llvm-6502/test/CodeGen/X86/jump_table_bitcast.ll
Tom Roeder 63dea2c952 Add Forward Control-Flow Integrity.
This commit adds a new pass that can inject checks before indirect calls to
make sure that these calls target known locations. It supports three types of
checks and, at compile time, it can take the name of a custom function to call
when an indirect call check fails. The default failure function ignores the
error and continues.

This pass incidentally moves the function JumpInstrTables::transformType from
private to public and makes it static (with a new argument that specifies the
table type to use); this is so that the CFI code can transform function types
at call sites to determine which jump-instruction table to use for the check at
that site.

Also, this removes support for jumptables in ARM, pending further performance
analysis and discussion.

Review: http://reviews.llvm.org/D4167



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221708 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:08:02 +00:00

44 lines
1.3 KiB
LLVM

; RUN: llc <%s -jump-table-type=single | FileCheck %s
target triple = "x86_64-unknown-linux-gnu"
define i32 @f() unnamed_addr jumptable {
ret i32 0
}
define i32 @g(i8* %a) unnamed_addr jumptable {
ret i32 0
}
define void @h(void ()* %func) unnamed_addr jumptable {
ret void
}
define i32 @main() {
%g = alloca i32 (...)*, align 8
store i32 (...)* bitcast (i32 ()* @f to i32 (...)*), i32 (...)** %g, align 8
; CHECK: movq $__llvm_jump_instr_table_0_[[ENTRY:1|2|3]],
; CHECK: movl $__llvm_jump_instr_table_0_[[ENTRY]],
%1 = load i32 (...)** %g, align 8
%call = call i32 (...)* %1()
call void (void ()*)* @h(void ()* bitcast (void (void ()*)* @h to void ()*))
; CHECK: movl $__llvm_jump_instr_table_0_{{1|2|3}},
; CHECK: callq h
%a = call i32 (i32*)* bitcast (i32 (i8*)* @g to i32(i32*)*)(i32* null)
; CHECK: callq g
ret i32 %a
}
; CHECK: .align 8, 0x90
; CHECK: .type __llvm_jump_instr_table_0_1,@function
; CHECK: __llvm_jump_instr_table_0_1:
; CHECK: jmp {{f|g|h}}@PLT
; CHECK: .align 8, 0x90
; CHECK: .type __llvm_jump_instr_table_0_2,@function
; CHECK: __llvm_jump_instr_table_0_2:
; CHECK: jmp {{f|g|h}}@PLT
; CHECK: .align 8, 0x90
; CHECK: .type __llvm_jump_instr_table_0_3,@function
; CHECK: __llvm_jump_instr_table_0_3:
; CHECK: jmp {{f|g|h}}@PLT