src: controllable entropy of inputs

src/config.py

@@ -60,6 +60,7 @@ class ConfCls:
     # Input Generator
     prng_seed: int = 10  # zero is a reserved value, do not use it
     avoid_data_dependencies: bool = True
+    input_mask: int = 0xffffffff
     # ==============================================================================================
     # Model
     model: str = 'x86-unicorn'  # options: 'x86-serializing', 'x86-unicorn'

src/custom_conf.yaml

@@ -11,8 +11,14 @@ supported_categories:
   - LOGICAL
   - POP
   - PUSH
-attacker_capability: l1d # ct, l1d
+attacker_capability: l1d
 contracts:
-  - seq
+#  - seq
 #  - cond
-#  - bpas
+  - bpas
+# max_nesting: 2
+# attack_variant: P+P
+enable_ssbp_patch: false
+enable_mds: false
+input_mask: 255
+#verbose: 999

src/executor.py

@@ -41,6 +41,7 @@ class X86Intel(Executor):
             write_to_pseudo_file("F", "/sys/x86-executor/measurement_mode")
         elif CONF.attack_variant == 'P+P':
             write_to_pseudo_file("P", "/sys/x86-executor/measurement_mode")
+        write_to_pseudo_file(CONF.input_mask, '/sys/x86-executor/input_mask')
 
     def load_test_case(self, test_case_asm: str):
         assemble(test_case_asm, 'generated.o')

src/model.py

@@ -215,12 +215,14 @@ class X86UnicornModel(Model):
         random_value = seed
         random_value = ((random_value * 2891336453) % POW32 + 12345) % POW32
         for i in range(0, 4096, 64):
-            self.emulator.mem_write(self.r14_init + i, random_value.to_bytes(8, byteorder='little'))
+            masked_rvalue = random_value & CONF.input_mask
+            self.emulator.mem_write(self.r14_init + i, masked_rvalue.to_bytes(8, byteorder='little'))
 
         # Values in registers
         for reg in [UC_X86_REG_RAX, UC_X86_REG_RBX, UC_X86_REG_RCX, UC_X86_REG_RDX]:
             random_value = ((random_value * 2891336453) % POW32 + 12345) % POW32
-            self.emulator.reg_write(reg, random_value)
+            masked_rvalue = random_value & CONF.input_mask
+            self.emulator.reg_write(reg, masked_rvalue)
 
         # FLAGS
         random_value = ((random_value * 2891336453) % POW32 + 12345) % POW32

src/tests/evict_second_line.asm

@@ -1,10 +1,9 @@
 .intel_syntax noprefix
 MFENCE
-MOV rbx, r14
-MOV rax, [rbx + 128]
-MOV rax, [rbx + 128]
-MOV rax, [rbx + 128]
-MOV rax, [rbx + 128]
-MOV rax, [rbx + 128]
-MOV rax, [rbx + 128]
+MOV rax, [r14 + 128]
+MOV rax, [r14 + 128]
+MOV rax, [r14 + 128]
+MOV rax, [r14 + 128]
+MOV rax, [r14 + 128]
+MOV rax, [r14 + 128]
 MFENCE