.map"
-			else
-				pstatus red NO
-			fi
-		elif [ -n "$vmlinux" ]; then
-			# look for the symbol
-			if which nm >/dev/null 2>&1; then
-				# the proper way: use nm and look for the symbol
-				if nm "$vmlinux" 2>/dev/null | grep -qw 'noretpoline_setup'; then
-					retpoline_compiler=1
-					pstatus green YES "noretpoline_setup found in vmlinux symbols"
-				else
-					pstatus red NO
+		if [ "$retpoline" = 1 ]; then
+			# Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm
+			# For gcc, this is -mindirect-branch=thunk-extern (detected by the kernel makefiles)
+			# See gcc commit https://github.com/hjl-tools/gcc/commit/23b517d4a67c02d3ef80b6109218f2aadad7bd79
+			# In latest retpoline LKML patches, the noretpoline_setup symbol exists only if CONFIG_RETPOLINE is set
+			# *AND* if the compiler is retpoline-compliant, so look for that symbol
+			#
+			# if there is "retpoline" in the file and NOT "minimal", then it's full retpoline
+			# (works for vanilla and Red Hat variants)
+			if [ "$opt_live" = 1 ] && [ -e "/sys/devices/system/cpu/vulnerabilities/spectre_v2" ]; then
+				if grep -qwi retpoline /sys/devices/system/cpu/vulnerabilities/spectre_v2; then
+					if grep -qwi minimal /sys/devices/system/cpu/vulnerabilities/spectre_v2; then
+						retpoline_compiler=0
+						retpoline_compiler_reason="kernel reports minimal retpoline compilation"
+					else
+						retpoline_compiler=1
+						retpoline_compiler_reason="kernel reports full retpoline compilation"
+					fi
+				fi
+			elif [ -n "$opt_map" ]; then
+				# look for the symbol
+				if grep -qw noretpoline_setup "$opt_map"; then
+					retpoline_compiler=1
+					retpoline_compiler_reason="noretpoline_setup symbol found in System.map"
+				fi
+			elif [ -n "$kernel" ]; then
+				# look for the symbol
+				if which "${opt_arch_prefix}nm" >/dev/null 2>&1; then
+					# the proper way: use nm and look for the symbol
+					if "${opt_arch_prefix}nm" "$kernel" 2>/dev/null | grep -qw 'noretpoline_setup'; then
+						retpoline_compiler=1
+						retpoline_compiler_reason="noretpoline_setup found in kernel symbols"
+					fi
+				elif grep -q noretpoline_setup "$kernel"; then
+					# if we don't have nm, nevermind, the symbol name is long enough to not have
+					# any false positive using good old grep directly on the binary
+					retpoline_compiler=1
+					retpoline_compiler_reason="noretpoline_setup found in kernel"
 				fi
-			elif grep -q noretpoline_setup "$vmlinux"; then
-				# if we don't have nm, nevermind, the symbol name is long enough to not have
-				# any false positive using good old grep directly on the binary
-				retpoline_compiler=1
-				pstatus green YES "noretpoline_setup found in vmlinux"
-			else
-				pstatus red NO
 			fi
+			if [ -n "$retpoline_compiler" ]; then
+				_info_nol "    * Kernel compiled with a retpoline-aware compiler: "
+				if [ "$retpoline_compiler" = 1 ]; then
+					if [ -n "$retpoline_compiler_reason" ]; then
+						pstatus green YES "$retpoline_compiler_reason"
+					else
+						pstatus green YES
+					fi
+				else
+					if [ -n "$retpoline_compiler_reason" ]; then
+						pstatus red NO "$retpoline_compiler_reason"
+					else
+						pstatus red NO
+					fi
+				fi
+			fi
+		fi
+
+		# only Red Hat has a tunable to disable it on runtime
+		if [ "$opt_live" = 1 ]; then
+			if [ -e "$specex_knob_dir/retp_enabled" ]; then
+				retp_enabled=$(cat "$specex_knob_dir/retp_enabled" 2>/dev/null)
+				_debug "retpoline: found $specex_knob_dir/retp_enabled=$retp_enabled"
+				_info_nol "    * Retpoline is enabled: "
+				if [ "$retp_enabled" = 1 ]; then
+					pstatus green YES
+				else
+					pstatus yellow NO
+				fi
+			fi
+		fi
+
+		# only for information, in verbose mode
+		if [ "$opt_verbose" -ge 2 ]; then
+			_info_nol "    * Local gcc is retpoline-aware: "
+			if which gcc >/dev/null 2>&1; then
+				if [ -n "$(gcc -mindirect-branch=thunk-extern --version 2>&1 >/dev/null)" ]; then
+					pstatus blue NO
+				else
+					pstatus green YES
+				fi
+			else
+				pstatus blue NO "gcc is not installed"
+			fi
+		fi
+
+		if is_skylake_cpu || [ "$opt_verbose" -ge 2 ]; then
+			_info_nol "  * Kernel supports RSB filling: "
+			if ! which "${opt_arch_prefix}strings" >/dev/null 2>&1; then
+				pstatus yellow UNKNOWN "missing '${opt_arch_prefix}strings' tool, please install it, usually it's in the binutils package"
+			elif [ -z "$kernel" ]; then
+				pstatus yellow UNKNOWN "kernel image missing"
+			else
+				rsb_filling=$("${opt_arch_prefix}strings" "$kernel" | grep -w 'Filling RSB on context switch')
+				if [ -n "$rsb_filling" ]; then
+					pstatus green YES
+				else
+					pstatus yellow NO
+				fi
+			fi
+		fi
+
+	elif [ "$sys_interface_available" = 0 ]; then
+		# we have no sysfs but were asked to use it only!
