bump to v0.23 to reflect changes

NRPE mode

README.md

@@ -1,51 +1,34 @@
 Spectre & Meltdown Checker
 ==========================
 
-A simple shell script to tell if your Linux installation is vulnerable
+A simple shell script to tell if your Linux installation is vulnerable against the 3 "speculative execution" CVEs.
-against the 3 "speculative execution" CVEs:
 
-CVE-2017-5753 bounds check bypass (Spectre Variant 1)
+Without options, it'll inspect you 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.
+
+The script will do its best to detect mitigations, including backported non-vanilla patches, regardless of the advertised kernel version number.
+
+## Example of script output
+
+![checker](https://framapic.org/FjroIZximyoM/EO5msoSMKb6L.png)
+
+## Quick summary of the CVEs
+
+**CVE-2017-5753** bounds check bypass (Spectre Variant 1)
 
    - Impact: Kernel & all software
    - Mitigation: recompile software *and* kernel with a modified compiler that introduces the LFENCE opcode at the proper positions in the resulting code
    - Performance impact of the mitigation: negligible
 
-CVE-2017-5715: branch target injection (Spectre Variant 2)
+**CVE-2017-5715** branch target injection (Spectre Variant 2)
 
    - Impact: Kernel
    - Mitigation 1: new opcode via microcode update that should be used by up to date compilers to protect the BTB (by flushing indirect branch predictors)
    - Mitigation 2: introducing "retpoline" into compilers, and recompile software/OS with it
    - Performance impact of the mitigation: high for mitigation 1, medium for mitigation 2, depending on your CPU
 
-CVE-2017-5754: rogue data cache load (Meltdown)
+**CVE-2017-5754** rogue data cache load (Meltdown)
 
    - Impact: Kernel
    - Mitigation: updated kernel (with PTI/KPTI patches), updating the kernel is enough
    - Performance impact of the mitigation: low to medium
-
-Example of the output of the script:
-
-
-```
-$ sudo ./spectre-meltdown-checker.sh
-Spectre and Meltdown mitigation detection tool v0.02
-
-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)
-> STATUS: VULNERABLE
-
-CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
-* Mitigation 1
-*   Hardware (CPU microcode) support for mitigation: NO
-*   Kernel support for IBRS: NO
-*   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)
-
-CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
-* Kernel supports Page Table Isolation (PTI): YES
-* PTI enabled and active: YES
-> STATUS: NOT VULNERABLE (PTI mitigates the vulnerability)
-```