[Lldb-commits] [lldb] [debugserver] Support for `qMemTags` packet (PR #160952)

[David Spickett via lldb-commits]

================
@@ -0,0 +1,94 @@
+"""Test MTE Memory Tagging on Apple platforms"""
+
+import lldb
+import re
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+import lldbsuite.test.cpu_feature as cpu_feature
+
+exe_name = "uaf_mte"  # Must match Makefile
+
+
+class TestDarwinMTE(TestBase):
+    NO_DEBUG_INFO_TESTCASE = True
+
+    @skipUnlessFeature(cpu_feature.AArch64.MTE)
+    def test_tag_fault(self):
+        self.build()
+        exe = self.getBuildArtifact(exe_name)
+
+        target = self.dbg.CreateTarget(exe)
+        self.assertTrue(target, VALID_TARGET)
+
+        process = target.LaunchSimple(None, None, None)
+        self.assertState(process.GetState(), lldb.eStateStopped, PROCESS_STOPPED)
+
+        self.expect(
+            "thread info",
+            substrs=[
+                "stop reason = EXC_ARM_MTE_TAG_FAULT",
+                "MTE tag mismatch detected",
+            ],
+        )
+
+    @skipUnlessFeature(cpu_feature.AArch64.MTE)
+    def test_memory_read_with_tags(self):
+        self.build()
+        lldbutil.run_to_source_breakpoint(
+            self, "// before free", lldb.SBFileSpec("main.c"), exe_name=exe_name
+        )
+
+        # (lldb) memory read ptr-16 ptr+48 --show-tags
+        # 0x7d2c00930: 00 00 00 00 00 00 00 00 d0 e3 a5 0a 02 00 00 00  ................ (tag: 0x3)
+        # 0x7d2c00940: 48 65 6c 6c 6f 00 00 00 00 00 00 00 00 00 00 00  Hello........... (tag: 0xb)
+        # 0x7d2c00950: 57 6f 72 6c 64 00 00 00 00 00 00 00 00 00 00 00  World........... (tag: 0xb)
+        # 0x7d2c00960: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ (tag: 0x9)
+        self.expect(
+            "memory read ptr-16 ptr+48 --show-tags",
+            substrs=[" Hello...........", " World..........."],
+            patterns=[r"(.*\(tag: 0x[0-9a-f]\)\n){4}"],
+        )
+
+    def _parse_pointer_tag(self):
+        return re.search(r"Logical tag: (0x[0-9a-f])", self.res.GetOutput()).group(1)
+
+    def _parse_memory_tags(self, expected_tag_count):
+        tags = re.findall(r"\): (0x[0-9a-f])", self.res.GetOutput())
+        self.assertEqual(len(tags), expected_tag_count)
+        return tags
+
+    @skipUnlessFeature(cpu_feature.AArch64.MTE)
+    def test_memory_tag_read(self):
+        self.build()
+        lldbutil.run_to_source_breakpoint(
+            self, "// before free", lldb.SBFileSpec("main.c"), exe_name=exe_name
+        )
+
+        # (lldb) memory tag read ptr-1 ptr+33
+        # Logical tag: 0x5
+        # Allocation tags:
+        # [0x100a65a40, 0x100a65a50): 0xf (mismatch)
+        # [0x100a65a50, 0x100a65a60): 0x5
+        # [0x100a65a60, 0x100a65a70): 0x5
+        # [0x100a65a70, 0x100a65a80): 0x2 (mismatch)
+        self.expect(
+            "memory tag read ptr-1 ptr+33",
+            substrs=["Logical tag: 0x", "Allocation tags:", "(mismatch)"],
+            patterns=[r"(\[.*\): 0x[0-9a-f].*\n){4}"],
+        )
+        self.assertEqual(self.res.GetOutput().count("(mismatch)"), 2)
+        ptr_tag = self._parse_pointer_tag()
+        tags = self._parse_memory_tags(4)
+        self.assertEqual(tags[1], ptr_tag)
+        self.assertEqual(tags[2], ptr_tag)
+        self.assertNotEqual(tags[0], ptr_tag)
----------------
DavidSpickett wrote:

You can't say "!= a known value" here because the allocator randomises, right?

Please add a comment saying that if so.

https://github.com/llvm/llvm-project/pull/160952