[PAC][clang] Define ptrauth driver flags and preprocessor features

kovdan01 · ahmedbougacha · kovdan01 · commit 919af72c0921 · 2024-03-20T00:13:13.000+03:00
Define the following clang driver flags:

- `-fptrauth-intrinsics`: `PointerAuth.intrinsics()` in `LangOptions`,
  `ptrauth_intrinsics` preprocessor feature;

- `-fptrauth-calls`: `PointerAuth.calls()` in `LangOptions`, `ptrauth_calls` and
  and `ptrauth_member_function_pointer_type_discrimination` preprocessor
  features;

- `-fptrauth-returns`: `PointerAuth.returns()` in `LangOptions`,
  `ptrauth_returns` preprocessor feature;

- `-fptrauth-auth-traps`: `PointerAuth.authTraps()` in `LangOptions`;

- `-fptrauth-vtable-pointer-address-discrimination`:
  `PointerAuth.vtptrAddressDiscrimination()` in `LangOptions`,
  `ptrauth_vtable_pointer_address_discrimination` preprocessor feature;

- `-fptrauth-vtable-pointer-type-discrimination`:
  `PointerAuth.vtptrTypeDiscrimination()` in `LangOptions`,
  `ptrauth_vtable_pointer_type_discrimination` preprocessor feature;

- `-fptrauth-init-fini`: `PointerAuth.initFini()` in `LangOptions`,
  `ptrauth_init_fini` preprocessor feature.

The patch only defines the flags and having corresponding `LangOptions`
set does not affect codegen yet.

Co-authored-by: Ahmed Bougacha &lt;ahmed@bougacha.org&gt;
diff --git a/clang/include/clang/Basic/Features.def b/clang/include/clang/Basic/Features.def
@@ -102,6 +102,12 @@ FEATURE(thread_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Thread))
 FEATURE(dataflow_sanitizer, LangOpts.Sanitize.has(SanitizerKind::DataFlow))
 FEATURE(scudo, LangOpts.Sanitize.hasOneOf(SanitizerKind::Scudo))
 FEATURE(ptrauth_intrinsics, LangOpts.PointerAuthIntrinsics)
+FEATURE(ptrauth_calls, LangOpts.PointerAuthCalls)
+FEATURE(ptrauth_returns, LangOpts.PointerAuthReturns)
+FEATURE(ptrauth_vtable_pointer_address_discrimination, LangOpts.PointerAuthVTPtrAddressDiscrimination)
+FEATURE(ptrauth_vtable_pointer_type_discrimination, LangOpts.PointerAuthVTPtrTypeDiscrimination)
+FEATURE(ptrauth_member_function_pointer_type_discrimination, LangOpts.PointerAuthCalls)
+FEATURE(ptrauth_init_fini, LangOpts.PointerAuthInitFini)
 FEATURE(swiftasynccc,
   PP.getTargetInfo().checkCallingConvention(CC_SwiftAsync) ==
   clang::TargetInfo::CCCR_OK)
diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def
@@ -162,6 +162,12 @@ LANGOPT(RelaxedTemplateTemplateArgs, 1, 0, "C++17 relaxed matching of template t
 LANGOPT(ExperimentalLibrary, 1, 0, "enable unstable and experimental library features")
 
 LANGOPT(PointerAuthIntrinsics, 1, 0, "pointer authentication intrinsics")
+LANGOPT(PointerAuthCalls  , 1, 0, "function pointer authentication")
+LANGOPT(PointerAuthReturns, 1, 0, "return pointer authentication")
+LANGOPT(PointerAuthAuthTraps, 1, 0, "pointer authentication failure traps")
+LANGOPT(PointerAuthVTPtrAddressDiscrimination, 1, 0, "incorporate address discrimination in authenticated vtable pointers")
+LANGOPT(PointerAuthVTPtrTypeDiscrimination, 1, 0, "incorporate type discrimination in authenticated vtable pointers")
+LANGOPT(PointerAuthInitFini, 1, 0, "sign function pointers in init/fini arrays")
 
