Merge "Move to isolated testing."
diff --git a/debuggerd/debuggerd_test.cpp b/debuggerd/debuggerd_test.cpp
index 1f0e420..fbc8b97 100644
--- a/debuggerd/debuggerd_test.cpp
+++ b/debuggerd/debuggerd_test.cpp
@@ -1099,3 +1099,30 @@
   // This should be good enough, though...
   ASSERT_LT(diff, 10) << "too many new tombstones; is something crashing in the background?";
 }
+
+static __attribute__((__noinline__)) void overflow_stack(void* p) {
+  void* buf[1];
+  buf[0] = p;
+  static volatile void* global = buf;
+  if (global) {
+    global = buf;
+    overflow_stack(&buf);
+  }
+}
+
+TEST_F(CrasherTest, stack_overflow) {
+  int intercept_result;
+  unique_fd output_fd;
+  StartProcess([]() { overflow_stack(nullptr); });
+
+  StartIntercept(&output_fd);
+  FinishCrasher();
+  AssertDeath(SIGSEGV);
+  FinishIntercept(&intercept_result);
+
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+
+  std::string result;
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(Cause: stack pointer[^\n]*stack overflow.\n)");
+}
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index d246722..da2ba58 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -86,7 +86,39 @@
   _LOG(log, logtype::HEADER, "Timestamp: %s\n", buf);
 }
 
-static void dump_probable_cause(log_t* log, const siginfo_t* si, unwindstack::Maps* maps) {
+static std::string get_stack_overflow_cause(uint64_t fault_addr, uint64_t sp,
+                                            unwindstack::Maps* maps) {
+  static constexpr uint64_t kMaxDifferenceBytes = 256;
+  uint64_t difference;
+  if (sp >= fault_addr) {
+    difference = sp - fault_addr;
+  } else {
+    difference = fault_addr - sp;
+  }
+  if (difference <= kMaxDifferenceBytes) {
+    // The faulting address is close to the current sp, check if the sp
+    // indicates a stack overflow.
+    // On arm, the sp does not get updated when the instruction faults.
+    // In this case, the sp will still be in a valid map, which is the
+    // last case below.
+    // On aarch64, the sp does get updated when the instruction faults.
+    // In this case, the sp will be in either an invalid map if triggered
+    // on the main thread, or in a guard map if in another thread, which
+    // will be the first case or second case from below.
+    unwindstack::MapInfo* map_info = maps->Find(sp);
+    if (map_info == nullptr) {
+      return "stack pointer is in a non-existent map; likely due to stack overflow.";
+    } else if ((map_info->flags & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)) {
+      return "stack pointer is not in a rw map; likely due to stack overflow.";
+    } else if ((sp - map_info->start) <= kMaxDifferenceBytes) {
+      return "stack pointer is close to top of stack; likely stack overflow.";
+    }
+  }
+  return "";
+}
+
+static void dump_probable_cause(log_t* log, const siginfo_t* si, unwindstack::Maps* maps,
+                                unwindstack::Regs* regs) {
   std::string cause;
   if (si->si_signo == SIGSEGV && si->si_code == SEGV_MAPERR) {
     if (si->si_addr < reinterpret_cast<void*>(4096)) {
@@ -101,11 +133,16 @@
       cause = "call to kuser_memory_barrier";
     } else if (si->si_addr == reinterpret_cast<void*>(0xffff0f60)) {
       cause = "call to kuser_cmpxchg64";
+    } else {
+      cause = get_stack_overflow_cause(reinterpret_cast<uint64_t>(si->si_addr), regs->sp(), maps);
     }
   } else if (si->si_signo == SIGSEGV && si->si_code == SEGV_ACCERR) {
-    unwindstack::MapInfo* map_info = maps->Find(reinterpret_cast<uint64_t>(si->si_addr));
+    uint64_t fault_addr = reinterpret_cast<uint64_t>(si->si_addr);
+    unwindstack::MapInfo* map_info = maps->Find(fault_addr);
     if (map_info != nullptr && map_info->flags == PROT_EXEC) {
       cause = "execute-only (no-read) memory access error; likely due to data in .text.";
+    } else {
+      cause = get_stack_overflow_cause(fault_addr, regs->sp(), maps);
     }
   } else if (si->si_signo == SIGSYS && si->si_code == SYS_SECCOMP) {
     cause = StringPrintf("seccomp prevented call to disallowed %s system call %d", ABI_STRING,
@@ -447,7 +484,7 @@
 
