[XRay] Add support for instrumentation of DSOs on x86_64

clang/include/clang/Basic/CodeGenOptions.def

@@ -133,6 +133,8 @@ CODEGENOPT(XRayIgnoreLoops , 1, 0)
 ///< Emit the XRay function index section.
 CODEGENOPT(XRayFunctionIndex , 1, 1)
 
+///< Set when -fxray-shared is enabled
+CODEGENOPT(XRayShared , 1, 0)
 
 ///< Set the minimum number of instructions in a function to determine selective
 ///< XRay instrumentation.

clang/include/clang/Driver/Options.td

@@ -2922,6 +2922,11 @@ def fxray_selected_function_group :
   HelpText<"When using -fxray-function-groups, select which group of functions to instrument. Valid range is 0 to fxray-function-groups - 1">,
   MarshallingInfoInt<CodeGenOpts<"XRaySelectedFunctionGroup">, "0">;
 
+defm xray_shared : BoolFOption<"xray-shared",
+  CodeGenOpts<"XRayShared">, DefaultFalse,
+  PosFlag<SetTrue, [], [ClangOption, CC1Option],
+          "Enable shared library instrumentation with XRay">,
+  NegFlag<SetFalse>>;
 
 defm fine_grained_bitfield_accesses : BoolOption<"f", "fine-grained-bitfield-accesses",
   CodeGenOpts<"FineGrainedBitfieldAccesses">, DefaultFalse,

clang/include/clang/Driver/XRayArgs.h

@@ -27,6 +27,7 @@ class XRayArgs {
   XRayInstrSet InstrumentationBundle;
   llvm::opt::Arg *XRayInstrument = nullptr;
   bool XRayRT = true;
+  bool XRayShared = false;
 
 public:
   /// Parses the XRay arguments from an argument list.
@@ -35,6 +36,9 @@ class XRayArgs {
                llvm::opt::ArgStringList &CmdArgs, types::ID InputType) const;
 
   bool needsXRayRt() const { return XRayInstrument && XRayRT; }
+  bool needsXRayDSORt() const {
+    return XRayInstrument && XRayRT && XRayShared;
+  }
   llvm::ArrayRef<std::string> modeList() const { return Modes; }
   XRayInstrSet instrumentationBundle() const { return InstrumentationBundle; }
 };

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -1629,10 +1629,14 @@ bool tools::addSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
 }
 
 bool tools::addXRayRuntime(const ToolChain&TC, const ArgList &Args, ArgStringList &CmdArgs) {
-  if (Args.hasArg(options::OPT_shared))
-    return false;
-
-  if (TC.getXRayArgs().needsXRayRt()) {
+  if (Args.hasArg(options::OPT_shared)) {
+    if (TC.getXRayArgs().needsXRayDSORt()) {
+      CmdArgs.push_back("--whole-archive");
+      CmdArgs.push_back(TC.getCompilerRTArgString(Args, "xray-dso"));
+      CmdArgs.push_back("--no-whole-archive");
+      return true;
+    }
+  } else if (TC.getXRayArgs().needsXRayRt()) {
     CmdArgs.push_back("--whole-archive");
     CmdArgs.push_back(TC.getCompilerRTArgString(Args, "xray"));
     for (const auto &Mode : TC.getXRayArgs().modeList())

clang/lib/Driver/XRayArgs.cpp

@@ -63,6 +63,23 @@ XRayArgs::XRayArgs(const ToolChain &TC, const ArgList &Args) {
         << XRayInstrument->getSpelling() << Triple.str();
   }
 
+  if (Args.hasFlag(options::OPT_fxray_shared,
+                   options::OPT_fno_xray_shared, false)) {
+    XRayShared = true;
+
+    // DSO instrumentation is currently limited to x86_64
+    if (Triple.getArch() != llvm::Triple::x86_64) {
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << "-fxray-shared" << Triple.str();
+    }
+
+    unsigned PICLvl = std::get<1>(tools::ParsePICArgs(TC, Args));
+    if (!PICLvl) {
+      D.Diag(diag::err_opt_not_valid_without_opt)
+          << "-fxray-shared" << "-fPIC";
+    }
+  }
+
   // Both XRay and -fpatchable-function-entry use
   // TargetOpcode::PATCHABLE_FUNCTION_ENTER.
   if (Arg *A = Args.getLastArg(options::OPT_fpatchable_function_entry_EQ))
@@ -177,6 +194,10 @@ void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
   Args.addOptOutFlag(CmdArgs, options::OPT_fxray_function_index,
                      options::OPT_fno_xray_function_index);
 