+		msg="/sys vulnerability interface use forced, but it's not available!"
+		status=UNK
+	fi
+
+	cve='CVE-2017-5715'
+	if ! is_cpu_vulnerable 2; then
+		# override status & msg in case CPU is not vulnerable after all
+		pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
+	else
+		if [ "$retpoline" = 1 ] && [ "$retpoline_compiler" = 1 ] && [ "$retp_enabled" != 0 ] && [ -n "$ibpb_enabled" ] && [ "$ibpb_enabled" -ge 1 ] && ( ! is_skylake_cpu || [ -n "$rsb_filling" ] ); then
+			pvulnstatus $cve OK "Full retpoline + IBPB are mitigating the vulnerability"
+		elif [ "$retpoline" = 1 ] && [ "$retpoline_compiler" = 1 ] && [ "$retp_enabled" != 0 ] && [ "$opt_paranoid" = 0 ] && ( ! is_skylake_cpu || [ -n "$rsb_filling" ] ); then
+			pvulnstatus $cve OK "Full retpoline is mitigating the vulnerability"
+			if [ -n "$cpuid_ibpb" ]; then
+				_warn "You should enable IBPB to complete retpoline as a Variant 2 mitigation"
+			else
+				_warn "IBPB is considered as a good addition to retpoline for Variant 2 mitigation, but your CPU microcode doesn't support it"
+			fi
+		elif [ -n "$ibrs_enabled" ] && [ -n "$ibpb_enabled" ] && [ "$ibrs_enabled" -ge 1 ] && [ "$ibpb_enabled" -ge 1 ]; then
+			pvulnstatus $cve OK "IBRS + IBPB are mitigating the vulnerability"
+		elif [ "$ibpb_enabled" = 2 ] && ! is_cpu_smt_enabled; then
+			pvulnstatus $cve OK "Full IBPB is mitigating the vulnerability"
+		elif [ -n "$bp_harden" ]; then
+			pvulnstatus $cve OK "Branch predictor hardening mitigates the vulnerability"
+		elif [ -z "$bp_harden" ] && [ "$cpu_vendor" = ARM ]; then
+			pvulnstatus $cve VULN "Branch predictor hardening is needed to mitigate the vulnerability"
+			explain "Your kernel has not been compiled with the CONFIG_UNMAP_KERNEL_AT_EL0 option, recompile it with this option enabled."
+		elif [ "$opt_live" != 1 ]; then
+			if [ "$retpoline" = 1 ] && [ -n "$ibpb_supported" ]; then
+				pvulnstatus $cve OK "offline mode: kernel supports retpoline + IBPB to mitigate the vulnerability"
+			elif [ -n "$ibrs_supported" ] && [ -n "$ibpb_supported" ]; then
+				pvulnstatus $cve OK "offline mode: kernel supports IBRS + IBPB to mitigate the vulnerability"
+			elif [ "$ibrs_can_tell" != 1 ]; then
+				pvulnstatus $cve UNK "offline mode: not enough information"
+				explain "Re-run this script with root privileges, and give it the kernel image (--kernel), the kernel configuration (--config) and the System.map file (--map) corresponding to the kernel you would like to inspect."
+			fi
+		fi
+
+		# if we arrive here and didn't already call pvulnstatus, then it's VULN, let's explain why
+		if [ "$pvulnstatus_last_cve" != "$cve" ]; then
+			# explain what's needed for this CPU
+			if is_skylake_cpu; then
+				pvulnstatus $cve VULN "IBRS+IBPB or retpoline+IBPB+RBS filling, is needed to mitigate the vulnerability"
+				explain "To mitigate this vulnerability, you need either IBRS + IBPB, both requiring hardware support from your CPU microcode in addition to kernel support, or a kernel compiled with retpoline and IBPB, with retpoline requiring a retpoline-aware compiler (re-run this script with -v to know if your version of gcc is retpoline-aware) and IBPB requiring hardware support from your CPU microcode. You also need a recent-enough kernel that supports RSB filling if you plan to use retpoline. For Skylake+ CPUs, the IBRS + IBPB approach is generally preferred as it guarantees complete protection, and the performance impact is not as high as with older CPUs in comparison with retpoline. More information about how to enable the missing bits for those two possible mitigations on your system follow. You only need to take one of the two approaches."
+			elif is_zen_cpu; then
+				pvulnstatus $cve VULN "retpoline+IBPB is needed to mitigate the vulnerability"
+				explain "To mitigate this vulnerability, You need a kernel compiled with retpoline + IBPB support, with retpoline requiring a retpoline-aware compiler (re-run this script with -v to know if your version of gcc is retpoline-aware) and IBPB requiring hardware support from your CPU microcode."
+			elif is_intel || is_amd; then
+				pvulnstatus $cve VULN "IBRS+IBPB or retpoline+IBPB is needed to mitigate the vulnerability"
+				explain "To mitigate this vulnerability, you need either IBRS + IBPB, both requiring hardware support from your CPU microcode in addition to kernel support, or a kernel compiled with retpoline and IBPB, with retpoline requiring a retpoline-aware compiler (re-run this script with -v to know if your version of gcc is retpoline-aware) and IBPB requiring hardware support from your CPU microcode. The retpoline + IBPB approach is generally preferred as the performance impact is lower. More information about how to enable the missing bits for those two possible mitigations on your system follow. You only need to take one of the two approaches."
