From: Zola Bridges Date: Tue, 27 Nov 2018 02:22:00 +0000 (+0000) Subject: Revert "[clang][slh] add attribute for speculative load hardening" X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=622167e77f58cee4ba9963c6e5d46bf4d8ac5cc0;p=clang Revert "[clang][slh] add attribute for speculative load hardening" until I figure out why the build is failing or timing out *************************** Summary: The prior diff had to be reverted because there were two tests that failed. I updated the two tests in this diff clang/test/Misc/pragma-attribute-supported-attributes-list.test clang/test/SemaCXX/attr-speculative-load-hardening.cpp LLVM IR already has an attribute for speculative_load_hardening. Before this commit, when a user passed the -mspeculative-load-hardening flag to Clang, every function would have this attribute added to it. This Clang attribute will allow users to opt into SLH on a function by function basis. This can be applied to functions and Objective C methods. Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D54915 This reverts commit a5b3c232d1e3613f23efbc3960f8e23ea70f2a79. (r347617) git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@347628 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/Basic/Attr.td b/include/clang/Basic/Attr.td index 5b52ba4f64..a6be48c234 100644 --- a/include/clang/Basic/Attr.td +++ b/include/clang/Basic/Attr.td @@ -3091,9 +3091,3 @@ def AlwaysDestroy : InheritableAttr { let Subjects = SubjectList<[Var]>; let Documentation = [AlwaysDestroyDocs]; } - -def SpeculativeLoadHardening : InheritableAttr { - let Spellings = [Clang<"speculative_load_hardening">]; - let Subjects = SubjectList<[Function, ObjCMethod], ErrorDiag>; - let Documentation = [SpeculativeLoadHardeningDocs]; -} diff --git a/include/clang/Basic/AttrDocs.td b/include/clang/Basic/AttrDocs.td index 203ae82719..e38c557f14 100644 --- a/include/clang/Basic/AttrDocs.td +++ b/include/clang/Basic/AttrDocs.td @@ -3629,27 +3629,3 @@ GNU inline semantics are the default behavior with ``-std=gnu89``, ``-std=c89``, ``-std=c94``, or ``-fgnu89-inline``. }]; } - -def SpeculativeLoadHardeningDocs : Documentation { - let Category = DocCatFunction; - let Content = [{ - This attribute can be applied to a function declaration in order to indicate - that `Speculative Load Hardening `_ - should be enabled for the function body. This can also be applied to a method - in Objective C. - - Speculative Load Hardening is a best-effort mitigation against - information leak attacks that make use of control flow - miss-speculation - specifically miss-speculation of whether a branch - is taken or not. Typically vulnerabilities enabling such attacks are - classified as "Spectre variant #1". Notably, this does not attempt to - mitigate against miss-speculation of branch target, classified as - "Spectre variant #2" vulnerabilities. - - When inlining, the attribute is sticky. Inlining a function that - carries this attribute will cause the caller to gain the - attribute. This is intended to provide a maximally conservative model - where the code in a function annotated with this attribute will always - (even after inlining) end up hardened. - }]; -} diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp index 6d89f3919f..0ec5c7fb45 100644 --- a/lib/CodeGen/CGCall.cpp +++ b/lib/CodeGen/CGCall.cpp @@ -1791,8 +1791,6 @@ void CodeGenModule::ConstructDefaultFnAttrList(StringRef Name, bool HasOptnone, if (CodeGenOpts.Backchain) FuncAttrs.addAttribute("backchain"); - // FIXME: The interaction of this attribute with the SLH command line flag - // has not been determined. if (CodeGenOpts.SpeculativeLoadHardening) FuncAttrs.addAttribute(llvm::Attribute::SpeculativeLoadHardening); } @@ -1856,8 +1854,6 @@ void CodeGenModule::ConstructAttributeList( FuncAttrs.addAttribute(llvm::Attribute::NoDuplicate); if (TargetDecl->hasAttr()) FuncAttrs.addAttribute(llvm::Attribute::Convergent); - if (TargetDecl->hasAttr()) - FuncAttrs.addAttribute(llvm::Attribute::SpeculativeLoadHardening); if (const FunctionDecl *Fn = dyn_cast(TargetDecl)) { AddAttributesFromFunctionProtoType( diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp index be662b9b91..9f5325d109 100644 --- a/lib/Sema/SemaDeclAttr.cpp +++ b/lib/Sema/SemaDeclAttr.cpp @@ -6373,9 +6373,6 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D, case ParsedAttr::AT_Section: handleSectionAttr(S, D, AL); break; - case ParsedAttr::AT_SpeculativeLoadHardening: - handleSimpleAttribute(S, D, AL); - break; case ParsedAttr::AT_CodeSeg: handleCodeSegAttr(S, D, AL); break; diff --git a/test/CodeGen/attr-speculative-load-hardening.cpp b/test/CodeGen/attr-speculative-load-hardening.cpp deleted file mode 100644 index e2eb805cbb..0000000000 --- a/test/CodeGen/attr-speculative-load-hardening.cpp +++ /dev/null @@ -1,18 +0,0 @@ -// RUN: %clang_cc1 -std=c++11 -disable-llvm-passes -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK1 -// RUN: %clang_cc1 -std=c++11 -disable-llvm-passes -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK2 -// -// Check that we set the attribute on each function. - -[[clang::speculative_load_hardening]] -int test1() { - return 42; -} - -int __attribute__((speculative_load_hardening)) test2() { - return 42; -} -// CHECK1: @{{.