+  if (XRayShared)
+    Args.addOptInFlag(CmdArgs, options::OPT_fxray_shared,
+                      options::OPT_fno_xray_shared);
+
   if (const Arg *A =
           Args.getLastArg(options::OPT_fxray_instruction_threshold_EQ)) {
     int Value;

clang/test/Driver/XRay/xray-shared.cpp

@@ -0,0 +1,17 @@
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -fPIC -fxray-instrument -fxray-shared -c %s -o /dev/null 2>&1 | FileCheck %s
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -fpic -fxray-instrument -fxray-shared -c %s -o /dev/null 2>&1 | FileCheck %s
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -fxray-instrument -fxray-shared -c %s -o /dev/null 2>&1 | FileCheck %s
+// RUN: not %clang -### --target=x86_64-unknown-linux-gnu -fno-PIC -fxray-instrument -fxray-shared -c %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=ERR-PIC
+// RUN: not %clang -### --target=x86_64-unknown-linux-gnu -fno-pic -fxray-instrument -fxray-shared -c %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=ERR-PIC
+
+// On 64 bit darwin, PIC is always enabled
+// RUN: %clang -### --target=x86_64-apple-darwin -fxray-instrument -fxray-shared -c %s -o /dev/null 2>&1 | FileCheck %s
+
+// Check unsupported targets
+// RUN: not %clang -### --target=aarch64-pc-freebsd -fPIC -fxray-instrument -fxray-shared -c %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=ERR-TARGET
+// RUN: not %clang -### --target=arm64-apple-macos -fPIC -fxray-instrument -fxray-shared -c %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=ERR-TARGET
+
+// CHECK: "-cc1" {{.*}}"-fxray-instrument" {{.*}}"-fxray-shared"
+// ERR-TARGET:   error: unsupported option '-fxray-shared' for target
+// ERR-PIC:   error: option '-fxray-shared' cannot be specified without '-fPIC'
+

compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake

@@ -104,6 +104,7 @@ else()
 set(ALL_XRAY_SUPPORTED_ARCH ${X86_64} ${ARM32} ${ARM64} ${MIPS32} ${MIPS64}
 		powerpc64le ${HEXAGON} ${LOONGARCH64})
 endif()
+set(ALL_XRAY_DSO_SUPPORTED_ARCH ${X86_64})
 set(ALL_SHADOWCALLSTACK_SUPPORTED_ARCH ${ARM64})
 
 if (UNIX)

compiler-rt/cmake/config-ix.cmake

@@ -668,6 +668,9 @@ if(APPLE)
   list_intersect(XRAY_SUPPORTED_ARCH
     ALL_XRAY_SUPPORTED_ARCH
     SANITIZER_COMMON_SUPPORTED_ARCH)
+  list_intersect(XRAY_DSO_SUPPORTED_ARCH
+    ALL_XRAY_DSO_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
   list_intersect(SHADOWCALLSTACK_SUPPORTED_ARCH
     ALL_SHADOWCALLSTACK_SUPPORTED_ARCH
     SANITIZER_COMMON_SUPPORTED_ARCH)
@@ -702,6 +705,7 @@ else()
   filter_available_targets(CFI_SUPPORTED_ARCH ${ALL_CFI_SUPPORTED_ARCH})
   filter_available_targets(SCUDO_STANDALONE_SUPPORTED_ARCH ${ALL_SCUDO_STANDALONE_SUPPORTED_ARCH})
   filter_available_targets(XRAY_SUPPORTED_ARCH ${ALL_XRAY_SUPPORTED_ARCH})
+  filter_available_targets(XRAY_DSO_SUPPORTED_ARCH ${ALL_XRAY_DSO_SUPPORTED_ARCH})
   filter_available_targets(SHADOWCALLSTACK_SUPPORTED_ARCH
     ${ALL_SHADOWCALLSTACK_SUPPORTED_ARCH})
   filter_available_targets(GWP_ASAN_SUPPORTED_ARCH ${ALL_GWP_ASAN_SUPPORTED_ARCH})

compiler-rt/include/xray/xray_interface.h

@@ -97,27 +97,50 @@ enum XRayPatchingStatus {
 /// for possible result values.
 extern XRayPatchingStatus __xray_patch();
 