+			else
+				# in that case, we might want to trust sysfs if it's there
+				if [ -n "$msg" ]; then
+					[ "$msg" = Vulnerable ] && msg="no known mitigation exists for your CPU vendor ($cpu_vendor)"
+					pvulnstatus $cve $status "$msg"
+				else
+					pvulnstatus $cve VULN "no known mitigation exists for your CPU vendor ($cpu_vendor)"
+				fi
+			fi
+		fi
+
+		# if we are in live mode, we can check for a lot more stuff and explain further
+		if [ "$opt_live" = 1 ] && [ "$vulnstatus" != "OK" ]; then
+			_explain_hypervisor="An updated CPU microcode will have IBRS/IBPB capabilities indicated in the Hardware Check section above. If you're running under an hypervisor (KVM, Xen, VirtualBox, VMware, ...), the hypervisor needs to be up to date to be able to export the new host CPU flags to the guest. You can run this script on the host to check if the host CPU is IBRS/IBPB. If it is, and it doesn't show up in the guest, upgrade the hypervisor."
+			# IBPB (amd & intel)
+			if ( [ -z "$ibpb_enabled" ] || [ "$ibpb_enabled" = 0 ] ) && ( is_intel || is_amd ); then
+				if [ -z "$cpuid_ibpb" ]; then
+					explain "The microcode of your CPU needs to be upgraded to be able to use IBPB. This is usually done at boot time by your kernel (the upgrade is not persistent across reboots which is why it's done at each boot). If you're using a distro, make sure you are up to date, as microcode updates are usually shipped alongside with the distro kernel. Availability of a microcode update for you CPU model depends on your CPU vendor. You can usually find out online if a microcode update is available for your CPU by searching for your CPUID (indicated in the Hardware Check section). $_explain_hypervisor"
+				fi
+				if [ -z "$ibpb_supported" ]; then
+					explain "Your kernel doesn't have IBPB support, so you need to either upgrade your kernel (if you're using a distro) or recompiling a more recent kernel."
+				fi
+				if [ -n "$cpuid_ibpb" ] && [ -n "$ibpb_supported" ]; then
+					if [ -e "$specex_knob_dir/ibpb_enabled" ]; then
+						# newer (April 2018) Red Hat kernels have ibpb_enabled as ro, and automatically enables it with retpoline
+						if [ ! -w "$specex_knob_dir/ibpb_enabled" ] && [ -e "$specex_knob_dir/retp_enabled" ]; then
+							explain "Both your CPU and your kernel have IBPB support, but it is currently disabled. You kernel should enable IBPB automatically if you enable retpoline. You may enable it with \`echo 1 > $specex_knob_dir/retp_enabled\`."
+						else
+							explain "Both your CPU and your kernel have IBPB support, but it is currently disabled. You may enable it with \`echo 1 > $specex_knob_dir/ibpb_enabled\`."
+						fi
+					else
+						explain "Both your CPU and your kernel have IBPB support, but it is currently disabled. You may enable it. Check in your distro's documentation on how to do this."
+					fi
+				fi
+			elif [ "$ibpb_enabled" = 2 ] && is_cpu_smt_enabled; then
+				explain "You have ibpb_enabled set to 2, but it only offers sufficient protection when simultaneous multi-threading (aka SMT or HyperThreading) is disabled. You should reboot your system with the kernel parameter \`nosmt\`."
+			fi
+			# /IBPB
+
+			# IBRS (amd & intel)
+			if ( [ -z "$ibrs_enabled" ] || [ "$ibrs_enabled" = 0 ] ) && ( is_intel || is_amd ); then
+				if [ -z "$cpuid_ibrs" ]; then
+					explain "The microcode of your CPU needs to be upgraded to be able to use IBRS. This is usually done at boot time by your kernel (the upgrade is not persistent across reboots which is why it's done at each boot). If you're using a distro, make sure you are up to date, as microcode updates are usually shipped alongside with the distro kernel. Availability of a microcode update for you CPU model depends on your CPU vendor. You can usually find out online if a microcode update is available for your CPU by searching for your CPUID (indicated in the Hardware Check section). $_explain_hypervisor"
+				fi
+				if [ -z "$ibrs_supported" ]; then
+					explain "Your kernel doesn't have IBRS support, so you need to either upgrade your kernel (if you're using a distro) or recompiling a more recent kernel."
+				fi
+				if [ -n "$cpuid_ibrs" ] && [ -n "$ibrs_supported" ]; then
+					if [ -e "$specex_knob_dir/ibrs_enabled" ]; then
+						explain "Both your CPU and your kernel have IBRS support, but it is currently disabled. You may enable it with \`echo 1 > $specex_knob_dir/ibrs_enabled\`."
+					else
+						explain "Both your CPU and your kernel have IBRS support, but it is currently disabled. You may enable it. Check in your distro's documentation on how to do this."