*}}test1{{.*}}[[SLH1:#[0-9]+]] -// CHECK1: attributes [[SLH1]] = { {{.*}}speculative_load_hardening{{.*}} } - -// CHECK2: @{{.*}}test2{{.*}}[[SLH2:#[0-9]+]] -// CHECK2: attributes [[SLH2]] = { {{.*}}speculative_load_hardening{{.*}} } diff --git a/test/CodeGen/attr-speculative-load-hardening.m b/test/CodeGen/attr-speculative-load-hardening.m deleted file mode 100644 index 2de945b974..0000000000 --- a/test/CodeGen/attr-speculative-load-hardening.m +++ /dev/null @@ -1,9 +0,0 @@ -// RUN: %clang -emit-llvm %s -o - -S | FileCheck %s -check-prefix=SLH - -int main() __attribute__((speculative_load_hardening)) { - return 0; -} - -// SLH: @{{.*}}main{{.*}}[[SLH:#[0-9]+]] - -// SLH: attributes [[SLH]] = { {{.*}}speculative_load_hardening{{.*}} } diff --git a/test/Misc/pragma-attribute-supported-attributes-list.test b/test/Misc/pragma-attribute-supported-attributes-list.test index 0aa923de7d..0a54c6c05a 100644 --- a/test/Misc/pragma-attribute-supported-attributes-list.test +++ b/test/Misc/pragma-attribute-supported-attributes-list.test @@ -2,7 +2,7 @@ // The number of supported attributes should never go down! -// CHECK: #pragma clang attribute supports 130 attributes: +// CHECK: #pragma clang attribute supports 129 attributes: // CHECK-NEXT: AMDGPUFlatWorkGroupSize (SubjectMatchRule_function) // CHECK-NEXT: AMDGPUNumSGPR (SubjectMatchRule_function) // CHECK-NEXT: AMDGPUNumVGPR (SubjectMatchRule_function) @@ -116,7 +116,6 @@ // CHECK-NEXT: ScopedLockable (SubjectMatchRule_record) // CHECK-NEXT: Section (SubjectMatchRule_function, SubjectMatchRule_variable_is_global, SubjectMatchRule_objc_method, SubjectMatchRule_objc_property) // CHECK-NEXT: SetTypestate (SubjectMatchRule_function_is_member) -// CHECK-NEXT: SpeculativeLoadHardening (SubjectMatchRule_function, SubjectMatchRule_objc_method) // CHECK-NEXT: SwiftContext (SubjectMatchRule_variable_is_parameter) // CHECK-NEXT: SwiftErrorResult (SubjectMatchRule_variable_is_parameter) // CHECK-NEXT: SwiftIndirectResult (SubjectMatchRule_variable_is_parameter) diff --git a/test/SemaCXX/attr-speculative-load-hardening.cpp b/test/SemaCXX/attr-speculative-load-hardening.cpp deleted file mode 100644 index bba3b6921e..0000000000 --- a/test/SemaCXX/attr-speculative-load-hardening.cpp +++ /dev/null @@ -1,34 +0,0 @@ -// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s - -int i __attribute__((speculative_load_hardening)); // expected-error {{'speculative_load_hardening' attribute only applies to functions}} - -void f1() __attribute__((speculative_load_hardening)); -void f2() __attribute__((speculative_load_hardening(1))); // expected-error {{'speculative_load_hardening' attribute takes no arguments}} - -template -void tf1() __attribute__((speculative_load_hardening)); - -int f3(int __attribute__((speculative_load_hardening)), int); // expected-error {{'speculative_load_hardening' attribute only applies to functions}} - -struct A { - int f __attribute__((speculative_load_hardening)); // expected-error {{'speculative_load_hardening' attribute only applies to functions}} - void mf1() __attribute__((speculative_load_hardening)); - static void mf2() __attribute__((speculative_load_hardening)); -}; - -int ci [[clang::speculative_load_hardening]]; // expected-error {{'speculative_load_hardening' attribute only applies to functions}} - -[[clang::speculative_load_hardening]] void cf1(); -[[clang::speculative_load_hardening(1)]] void cf2(); // expected-error {{'speculative_load_hardening' attribute takes no arguments}} - -template -[[clang::speculative_load_hardening]] -void ctf1(); - -int cf3(int c[[clang::speculative_load_hardening]], int); // expected-error {{'speculative_load_hardening' attribute only applies to functions}} - -struct CA { - int f [[clang::speculative_load_hardening]]; // expected-error {{'speculative_load_hardening' attribute only applies to functions}} - [[clang::speculative_load_hardening]] void mf1(); - [[clang::speculative_load_hardening]] static void mf2(); -};