remove dependency on rdmsr

spectre-meltdown-checker.sh

@@ -1,7 +1,7 @@
 #! /bin/sh
 # Spectre & Meltdown checker
 # Stephane Lesimple
-VERSION=0.04
+VERSION=0.06
 
 pstatus()
 {
@@ -11,7 +11,7 @@ pstatus()
 		yellow) col="\033[103m\033[30m";;
 		*)      col="";;
 	esac
-	/bin/echo -ne "$col$2\033[0m"
+	/bin/echo -ne "$col $2 \033[0m"
 	[ -n "$3" ] && /bin/echo -n " ($3)"
 	/bin/echo
 }
@@ -116,14 +116,13 @@ 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
-	dd if=/dev/cpu/0/msr of=/dev/null bs=1 count=8 skip=72 2>/dev/null
+	# same that rdmsr 0x48 but without needing the rdmsr tool
+	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
-	#dd if=/dev/cpu/0/msr of=/dev/null bs=1 count=8 skip=73 2>/dev/null
-	#/bin/echo $?
 fi
 
 if [ "$insmod_msr" = 1 ]; then
@@ -163,7 +162,7 @@ if [ "$mounted_debugfs" = 1 ]; then
 fi
 
 /bin/echo "* Mitigation 2"
-/bin/echo -n "*   Kernel recompiled with retpolines: "
+/bin/echo -n "*   Kernel compiled with retpolines: "
 # XXX this doesn't mean the kernel has been compiled with a retpoline-aware gcc
 if [ -e /proc/config.gz ]; then
 	if zgrep -q '^CONFIG_RETPOLINE=y' /proc/config.gz; then
@@ -189,7 +188,7 @@ elif [ "$ibrs_enabled" = 1 -o "$ibrs_enabled" = 2 ]; then
 elif [ "$retpoline" = 1 ]; then
 	pstatus green "NOT VULNERABLE" "retpolines mitigate the vulnerability"
 else
-	pstatus red VULNERABLE "IBRS hardware + kernel support OR kernel with retpolines kernel are needed to mitigate the vulnerability"
+	pstatus red VULNERABLE "IBRS hardware + kernel support OR kernel with retpolines are needed to mitigate the vulnerability"
 fi
 
 # MELTDOWN