+					fi
+				fi
+			fi
+			# /IBRS
+			unset _explain_hypervisor
+
+			# RETPOLINE (amd & intel)
+			if is_amd || is_intel; then
+				if [ "$retpoline" = 0 ]; then
+					explain "Your kernel is not compiled with retpoline support, so you need to either upgrade your kernel (if you're using a distro) or recompile your kernel with the CONFIG_RETPOLINE option enabled. You also need to compile your kernel with  a retpoline-aware compiler (re-run this script with -v to know if your version of gcc is retpoline-aware)."
+				elif [ "$retpoline" = 1 ] && [ "$retpoline_compiler" = 0 ]; then
+					explain "Your kernel is compiled with retpoline, but without a retpoline-aware compiler (re-run this script with -v to know if your version of gcc is retpoline-aware)."
+				elif [ "$retpoline" = 1 ] && [ "$retpoline_compiler" = 1 ] && [ "$retp_enabled" = 0 ]; then
+					explain "Your kernel has retpoline support and has been compiled with a retpoline-aware compiler, but retpoline is disabled. You should enable it with \`echo 1 > $specex_knob_dir/retp_enabled\`."
+				fi
+			fi
+			# /RETPOLINE
+		fi
+	fi
+	# sysfs msgs:
+	#1 "Vulnerable"
+	#2 "Vulnerable: Minimal generic ASM retpoline"
+	#2 "Vulnerable: Minimal AMD ASM retpoline"
+	# "Mitigation: Full generic retpoline"
+	# "Mitigation: Full AMD retpoline"
+	# $MITIGATION + ", IBPB"
+	# $MITIGATION + ", IBRS_FW"
+	#5 $MITIGATION + " - vulnerable module loaded"
+	# Red Hat only:
+	#2 "Vulnerable: Minimal ASM retpoline",
+	#3 "Vulnerable: Retpoline without IBPB",
+	#4 "Vulnerable: Retpoline on Skylake+",
+	#5 "Vulnerable: Retpoline with unsafe module(s)",
+	# "Mitigation: Full retpoline",
+	# "Mitigation: Full retpoline and IBRS (user space)",
+	# "Mitigation: IBRS (kernel)",
+	# "Mitigation: IBRS (kernel and user space)",
+	# "Mitigation: IBP disabled",
+}
+
+check_variant2_bsd()
+{
+	_info     "* Mitigation 1"
+	_info_nol "  * Kernel supports IBRS: "
+	ibrs_disabled=$(sysctl -n hw.ibrs_disable 2>/dev/null)
+	if [ -z "$ibrs_disabled" ]; then
+		pstatus yellow NO
+	else
+		pstatus green YES
+	fi
+
+	_info_nol "  * IBRS enabled and active: "
+	ibrs_active=$(sysctl -n hw.ibrs_active 2>/dev/null)
+	if [ "$ibrs_active" = 1 ]; then
+		pstatus green YES
+	else
+		pstatus yellow NO
+	fi
+
+	_info     "* Mitigation 2"
+	_info_nol "  * Kernel compiled with RETPOLINE: "
+	if [ -n "$kernel_err" ]; then
+		pstatus yellow UNKNOWN "couldn't check ($kernel_err)"
+	else
+		if ! which "${opt_arch_prefix}readelf" >/dev/null 2>&1; then
+			pstatus yellow UNKNOWN "missing '${opt_arch_prefix}readelf' tool, please install it, usually it's in the binutils package"
 		else
-			pstatus yellow UNKNOWN "couldn't find your kernel image or System.map"
+			nb_thunks=$("${opt_arch_prefix}readelf" -s "$kernel" | grep -c -e __llvm_retpoline_ -e __llvm_external_retpoline_ -e __x86_indirect_thunk_)
+			if [ "$nb_thunks" -gt 0 ]; then
+				retpoline=1
+				pstatus green YES "found $nb_thunks thunk(s)"
+			else
+				pstatus yellow NO
+			fi
 		fi
 	fi
 
-	# if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it
-	if [ "$sys_interface_available" = 0 ] && ! is_cpu_vulnerable 2; then
+	cve='CVE-2017-5715'
+	if ! is_cpu_vulnerable 2; then
 		# override status & msg in case CPU is not vulnerable after all
-		pvulnstatus CVE-2017-5715 OK "your CPU vendor reported your CPU model as not vulnerable"
-	elif [ -z "$msg" ]; then
-		# if msg is empty, sysfs check didn't fill it, rely on our own test
-		if [ "$retpoline" = 1 -a "$retpoline_compiler" = 1 ]; then
-			pvulnstatus CVE-2017-5715 OK "retpoline mitigate the vulnerability"
-		elif [ "$opt_live" = 1 ]; then
-			if [ "$ibrs_enabled" = 1 -o "$ibrs_enabled" = 2 ]; then
-				pvulnstatus CVE-2017-5715 OK "IBRS mitigates the vulnerability"
-			else
-				pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
-			fi
-		else
-			if [ "$ibrs_supported" = 1 ]; then
-				pvulnstatus CVE-2017-5715 OK "offline mode: IBRS will mitigate the vulnerability if enabled at runtime"
-			else
-				pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
-			fi
-		fi
+		pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
+	elif [ "$retpoline" = 1 ]; then
+		pvulnstatus $cve OK "Retpoline mitigates the vulnerability"
+	elif [ "$ibrs_active" = 1 ]; then
+		pvulnstatus $cve OK "IBRS mitigates the vulnerability"
+	elif [ "$ibrs_disabled" = 0 ]; then
+		pvulnstatus $cve VULN "IBRS is supported by your kernel but your CPU microcode lacks support"
+		explain "The microcode of your CPU needs to be upgraded to be able to use IBRS. Availability of a microcode update for you CPU model depends on your CPU vendor. You can usually find out online if a microcode update is available for your CPU by searching for your CPUID (indicated in the Hardware Check section). To do a microcode update, you can search the ports for the \`cpupdate\` tool. Microcode updates done this way are not reboot-proof, so be sure to do it every time the system boots up."
+	elif [ "$ibrs_disabled" = 1 ]; then
+		pvulnstatus $cve VULN "IBRS is supported but administratively disabled on your system"
+		explain "To enable IBRS, use \`sysctl hw.ibrs_disable=0\`"
 	else
-		pvulnstatus CVE-2017-5715 "$status" "$msg"
+		pvulnstatus $cve VULN "IBRS is needed to mitigate the vulnerability but your kernel is missing support"
+		explain "You need to either upgrade your kernel or recompile yourself a more recent version having IBRS support"
 	fi
 }
 
 ########################
 # MELTDOWN aka VARIANT 3
+
+# no security impact but give a hint to the user in verbose mode
+# about PCID/INVPCID cpuid features that must be present to avoid
+# too big a performance impact with PTI
+# refs:
+# https://marc.info/?t=151532047900001&r=1&w=2
+# https://groups.google.com/forum/m/#!topic/mechanical-sympathy/L9mHTbeQLNU
+pti_performance_check()
+{
+	_info_nol "  * Reduced performance impact of PTI: "
+	if [ -e "$procfs/cpuinfo" ] && grep ^flags "$procfs/cpuinfo" | grep -qw pcid; then
+		cpu_pcid=1
+	else
+		read_cpuid 0x1 $ECX 17 1 1; ret=$?
+		[ $ret -eq 0 ] && cpu_pcid=1
+	fi
+
+	if [ -e "$procfs/cpuinfo" ] && grep ^flags "$procfs/cpuinfo" | grep -qw invpcid; then
+		cpu_invpcid=1
+	else
+		read_cpuid 0x7 $EBX 10 1 1; ret=$?
+		[ $ret -eq 0 ] && cpu_invpcid=1
+	fi
+
+	if [ "$cpu_invpcid" = 1 ]; then
+		pstatus green YES 'CPU supports INVPCID, performance impact of PTI will be greatly reduced'
+	elif [ "$cpu_pcid" = 1 ]; then
+		pstatus green YES 'CPU supports PCID, performance impact of PTI will be reduced'
+	else
+		pstatus blue NO 'PCID/INVPCID not supported, performance impact of PTI will be significant'
+	fi
+}
+
 check_variant3()
 {
 	_info "\033[1;34mCVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'\033[0m"
+	if [ "$os" = Linux ]; then
+		check_variant3_linux
+	elif echo "$os" | grep -q BSD; then
+		check_variant3_bsd
+	else
+		_warn "Unsupported OS ($os)"
+	fi
+}
 
+check_variant3_linux()
+{
 	status=UNK
 	sys_interface_available=0
 	msg=''
 	if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/meltdown"; then
 		# this kernel has the /sys interface, trust it over everything
 		sys_interface_available=1
-	else
+	fi
+	if [ "$opt_sysfs_only" != 1 ]; then
 		_info_nol "* Kernel supports Page Table Isolation (PTI): "
-		kpti_support=0
+		kpti_support=''
 		kpti_can_tell=0
 		if [ -n "$opt_config" ]; then
 			kpti_can_tell=1
-			if grep -Eq '^(CONFIG_PAGE_TABLE_ISOLATION|CONFIG_KAISER)=y' "$opt_config"; then
-				_debug "kpti_support: found option "$(grep -E '^(CONFIG_PAGE_TABLE_ISOLATION|CONFIG_KAISER)=y' "$opt_config")" in $opt_config"
-				kpti_support=1
+			kpti_support=$(grep -w -e CONFIG_PAGE_TABLE_ISOLATION=y -e CONFIG_KAISER=y -e CONFIG_UNMAP_KERNEL_AT_EL0=y "$opt_config")
+			if [ -n "$kpti_support" ]; then
+				_debug "kpti_support: found option '$kpti_support' in $opt_config"
 			fi
 		fi
-		if [ "$kpti_support" = 0 -a -n "$opt_map" ]; then
+		if [ -z "$kpti_support" ] && [ -n "$opt_map" ]; then
 			# it's not an elif: some backports don't have the PTI config but still include the patch
 			# so we try to find an exported symbol that is part of the PTI patch in System.map
+			# parse_kpti: arm
 			kpti_can_tell=1
-			if grep -qw kpti_force_enabled "$opt_map"; then
-				_debug "kpti_support: found kpti_force_enabled in $opt_map"
-				kpti_support=1
+			kpti_support=$(grep -w -e kpti_force_enabled -e parse_kpti "$opt_map")
+			if [ -n "$kpti_support" ]; then
+				_debug "kpti_support: found '$kpti_support' in $opt_map"
 			fi
 		fi
-		if [ "$kpti_support" = 0 -a -n "$vmlinux" ]; then
-			# same as above but in case we don't have System.map and only vmlinux, look for the
+		if [ -z "$kpti_support" ] && [ -n "$kernel" ]; then
+			# same as above but in case we don't have System.map and only kernel, look for the
 			# nopti option that is part of the patch (kernel command line option)
+			# 'kpti=': arm
 			kpti_can_tell=1
-			if ! which strings >/dev/null 2>&1; then