+extern XRayPatchingStatus __xray_patch_object(int32_t ObjId);
+
 /// Reverses the effect of __xray_patch(). See XRayPatchingStatus for possible
 /// result values.
 extern XRayPatchingStatus __xray_unpatch();
 
+extern XRayPatchingStatus __xray_unpatch_object(int32_t ObjId);
+
 /// This patches a specific function id. See XRayPatchingStatus for possible
 /// result values.
 extern XRayPatchingStatus __xray_patch_function(int32_t FuncId);
 
+extern XRayPatchingStatus __xray_patch_function_in_object(int32_t FuncId,
+                                                          int32_t ObjId);
+
 /// This unpatches a specific function id. See XRayPatchingStatus for possible
 /// result values.
 extern XRayPatchingStatus __xray_unpatch_function(int32_t FuncId);
 
+extern XRayPatchingStatus __xray_unpatch_function_in_object(int32_t FuncId,
+                                                            int32_t ObjId);
+
 /// This function returns the address of the function provided a valid function
 /// id. We return 0 if we encounter any error, even if 0 may be a valid function
 /// address.
 extern uintptr_t __xray_function_address(int32_t FuncId);
 
+extern uintptr_t __xray_function_address_in_object(int32_t FuncId,
+                                                   int32_t ObjId);
+
 /// This function returns the maximum valid function id. Returns 0 if we
 /// encounter errors (when there are no instrumented functions, etc.).
 extern size_t __xray_max_function_id();
 
+extern size_t __xray_max_function_id_in_object(int32_t ObjId);
+
+extern size_t __xray_num_objects();
+
+extern int32_t __xray_unpack_function_id(int32_t PackedId);
+
+extern int32_t __xray_unpack_object_id(int32_t PackedId);
+
+extern int32_t __xray_pack_id(int32_t FuncId, int32_t ObjId);
+
 /// Initialize the required XRay data structures. This is useful in cases where
 /// users want to control precisely when the XRay instrumentation data
 /// structures are initialized, for example when the XRay library is built with

compiler-rt/lib/xray/CMakeLists.txt

@@ -10,6 +10,10 @@ set(XRAY_SOURCES
   xray_utils.cpp
   )
 
+set(XRAY_DSO_SOURCES
+  xray_dso_init.cpp
+  )
+
 # Implementation files for all XRay modes.
 set(XRAY_FDR_MODE_SOURCES
   xray_fdr_flags.cpp
@@ -33,6 +37,11 @@ set(x86_64_SOURCES
   xray_trampoline_x86_64.S
   )
 
+set(x86_64_DSO_SOURCES
+   xray_trampoline_x86_64.S
+   )
+
+
 set(arm_SOURCES
   xray_arm.cpp
   xray_trampoline_arm.S
@@ -128,10 +137,12 @@ set(XRAY_IMPL_HEADERS
 # consumption by tests.
 set(XRAY_ALL_SOURCE_FILES
   ${XRAY_SOURCES}
+  ${XRAY_DSO_SOURCES}
   ${XRAY_FDR_MODE_SOURCES}
   ${XRAY_BASIC_MODE_SOURCES}
   ${XRAY_PROFILING_MODE_SOURCES}
   ${x86_64_SOURCES}
+  ${x86_64_DSO_SOURCES}
   ${arm_SOURCES}
   ${armhf_SOURCES}
   ${hexagon_SOURCES}
@@ -162,6 +173,9 @@ set(XRAY_CFLAGS
   ${COMPILER_RT_CXX_CFLAGS})
 set(XRAY_COMMON_DEFINITIONS SANITIZER_COMMON_NO_REDEFINE_BUILTINS XRAY_HAS_EXCEPTIONS=1)
 
+# DSO trampolines need to be compiled with GOT addressing
+set(XRAY_COMMON_DEFINITIONS_DSO ${XRAY_COMMON_DEFINITIONS} XRAY_PIC)
+
 # Too many existing bugs, needs cleanup.
 append_list_if(COMPILER_RT_HAS_WNO_FORMAT -Wno-format XRAY_CFLAGS)
 
