detect kpti directly in vmlinux if option is not there

README.md

@@ -28,7 +28,7 @@ Example of the output of the script:
 
 ```
 $ sudo ./spectre-meltdown-checker.sh
-Spectre and Meltdown mitigation detection tool v0.02
+Spectre and Meltdown mitigation detection tool v0.07
 
 CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
 * Kernel compiled with LFENCE opcode inserted at the proper places:  NO  (only 38 opcodes found, should be >= 60)
@@ -41,8 +41,8 @@ CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
 *   IBRS enabled for Kernel space:  NO
 *   IBRS enabled for User space:  NO
 * Mitigation 2
-*   Kernel recompiled with retpolines: UNKNOWN (check not yet implemented)
-> STATUS: VULNERABLE (IBRS hardware + kernel support OR retpolines-compiled kernel are needed to mitigate the vulnerability)
+*   Kernel compiled with retpolines:  NO
+> STATUS:  VULNERABLE  (IBRS hardware + kernel support OR kernel with retpolines are needed to mitigate the vulnerability)
 
 CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
 * Kernel supports Page Table Isolation (PTI):  YES

spectre-meltdown-checker.sh

@@ -1,7 +1,7 @@
 #! /bin/sh
 # Spectre & Meltdown checker
 # Stephane Lesimple
-VERSION=0.07
+VERSION=0.08
 
 pstatus()
 {
@@ -95,7 +95,6 @@ else
 			pstatus green YES "$nb_lfence opcodes found, which is >= 60"
 			status=2
 		fi
-		rm -f $vmlinux
 	fi
 fi
 
@@ -218,6 +217,14 @@ elif [ -e /boot/System.map-$(uname -r) ]; then
 	else
 		pstatus red NO
 	fi
+elif [ -n "$vmlinux" ]; then
+	# some backports don't have the option but still have the patch, try to find out
+	if strings "$vmlinux" | grep -qw nopti; then
+		pstatus green YES
+		kpti_support=1
+	else
+		pstatus red NO
+	fi
 else
 	pstatus yellow UNKNOWN "couldn't read your kernel configuration"
 fi
@@ -226,7 +233,7 @@ fi
 if grep ^flags /proc/cpuinfo | grep -qw pti; then
 	pstatus green YES
 	kpti_enabled=1
-elif dmesg | grep -q 'Kernel/User page tables isolation: enabled'; then
+elif dmesg | grep -Eq 'Kernel/User page tables isolation: enabled|Kernel page table isolation enabled'; then
 	pstatus green YES
 	kpti_enabled=1
 else
@@ -249,3 +256,5 @@ if [ "$USER" != root ]; then
 	/bin/echo "You can try the following command: sudo $0"
 fi
 
+[ -n "$vmlinux" ] && rm -f "$vmlinux"
+