Skip test_faulthandler too, and oh hey, I fixed that one!

Author: StanFromIreland

.github/workflows/reusable-san.yml

@@ -83,11 +83,13 @@ jobs:
       run: make -j4
     - name: Display build info
       run: make pythoninfo
+    # test_{capi,faulthandler} are skipped under UBSan because
+    # they raise signals that UBSan with halt_on_error=1 intercepts.
     - name: Tests
       run: >-
         ./python -m test
         ${{ inputs.sanitizer == 'TSan' && '--tsan' || '' }}
-        ${{ inputs.sanitizer == 'UBSan' && '-x test_capi' || '' }}
+        ${{ inputs.sanitizer == 'UBSan' && '-x test_capi -x test_faulthandler' || '' }}
         -j4
     - name: Parallel tests
       if: >-

Tools/ubsan/suppressions.txt

@@ -1,17 +1,21 @@
 # This file contains suppressions for the UndefinedBehaviour sanitizer.
 #
+# Reference: https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#runtime-suppressions
+#
 # When adding a suppression, include a comment referencing a GitHub issue
 # that describes how to reproduce the race and includes the relevant UBSan
 # output.
 
+# Objects/object.c:97:5: runtime error: member access within null pointer of type 'PyThreadState' (aka 'struct _ts')
 null:Objects/object.c
-bool:Objects/memoryobject.c
 
-# Modules/binascii.c:1243:42: runtime error: left shift of 128 by 24 places cannot be represented in type 'int'
-shift-base:Modules/binascii.c
+# Objects/memoryobject.c:3032:15: runtime error: load of value 2, which is not a valid value for type 'bool'
+bool:Objects/memoryobject.c
 
 # Modules/_ctypes/cfield.c:644:1: runtime error: left shift of 1 by 63 places cannot be represented in type 'int64_t' (aka 'long')
 shift-base:Modules/_ctypes/cfield.c
+
+# Modules/_ctypes/cfield.c:640:1: runtime error: signed integer overflow: -2147483648 - 1 cannot be represented in type 'int'
 signed-integer-overflow:Modules/_ctypes/cfield.c
 
 # Modules/_zstd/decompressor.c:598:56: runtime error: applying non-zero offset 18446744073709551615 to null pointer