bolt/test/runtime/X86/jt-symbol-disambiguation-2.s

   1 # In this test case, we reproduce the behavior seen in gcc where the
   2 # base address of a data object is decremented by some number and lands
   3 # inside a jump table from another function.
   4
   5 # REQUIRES: system-linux
   6
   7 # RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %s -o %t.o
   8 # RUN: llvm-strip --strip-unneeded %t.o
   9 # RUN: %clang %cflags -no-pie -nostartfiles -nostdlib -lc %t.o -o %t.exe -Wl,-q
  10
  11 # RUN: llvm-bolt %t.exe -o %t.exe.bolt --relocs=1 --lite=0 \
  12 # RUN:   --reorder-blocks=reverse -jump-tables=move
  13
  14 # RUN: %t.exe.bolt 1 2 3
  15
  16   .file "jt-symbol-disambiguation-2.s"
  17   .text
  18
  19 # ----
  20 # Func foo contains a jump table whose start is colocated with a
  21 # symbol marking the end of a data table
  22 # ----
  23   .globl foo
  24   .type foo, @function
  25 foo:
  26   .cfi_startproc
  27   xor    %rax,%rax
  28   and    $0x3,%rdi
  29   leaq   .JT1(%rip), %rax
  30   movslq  (%rax, %rdi, 4), %rdi
  31   addq   %rax, %rdi
  32   jmpq   *%rdi
  33 .LBB1:
  34   movl   $0x1,%eax
  35   jmp    .LBB5
  36 .LBB2:
  37   movl   $0x2,%eax
  38   jmp    .LBB5
  39 .LBB3:
  40   movl   $0x3,%eax
  41   jmp    .LBB5
  42 .LBB4:
  43   movl   $0x4,%eax
  44 .LBB5:
  45   retq
  46   .cfi_endproc
  47   .size foo, .-foo
  48
  49 # ----
  50 # Func _start scans an object with indexed access using %rax * 8 as an
  51 # index. However, %rax is known to be at least one, so the compiler
  52 # loads the pointer for the base address as object - 8 instead of just
  53 # object.
  54 # ----
  55   .globl _start
  56   .type _start, @function
  57 _start:
  58   .cfi_startproc
  59   movq   (%rsp), %rdi
  60   callq foo
  61   xorq   %rbx, %rbx
  62   leaq   .object-8(%rip), %rsi  # indexed access base address
  63   movq   $1, %rax               # start index
  64 .LBB6:
  65   cmpq $4, %rax
  66   je .LBB7
  67   addq (%rsi,%rax,8), %rbx
  68   incq %rax   # ++iterator
  69   jmp .LBB6
  70 .LBB7:
  71   cmpq  $1368, %rbx             # check .object contents integrity
  72   jne   .LBB_BAD
  73   xor   %rdi, %rdi
  74   callq exit@PLT
  75   retq
  76 .LBB_BAD:
  77   leaq  .message, %rdi
  78   callq puts@PLT
  79   movq  $1, %rdi
  80   callq exit@PLT
  81   retq
  82   .cfi_endproc
  83   .size _start, .-_start
  84
  85 # ----
  86 # Data section
  87 # ----
  88   .section .rodata,"a",@progbits
  89   .p2align 3
  90 .JT1:
  91   .long .LBB1 - .JT1
  92   .long .LBB2 - .JT1
  93   .long .LBB3 - .JT1
  94   .long .LBB4 - .JT1
  95 .object:
  96   .quad 123
  97   .quad 456
  98   .quad 789
  99 .message:
 100   .asciz "RUNTIME ASSERTION FAILURE: references in test binary are corrupt after BOLT"