-				pstatus yellow UNKNOWN "missing 'strings' tool, please install it, usually it's in the binutils package"
+			if ! which "${opt_arch_prefix}strings" >/dev/null 2>&1; then
+				pstatus yellow UNKNOWN "missing '${opt_arch_prefix}strings' tool, please install it, usually it's in the binutils package"
 			else
-				if strings "$vmlinux" | grep -qw nopti; then
-					_debug "kpti_support: found nopti string in $vmlinux"
-					kpti_support=1
+				kpti_support=$("${opt_arch_prefix}strings" "$kernel" | grep -w -e nopti -e kpti=)
+				if [ -n "$kpti_support" ]; then
+					_debug "kpti_support: found '$kpti_support' in $kernel"
 				fi
 			fi
 		fi
 
-		if [ "$kpti_support" = 1 ]; then
-			pstatus green YES
+		if [ -n "$kpti_support" ]; then
+			if [ "$opt_verbose" -ge 2 ]; then
+				pstatus green YES "found '$kpti_support'"
+			else
+				pstatus green YES
+			fi
 		elif [ "$kpti_can_tell" = 1 ]; then
-			pstatus red NO
+			pstatus yellow NO
 		else
 			pstatus yellow UNKNOWN "couldn't read your kernel configuration nor System.map file"
 		fi
 
 		mount_debugfs
-		_info_nol "* PTI enabled and active: "
+		_info_nol "  * PTI enabled and active: "
 		if [ "$opt_live" = 1 ]; then
 			dmesg_grep="Kernel/User page tables isolation: enabled"
 			dmesg_grep="$dmesg_grep|Kernel page table isolation enabled"
 			dmesg_grep="$dmesg_grep|x86/pti: Unmapping kernel while in userspace"
-			if grep ^flags /proc/cpuinfo | grep -qw pti; then
+			if grep ^flags "$procfs/cpuinfo" | grep -qw pti; then
 				# vanilla PTI patch sets the 'pti' flag in cpuinfo
-				_debug "kpti_enabled: found 'pti' flag in /proc/cpuinfo"
+				_debug "kpti_enabled: found 'pti' flag in $procfs/cpuinfo"
 				kpti_enabled=1
-			elif grep ^flags /proc/cpuinfo | grep -qw kaiser; then
+			elif grep ^flags "$procfs/cpuinfo" | grep -qw kaiser; then
 				# kernel line 4.9 sets the 'kaiser' flag in cpuinfo
-				_debug "kpti_enabled: found 'kaiser' flag in /proc/cpuinfo"
+				_debug "kpti_enabled: found 'kaiser' flag in $procfs/cpuinfo"
 				kpti_enabled=1
 			elif [ -e /sys/kernel/debug/x86/pti_enabled ]; then
-				# RedHat Backport creates a dedicated file, see https://access.redhat.com/articles/3311301
+				# Red Hat Backport creates a dedicated file, see https://access.redhat.com/articles/3311301
 				kpti_enabled=$(cat /sys/kernel/debug/x86/pti_enabled 2>/dev/null)
 				_debug "kpti_enabled: file /sys/kernel/debug/x86/pti_enabled exists and says: $kpti_enabled"
-			elif dmesg | grep -Eq "$dmesg_grep"; then
-				# if we can't find the flag, grep dmesg output
-				_debug "kpti_enabled: found hint in dmesg: "$(dmesg | grep -E "$dmesg_grep")
-				kpti_enabled=1
-			elif [ -r /var/log/dmesg ] && grep -Eq "$dmesg_grep" /var/log/dmesg; then
-				# if we can't find the flag in dmesg output, grep in /var/log/dmesg when readable
-				_debug "kpti_enabled: found hint in /var/log/dmesg: "$(grep -E "$dmesg_grep" /var/log/dmesg)
-				kpti_enabled=1
-			else
+			fi
+			if [ -z "$kpti_enabled" ]; then
+				dmesg_grep "$dmesg_grep"; ret=$?
+				if [ $ret -eq 0 ]; then
+					_debug "kpti_enabled: found hint in dmesg: $dmesg_grepped"
+					kpti_enabled=1
+				elif [ $ret -eq 2 ]; then
+					_debug "kpti_enabled: dmesg truncated"
+					kpti_enabled=-1
+				fi
+			fi
+			if [ -z "$kpti_enabled" ]; then
 				_debug "kpti_enabled: couldn't find any hint that PTI is enabled"
 				kpti_enabled=0
 			fi
 			if [ "$kpti_enabled" = 1 ]; then
 				pstatus green YES
+			elif [ "$kpti_enabled" = -1 ]; then
+				pstatus yellow UNKNOWN "dmesg truncated, please reboot and relaunch this script"
 			else
-				pstatus red NO
+				pstatus yellow NO
 			fi
 		else
-			pstatus blue N/A "can't verify if PTI is enabled in offline mode"
+			pstatus blue N/A "not testable in offline mode"
+		fi
+
+		pti_performance_check
+
+	elif [ "$sys_interface_available" = 0 ]; then
+		# we have no sysfs but were asked to use it only!
+		msg="/sys vulnerability interface use forced, but it's not available!"
