llvm/test/CodeGen/X86/win32-eh.ll
Etienne Bergeron 8d600b5b39 [StackProtector] Fix computation of GSCookieOffset and EHCookieOffset with SEH4
Summary:
Fix the computation of the offsets present in the scopetable when using the
SEH (__except_handler4).

This patch added an intrinsic to track the position of the allocation on the
stack of the EHGuard. This position is needed when producing the ScopeTable.

```
    struct _EH4_SCOPETABLE {
        DWORD GSCookieOffset;
        DWORD GSCookieXOROffset;
        DWORD EHCookieOffset;
        DWORD EHCookieXOROffset;
        _EH4_SCOPETABLE_RECORD ScopeRecord[1];
    };

    struct _EH4_SCOPETABLE_RECORD {
        DWORD EnclosingLevel;
        long (*FilterFunc)();
            union {
            void (*HandlerAddress)();
            void (*FinallyFunc)();
        };
    };
```

The code to generate the EHCookie is added in `X86WinEHState.cpp`.
Which is adding these instructions when using SEH4.

```
Lfunc_begin0:
# BB#0:                                 # %entry
	pushl	%ebp
	movl	%esp, %ebp
	pushl	%ebx
	pushl	%edi
	pushl	%esi
	subl	$28, %esp
	movl	%ebp, %eax                <<-- Loading FramePtr
	movl	%esp, -36(%ebp)
	movl	$-2, -16(%ebp)
	movl	$L__ehtable$use_except_handler4_ssp, %ecx
	xorl	___security_cookie, %ecx
	movl	%ecx, -20(%ebp)
	xorl	___security_cookie, %eax  <<-- XOR FramePtr and Cookie
	movl	%eax, -40(%ebp)           <<-- Storing EHGuard
	leal	-28(%ebp), %eax
	movl	$__except_handler4, -24(%ebp)
	movl	%fs:0, %ecx
	movl	%ecx, -28(%ebp)
	movl	%eax, %fs:0
	movl	$0, -16(%ebp)
	calll	_may_throw_or_crash
LBB1_1:                                 # %cont
	movl	-28(%ebp), %eax
	movl	%eax, %fs:0
	addl	$28, %esp
	popl	%esi
	popl	%edi
	popl	%ebx
	popl	%ebp
	retl

```

And the corresponding offset is computed:
```
Luse_except_handler4_ssp$parent_frame_offset = -36
	.p2align	2
L__ehtable$use_except_handler4_ssp:
	.long	-2                      # GSCookieOffset
	.long	0                       # GSCookieXOROffset
	.long	-40                     # EHCookieOffset    <<----
	.long	0                       # EHCookieXOROffset
	.long	-2                      # ToState
	.long	_catchall_filt          # FilterFunction
	.long	LBB1_2                  # ExceptionHandler

```

Clang is not yet producing function using SEH4, but it's a work in progress.
This patch is a step toward having a valid implementation of SEH4.
Unfortunately, it is not yet fully working. The EH registration block is not
allocated at the right offset on the stack.

Reviewers: rnk, majnemer

Subscribers: llvm-commits, chrisha

Differential Revision: http://reviews.llvm.org/D21231

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273281 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-21 15:58:55 +00:00