   if (thread_info.siginfo) {
     dump_signal_info(log, thread_info, unwinder->GetProcessMemory().get());
-    dump_probable_cause(log, thread_info.siginfo, unwinder->GetMaps());
+    dump_probable_cause(log, thread_info.siginfo, unwinder->GetMaps(), thread_info.registers.get());
   }
 
   if (primary_thread) {
diff --git a/init/builtins.cpp b/init/builtins.cpp
index ba2c7ac..ceab568 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -42,6 +42,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include <ApexProperties.sysprop.h>
 #include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
@@ -130,6 +131,13 @@
     if (args.context != kInitContext) {
         return Error() << "command 'class_start_post_data' only available in init context";
     }
+    static bool is_apex_updatable = android::sysprop::ApexProperties::updatable().value_or(false);
+
+    if (!is_apex_updatable) {
+        // No need to start these on devices that don't support APEX, since they're not
+        // stopped either.
+        return {};
+    }
     for (const auto& service : ServiceList::GetInstance()) {
         if (service->classnames().count(args[1])) {
             if (auto result = service->StartIfPostData(); !result) {
@@ -155,6 +163,11 @@
     if (args.context != kInitContext) {
         return Error() << "command 'class_reset_post_data' only available in init context";
     }
+    static bool is_apex_updatable = android::sysprop::ApexProperties::updatable().value_or(false);
+    if (!is_apex_updatable) {
+        // No need to stop these on devices that don't support APEX.
+        return {};
+    }
     ForEachServiceInClass(args[1], &Service::ResetIfPostData);
     return {};
 }
diff --git a/libmeminfo/Android.bp b/libmeminfo/Android.bp
index fc022bd..8eb41b9 100644
--- a/libmeminfo/Android.bp
+++ b/libmeminfo/Android.bp
@@ -30,6 +30,7 @@
 
 cc_library {
     name: "libmeminfo",
+    host_supported: true,
     defaults: ["libmeminfo_defaults"],
     export_include_dirs: ["include"],
     export_shared_lib_headers: ["libbase"],
diff --git a/libmeminfo/tools/Android.bp b/libmeminfo/tools/Android.bp
index 2e89c41..a592a25 100644
--- a/libmeminfo/tools/Android.bp
+++ b/libmeminfo/tools/Android.bp
@@ -56,6 +56,7 @@
 
 cc_binary {
     name: "showmap",
+    host_supported: true,
     cflags: [
         "-Wall",
         "-Werror",
diff --git a/libmeminfo/tools/showmap.cpp b/libmeminfo/tools/showmap.cpp
index a80fa76..8ea2108 100644
--- a/libmeminfo/tools/showmap.cpp
+++ b/libmeminfo/tools/showmap.cpp
@@ -18,6 +18,7 @@
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/signal.h>
 #include <sys/types.h>
 #include <unistd.h>
 
@@ -56,7 +57,7 @@
 static VmaInfo g_total;
 static std::vector<VmaInfo> g_vmas;
 