+		status=UNK
+	fi
+
+
+	# Test if the current host is a Xen PV Dom0 / DomU
+	if [ -d "/proc/xen" ]; then
+		# XXX do we have a better way that relying on dmesg?
+		dmesg_grep 'Booting paravirtualized kernel on Xen$'; ret=$?
+		if [ $ret -eq 2 ]; then
+			_warn "dmesg truncated, Xen detection will be unreliable. Please reboot and relaunch this script"
+		elif [ $ret -eq 0 ]; then
+			if [ -e /proc/xen/capabilities ] && grep -q "control_d" /proc/xen/capabilities; then
+				xen_pv_domo=1
+			else
+				xen_pv_domu=1
+			fi
+			# PVHVM guests also print 'Booting paravirtualized kernel', so we need this check.
+			dmesg_grep 'Xen HVM callback vector for event delivery is enabled$'; ret=$?
+			if [ $ret -eq 0 ]; then
+				xen_pv_domu=0
+			fi
+		fi
+	fi
+
+	if [ "$opt_live" = 1 ]; then
+		# checking whether we're running under Xen PV 64 bits. If yes, we are affected by variant3
+		# (unless we are a Dom0)
+		_info_nol "* Running as a Xen PV DomU: "
+		if [ "$xen_pv_domu" = 1 ]; then
+			pstatus yellow YES
+		else
+			pstatus blue NO
 		fi
 	fi
 
-	# if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it
 	cve='CVE-2017-5754'
-	if [ "$sys_interface_available" = 0 ] && ! is_cpu_vulnerable 3; then
+	if ! is_cpu_vulnerable 3; then
 		# override status & msg in case CPU is not vulnerable after all
 		pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
 	elif [ -z "$msg" ]; then
@@ -929,54 +2714,142 @@ check_variant3()
 		if [ "$opt_live" = 1 ]; then
 			if [ "$kpti_enabled" = 1 ]; then
 				pvulnstatus $cve OK "PTI mitigates the vulnerability"
+			elif [ "$xen_pv_domo" = 1 ]; then
+				pvulnstatus $cve OK "Xen Dom0s are safe and do not require PTI"
+			elif [ "$xen_pv_domu" = 1 ]; then
+				pvulnstatus $cve VULN "Xen PV DomUs are vulnerable and need to be run in HVM, PVHVM, PVH mode, or the Xen hypervisor must have the Xen's own PTI patch"
+				explain "Go to https://blog.xenproject.org/2018/01/22/xen-project-spectre-meltdown-faq-jan-22-update/ for more information"
+			elif [ "$kpti_enabled" = -1 ]; then
+				pvulnstatus $cve UNK "couldn't find any clue of PTI activation due to a truncated dmesg, please reboot and relaunch this script"
 			else
 				pvulnstatus $cve VULN "PTI is needed to mitigate the vulnerability"
+				if [ -n "$kpti_support" ]; then
+					if [ -e "/sys/kernel/debug/x86/pti_enabled" ]; then
+						explain "Your kernel supports PTI but it's disabled, you can enable it with \`echo 1 > /sys/kernel/debug/x86/pti_enabled\`"
+					elif grep -q -w nopti -w pti=off /proc/cmdline; then
+						explain "Your kernel supports PTI but it has been disabled on command-line, remove the nopti or pti=off option from your bootloader configuration"
+					else
+						explain "Your kernel supports PTI but it has been disabled, check \`dmesg\` right after boot to find clues why the system disabled it"
+					fi
+				else
+					explain "If you're using a distro kernel, upgrade your distro to get the latest kernel available. Otherwise, recompile the kernel with the CONFIG_PAGE_TABLE_ISOLATION option (named CONFIG_KAISER for some kernels), or the CONFIG_UNMAP_KERNEL_AT_EL0 option (for ARM64)"
+				fi
 			fi
 		else
-			if [ "$kpti_support" = 1 ]; then
+			if [ -n "$kpti_support" ]; then
 				pvulnstatus $cve OK "offline mode: PTI will mitigate the vulnerability if enabled at runtime"
-			else
+			elif [ "$kpti_can_tell" = 1 ]; then
 				pvulnstatus $cve VULN "PTI is needed to mitigate the vulnerability"
+				explain "If you're using a distro kernel, upgrade your distro to get the latest kernel available. Otherwise, recompile the kernel with the CONFIG_PAGE_TABLE_ISOLATION option (named CONFIG_KAISER for some kernels), or the CONFIG_UNMAP_KERNEL_AT_EL0 option (for ARM64)"
+			else
+				pvulnstatus $cve UNK "offline mode: not enough information"
+				explain "Re-run this script with root privileges, and give it the kernel image (--kernel), the kernel configuration (--config) and the System.map file (--map) corresponding to the kernel you would like to inspect."