@@ -201,7 +215,16 @@ if (APPLE)
     CFLAGS ${XRAY_CFLAGS}
     DEFS ${XRAY_COMMON_DEFINITIONS}
     DEPS ${XRAY_DEPS})
+  add_compiler_rt_object_libraries(RTXrayDSO
+    OS ${XRAY_SUPPORTED_OS}
+    ARCHS ${XRAY_DSO_SUPPORTED_ARCH}
+    SOURCES ${XRAY_DSO_SOURCES}
+    ADDITIONAL_HEADERS ${XRAY_IMPL_HEADERS}
+    CFLAGS ${XRAY_CFLAGS}
+    DEFS ${XRAY_COMMON_DEFINITIONS_DSO}
+    DEPS ${XRAY_DEPS})
   set(XRAY_RTXRAY_ARCH_LIBS "")
+  set(XRAY_DSO_RTXRAY_ARCH_LIBS "")
   foreach(arch ${XRAY_SUPPORTED_ARCH})
     if(NOT ${arch} IN_LIST XRAY_SOURCE_ARCHS)
       continue()
@@ -215,6 +238,17 @@ if (APPLE)
       DEFS ${XRAY_COMMON_DEFINITIONS}
       DEPS ${XRAY_DEPS})
     list(APPEND XRAY_RTXRAY_ARCH_LIBS RTXray_${arch})
+    if (${arch} IN_LIST XRAY_DSO_SUPPORTED_ARCH)
+      add_compiler_rt_object_libraries(RTXrayDSO_${arch}
+        OS ${XRAY_SUPPORTED_OS}
+        ARCHS ${XRAY_DSO_SUPPORTED_ARCH}
+        SOURCES ${${arch}_DSO_SOURCES}
+        ADDITIONAL_HEADERS ${XRAY_IMPL_HEADERS}
+        CFLAGS ${XRAY_CFLAGS}
+        DEFS ${XRAY_COMMON_DEFINITIONS_DSO}
+        DEPS ${XRAY_DEPS})
+      list(APPEND XRAY_DSO_RTXRAY_ARCH_LIBS RTXrayDSO_${arch})
+    endif()
   endforeach()
   add_compiler_rt_object_libraries(RTXrayFDR
     OS ${XRAY_SUPPORTED_OS}
@@ -252,6 +286,17 @@ if (APPLE)
     LINK_FLAGS ${XRAY_LINK_FLAGS} ${WEAK_SYMBOL_LINK_FLAGS}
     LINK_LIBS ${XRAY_LINK_LIBS}
     PARENT_TARGET xray)
+  add_compiler_rt_runtime(clang_rt.xray-dso
+    STATIC
+    OS ${XRAY_SUPPORTED_OS}
+    ARCHS ${XRAY_DSO_SUPPORTED_ARCH}
+    OBJECT_LIBS RTXrayDSO ${XRAY_DSO_RTXRAY_ARCH_LIBS}
+    CFLAGS ${XRAY_CFLAGS}
+    DEFS ${XRAY_COMMON_DEFINITIONS}
+    LINK_FLAGS ${XRAY_LINK_FLAGS} ${WEAK_SYMBOL_LINK_FLAGS}
+    LINK_LIBS ${XRAY_LINK_LIBS}
+    PARENT_TARGET xray)
+
   add_compiler_rt_runtime(clang_rt.xray-fdr
     STATIC
     OS ${XRAY_SUPPORTED_OS}
@@ -346,16 +391,37 @@ else() # not Apple
       DEFS ${XRAY_COMMON_DEFINITIONS}
       OBJECT_LIBS RTXrayBASIC
       PARENT_TARGET xray)
-   # Profiler Mode runtime
-   add_compiler_rt_runtime(clang_rt.xray-profiling
-     STATIC
-     ARCHS ${arch}
-     CFLAGS ${XRAY_CFLAGS}
-     LINK_FLAGS ${XRAY_LINK_FLAGS}
-     LINK_LIBS ${XRAY_LINK_LIBS}
-     DEFS ${XRAY_COMMON_DEFINITIONS}
-     OBJECT_LIBS RTXrayPROFILING
-     PARENT_TARGET xray)
+    # Profiler Mode runtime
+    add_compiler_rt_runtime(clang_rt.xray-profiling
+      STATIC
+      ARCHS ${arch}
+      CFLAGS ${XRAY_CFLAGS}
+      LINK_FLAGS ${XRAY_LINK_FLAGS}
+      LINK_LIBS ${XRAY_LINK_LIBS}
+      DEFS ${XRAY_COMMON_DEFINITIONS}
+      OBJECT_LIBS RTXrayPROFILING
+      PARENT_TARGET xray)
+
+    if (${arch} IN_LIST XRAY_DSO_SUPPORTED_ARCH)
+      # TODO: Only implemented for X86 at the moment
+      add_compiler_rt_object_libraries(RTXrayDSO
+        ARCHS ${arch}
+        SOURCES ${XRAY_DSO_SOURCES} ${${arch}_DSO_SOURCES} 
+        ADDITIONAL_HEADERS ${XRAY_IMPL_HEADERS}
+        CFLAGS ${XRAY_CFLAGS}
+        DEFS ${XRAY_COMMON_DEFINITIONS_DSO}
+        DEPS ${XRAY_DEPS})
+      # DSO runtime archive
+      add_compiler_rt_runtime(clang_rt.xray-dso
+        STATIC
+        ARCHS ${arch}
+        CFLAGS ${XRAY_CFLAGS}
+        LINK_FLAGS ${XRAY_LINK_FLAGS}
+        LINK_LIBS ${XRAY_LINK_LIBS}
+        DEFS ${XRAY_COMMON_DEFINITIONS}
+        OBJECT_LIBS RTXrayDSO
+        PARENT_TARGET xray)
+    endif()
   endforeach()
 endif() # not Apple
 

