Bug 1291377 - Don't use custom linker on Android 6.0+ r=glandium

We still need it for Android < 6.0 (API 23) because otherwise we don't
have a way to hook up mozalloc.

Differential Revision: https://phabricator.services.mozilla.com/D66993

--HG--
extra : moz-landing-system : lando

mozglue/baseprofiler/lul/AutoObjectMapper.cpp

@@ -23,6 +23,9 @@
 #  if defined(MOZ_LINKER)
 #    include <dlfcn.h>
 #    include "mozilla/Types.h"
+#    if defined(ANDROID)
+#      include <sys/system_properties.h>
+#    endif
 // FIXME move these out of mozglue/linker/ElfLoader.h into their
 // own header, so as to avoid conflicts arising from two definitions
 // of Array
@@ -96,6 +99,22 @@ bool AutoObjectMapperPOSIX::Map(/*OUT*/ void** start, /*OUT*/ size_t* length,
 }
 
 #  if defined(MOZ_LINKER)
+#    if defined(ANDROID)
+static int GetAndroidSDKVersion() {
+  static int version = 0;
+  if (version) {
+    return version;
+  }
+
+  char version_string[PROP_VALUE_MAX] = {'\0'};
+  int len = __system_property_get("ro.build.version.sdk", version_string);
+  if (len) {
+    version = static_cast<int>(strtol(version_string, nullptr, 10));
+  }
+  return version;
+}
+#    endif
+
 AutoObjectMapperFaultyLib::AutoObjectMapperFaultyLib(void (*aLog)(const char*))
     : AutoObjectMapperPOSIX(aLog), mHdl(nullptr) {}
 
@@ -122,6 +141,13 @@ bool AutoObjectMapperFaultyLib::Map(/*OUT*/ void** start,
                                     /*OUT*/ size_t* length,
                                     std::string fileName) {
   MOZ_ASSERT(!mHdl);
+
+#    if defined(ANDROID)
+  if (GetAndroidSDKVersion() >= 23) {
+    return AutoObjectMapperPOSIX::Map(start, length, fileName);
+  }
+#    endif
+
   return false;
 }
 

mozglue/linker/ElfLoader.cpp

@@ -28,6 +28,24 @@ mozilla::Atomic<size_t, mozilla::ReleaseAcquire> gPageSize;
 #  include <math.h>
 
 #  include <android/api-level.h>
+
+/**
+ * Return the current Android version, or 0 on failure.
+ */
+static int GetAndroidSDKVersion() {
+  static int version = 0;
+  if (version) {
+    return version;
+  }
+
+  char version_string[PROP_VALUE_MAX] = {'\0'};
+  int len = __system_property_get("ro.build.version.sdk", version_string);
+  if (len) {
+    version = static_cast<int>(strtol(version_string, nullptr, 10));
+  }
+  return version;
+}
+
 #  if __ANDROID_API__ < 8
 /* Android API < 8 doesn't provide sigaltstack */
 
@@ -61,12 +79,20 @@ extern "C" Elf::Dyn _DYNAMIC[];
  */
 
 void* __wrap_dlopen(const char* path, int flags) {
+  if (GetAndroidSDKVersion() >= 23) {
+    return dlopen(path, flags);
+  }
+
   RefPtr<LibHandle> handle = ElfLoader::Singleton.Load(path, flags);
   if (handle) handle->AddDirectRef();
   return handle;
 }
 
 const char* __wrap_dlerror(void) {
+  if (GetAndroidSDKVersion() >= 23) {
+    return dlerror();
+  }
+
   const char* error = ElfLoader::Singleton.lastError.exchange(nullptr);
   if (error) {
     // Return a custom error if available.
@@ -77,6 +103,10 @@ const char* __wrap_dlerror(void) {
 }
 
