Files
clang-p2996/llvm/test/CodeGen/X86/shadow-stack.ll
Matt Arsenault 2790516418 X86: Use MOV32r0 pseudo instead of directly emitting xor
This was producing reg = xor undef reg, undef reg. This looks similar
to a use of a value to define itself, and I want to disallow undef
uses for SSA virtual registers. If this were to use implicit_def,
there's no guarantee the two operands end up using the same register
(I think no guarantee exists even if the two operands start out as the
same register, but this was violated when I switched this to use an
explicit implicit_def). The MOV32r0 pseudo evidently exists to handle
this case, so use it instead. This was more work than I expected for
the 64-bit case, but I didn't see any helper for materializing a
64-bit 0.
2020-06-29 14:45:20 -04:00

241 lines
7.6 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple x86_64-apple-macosx10.13.0 < %s | FileCheck %s --check-prefix=X86_64
; RUN: llc -mtriple i386-apple-macosx10.13.0 < %s | FileCheck %s --check-prefix=X86
; The MacOS tripples are used to get trapping behavior on the "unreachable" IR
; instruction, so that the placement of the ud2 instruction could be verified.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; The IR was created using the following C code:
;; typedef void *jmp_buf;
;; jmp_buf buf;
;;
;; __attribute__((noinline)) int bar(int i) {
;; int j = i - 111;
;; __builtin_longjmp(&buf, 1);
;; return j;
;; }
;;
;; int foo(int i) {
;; int j = i * 11;
;; if (!__builtin_setjmp(&buf)) {
;; j += 33 + bar(j);
;; }
;; return j + i;
;; }
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@buf = common local_unnamed_addr global i8* null, align 8
; Functions that use LongJmp should fix the Shadow Stack using previosuly saved
; ShadowStackPointer in the input buffer.
; The fix requires unwinding the shadow stack to the last SSP.
define i32 @bar(i32 %i) local_unnamed_addr {
; X86_64-LABEL: bar:
; X86_64: ## %bb.0: ## %entry
; X86_64-NEXT: pushq %rbp
; X86_64-NEXT: .cfi_def_cfa_offset 16
; X86_64-NEXT: .cfi_offset %rbp, -16
; X86_64-NEXT: movq _buf@{{.*}}(%rip), %rax
; X86_64-NEXT: movq (%rax), %rax
; X86_64-NEXT: xorl %edx, %edx
; X86_64-NEXT: rdsspq %rdx
; X86_64-NEXT: testq %rdx, %rdx
; X86_64-NEXT: je LBB0_5
; X86_64-NEXT: ## %bb.1: ## %entry
; X86_64-NEXT: movq 24(%rax), %rcx
; X86_64-NEXT: subq %rdx, %rcx
; X86_64-NEXT: jbe LBB0_5
; X86_64-NEXT: ## %bb.2: ## %entry
; X86_64-NEXT: shrq $3, %rcx
; X86_64-NEXT: incsspq %rcx
; X86_64-NEXT: shrq $8, %rcx
; X86_64-NEXT: je LBB0_5
; X86_64-NEXT: ## %bb.3: ## %entry
; X86_64-NEXT: shlq %rcx
; X86_64-NEXT: movq $128, %rdx
; X86_64-NEXT: LBB0_4: ## %entry