-[[noreturn]] static void usage(int exit_status) {
+[[noreturn]] static void usage(const char* progname, int exit_status) {
     fprintf(stderr,
             "%s [-aqtv] [-f FILE] PID\n"
             "-a\taddresses (show virtual memory map)\n"
@@ -64,7 +65,7 @@
             "-t\tterse (show only items with private pages)\n"
             "-v\tverbose (don't coalesce maps with the same name)\n"
             "-f\tFILE (read from input from FILE instead of PID)\n",
-            getprogname());
+            progname);
 
     exit(exit_status);
 }
@@ -239,22 +240,22 @@
                 g_filename = optarg;
                 break;
             case 'h':
-                usage(EXIT_SUCCESS);
+                usage(argv[0], EXIT_SUCCESS);
             default:
-                usage(EXIT_FAILURE);
+                usage(argv[0], EXIT_FAILURE);
         }
     }
 
     if (g_filename.empty()) {
         if ((argc - 1) < optind) {
             fprintf(stderr, "Invalid arguments: Must provide <pid> at the end\n");
-            usage(EXIT_FAILURE);
+            usage(argv[0], EXIT_FAILURE);
         }
 
         g_pid = atoi(argv[optind]);
         if (g_pid <= 0) {
             fprintf(stderr, "Invalid process id %s\n", argv[optind]);
-            usage(EXIT_FAILURE);
+            usage(argv[0], EXIT_FAILURE);
         }
 
         g_filename = ::android::base::StringPrintf("/proc/%d/smaps", g_pid);
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index dfe9747..73237e6 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -125,10 +125,6 @@
         },
     },
 
-    whole_static_libs: [
-        "libdemangle"
-    ],
-
     static_libs: [
         "libprocinfo",
     ],
diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index c95f852..7556482 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -27,8 +27,6 @@
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 
-#include <demangle.h>
-
 #include <unwindstack/Elf.h>
 #include <unwindstack/JitDebug.h>
 #include <unwindstack/MapInfo.h>
@@ -40,6 +38,9 @@
 #include <unwindstack/DexFiles.h>
 #endif
 
+// Use the demangler from libc++.
+extern "C" char* __cxa_demangle(const char*, char*, size_t*, int* status);
+
 namespace unwindstack {
 
 // Inject extra 'virtual' frame that represents the dex pc data.
@@ -330,7 +331,14 @@
   }
 
   if (!frame.function_name.empty()) {
-    data += " (" + demangle(frame.function_name.c_str());
+    char* demangled_name = __cxa_demangle(frame.function_name.c_str(), nullptr, nullptr, nullptr);
+    if (demangled_name == nullptr) {
+      data += " (" + frame.function_name;
+    } else {
+      data += " (";
+      data += demangled_name;
+      free(demangled_name);
+    }
     if (frame.function_offset != 0) {
       data += android::base::StringPrintf("+%" PRId64, frame.function_offset);
     }
diff --git a/libunwindstack/tests/UnwindOfflineTest.cpp b/libunwindstack/tests/UnwindOfflineTest.cpp
index e6158a2..bded57a 100644
--- a/libunwindstack/tests/UnwindOfflineTest.cpp
+++ b/libunwindstack/tests/UnwindOfflineTest.cpp
@@ -1482,11 +1482,15 @@
       "  #09 pc 0000000000ed5e25  perfetto_unittests "
       "(testing::internal::UnitTestImpl::RunAllTests()+581)\n"
       "  #10 pc 0000000000ef63f3  perfetto_unittests "
-      "(_ZN7testing8internal38HandleSehExceptionsInMethodIfSupportedINS0_12UnitTestImplEbEET0_PT_"
-      "MS4_FS3_vEPKc+131)\n"
+      "(bool "
+      "testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, "
+      "bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char "
+      "const*)+131)\n"
       "  #11 pc 0000000000ee2a21  perfetto_unittests "
-      "(_ZN7testing8internal35HandleExceptionsInMethodIfSupportedINS0_12UnitTestImplEbEET0_PT_MS4_"
-      "FS3_vEPKc+113)\n"
+      "(bool "
+      "testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, "
+      "bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char "
+      "const*)+113)\n"
       "  #12 pc 0000000000ed5bb9  perfetto_unittests (testing::UnitTest::Run()+185)\n"
       "  #13 pc 0000000000e900f0  perfetto_unittests (RUN_ALL_TESTS()+16)\n"
       "  #14 pc 0000000000e900d8  perfetto_unittests (main+56)\n"