compiler-rt/lib/xray/xray_dso_init.cpp

@@ -0,0 +1,62 @@
+//===-- xray_init.cpp -------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of XRay, a dynamic runtime instrumentation system.
+//
+// XRay initialisation logic for DSOs.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_atomic.h"
+#include "xray_defs.h"
+#include "xray_flags.h"
+#include "xray_interface_internal.h"
+
+using namespace __sanitizer;
+
+extern "C" {
+extern const XRaySledEntry __start_xray_instr_map[] __attribute__((weak))
+__attribute__((visibility("hidden")));
+extern const XRaySledEntry __stop_xray_instr_map[] __attribute__((weak))
+__attribute__((visibility("hidden")));
+extern const XRayFunctionSledIndex __start_xray_fn_idx[] __attribute__((weak))
+__attribute__((visibility("hidden")));
+extern const XRayFunctionSledIndex __stop_xray_fn_idx[] __attribute__((weak))
+__attribute__((visibility("hidden")));
+
+#if SANITIZER_APPLE
+// HACK: This is a temporary workaround to make XRay build on
+// Darwin, but it will probably not work at runtime.
+extern const XRaySledEntry __start_xray_instr_map[] = {};
+extern const XRaySledEntry __stop_xray_instr_map[] = {};
+extern const XRayFunctionSledIndex __start_xray_fn_idx[] = {};
+extern const XRayFunctionSledIndex __stop_xray_fn_idx[] = {};
+#endif
+}
+
+// Handler functions to call in the patched entry/exit sled.
+extern atomic_uintptr_t XRayPatchedFunction;
+extern atomic_uintptr_t XRayArgLogger;
+extern atomic_uintptr_t XRayPatchedCustomEvent;
+extern atomic_uintptr_t XRayPatchedTypedEvent;
+
+static int __xray_object_id{-1};
+
+// Note: .preinit_array initialization does not work for DSOs
+__attribute__((constructor(0))) static void
+__xray_init_dso() XRAY_NEVER_INSTRUMENT {
+  // Register sleds in main XRay runtime.
+  __xray_object_id =
+      __xray_register_dso(__start_xray_instr_map, __stop_xray_instr_map,
+                          __start_xray_fn_idx, __stop_xray_fn_idx, {});
+}
+
+__attribute__((destructor(0))) static void
+__xray_finalize_dso() XRAY_NEVER_INSTRUMENT {
+  // Inform the main runtime that this DSO is no longer used.
+  __xray_deregister_dso(__xray_object_id);
+}