 LANGOPT(DoubleSquareBracketAttributes, 1, 0, "'[[]]' attributes extension for all language standard modes")
 
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -4110,8 +4110,26 @@ let Group = f_Group in {
   let Visibility = [ClangOption,CC1Option] in {
     def fptrauth_intrinsics : Flag<["-"], "fptrauth-intrinsics">,
       HelpText<"Enable pointer authentication intrinsics">;
+    def fptrauth_calls : Flag<["-"], "fptrauth-calls">,
+      HelpText<"Enable signing and authentication of all indirect calls">;
+    def fptrauth_returns : Flag<["-"], "fptrauth-returns">,
+      HelpText<"Enable signing and authentication of return addresses">;
+    def fptrauth_auth_traps : Flag<["-"], "fptrauth-auth-traps">,
+      HelpText<"Enable traps on authentication failures">;
+    def fptrauth_vtable_pointer_address_discrimination : Flag<["-"], "fptrauth-vtable-pointer-address-discrimination">,
+      HelpText<"Enable address discrimination of vtable pointers">;
+    def fptrauth_vtable_pointer_type_discrimination : Flag<["-"], "fptrauth-vtable-pointer-type-discrimination">,
+      HelpText<"Enable type discrimination of vtable pointers">;
+    def fptrauth_init_fini : Flag<["-"], "fptrauth-init-fini">,
+      HelpText<"Enable signing of function pointers in init/fini arrays">;
   }
   def fno_ptrauth_intrinsics : Flag<["-"], "fno-ptrauth-intrinsics">;
+  def fno_ptrauth_calls : Flag<["-"], "fno-ptrauth-calls">;
+  def fno_ptrauth_returns : Flag<["-"], "fno-ptrauth-returns">;
+  def fno_ptrauth_auth_traps : Flag<["-"], "fno-ptrauth-auth-traps">;
+  def fno_ptrauth_vtable_pointer_address_discrimination : Flag<["-"], "fno-ptrauth-vtable-pointer-address-discrimination">;
+  def fno_ptrauth_vtable_pointer_type_discrimination : Flag<["-"], "fno-ptrauth-vtable-pointer-type-discrimination">;
+  def fno_ptrauth_init_fini : Flag<["-"], "fno-ptrauth-init-fini">;
 }
 
 def fenable_matrix : Flag<["-"], "fenable-matrix">, Group<f_Group>,
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -7203,6 +7203,33 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                    options::OPT_fno_ptrauth_intrinsics, false))
     CmdArgs.push_back("-fptrauth-intrinsics");
 
+  if (Args.hasFlag(options::OPT_fptrauth_calls, options::OPT_fno_ptrauth_calls,
+                   false))
+    CmdArgs.push_back("-fptrauth-calls");
+
+  if (Args.hasFlag(options::OPT_fptrauth_returns,
+                   options::OPT_fno_ptrauth_returns, false))
+    CmdArgs.push_back("-fptrauth-returns");
+
+  if (Args.hasFlag(options::OPT_fptrauth_auth_traps,
+                   options::OPT_fno_ptrauth_auth_traps, false))
+    CmdArgs.push_back("-fptrauth-auth-traps");
+
+  if (Args.hasFlag(
+          options::OPT_fptrauth_vtable_pointer_address_discrimination,
+          options::OPT_fno_ptrauth_vtable_pointer_address_discrimination,
+          false))
+    CmdArgs.push_back("-fptrauth-vtable-pointer-address-discrimination");
+
+  if (Args.hasFlag(options::OPT_fptrauth_vtable_pointer_type_discrimination,
+                   options::OPT_fno_ptrauth_vtable_pointer_type_discrimination,
+                   false))
+    CmdArgs.push_back("-fptrauth-vtable-pointer-type-discrimination");
+
+  if (Args.hasFlag(options::OPT_fptrauth_init_fini,
+                   options::OPT_fno_ptrauth_init_fini, false))
+    CmdArgs.push_back("-fptrauth-init-fini");
+
   // -fsigned-bitfields is default, and clang doesn't yet support
   // -funsigned-bitfields.
   if (!Args.hasFlag(options::OPT_fsigned_bitfields,
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3297,11 +3297,31 @@ static void GeneratePointerAuthArgs(const LangOptions &Opts,
                                     ArgumentConsumer Consumer) {
   if (Opts.PointerAuthIntrinsics)
     GenerateArg(Consumer, OPT_fptrauth_intrinsics);
+  if (Opts.PointerAuthCalls)
+    GenerateArg(Consumer, OPT_fptrauth_calls);
+  if (Opts.PointerAuthReturns)
+    GenerateArg(Consumer, OPT_fptrauth_returns);
+  if (Opts.PointerAuthAuthTraps)
+    GenerateArg(Consumer, OPT_fptrauth_auth_traps);
+  if (Opts.PointerAuthVTPtrAddressDiscrimination)
+    GenerateArg(Consumer, OPT_fptrauth_vtable_pointer_address_discrimination);
+  if (Opts.PointerAuthVTPtrTypeDiscrimination)
+    GenerateArg(Consumer, OPT_fptrauth_vtable_pointer_type_discrimination);
+  if (Opts.PointerAuthInitFini)
+    GenerateArg(Consumer, OPT_fptrauth_init_fini);
 }
 
