Turn some error conditions into assertions (part 3)

[kconfig-hardened-check.git] / kconfig_hardened_check / __init__.py

diff --git a/kconfig_hardened_check/__init__.py b/kconfig_hardened_check/__init__.py
index 7ac709fa328e76852fe601706244c3d8142c7146..0ed7dd349ff4370d947e81390f0815be8c29d466 100644 (file)
--- a/kconfig_hardened_check/__init__.py
+++ b/kconfig_hardened_check/__init__.py
@@ -11,7 +11,6 @@
 #
 #
 # N.B Hardening command line parameters:
-#    slab_nomerge
 #    page_alloc.shuffle=1
 #    iommu=force (does it help against DMA attacks?)
 #    iommu.passthrough=0
@@ -27,7 +26,6 @@
 #           mitigations=auto,nosmt (nosmt is slow)
 #       X86:
 #           spectre_v2=on
-#           pti=on
 #           spec_store_bypass_disable=on
 #           l1tf=full,force
 #           l1d_flush=on (a part of the l1tf option)
@@ -38,6 +36,7 @@
 #           ssbd=force-on
 #
 #    Should NOT be set:
+#           slab_merge
 #           nokaslr
 #           rodata=off
 #           sysrq_always_enabled
@@ -89,8 +88,8 @@ SIMPLE_OPTION_TYPES = ('kconfig', 'version', 'cmdline')
 class OptCheck:
     # Constructor without the 'expected' parameter is for option presence checks (any value is OK)
     def __init__(self, reason, decision, name, expected=None):
-        if not reason or not decision or not name:
-            sys.exit('[!] ERROR: invalid {} check for "{}"'.format(self.__class__.__name__, name))
+        assert(reason and decision and name), \
+               'invalid {} check for "{}"'.format(self.__class__.__name__, name)
         self.name = name
         self.expected = expected
         self.decision = decision
@@ -186,12 +185,12 @@ class VersionCheck:
 class ComplexOptCheck:
     def __init__(self, *opts):
         self.opts = opts
-        if not self.opts:
-            sys.exit('[!] ERROR: empty {} check'.format(self.__class__.__name__))
-        if len(self.opts) == 1:
-            sys.exit('[!] ERROR: useless {} check'.format(self.__class__.__name__))
-        if not isinstance(opts[0], KconfigCheck) and not isinstance(opts[0], CmdlineCheck):
-            sys.exit('[!] ERROR: invalid {} check: {}'.format(self.__class__.__name__, opts))
+        assert(self.opts), \
+               'empty {} check'.format(self.__class__.__name__)
+        assert(len(self.opts) != 1), \
+                'useless {} check: {}'.format(self.__class__.__name__, opts)
+        assert(isinstance(opts[0], KconfigCheck) or isinstance(opts[0], CmdlineCheck)), \
+               'invalid {} check: {}'.format(self.__class__.__name__, opts)
         self.result = None
 
     @property
@@ -241,8 +240,6 @@ class OR(ComplexOptCheck):
     #     OR(<X_is_hardened>, <X_is_disabled>)
     #     OR(<X_is_hardened>, <old_X_is_hardened>)
     def check(self):
-        if not self.opts:
-            sys.exit('[!] ERROR: invalid OR check')
         for i, opt in enumerate(self.opts):
             opt.check()
             if opt.result.startswith('OK'):
@@ -255,9 +252,10 @@ class OR(ComplexOptCheck):
                         self.result = 'OK: {} not found'.format(opt.name)
                     elif opt.result == 'OK: is present':
                         self.result = 'OK: {} is present'.format(opt.name)
-                    # VersionCheck provides enough info
-                    elif not opt.result.startswith('OK: version'):
-                        sys.exit('[!] ERROR: unexpected OK description "{}"'.format(opt.result))
+                    else:
+                        # VersionCheck provides enough info
+                        assert(opt.result.startswith('OK: version')), \
+                               'unexpected OK description "{}"'.format(opt.result)
                 return
         self.result = self.opts[0].result
 
@@ -285,10 +283,9 @@ class AND(ComplexOptCheck):
                 else:
                     # VersionCheck provides enough info
                     self.result = opt.result
-                    if not opt.result.startswith('FAIL: version'):
-                        sys.exit('[!] ERROR: unexpected FAIL description "{}"'.format(opt.result))
+                    assert(opt.result.startswith('FAIL: version')), \
+                           'unexpected FAIL description "{}"'.format(opt.result)
                 return
-        sys.exit('[!] ERROR: invalid AND check')
 
 
 def detect_arch(fname, archs):
@@ -467,7 +464,8 @@ def add_kconfig_checks(l, arch):
     l += [KconfigCheck('self_protection', 'clipos', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
     l += [OR(KconfigCheck('self_protection', 'clipos', 'EFI_DISABLE_PCI_DMA', 'y'),
              efi_not_set)]
-    l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')] # slab_nomerge
+    l += [OR(KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set'),
+             CmdlineCheck('self_protection', 'kspp', 'slab_nomerge'))] # option presence check
     l += [KconfigCheck('self_protection', 'clipos', 'RANDOM_TRUST_BOOTLOADER', 'is not set')]
     l += [KconfigCheck('self_protection', 'clipos', 'RANDOM_TRUST_CPU', 'is not set')]
     l += [AND(KconfigCheck('self_protection', 'clipos', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'),
@@ -660,6 +658,8 @@ def add_cmdline_checks(l, arch):
     # Calling the CmdlineCheck class constructor:
     #     CmdlineCheck(reason, decision, name, expected)
 
+    if arch in ('X86_64', 'X86_32'):
+        l += [CmdlineCheck('self_protection', 'kspp', 'pti', 'on')]
     # TODO: add other
 
 
@@ -676,8 +676,8 @@ def print_unknown_options(checklist, parsed_options):
                     known_options.append(o2.name)
                 continue
             for o3 in o2.opts:
-                if o3.type == 'complex':
-                    sys.exit('[!] ERROR: unexpected ComplexOptCheck inside {}'.format(o2.name))
+                assert(o3.type != 'complex'), \
+                       'unexpected ComplexOptCheck inside {}'.format(o2.name)
                 if hasattr(o3, 'name'):
                     known_options.append(o3.name)
 
@@ -735,12 +735,12 @@ def print_checklist(mode, checklist, with_results):
 
 
 def populate_simple_opt_with_data(opt, data, data_type):
-    if opt.type == 'complex':
-        sys.exit('[!] ERROR: unexpected ComplexOptCheck {}: {}'.format(opt.name, vars(opt)))
-    if opt.type not in SIMPLE_OPTION_TYPES:
-        sys.exit('[!] ERROR: invalid opt type "{}" for {}'.format(opt.type, opt.name))
-    if data_type not in SIMPLE_OPTION_TYPES:
-        sys.exit('[!] ERROR: invalid data type "{}"'.format(data_type))
+    assert(opt.type != 'complex'), \
+           'unexpected ComplexOptCheck "{}"'.format(opt.name)
+    assert(opt.type in SIMPLE_OPTION_TYPES), \
+           'invalid opt type "{}"'.format(opt.type)
+    assert(data_type in SIMPLE_OPTION_TYPES), \
+           'invalid data type "{}"'.format(data_type)
 
     if data_type != opt.type:
         return
@@ -849,6 +849,9 @@ def main():
     config_checklist = []
 
     if args.config:
+        if args.print:
+            sys.exit('[!] ERROR: --config and --print can\'t be used together')
+
         if mode != 'json':
             print('[+] Kconfig file to check: {}'.format(args.config))
             if args.cmdline: