lld/test/ELF/gnu-ifunc-plt.s

   1 // REQUIRES: x86
   2
   3 /// For non-preemptable ifunc, place ifunc PLT entries to the .iplt section.
   4
   5 // RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %S/Inputs/shared2-x86-64.s -o %t1.o
   6 // RUN: ld.lld %t1.o --shared -soname=so -o %t.so
   7 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
   8 // RUN: ld.lld --hash-style=sysv %t.so %t.o -o %tout
   9 // RUN: llvm-objdump -d --no-show-raw-insn --print-imm-hex %tout | FileCheck %s --check-prefix=DISASM
  10 // RUN: llvm-objdump -s %tout | FileCheck %s --check-prefix=GOTPLT
  11 // RUN: llvm-readobj -r --dynamic-table %tout | FileCheck %s
  12
  13 /// Check that the PLTRELSZ tag does not include the IRELATIVE relocations
  14 // CHECK: DynamicSection [
  15 // CHECK:   0x0000000000000008 RELASZ               72 (bytes)
  16 // CHECK:   0x0000000000000002 PLTRELSZ             48 (bytes)
  17
  18 /// Check that the IRELATIVE relocations are placed to the .rela.dyn section after
  19 /// other regular relocations (e.g. GLOB_DAT).
  20 // CHECK:      Relocations [
  21 // CHECK-NEXT:   Section (4) .rela.dyn {
  22 // CHECK-NEXT:     0x202480 R_X86_64_GLOB_DAT bar3 0x0
  23 // CHECK-NEXT:     0x2034B0 R_X86_64_IRELATIVE - 0x201318
  24 // CHECK-NEXT:     0x2034B8 R_X86_64_IRELATIVE - 0x201319
  25 // CHECK-NEXT:   }
  26 // CHECK-NEXT:   Section (5) .rela.plt {
  27 // CHECK-NEXT:     0x2034A0 R_X86_64_JUMP_SLOT bar2 0x0
  28 // CHECK-NEXT:     0x2034A8 R_X86_64_JUMP_SLOT zed2 0x0
  29 // CHECK-NEXT:   }
  30
  31 /// Check that .got.plt entries point back to PLT header
  32 // GOTPLT: Contents of section .got.plt:
  33 // GOTPLT-NEXT:  203488 90232000 00000000 00000000 00000000
  34 // GOTPLT-NEXT:  203498 00000000 00000000 56132000 00000000
  35 // GOTPLT-NEXT:  2034a8 66132000 00000000 00000000 00000000
  36 // GOTPLT-NEXT:  2034b8 00000000 00000000
  37
  38 /// Check that we have 2 PLT sections: one regular .plt section and one
  39 /// .iplt section for ifunc entries.
  40 // DISASM: Disassembly of section .text:
  41 // DISASM-EMPTY:
  42 // DISASM-NEXT: <foo>:
  43 // DISASM-NEXT:   201318:       retq
  44 // DISASM:      <bar>:
  45 // DISASM-NEXT:   201319:       retq
  46 // DISASM:      <_start>:
  47 // DISASM-NEXT:   20131a:       callq   0x201370
  48 // DISASM-NEXT:   20131f:       callq   0x201380
  49 // DISASM-NEXT:                 callq   {{.*}} <bar2@plt>
  50 // DISASM-NEXT:                 callq   {{.*}} <zed2@plt>
  51 // DISASM-NEXT:                 jmpq    *0x114c(%rip)
  52 // DISASM-EMPTY:
  53 // DISASM-NEXT: Disassembly of section .plt:
  54 // DISASM-EMPTY:
  55 // DISASM-NEXT: <.plt>:
  56 // DISASM-NEXT:   201340:       pushq   0x214a(%rip)
  57 // DISASM-NEXT:   201346:       jmpq    *0x214c(%rip)
  58 // DISASM-NEXT:   20134c:       nopl    (%rax)
  59 // DISASM-EMPTY:
  60 // DISASM-NEXT:   <bar2@plt>:
  61 // DISASM-NEXT:   201350:       jmpq    *0x214a(%rip)
  62 // DISASM-NEXT:   201356:       pushq   $0x0
  63 // DISASM-NEXT:   20135b:       jmp     0x201340 <.plt>
  64 // DISASM-EMPTY:
  65 // DISASM-NEXT:   <zed2@plt>:
  66 // DISASM-NEXT:   201360:       jmpq    *0x2142(%rip)
  67 // DISASM-NEXT:   201366:       pushq   $0x1
  68 // DISASM-NEXT:   20136b:       jmp     0x201340 <.plt>
  69 // DISASM-EMPTY:
  70 // DISASM-NEXT: Disassembly of section .iplt:
  71 // DISASM-EMPTY:
  72 // DISASM-NEXT: <.iplt>:
  73 // DISASM-NEXT:   201370:       jmpq    *0x213a(%rip)
  74 // DISASM-NEXT:   201376:       pushq   $0x0
  75 // DISASM-NEXT:   20137b:       jmp     0x201340 <.plt>
  76 // DISASM-NEXT:   201380:       jmpq    *0x2132(%rip)
  77 // DISASM-NEXT:   201386:       pushq   $0x1
  78 // DISASM-NEXT:   20138b:       jmp     0x201340 <.plt>
  79
  80 // Test that --shuffle-sections does not affect the order of relocations and that
  81 // we still place IRELATIVE relocations last. Check both random seed (0) and an
  82 // arbitrary seed that was known to break the order of relocations previously (3).
  83 // RUN: ld.lld --shuffle-sections='*=3' %t.so %t.o -o %tout2
  84 // RUN: llvm-readobj --relocations %tout2 | FileCheck %s --check-prefix=SHUFFLE
  85 // RUN: ld.lld --shuffle-sections='*=0' %t.so %t.o -o %tout3
  86 // RUN: llvm-readobj --relocations %tout3 | FileCheck %s --check-prefix=SHUFFLE
  87
  88 // SHUFFLE:      Section {{.*}} .rela.dyn {
  89 // SHUFFLE-NEXT:   R_X86_64_GLOB_DAT
  90 // SHUFFLE-NEXT:   R_X86_64_IRELATIVE
  91 // SHUFFLE-NEXT:   R_X86_64_IRELATIVE
  92 // SHUFFLE-NEXT: }
  93
  94 .text
  95 .type foo STT_GNU_IFUNC
  96 .globl foo
  97 foo:
  98  ret
  99
 100 .type bar STT_GNU_IFUNC
 101 .globl bar
 102 bar:
 103  ret
 104
 105 .globl _start
 106 _start:
 107  call foo
 108  call bar
 109  call bar2
 110  call zed2
 111  jmp *bar3@GOTPCREL(%rip)