This is an archive of the discontinued LLVM Phabricator instance.

Differential D14974

[safestack] Fix alignment of dynamic allocas.
ClosedPublic

Authored by eugenis on Nov 24 2015, 5:27 PM.

Download Raw Diff

Details

Reviewers

Summary

Fixes PR25588.

Diff Detail

Repository: rL LLVM

Event Timeline

eugenis updated this revision to Diff 41101.Nov 24 2015, 5:27 PM

eugenis retitled this revision from to [safestack] Fix alignment of dynamic allocas..

eugenis updated this object.

eugenis added a reviewer: pcc.

eugenis set the repository for this revision to rL LLVM.

eugenis added a subscriber: llvm-commits.

LGTM

This revision is now accepted and ready to land.Nov 25 2015, 2:53 PM

r254109, thanks

Revision Contents

Path

Size

lib/

Transforms/

Instrumentation/

2 lines

test/

Transforms/

SafeStack/

2 lines

Diff 41101

lib/Transforms/Instrumentation/SafeStack.cpp

	Show First 20 Lines • Show All 535 Lines • ▼ Show 20 Lines		Value *NewTop = IRB.CreateIntToPtr(
	IRB.CreateAnd(SP, ConstantInt::get(IntPtrTy, ~uint64_t(Align - 1))),			IRB.CreateAnd(SP, ConstantInt::get(IntPtrTy, ~uint64_t(Align - 1))),
	StackPtrTy);			StackPtrTy);

	// Save the stack pointer.			// Save the stack pointer.
	IRB.CreateStore(NewTop, UnsafeStackPtr);			IRB.CreateStore(NewTop, UnsafeStackPtr);
	if (DynamicTop)			if (DynamicTop)
	IRB.CreateStore(NewTop, DynamicTop);			IRB.CreateStore(NewTop, DynamicTop);

	Value *NewAI = IRB.CreateIntToPtr(SP, AI->getType());			Value *NewAI = IRB.CreatePointerCast(NewTop, AI->getType());
	if (AI->hasName() && isa<Instruction>(NewAI))			if (AI->hasName() && isa<Instruction>(NewAI))
	NewAI->takeName(AI);			NewAI->takeName(AI);

	replaceDbgDeclareForAlloca(AI, NewAI, DIB, /Deref=/true);			replaceDbgDeclareForAlloca(AI, NewAI, DIB, /Deref=/true);
	AI->replaceAllUsesWith(NewAI);			AI->replaceAllUsesWith(NewAI);
	AI->eraseFromParent();			AI->eraseFromParent();
	}			}

	▲ Show 20 Lines • Show All 116 Lines • Show Last 20 Lines

test/Transforms/SafeStack/setjmp2.ll

	Show All 19 Lines		entry:
	; CHECK-NEXT: %[[MUL:.*]] = mul i64 %[[ZEXT]], 4			; CHECK-NEXT: %[[MUL:.*]] = mul i64 %[[ZEXT]], 4
	; CHECK-NEXT: %[[SP2:.]] = load i8, i8** @__safestack_unsafe_stack_ptr			; CHECK-NEXT: %[[SP2:.]] = load i8, i8** @__safestack_unsafe_stack_ptr
	; CHECK-NEXT: %[[PTRTOINT:.]] = ptrtoint i8 %[[SP2]] to i64			; CHECK-NEXT: %[[PTRTOINT:.]] = ptrtoint i8 %[[SP2]] to i64
	; CHECK-NEXT: %[[SUB:.*]] = sub i64 %[[PTRTOINT]], %[[MUL]]			; CHECK-NEXT: %[[SUB:.*]] = sub i64 %[[PTRTOINT]], %[[MUL]]
	; CHECK-NEXT: %[[AND:.*]] = and i64 %[[SUB]], -16			; CHECK-NEXT: %[[AND:.*]] = and i64 %[[SUB]], -16
	; CHECK-NEXT: %[[INTTOPTR:.]] = inttoptr i64 %[[AND]] to i8			; CHECK-NEXT: %[[INTTOPTR:.]] = inttoptr i64 %[[AND]] to i8
	; CHECK-NEXT: store i8* %[[INTTOPTR]], i8** @__safestack_unsafe_stack_ptr			; CHECK-NEXT: store i8* %[[INTTOPTR]], i8** @__safestack_unsafe_stack_ptr
	; CHECK-NEXT: store i8* %[[INTTOPTR]], i8** %unsafe_stack_dynamic_ptr			; CHECK-NEXT: store i8* %[[INTTOPTR]], i8** %unsafe_stack_dynamic_ptr
	; CHECK-NEXT: %[[ALLOCA:.]] = inttoptr i64 %[[SUB]] to i32			; CHECK-NEXT: %[[ALLOCA:.]] = bitcast i8 %[[INTTOPTR]] to i32*
	%a = alloca i32, i32 %size			%a = alloca i32, i32 %size

	; CHECK: setjmp			; CHECK: setjmp
	; CHECK-NEXT: %[[LOAD:.]] = load i8, i8** %[[DYNPTR]]			; CHECK-NEXT: %[[LOAD:.]] = load i8, i8** %[[DYNPTR]]
	; CHECK-NEXT: store i8* %[[LOAD]], i8** @__safestack_unsafe_stack_ptr			; CHECK-NEXT: store i8* %[[LOAD]], i8** @__safestack_unsafe_stack_ptr
	%call = call i32 @_setjmp(%struct.__jmp_buf_tag* getelementptr inbounds ([1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* @buf, i32 0, i32 0)) returns_twice			%call = call i32 @_setjmp(%struct.__jmp_buf_tag* getelementptr inbounds ([1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* @buf, i32 0, i32 0)) returns_twice

	; CHECK: call void @funcall(i32* %[[ALLOCA]])			; CHECK: call void @funcall(i32* %[[ALLOCA]])
	call void @funcall(i32* %a)			call void @funcall(i32* %a)
	ret i32 0			ret i32 0
	}			}

	declare i32 @_setjmp(%struct.__jmp_buf_tag*)			declare i32 @_setjmp(%struct.__jmp_buf_tag*)
	declare void @funcall(i32*)			declare void @funcall(i32*)