193 lines
5.7 KiB
LLVM

; RUN: llc -mtriple=i686-pc-windows-msvc < %s | FileCheck %s
declare void @may_throw_or_crash()
declare i32 @_except_handler3(...)
declare i32 @_except_handler4(...)
declare i32 @__CxxFrameHandler3(...)
declare void @llvm.eh.begincatch(i8*, i8*)
declare void @llvm.eh.endcatch()
declare i32 @llvm.eh.typeid.for(i8*)
define internal i32 @catchall_filt() {
ret i32 1
}
define void @use_except_handler3() personality i32 (...)* @_except_handler3 {
entry:
invoke void @may_throw_or_crash()
to label %cont unwind label %lpad
cont:
ret void
lpad:
%cs = catchswitch within none [label %catch] unwind to caller
catch:
%p = catchpad within %cs [i8* bitcast (i32 ()* @catchall_filt to i8*)]
catchret from %p to label %cont
}
; CHECK-LABEL: _use_except_handler3:
; CHECK: pushl %ebp
; CHECK: movl %esp, %ebp
; CHECK: pushl %ebx
; CHECK: pushl %edi
; CHECK: pushl %esi
; CHECK: subl ${{[0-9]+}}, %esp
; CHECK: movl $-1, -16(%ebp)
; CHECK: movl $L__ehtable$use_except_handler3, -20(%ebp)
; CHECK: leal -28(%ebp), %[[node:[^ ,]*]]
; CHECK: movl $__except_handler3, -24(%ebp)
; CHECK: movl %fs:0, %[[next:[^ ,]*]]
; CHECK: movl %[[next]], -28(%ebp)
; CHECK: movl %[[node]], %fs:0
; CHECK: calll _may_throw_or_crash
; CHECK: movl -28(%ebp), %[[next:[^ ,]*]]
; CHECK: movl %[[next]], %fs:0
; CHECK: retl
; CHECK: LBB1_2: # %catch{{$}}
; CHECK: .section .xdata,"dr"
; CHECK-LABEL: L__ehtable$use_except_handler3:
; CHECK-NEXT: .long -1
; CHECK-NEXT: .long _catchall_filt
; CHECK-NEXT: .long LBB1_2
define void @use_except_handler4() personality i32 (...)* @_except_handler4 {
entry:
invoke void @may_throw_or_crash()
to label %cont unwind label %lpad
cont:
ret void
lpad:
%cs = catchswitch within none [label %catch] unwind to caller
catch:
%p = catchpad within %cs [i8* bitcast (i32 ()* @catchall_filt to i8*)]
catchret from %p to label %cont
}
; CHECK-LABEL: _use_except_handler4:
; CHECK: pushl %ebp
; CHECK: movl %esp, %ebp
; CHECK: subl ${{[0-9]+}}, %esp
; CHECK: movl %esp, -36(%ebp)
; CHECK: movl $-2, -16(%ebp)
; CHECK: movl $L__ehtable$use_except_handler4, %[[lsda:[^ ,]*]]
; CHECK: xorl ___security_cookie, %[[lsda]]
; CHECK: movl %[[lsda]], -20(%ebp)
; CHECK: leal -28(%ebp), %[[node:[^ ,]*]]
; CHECK: movl $__except_handler4, -24(%ebp)
; CHECK: movl %fs:0, %[[next:[^ ,]*]]
; CHECK: movl %[[next]], -28(%ebp)
; CHECK: movl %[[node]], %fs:0
; CHECK: calll _may_throw_or_crash
; CHECK: movl -28(%ebp), %[[next:[^ ,]*]]
; CHECK: movl %[[next]], %fs:0
; CHECK: retl
; CHECK: LBB2_2: # %catch{{$}}
; CHECK: .section .xdata,"dr"
; CHECK-LABEL: L__ehtable$use_except_handler4:
; CHECK-NEXT: .long -2
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long -40
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long -2
; CHECK-NEXT: .long _catchall_filt
; CHECK-NEXT: .long LBB2_2
define void @use_except_handler4_ssp() sspstrong personality i32 (...)* @_except_handler4 {
entry:
invoke void @may_throw_or_crash()
to label %cont unwind label %lpad
cont:
ret void
lpad:
%cs = catchswitch within none [label %catch] unwind to caller
catch:
%p = catchpad within %cs [i8* bitcast (i32 ()* @catchall_filt to i8*)]
catchret from %p to label %cont
}
; CHECK-LABEL: _use_except_handler4_ssp:
; CHECK: pushl %ebp
; CHECK: movl %esp, %ebp
; CHECK: subl ${{[0-9]+}}, %esp
; CHECK: movl %ebp, %[[ehguard:[^ ,]*]]
; CHECK: movl %esp, -36(%ebp)
; CHECK: movl $-2, -16(%ebp)
; CHECK: movl $L__ehtable$use_except_handler4_ssp, %[[lsda:[^ ,]*]]
; CHECK: xorl ___security_cookie, %[[lsda]]
; CHECK: movl %[[lsda]], -20(%ebp)
; CHECK: xorl ___security_cookie, %[[ehguard]]
; CHECK: movl %[[ehguard]], -40(%ebp)
; CHECK: leal -28(%ebp), %[[node:[^ ,]*]]
; CHECK: movl $__except_handler4, -24(%ebp)
; CHECK: movl %fs:0, %[[next:[^ ,]*]]
; CHECK: movl %[[next]], -28(%ebp)
; CHECK: movl %[[node]], %fs:0
; CHECK: calll _may_throw_or_crash
; CHECK: movl -28(%ebp), %[[next:[^ ,]*]]
; CHECK: movl %[[next]], %fs:0
; CHECK: retl
; CHECK: [[catch:[^ ,]*]]: # %catch{{$}}
; CHECK: .section .xdata,"dr"
; CHECK-LABEL: L__ehtable$use_except_handler4_ssp:
; CHECK-NEXT: .long -2
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long -40
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long -2
; CHECK-NEXT: .long _catchall_filt
; CHECK-NEXT: .long [[catch]]
define void @use_CxxFrameHandler3() personality i32 (...)* @__CxxFrameHandler3 {
invoke void @may_throw_or_crash()
to label %cont unwind label %catchall
cont:
ret void
catchall:
%cs = catchswitch within none [label %catch] unwind to caller
catch:
%p = catchpad within %cs [i8* null, i32 64, i8* null]
catchret from %p to label %cont
}
; CHECK-LABEL: _use_CxxFrameHandler3:
; CHECK: pushl %ebp
; CHECK: movl %esp, %ebp
; CHECK: subl ${{[0-9]+}}, %esp
; CHECK: movl %esp, -28(%ebp)
; CHECK: movl $-1, -16(%ebp)
; CHECK: leal -24(%ebp), %[[node:[^ ,]*]]
; CHECK: movl $___ehhandler$use_CxxFrameHandler3, -20(%ebp)
; CHECK: movl %fs:0, %[[next:[^ ,]*]]
; CHECK: movl %[[next]], -24(%ebp)
; CHECK: movl %[[node]], %fs:0
; CHECK: movl $0, -16(%ebp)
; CHECK: calll _may_throw_or_crash
; CHECK: movl -24(%ebp), %[[next:[^ ,]*]]
; CHECK: movl %[[next]], %fs:0
; CHECK: retl
; CHECK: .section .xdata,"dr"
; CHECK: .p2align 2
; CHECK-LABEL: L__ehtable$use_CxxFrameHandler3:
; CHECK-NEXT: .long 429065506
; CHECK-NEXT: .long 2
; CHECK-NEXT: .long ($stateUnwindMap$use_CxxFrameHandler3)
; CHECK-NEXT: .long 1
; CHECK-NEXT: .long ($tryMap$use_CxxFrameHandler3)
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long 1
; CHECK-LABEL: ___ehhandler$use_CxxFrameHandler3:
; CHECK: movl $L__ehtable$use_CxxFrameHandler3, %eax
; CHECK: jmp ___CxxFrameHandler3 # TAILCALL
; CHECK: .safeseh __except_handler3
; CHECK: .safeseh __except_handler4
; CHECK: .safeseh ___ehhandler$use_CxxFrameHandler3