 static void ParsePointerAuthArgs(LangOptions &Opts, ArgList &Args,
                                  DiagnosticsEngine &Diags) {
   Opts.PointerAuthIntrinsics = Args.hasArg(OPT_fptrauth_intrinsics);
+  Opts.PointerAuthCalls = Args.hasArg(OPT_fptrauth_calls);
+  Opts.PointerAuthReturns = Args.hasArg(OPT_fptrauth_returns);
+  Opts.PointerAuthAuthTraps = Args.hasArg(OPT_fptrauth_auth_traps);
+  Opts.PointerAuthVTPtrAddressDiscrimination =
+      Args.hasArg(OPT_fptrauth_vtable_pointer_address_discrimination);
+  Opts.PointerAuthVTPtrTypeDiscrimination =
+      Args.hasArg(OPT_fptrauth_vtable_pointer_type_discrimination);
+  Opts.PointerAuthInitFini = Args.hasArg(OPT_fptrauth_init_fini);
 }
 
 /// Check if input file kind and language standard are compatible.
diff --git a/clang/test/Driver/ptrauth.c b/clang/test/Driver/ptrauth.c
@@ -0,0 +1,32 @@
+// Check that we can manually enable specific ptrauth features.
+
+// RUN: %clang -target aarch64 -c %s -### 2>&1 | FileCheck %s --check-prefix NONE
+// NONE: "-cc1"
+// NONE-NOT: "-fptrauth-intrinsics"
+// NONE-NOT: "-fptrauth-calls"
+// NONE-NOT: "-fptrauth-returns"
+// NONE-NOT: "-fptrauth-auth-traps"
+// NONE-NOT: "-fptrauth-vtable-pointer-address-discrimination"
+// NONE-NOT: "-fptrauth-vtable-pointer-type-discrimination"
+// NONE-NOT: "-fptrauth-init-fini"
+
+// RUN: %clang -target aarch64 -fptrauth-intrinsics -c %s -### 2>&1 | FileCheck %s --check-prefix INTRIN
+// INTRIN: "-cc1"{{.*}} {{.*}} "-fptrauth-intrinsics"
+
+// RUN: %clang -target aarch64 -fptrauth-calls -c %s -### 2>&1 | FileCheck %s --check-prefix CALL
+// CALL: "-cc1"{{.*}} {{.*}} "-fptrauth-calls"
+
+// RUN: %clang -target aarch64 -fptrauth-returns -c %s -### 2>&1 | FileCheck %s --check-prefix RETURN
+// RETURN: "-cc1"{{.*}} {{.*}} "-fptrauth-returns"
+
+// RUN: %clang -target aarch64 -fptrauth-auth-traps -c %s -### 2>&1 | FileCheck %s --check-prefix TRAPS
+// TRAPS: "-cc1"{{.*}} {{.*}} "-fptrauth-auth-traps"
+
+// RUN: %clang -target aarch64 -fptrauth-vtable-pointer-address-discrimination -c %s -### 2>&1 | FileCheck %s --check-prefix VPTR_ADDR_DISCR
+// VPTR_ADDR_DISCR: "-cc1"{{.*}} {{.*}} "-fptrauth-vtable-pointer-address-discrimination"
+
+// RUN: %clang -target aarch64 -fptrauth-vtable-pointer-type-discrimination -c %s -### 2>&1 | FileCheck %s --check-prefix VPTR_TYPE_DISCR
+// VPTR_TYPE_DISCR: "-cc1"{{.*}} {{.*}} "-fptrauth-vtable-pointer-type-discrimination"
+
+// RUN: %clang -target aarch64 -fptrauth-init-fini -c %s -### 2>&1 | FileCheck %s --check-prefix INITFINI
+// INITFINI: "-cc1"{{.*}} {{.*}} "-fptrauth-init-fini"
diff --git a/clang/test/Preprocessor/ptrauth_feature.c b/clang/test/Preprocessor/ptrauth_feature.c
@@ -1,5 +1,59 @@
