hwasan: Implement lazy thread initialization for the interceptor ABI.

The problem is similar to D55986 but for threads: a process with the
interceptor hwasan library loaded might have some threads started by
instrumented libraries and some by uninstrumented libraries, and we
need to be able to run instrumented code on the latter.

The solution is to perform per-thread initialization lazily. If a
function needs to access shadow memory or add itself to the per-thread
ring buffer its prologue checks to see whether the value in the
sanitizer TLS slot is null, and if so it calls __hwasan_thread_enter
and reloads from the TLS slot. The runtime does the same thing if it
needs to access this data structure.

This change means that the code generator needs to know whether we
are targeting the interceptor runtime, since we don't want to pay
the cost of lazy initialization when targeting a platform with native
hwasan support. A flag -fsanitize-hwaddress-abi={interceptor,platform}
has been introduced for selecting the runtime ABI to target. The
default ABI is set to interceptor since it's assumed that it will
be more common that users will be compiling application code than
platform code.

Because we can no longer assume that the TLS slot is initialized,
the pthread_create interceptor is no longer necessary, so it has
been removed.

Ideally, lazy initialization should only cost one instruction in the
hot path, but at present the call may cause us to spill arguments
to the stack, which means more instructions in the hot path (or
theoretically in the cold path if the spills are moved with shrink
wrapping). With an appropriately chosen calling convention for
the per-thread initialization function (TODO) the hot path should
always need just one instruction and the cold path should need two
instructions with no spilling required.

Differential Revision: https://reviews.llvm.org/D56038

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@350429 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/CodeGenOptions.h b/include/clang/Basic/CodeGenOptions.h
index a12744ee3d2be79afdc51ae405039e8ecd251699..ec6eda7fb7881e19cd791014d2aff73006db9319 100644 (file)
--- a/include/clang/Basic/CodeGenOptions.h
+++ b/include/clang/Basic/CodeGenOptions.h
@@ -286,6 +286,8 @@ public:
   /// Set of XRay instrumentation kinds to emit.
   XRayInstrSet XRayInstrumentationBundle;
 
+  std::vector<std::string> DefaultFunctionAttrs;
+
 public:
   // Define accessors/mutators for code generation options of enumeration type.
 #define CODEGENOPT(Name, Bits, Default)

diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index c0e73e56d7abf6b873c9ee6d5288b070fbba250d..07c76884063f75e54fba0e30c81eb65995a2c3d5 100644 (file)
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -163,6 +163,8 @@ let Flags = [CC1Option, CC1AsOption, NoDriverOption] in {
 def debug_info_kind_EQ : Joined<["-"], "debug-info-kind=">;
 def debug_info_macro : Flag<["-"], "debug-info-macro">,
   HelpText<"Emit macro debug information">;
+def default_function_attr : Separate<["-"], "default-function-attr">,
+  HelpText<"Apply given attribute to all functions">;
 def dwarf_version_EQ : Joined<["-"], "dwarf-version=">;
 def debugger_tuning_EQ : Joined<["-"], "debugger-tuning=">;
 def fdebug_compilation_dir : Separate<["-"], "fdebug-compilation-dir">,

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 809b28b9ddbb7b53f20ac5681cf2aac58636321d..1c5cae683a1b493af898791309fa54e7bd2e3abf 100644 (file)
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -998,6 +998,10 @@ def fno_sanitize_address_use_odr_indicator
     : Flag<["-"], "fno-sanitize-address-use-odr-indicator">,
       Group<f_clang_Group>,
       HelpText<"Disable ODR indicator globals">;
+def fsanitize_hwaddress_abi_EQ
+    : Joined<["-"], "fsanitize-hwaddress-abi=">,
+      Group<f_clang_Group>,
+      HelpText<"Select the HWAddressSanitizer ABI to target (interceptor or platform, default interceptor)">;
 def fsanitize_recover : Flag<["-"], "fsanitize-recover">, Group<f_clang_Group>;
 def fno_sanitize_recover : Flag<["-"], "fno-sanitize-recover">,
                            Flags<[CoreOption, DriverOption]>,

diff --git a/include/clang/Driver/SanitizerArgs.h b/include/clang/Driver/SanitizerArgs.h
index 55c5826bfb0072fe9ec6045836736601969aa6d0..02338c22165b74b15ccc59896653d9a220662163 100644 (file)
--- a/include/clang/Driver/SanitizerArgs.h
+++ b/include/clang/Driver/SanitizerArgs.h
@@ -39,6 +39,7 @@ class SanitizerArgs {
   bool AsanPoisonCustomArrayCookie = false;
   bool AsanGlobalsDeadStripping = false;
   bool AsanUseOdrIndicator = false;
+  std::string HwasanAbi;
   bool LinkCXXRuntimes = false;
   bool NeedPIE = false;
   bool SafeStackRuntime = false;

diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 64e18e171e01931ef9a45715377743cd2b32bf43..09116d465e3388ad7571d0694fa6862f67b61268 100644 (file)
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -1816,6 +1816,12 @@ void CodeGenModule::ConstructDefaultFnAttrList(StringRef Name, bool HasOptnone,
     if (CodeGenOpts.FlushDenorm)
       FuncAttrs.addAttribute("nvptx-f32ftz", "true");
   }
+
+  for (StringRef Attr : CodeGenOpts.DefaultFunctionAttrs) {
+    StringRef Var, Value;
+    std::tie(Var, Value) = Attr.split('=');
+    FuncAttrs.addAttribute(Var, Value);
+  }
 }
 
 void CodeGenModule::AddDefaultFnAttrs(llvm::Function &F) {

diff --git a/lib/Driver/SanitizerArgs.cpp b/lib/Driver/SanitizerArgs.cpp
index 4e0d7491bbec01cbbd65315c66ef8dde997e9fe8..6667cbb347cd354665ca1f5edb560c8ee49ff228 100644 (file)
--- a/lib/Driver/SanitizerArgs.cpp
+++ b/lib/Driver/SanitizerArgs.cpp
@@ -741,6 +741,18 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
     AsanUseAfterScope = false;
   }
 
+  if (AllAddedKinds & HWAddress) {
+    if (Arg *HwasanAbiArg =
+            Args.getLastArg(options::OPT_fsanitize_hwaddress_abi_EQ)) {
+      HwasanAbi = HwasanAbiArg->getValue();
+      if (HwasanAbi != "platform" && HwasanAbi != "interceptor")
+        D.Diag(clang::diag::err_drv_invalid_value)
+            << HwasanAbiArg->getAsString(Args) << HwasanAbi;
+    } else {
+      HwasanAbi = "interceptor";
+    }
+  }
+
   if (AllAddedKinds & SafeStack) {
     // SafeStack runtime is built into the system on Fuchsia.
     SafeStackRuntime = !TC.getTriple().isOSFuchsia();
@@ -913,6 +925,11 @@ void SanitizerArgs::addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
   if (AsanUseOdrIndicator)
     CmdArgs.push_back("-fsanitize-address-use-odr-indicator");
 
+  if (!HwasanAbi.empty()) {
+    CmdArgs.push_back("-default-function-attr");
+    CmdArgs.push_back(Args.MakeArgString("hwasan-abi=" + HwasanAbi));
+  }
+
   // MSan: Workaround for PR16386.
   // ASan: This is mainly to help LSan with cases such as
   // https://github.com/google/sanitizers/issues/373

diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 39152fda998707967ea2a0e2b3497290a09b040c..00083bd6225ab3bafbe6def5d6e2747631752522 100644 (file)
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -1319,6 +1319,8 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
 
   Opts.SpeculativeLoadHardening = Args.hasArg(OPT_mspeculative_load_hardening);
 
+  Opts.DefaultFunctionAttrs = Args.getAllArgValues(OPT_default_function_attr);
+
   return Success;
 }
 

diff --git a/test/CodeGen/default-function-attr.c b/test/CodeGen/default-function-attr.c
new file mode 100644 (file)
index 0000000..b0d1398
--- /dev/null
+++ b/test/CodeGen/default-function-attr.c
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -default-function-attr foo=bar -emit-llvm %s -o - | FileCheck %s
+
+// CHECK: define void @foo() #[[X:[0-9]+]]
+void foo() {}
+
+// CHECK: attributes #[[X]] = {{.*}} "foo"="bar"

diff --git a/test/Driver/fsanitize.c b/test/Driver/fsanitize.c
index 0a82174aaa41c6d4cbd7dfec50194a7bd7ba1ab4..de455617141157991c90c865a7c2e657e3f79d0b 100644 (file)
--- a/test/Driver/fsanitize.c
+++ b/test/Driver/fsanitize.c
@@ -837,3 +837,11 @@
 //
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=scudo,kernel-memory  %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO-KMSAN
 // CHECK-SCUDO-KMSAN: error: invalid argument '-fsanitize=kernel-memory' not allowed with '-fsanitize=scudo'
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=hwaddress %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-HWASAN-INTERCEPTOR-ABI
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=hwaddress -fsanitize-hwaddress-abi=interceptor %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-HWASAN-INTERCEPTOR-ABI
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=hwaddress -fsanitize-hwaddress-abi=platform %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-HWASAN-PLATFORM-ABI
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=hwaddress -fsanitize-hwaddress-abi=foo %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-HWASAN-FOO-ABI
+// CHECK-HWASAN-INTERCEPTOR-ABI: "-default-function-attr" "hwasan-abi=interceptor"
+// CHECK-HWASAN-PLATFORM-ABI: "-default-function-attr" "hwasan-abi=platform"
+// CHECK-HWASAN-FOO-ABI: error: invalid value 'foo' in '-fsanitize-hwaddress-abi=foo'