 			fi
 		fi
 	else
+		if [ "$xen_pv_domo" = 1 ]; then
+			msg="Xen Dom0s are safe and do not require PTI"
+			status="OK"
+		elif [ "$xen_pv_domu" = 1 ]; then
+			msg="Xen PV DomUs are vulnerable and need to be run in HVM, PVHVM, PVH mode, or the Xen hypervisor must have the Xen's own PTI patch"
+			status="VULN"
+			_explain="Go to https://blog.xenproject.org/2018/01/22/xen-project-spectre-meltdown-faq-jan-22-update/ for more information"
+		elif [ "$msg" = "Vulnerable" ]; then
+			msg="PTI is needed to mitigate the vulnerability"
+			_explain="If you're using a distro kernel, upgrade your distro to get the latest kernel available. Otherwise, recompile the kernel with the CONFIG_PAGE_TABLE_ISOLATION option (named CONFIG_KAISER for some kernels), or the CONFIG_UNMAP_KERNEL_AT_EL0 option (for ARM64)"
+		fi
 		pvulnstatus $cve "$status" "$msg"
+		[ -z "$_explain" ] && [ "$msg" = "Vulnerable" ] && _explain="If you're using a distro kernel, upgrade your distro to get the latest kernel available. Otherwise, recompile the kernel with the CONFIG_PAGE_TABLE_ISOLATION option (named CONFIG_KAISER for some kernels), or the CONFIG_UNMAP_KERNEL_AT_EL0 option (for ARM64)"
+		[ -n "$_explain" ] && explain "$_explain"
+		unset _explain
+	fi
+
+	# Warn the user about XSA-254 recommended mitigations
+	if [ "$xen_pv_domo" = 1 ]; then
+		_warn
+		_warn "This host is a Xen Dom0. Please make sure that you are running your DomUs"
+		_warn "in HVM, PVHVM or PVH mode to prevent any guest-to-host / host-to-guest attacks."
+		_warn
+		_warn "See https://blog.xenproject.org/2018/01/22/xen-project-spectre-meltdown-faq-jan-22-update/ and XSA-254 for details."
 	fi
 }
 
+check_variant3_bsd()
+{
+	_info_nol "* Kernel supports Page Table Isolation (PTI): "
+	kpti_enabled=$(sysctl -n vm.pmap.pti 2>/dev/null)
+	if [ -z "$kpti_enabled" ]; then
+		pstatus yellow NO
+	else
+		pstatus green YES
+	fi
+
+	_info_nol "  * PTI enabled and active: "
+	if [ "$kpti_enabled" = 1 ]; then
+		pstatus green YES
+	else
+		pstatus yellow NO
+	fi
+
+	pti_performance_check
+
+	cve='CVE-2017-5754'
+	if ! is_cpu_vulnerable 3; then
+		# override status & msg in case CPU is not vulnerable after all
+		pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
+	elif [ "$kpti_enabled" = 1 ]; then
+		pvulnstatus $cve OK "PTI mitigates the vulnerability"
+	elif [ -n "$kpti_enabled" ]; then
+		pvulnstatus $cve VULN "PTI is supported but disabled on your system"
+	else
+		pvulnstatus $cve VULN "PTI is needed to mitigate the vulnerability"
+	fi
+}
+
+if [ "$opt_no_hw" = 0 ] && [ -z "$opt_arch_prefix" ]; then
+	check_cpu
+	check_cpu_vulnerabilities
+	_info
+fi
+
 # now run the checks the user asked for
-if [ "$opt_variant1" = 1 -o "$opt_allvariants" = 1 ]; then
+if [ "$opt_variant1" = 1 ] || [ "$opt_allvariants" = 1 ]; then
 	check_variant1
 	_info
 fi
-if [ "$opt_variant2" = 1 -o "$opt_allvariants" = 1 ]; then
+if [ "$opt_variant2" = 1 ] || [ "$opt_allvariants" = 1 ]; then
 	check_variant2
 	_info
 fi
-if [ "$opt_variant3" = 1 -o "$opt_allvariants" = 1 ]; then
+if [ "$opt_variant3" = 1 ] || [ "$opt_allvariants" = 1 ]; then
 	check_variant3
 	_info
 fi
 
+_vars=$(set | grep -Ev '^[A-Z_[:space:]]' | sort | tr "\n" '|')
+_debug "variables at end of script: $_vars"
+
 _info "A false sense of security is worse than no security at all, see --disclaimer"
 
-# this'll umount only if we mounted debugfs ourselves
-umount_debugfs
-
-# cleanup the temp decompressed config
-[ -n "$dumped_config" ] && rm -f "$dumped_config"
-
-if [ "$opt_batch" = 1 -a "$opt_batch_format" = "nrpe" ]; then
+if [ "$opt_batch" = 1 ] && [ "$opt_batch_format" = "nrpe" ]; then
 	if [ ! -z "$nrpe_vuln" ]; then
 		echo "Vulnerable:$nrpe_vuln"
 	else
 		echo "OK"
 	fi
-	[ "$nrpe_critical" = 1 ] && exit 2  # critical
-	[ "$nrpe_unknown" = 1 ] && exit 3  # unknown
-	exit 0  # ok
 fi
 
-if [ "$opt_batch" = 1 -a "$opt_batch_format" = "json" ]; then
-	_echo 0 ${json_output%?}]
+if [ "$opt_batch" = 1 ] && [ "$opt_batch_format" = "json" ]; then
+	_echo 0 "${json_output%?}]"
 fi
+
+if [ "$opt_batch" = 1 ] && [ "$opt_batch_format" = "prometheus" ]; then
+	echo "# TYPE specex_vuln_status untyped"
+	echo "# HELP specex_vuln_status Exposure of system to speculative execution vulnerabilities"
+	echo "$prometheus_output"
+fi
+
+# exit with the proper exit code
+[ "$global_critical" = 1 ] && exit 2  # critical
+[ "$global_unknown"  = 1 ] && exit 3  # unknown
+exit 0  # ok