; X86_64-NEXT: ## =>This Inner Loop Header: Depth=1
; X86_64-NEXT: incsspq %rdx
; X86_64-NEXT: decq %rcx
; X86_64-NEXT: jne LBB0_4
; X86_64-NEXT: LBB0_5: ## %entry
; X86_64-NEXT: movq (%rax), %rbp
; X86_64-NEXT: movq 8(%rax), %rcx
; X86_64-NEXT: movq 16(%rax), %rsp
; X86_64-NEXT: jmpq *%rcx
;
; X86-LABEL: bar:
; X86: ## %bb.0: ## %entry
; X86-NEXT: pushl %ebp
; X86-NEXT: .cfi_def_cfa_offset 8
; X86-NEXT: .cfi_offset %ebp, -8
; X86-NEXT: movl L_buf$non_lazy_ptr, %eax
; X86-NEXT: movl (%eax), %eax
; X86-NEXT: xorl %edx, %edx
; X86-NEXT: rdsspd %edx
; X86-NEXT: testl %edx, %edx
; X86-NEXT: je LBB0_5
; X86-NEXT: ## %bb.1: ## %entry
; X86-NEXT: movl 12(%eax), %ecx
; X86-NEXT: subl %edx, %ecx
; X86-NEXT: jbe LBB0_5
; X86-NEXT: ## %bb.2: ## %entry
; X86-NEXT: shrl $2, %ecx
; X86-NEXT: incsspd %ecx
; X86-NEXT: shrl $8, %ecx
; X86-NEXT: je LBB0_5
; X86-NEXT: ## %bb.3: ## %entry
; X86-NEXT: shll %ecx
; X86-NEXT: movl $128, %edx
; X86-NEXT: LBB0_4: ## %entry
; X86-NEXT: ## =>This Inner Loop Header: Depth=1
; X86-NEXT: incsspd %edx
; X86-NEXT: decl %ecx
; X86-NEXT: jne LBB0_4
; X86-NEXT: LBB0_5: ## %entry
; X86-NEXT: movl (%eax), %ebp
; X86-NEXT: movl 4(%eax), %ecx
; X86-NEXT: movl 8(%eax), %esp
; X86-NEXT: jmpl *%ecx
entry:
%0 = load i8*, i8** @buf, align 8
tail call void @llvm.eh.sjlj.longjmp(i8* %0)
unreachable
}
declare void @llvm.eh.sjlj.longjmp(i8*)
; Functions that call SetJmp should save the current ShadowStackPointer for
; future fixing of the Shadow Stack.
define i32 @foo(i32 %i) local_unnamed_addr {
; X86_64-LABEL: foo:
; X86_64: ## %bb.0: ## %entry
; X86_64-NEXT: pushq %rbp
; X86_64-NEXT: .cfi_def_cfa_offset 16
; X86_64-NEXT: .cfi_offset %rbp, -16
; X86_64-NEXT: movq %rsp, %rbp
; X86_64-NEXT: .cfi_def_cfa_register %rbp
; X86_64-NEXT: pushq %r15
; X86_64-NEXT: pushq %r14
; X86_64-NEXT: pushq %r13
; X86_64-NEXT: pushq %r12
; X86_64-NEXT: pushq %rbx
; X86_64-NEXT: pushq %rax
; X86_64-NEXT: .cfi_offset %rbx, -56
; X86_64-NEXT: .cfi_offset %r12, -48
; X86_64-NEXT: .cfi_offset %r13, -40
; X86_64-NEXT: .cfi_offset %r14, -32
; X86_64-NEXT: .cfi_offset %r15, -24
; X86_64-NEXT: ## kill: def $edi killed $edi def $rdi
; X86_64-NEXT: movq %rdi, {{[-0-9]+}}(%r{{[sb]}}p) ## 8-byte Spill
; X86_64-NEXT: movq _buf@{{.*}}(%rip), %rax
; X86_64-NEXT: movq (%rax), %rax
; X86_64-NEXT: movq %rbp, (%rax)
; X86_64-NEXT: movq %rsp, 16(%rax)
; X86_64-NEXT: leaq {{.*}}(%rip), %rcx
; X86_64-NEXT: movq %rcx, 8(%rax)
; X86_64-NEXT: xorq %rcx, %rcx
; X86_64-NEXT: rdsspq %rcx
; X86_64-NEXT: movq %rcx, 24(%rax)
; X86_64-NEXT: #EH_SjLj_Setup LBB1_4
; X86_64-NEXT: ## %bb.1: ## %entry
; X86_64-NEXT: xorl %eax, %eax
; X86_64-NEXT: jmp LBB1_2
