r347628 - Revert "[clang][slh] add attribute for speculative load hardening"
Zola Bridges via cfe-commits
cfe-commits at lists.llvm.org
Mon Nov 26 18:22:01 PST 2018
Author: zbrid
Date: Mon Nov 26 18:22:00 2018
New Revision: 347628
URL: http://llvm.org/viewvc/llvm-project?rev=347628&view=rev
Log:
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)
Removed:
cfe/trunk/test/CodeGen/attr-speculative-load-hardening.cpp
cfe/trunk/test/CodeGen/attr-speculative-load-hardening.m
cfe/trunk/test/SemaCXX/attr-speculative-load-hardening.cpp
Modified:
cfe/trunk/include/clang/Basic/Attr.td
cfe/trunk/include/clang/Basic/AttrDocs.td
cfe/trunk/lib/CodeGen/CGCall.cpp
cfe/trunk/lib/Sema/SemaDeclAttr.cpp
cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test
Modified: cfe/trunk/include/clang/Basic/Attr.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=347628&r1=347627&r2=347628&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/Attr.td (original)
+++ cfe/trunk/include/clang/Basic/Attr.td Mon Nov 26 18:22:00 2018
@@ -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];
-}
Modified: cfe/trunk/include/clang/Basic/AttrDocs.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/AttrDocs.td?rev=347628&r1=347627&r2=347628&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/AttrDocs.td (original)
+++ cfe/trunk/include/clang/Basic/AttrDocs.td Mon Nov 26 18:22:00 2018
@@ -3629,27 +3629,3 @@ GNU inline semantics are the default beh
``-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 <https://llvm.org/docs/SpeculativeLoadHardening.html>`_
- 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.
- }];
-}
Modified: cfe/trunk/lib/CodeGen/CGCall.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCall.cpp?rev=347628&r1=347627&r2=347628&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCall.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCall.cpp Mon Nov 26 18:22:00 2018
@@ -1791,8 +1791,6 @@ void CodeGenModule::ConstructDefaultFnAt
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::ConstructAttributeLi
FuncAttrs.addAttribute(llvm::Attribute::NoDuplicate);
if (TargetDecl->hasAttr<ConvergentAttr>())
FuncAttrs.addAttribute(llvm::Attribute::Convergent);
- if (TargetDecl->hasAttr<SpeculativeLoadHardeningAttr>())
- FuncAttrs.addAttribute(llvm::Attribute::SpeculativeLoadHardening);
if (const FunctionDecl *Fn = dyn_cast<FunctionDecl>(TargetDecl)) {
AddAttributesFromFunctionProtoType(
Modified: cfe/trunk/lib/Sema/SemaDeclAttr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclAttr.cpp?rev=347628&r1=347627&r2=347628&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclAttr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclAttr.cpp Mon Nov 26 18:22:00 2018
@@ -6373,9 +6373,6 @@ static void ProcessDeclAttribute(Sema &S
case ParsedAttr::AT_Section:
handleSectionAttr(S, D, AL);
break;
- case ParsedAttr::AT_SpeculativeLoadHardening:
- handleSimpleAttribute<SpeculativeLoadHardeningAttr>(S, D, AL);
- break;
case ParsedAttr::AT_CodeSeg:
handleCodeSegAttr(S, D, AL);
break;
Removed: cfe/trunk/test/CodeGen/attr-speculative-load-hardening.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/attr-speculative-load-hardening.cpp?rev=347627&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/attr-speculative-load-hardening.cpp (original)
+++ cfe/trunk/test/CodeGen/attr-speculative-load-hardening.cpp (removed)
@@ -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{{.*}} }
Removed: cfe/trunk/test/CodeGen/attr-speculative-load-hardening.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/attr-speculative-load-hardening.m?rev=347627&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/attr-speculative-load-hardening.m (original)
+++ cfe/trunk/test/CodeGen/attr-speculative-load-hardening.m (removed)
@@ -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{{.*}} }
Modified: cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test?rev=347628&r1=347627&r2=347628&view=diff
==============================================================================
--- cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test (original)
+++ cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test Mon Nov 26 18:22:00 2018
@@ -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)
Removed: cfe/trunk/test/SemaCXX/attr-speculative-load-hardening.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/attr-speculative-load-hardening.cpp?rev=347627&view=auto
==============================================================================
--- cfe/trunk/test/SemaCXX/attr-speculative-load-hardening.cpp (original)
+++ cfe/trunk/test/SemaCXX/attr-speculative-load-hardening.cpp (removed)
@@ -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 <typename T>
-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 <typename T>
-[[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();
-};
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