 void* __wrap_dlsym(void* handle, const char* symbol) {
+  if (GetAndroidSDKVersion() >= 23) {
+    return dlsym(handle, symbol);
+  }
+
   if (!handle) {
     ElfLoader::Singleton.lastError = "dlsym(NULL, sym) unsupported";
     return nullptr;
@@ -91,6 +121,10 @@ void* __wrap_dlsym(void* handle, const char* symbol) {
 }
 
 int __wrap_dlclose(void* handle) {
+  if (GetAndroidSDKVersion() >= 23) {
+    return dlclose(handle);
+  }
+
   if (!handle) {
     ElfLoader::Singleton.lastError = "No handle given to dlclose()";
     return -1;
@@ -100,6 +134,10 @@ int __wrap_dlclose(void* handle) {
 }
 
 int __wrap_dladdr(void* addr, Dl_info* info) {
+  if (GetAndroidSDKVersion() >= 23) {
+    return dladdr(addr, info);
+  }
+
   RefPtr<LibHandle> handle = ElfLoader::Singleton.GetHandleByPtr(addr);
   if (!handle) {
     return dladdr(addr, info);
@@ -197,6 +235,10 @@ int DlIteratePhdrHelper::fill_and_call(dl_phdr_cb callback, const void* l_addr,
 }
 
 int __wrap_dl_iterate_phdr(dl_phdr_cb callback, void* data) {
+  if (GetAndroidSDKVersion() >= 23) {
+    return dl_iterate_phdr(callback, data);
+  }
+
   DlIteratePhdrHelper helper;
   AutoLock lock(&ElfLoader::Singleton.handlesMutex);
 
@@ -275,25 +317,6 @@ const char* LeafName(const char* path) {
   return path;
 }
 
-#if defined(ANDROID)
-/**
- * Return the current Android version, or 0 on failure.
- */
-int GetAndroidSDKVersion() {
-  static int version = 0;
-  if (version) {
-    return version;
-  }
-
-  char version_string[PROP_VALUE_MAX] = {'\0'};
-  int len = __system_property_get("ro.build.version.sdk", version_string);
-  if (len) {
-    version = static_cast<int>(strtol(version_string, nullptr, 10));
-  }
-  return version;
-}
-#endif
-
 /**
  * Run the given lambda while holding the internal lock of the system linker.
  * To take the lock, we call the system dl_iterate_phdr and invoke the lambda

tools/profiler/lul/AutoObjectMapper.cpp

@@ -19,6 +19,10 @@
 #if defined(MOZ_LINKER)
 #  include <dlfcn.h>
 #  include "mozilla/Types.h"
+#  if defined(ANDROID)
+#    include <sys/system_properties.h>
+#  endif
+
 // FIXME move these out of mozglue/linker/ElfLoader.h into their
 // own header, so as to avoid conflicts arising from two definitions
 // of Array
@@ -140,11 +144,33 @@ AutoObjectMapperFaultyLib::~AutoObjectMapperFaultyLib() {
   // either by faulty.lib or by the parent class, but not by both.
 }
 
+#  if defined(ANDROID)
+static int GetAndroidSDKVersion() {
+  static int version = 0;
+  if (version) {
+    return version;
+  }
+
+  char version_string[PROP_VALUE_MAX] = {'\0'};
+  int len = __system_property_get("ro.build.version.sdk", version_string);
+  if (len) {
+    version = static_cast<int>(strtol(version_string, nullptr, 10));
+  }
+  return version;
+}
+#  endif
+
 bool AutoObjectMapperFaultyLib::Map(/*OUT*/ void** start,
                                     /*OUT*/ size_t* length,
                                     std::string fileName) {
   MOZ_ASSERT(!mHdl);
 
+#  if defined(ANDROID)
+  if (GetAndroidSDKVersion() >= 23) {
+    return AutoObjectMapperPOSIX::Map(start, length, fileName);
+  }
+#  endif
+
   if (fileName == "libmozglue.so") {
     // Do (2) in the comment above.
     char* libdir = get_installation_lib_dir();