; X86_64-NEXT: LBB1_4: ## Block address taken
; X86_64-NEXT: ## %entry
; X86_64-NEXT: movl $1, %eax
; X86_64-NEXT: LBB1_2: ## %entry
; X86_64-NEXT: testl %eax, %eax
; X86_64-NEXT: je LBB1_5
; X86_64-NEXT: ## %bb.3: ## %if.end
; X86_64-NEXT: movq {{[-0-9]+}}(%r{{[sb]}}p), %rax ## 8-byte Reload
; X86_64-NEXT: shll $2, %eax
; X86_64-NEXT: leal (%rax,%rax,2), %eax
; X86_64-NEXT: addq $8, %rsp
; X86_64-NEXT: popq %rbx
; X86_64-NEXT: popq %r12
; X86_64-NEXT: popq %r13
; X86_64-NEXT: popq %r14
; X86_64-NEXT: popq %r15
; X86_64-NEXT: popq %rbp
; X86_64-NEXT: retq
; X86_64-NEXT: LBB1_5: ## %if.then
; X86_64-NEXT: callq _bar
; X86_64-NEXT: ud2
;
; X86-LABEL: foo:
; X86: ## %bb.0: ## %entry
; X86-NEXT: pushl %ebp
; X86-NEXT: .cfi_def_cfa_offset 8
; X86-NEXT: .cfi_offset %ebp, -8
; X86-NEXT: movl %esp, %ebp
; X86-NEXT: .cfi_def_cfa_register %ebp
; X86-NEXT: pushl %ebx
; X86-NEXT: pushl %edi
; X86-NEXT: pushl %esi
; X86-NEXT: subl $12, %esp
; X86-NEXT: .cfi_offset %esi, -20
; X86-NEXT: .cfi_offset %edi, -16
; X86-NEXT: .cfi_offset %ebx, -12
; X86-NEXT: movl L_buf$non_lazy_ptr, %eax
; X86-NEXT: movl (%eax), %eax
; X86-NEXT: movl %ebp, (%eax)
; X86-NEXT: movl %esp, 16(%eax)
; X86-NEXT: movl $LBB1_4, 4(%eax)
; X86-NEXT: xorl %ecx, %ecx
; X86-NEXT: rdsspd %ecx
; X86-NEXT: movl %ecx, 12(%eax)
; X86-NEXT: #EH_SjLj_Setup LBB1_4
; X86-NEXT: ## %bb.1: ## %entry
; X86-NEXT: xorl %eax, %eax
; X86-NEXT: jmp LBB1_2
; X86-NEXT: LBB1_4: ## Block address taken
; X86-NEXT: ## %entry
; X86-NEXT: movl $1, %eax
; X86-NEXT: LBB1_2: ## %entry
; X86-NEXT: testl %eax, %eax
; X86-NEXT: je LBB1_5
; X86-NEXT: ## %bb.3: ## %if.end
; X86-NEXT: movl 8(%ebp), %eax
; X86-NEXT: shll $2, %eax
; X86-NEXT: leal (%eax,%eax,2), %eax
; X86-NEXT: addl $12, %esp
; X86-NEXT: popl %esi
; X86-NEXT: popl %edi
; X86-NEXT: popl %ebx
; X86-NEXT: popl %ebp
; X86-NEXT: retl
; X86-NEXT: LBB1_5: ## %if.then
; X86-NEXT: calll _bar
; X86-NEXT: ud2
entry:
%0 = load i8*, i8** @buf, align 8
%1 = bitcast i8* %0 to i8**
%2 = tail call i8* @llvm.frameaddress(i32 0)
store i8* %2, i8** %1, align 8
%3 = tail call i8* @llvm.stacksave()
%4 = getelementptr inbounds i8, i8* %0, i64 16
%5 = bitcast i8* %4 to i8**
store i8* %3, i8** %5, align 8
%6 = tail call i32 @llvm.eh.sjlj.setjmp(i8* %0)
%tobool = icmp eq i32 %6, 0
br i1 %tobool, label %if.then, label %if.end
if.then: ; preds = %entry
%call = tail call i32 @bar(i32 undef)
unreachable
if.end: ; preds = %entry
%add2 = mul nsw i32 %i, 12
ret i32 %add2
}
declare i8* @llvm.frameaddress(i32)
declare i8* @llvm.stacksave()
declare i32 @llvm.eh.sjlj.setjmp(i8*)
!llvm.module.flags = !{!0}
!0 = !{i32 4, !"cf-protection-return", i32 1}