[WIP] [clang] Align cleanup structs to prevent SIGBUS on sparc32 #152866
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The cleanup structs expect that pointers and (u)int64_t have the same alignment requirements, which isn't true on sparc32, which causes SIGBUSes. See also: llvm#66620
llvmbot
added
clang
|
@llvm/pr-subscribers-clang Author: Koakuma (koachan) ChangesThe cleanup structs expect that pointers and (u)int64_t have the same alignment requirements, which isn't true on sparc32, which causes SIGBUSes. See also: #66620 Full diff: https://github.com/llvm/llvm-project/pull/152866.diff 3 Files Affected:
diff --git a/clang/include/clang/AST/APValue.h b/clang/include/clang/AST/APValue.h
index 9999a30c51ade..167fa7078d028 100644
--- a/clang/include/clang/AST/APValue.h
+++ b/clang/include/clang/AST/APValue.h
@@ -143,7 +143,7 @@ class APValue {
AddrLabelDiff
};
- class LValueBase {
+ class alignas(8) LValueBase {
typedef llvm::PointerUnion<const ValueDecl *, const Expr *, TypeInfoLValue,
DynamicAllocLValue>
PtrTy;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index bf16d727bac04..393c5161177df 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -725,7 +725,7 @@ class CodeGenFunction : public CodeGenTypeCache {
};
/// Header for data within LifetimeExtendedCleanupStack.
- struct LifetimeExtendedCleanupHeader {
+ struct alignas(8) LifetimeExtendedCleanupHeader {
/// The size of the following cleanup object.
unsigned Size;
/// The kind of cleanup to push.
@@ -947,7 +947,8 @@ class CodeGenFunction : public CodeGenTypeCache {
LifetimeExtendedCleanupStack.size() + sizeof(Header) + Header.Size +
(Header.IsConditional ? sizeof(ActiveFlag) : 0));
- static_assert(sizeof(Header) % alignof(T) == 0,
+ static_assert((alignof(LifetimeExtendedCleanupHeader) == alignof(T)) &&
+ (alignof(T) == alignof(RawAddress)),
"Cleanup will be allocated on misaligned address");
char *Buffer = &LifetimeExtendedCleanupStack[OldSize];
new (Buffer) LifetimeExtendedCleanupHeader(Header);
diff --git a/clang/lib/CodeGen/EHScopeStack.h b/clang/lib/CodeGen/EHScopeStack.h
index ed11dc2bb05d7..1a9cff48ad852 100644
--- a/clang/lib/CodeGen/EHScopeStack.h
+++ b/clang/lib/CodeGen/EHScopeStack.h
@@ -143,7 +143,7 @@ class EHScopeStack {
///
/// Cleanup implementations should generally be declared in an
/// anonymous namespace.
- class Cleanup {
+ class alignas(8) Cleanup {
// Anchor the construction vtable.
virtual void anchor();
|
|
@llvm/pr-subscribers-clang-codegen Author: Koakuma (koachan) ChangesThe cleanup structs expect that pointers and (u)int64_t have the same alignment requirements, which isn't true on sparc32, which causes SIGBUSes. See also: #66620 Full diff: https://github.com/llvm/llvm-project/pull/152866.diff 3 Files Affected:
diff --git a/clang/include/clang/AST/APValue.h b/clang/include/clang/AST/APValue.h
index 9999a30c51ade..167fa7078d028 100644
--- a/clang/include/clang/AST/APValue.h
+++ b/clang/include/clang/AST/APValue.h
@@ -143,7 +143,7 @@ class APValue {
AddrLabelDiff
};
- class LValueBase {
+ class alignas(8) LValueBase {
typedef llvm::PointerUnion<const ValueDecl *, const Expr *, TypeInfoLValue,
DynamicAllocLValue>
PtrTy;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index bf16d727bac04..393c5161177df 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -725,7 +725,7 @@ class CodeGenFunction : public CodeGenTypeCache {
};
/// Header for data within LifetimeExtendedCleanupStack.
- struct LifetimeExtendedCleanupHeader {
+ struct alignas(8) LifetimeExtendedCleanupHeader {
/// The size of the following cleanup object.
unsigned Size;
/// The kind of cleanup to push.
@@ -947,7 +947,8 @@ class CodeGenFunction : public CodeGenTypeCache {
LifetimeExtendedCleanupStack.size() + sizeof(Header) + Header.Size +
(Header.IsConditional ? sizeof(ActiveFlag) : 0));
- static_assert(sizeof(Header) % alignof(T) == 0,
+ static_assert((alignof(LifetimeExtendedCleanupHeader) == alignof(T)) &&
+ (alignof(T) == alignof(RawAddress)),
"Cleanup will be allocated on misaligned address");
char *Buffer = &LifetimeExtendedCleanupStack[OldSize];
new (Buffer) LifetimeExtendedCleanupHeader(Header);
diff --git a/clang/lib/CodeGen/EHScopeStack.h b/clang/lib/CodeGen/EHScopeStack.h
index ed11dc2bb05d7..1a9cff48ad852 100644
--- a/clang/lib/CodeGen/EHScopeStack.h
+++ b/clang/lib/CodeGen/EHScopeStack.h
@@ -143,7 +143,7 @@ class EHScopeStack {
///
/// Cleanup implementations should generally be declared in an
/// anonymous namespace.
- class Cleanup {
+ class alignas(8) Cleanup {
// Anchor the construction vtable.
virtual void anchor();
|
|
I've run a However, when trying an Besides, I think it would be clearer to use |
Changed to this, it should fix the i386 issue. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The cleanup structs expect that pointers and (u)int64_t have the same alignment requirements, which isn't true on sparc32, which causes SIGBUSes.
See also: #66620