-// RUN: %clang_cc1 %s -E -triple=arm64-- | FileCheck %s --check-prefixes=NOINTRIN
-// RUN: %clang_cc1 %s -E -triple=arm64-- -fptrauth-intrinsics | FileCheck %s --check-prefixes=INTRIN
+// RUN: %clang_cc1 -E %s -triple=aarch64 \
+// RUN:   -fptrauth-intrinsics \
+// RUN:   -fptrauth-calls \
+// RUN:   -fptrauth-returns \
+// RUN:   -fptrauth-vtable-pointer-address-discrimination \
+// RUN:   -fptrauth-vtable-pointer-type-discrimination \
+// RUN:   -fptrauth-init-fini | \
+// RUN:   FileCheck %s --check-prefixes=INTRIN,CALLS,RETS,VPTR_ADDR_DISCR,VPTR_TYPE_DISCR,INITFINI
+
+// RUN: %clang_cc1 -E %s -triple=aarch64 \
+// RUN:   -fptrauth-calls \
+// RUN:   -fptrauth-returns \
+// RUN:   -fptrauth-vtable-pointer-address-discrimination \
+// RUN:   -fptrauth-vtable-pointer-type-discrimination \
+// RUN:   -fptrauth-init-fini | \
+// RUN:   FileCheck %s --check-prefixes=NOINTRIN,CALLS,RETS,VPTR_ADDR_DISCR,VPTR_TYPE_DISCR,INITFINI
+
+// RUN: %clang_cc1 -E %s -triple=aarch64 \
+// RUN:   -fptrauth-intrinsics \
+// RUN:   -fptrauth-returns \
+// RUN:   -fptrauth-vtable-pointer-address-discrimination \
+// RUN:   -fptrauth-vtable-pointer-type-discrimination \
+// RUN:   -fptrauth-init-fini | \
+// RUN:   FileCheck %s --check-prefixes=INTRIN,NOCALLS,RETS,VPTR_ADDR_DISCR,VPTR_TYPE_DISCR,INITFINI
+
+// RUN: %clang_cc1 -E %s -triple=aarch64 \
+// RUN:   -fptrauth-intrinsics \
+// RUN:   -fptrauth-calls \
+// RUN:   -fptrauth-vtable-pointer-address-discrimination \
+// RUN:   -fptrauth-vtable-pointer-type-discrimination \
+// RUN:   -fptrauth-init-fini | \
+// RUN:   FileCheck %s --check-prefixes=INTRIN,CALLS,NORETS,VPTR_ADDR_DISCR,VPTR_TYPE_DISCR,INITFINI
+
+// RUN: %clang_cc1 -E %s -triple=aarch64 \
+// RUN:   -fptrauth-intrinsics \
+// RUN:   -fptrauth-calls \
+// RUN:   -fptrauth-returns \
+// RUN:   -fptrauth-vtable-pointer-type-discrimination \
+// RUN:   -fptrauth-init-fini | \
+// RUN:   FileCheck %s --check-prefixes=INTRIN,CALLS,RETS,NOVPTR_ADDR_DISCR,VPTR_TYPE_DISCR,INITFINI
+
+// RUN: %clang_cc1 -E %s -triple=aarch64 \
+// RUN:   -fptrauth-intrinsics \
+// RUN:   -fptrauth-calls \
+// RUN:   -fptrauth-returns \
+// RUN:   -fptrauth-vtable-pointer-address-discrimination \
+// RUN:   -fptrauth-init-fini | \
+// RUN:   FileCheck %s --check-prefixes=INTRIN,CALLS,RETS,VPTR_ADDR_DISCR,NOVPTR_TYPE_DISCR,INITFINI
+
+// RUN: %clang_cc1 -E %s -triple=aarch64 \
+// RUN:   -fptrauth-intrinsics \
+// RUN:   -fptrauth-calls \
+// RUN:   -fptrauth-returns \
+// RUN:   -fptrauth-vtable-pointer-address-discrimination \
+// RUN:   -fptrauth-vtable-pointer-type-discrimination | \
+// RUN:   FileCheck %s --check-prefixes=INTRIN,CALLS,RETS,VPTR_ADDR_DISCR,VPTR_TYPE_DISCR,NOINITFINI
 
 #if __has_feature(ptrauth_intrinsics)
 // INTRIN: has_ptrauth_intrinsics
@@ -8,3 +62,52 @@ void has_ptrauth_intrinsics() {}
 // NOINTRIN: no_ptrauth_intrinsics
 void no_ptrauth_intrinsics() {}
 #endif
+
+#if __has_feature(ptrauth_calls)
+// CALLS: has_ptrauth_calls
+void has_ptrauth_calls() {}
+#else
+// NOCALLS: no_ptrauth_calls
+void no_ptrauth_calls() {}
+#endif
+
+// This is always enabled when ptrauth_calls is enabled
+#if __has_feature(ptrauth_member_function_pointer_type_discrimination)
+// CALLS: has_ptrauth_member_function_pointer_type_discrimination
+void has_ptrauth_member_function_pointer_type_discrimination() {}
+#else
+// NOCALLS: no_ptrauth_member_function_pointer_type_discrimination
+void no_ptrauth_member_function_pointer_type_discrimination() {}
+#endif
+
+#if __has_feature(ptrauth_returns)
+// RETS: has_ptrauth_returns
+void has_ptrauth_returns() {}
+#else
+// NORETS: no_ptrauth_returns
+void no_ptrauth_returns() {}
+#endif
+
+#if __has_feature(ptrauth_vtable_pointer_address_discrimination)
+// VPTR_ADDR_DISCR: has_ptrauth_vtable_pointer_address_discrimination
+void has_ptrauth_vtable_pointer_address_discrimination() {}
+#else
+// NOVPTR_ADDR_DISCR: no_ptrauth_vtable_pointer_address_discrimination
+void no_ptrauth_vtable_pointer_address_discrimination() {}
+#endif
+
+#if __has_feature(ptrauth_vtable_pointer_type_discrimination)
+// VPTR_TYPE_DISCR: has_ptrauth_vtable_pointer_type_discrimination
+void has_ptrauth_vtable_pointer_type_discrimination() {}
+#else
+// NOVPTR_TYPE_DISCR: no_ptrauth_vtable_pointer_type_discrimination
+void no_ptrauth_vtable_pointer_type_discrimination() {}
+#endif
+
+#if __has_feature(ptrauth_init_fini)
+// INITFINI: has_ptrauth_init_fini
+void has_ptrauth_init_fini() {}
+#else
+// NOINITFINI: no_ptrauth_init_fini
+void no_ptrauth_init_fini() {}
+#endif
