[PATCH] D59780: Support Intel Control-flow Enforcement Technology

[Xiang Zhang via Phabricator via llvm-commits]

xiangzhangllvm added a comment.

  > gcc -fcf-protection=full -c a.c
  > gcc -fcf-protection=full a.c -o a '-###'   # Retrieve linker command line, replace ld with 

> My GCC crt files are not CET compatible but I think that is probably irrelevant.
> 
>   % ld.lld --eh-frame-hdr -m elf_x86_64 "--hash-style=gnu" -dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie -o a /usr/lib/gcc/x86_64-linux-gnu/8/../../
>   ../x86_64-linux-gnu/Scrt1.o /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/8/crtbeginS.o -L/usr/lib/gc
>   c/x86_64-linux-gnu/8 -L/usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/8/../../../../lib -L/lib/x86_64-linux
>   -gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/8/../../.. a.o -lgcc --push-state --as-needed -lgcc_s
>    --pop-state -lc -lgcc --push-state --as-needed -lgcc_s --pop-state /usr/lib/gcc/x86_64-linux-gnu/8/crtendS.o /usr/lib/gcc/x86_64-linux-gnu/8/../../..
>   /x86_64-linux-gnu/crtn.o --require-cet -o a                                                                                                          
>   ld.lld: warning: /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/Scrt1.o: --require-cet: file is not compatible with CET
>   ld.lld: warning: /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/crti.o: --require-cet: file is not compatible with CET
>   ld.lld: warning: /usr/lib/gcc/x86_64-linux-gnu/8/crtbeginS.o: --require-cet: file is not compatible with CET
>   ld.lld: warning: /usr/lib/x86_64-linux-gnu/libc_nonshared.a(elf-init.oS): --require-cet: file is not compatible with CET
>   ld.lld: warning: /usr/lib/gcc/x86_64-linux-gnu/8/crtendS.o: --require-cet: file is not compatible with CET
>   ld.lld: warning: /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/crtn.o: --require-cet: file is not compatible with CET
> 
> 
> OK, it segfaults. So there may be some issues in the PLT.
> 
>   ./a => segmentation fault

Can you share your a.c code?
I test the "hello world" test, it is ok.  (At first I use as 2.25, it failed at assembling.)

  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$gcc -fcf-protection=full main.c -S -o main.s
  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$cat main.c
  #include<stdio.h>
  int main() {
   printf("Hello llvm!\n");
    return 0;
  }
  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$gcc -fcf-protection=full main.c -S -o main.s
  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$/rdrive/ref/binutils/2.29/rhel70/efi2/bfd/bin/as --64 main.s -o main.o
  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$/rdrive/ref/binutils/2.29/rhel70/efi2/bfd/bin/as -version
  GNU assembler (GNU Binutils) 2.29
  Copyright (C) 2017 Free Software Foundation, Inc.
  This program is free software; you may redistribute it under the terms of
  the GNU General Public License version 3 or later.
  This program has absolutely no warranty.
  This assembler was configured for a target of `x86_64-linux-gnu'.
  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$../build-cet/bin/ld.lld --require-cet -plugin /nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../libexec/gcc/x86_64-linux-gnu/8.3.0/liblto_plugin.so "-plugin-opt=/nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../libexec/gcc/x86_64-linux-gnu/8.3.0/lto-wrapper" "-plugin-opt=-fresolution=/tmp/ccQKvMnE.res" "-plugin-opt=-pass-through=-lgcc" "-plugin-opt=-pass-through=-lgcc_s" "-plugin-opt=-pass-through=-lc" "-plugin-opt=-pass-through=-lgcc" "-plugin-opt=-pass-through=-lgcc_s" --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o a.out /lib/../lib64/crt1.o /lib/../lib64/crti.o /nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../lib/gcc/x86_64-linux-gnu/8.3.0/crtbegin.o -L/nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../lib/gcc/x86_64-linux-gnu/8.3.0 -L/nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../lib/gcc -L/nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../lib/gcc/x86_64-linux-gnu/8.3.0/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../lib/gcc/x86_64-linux-gnu/8.3.0/../../.. main.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../lib/gcc/x86_64-linux-gnu/8.3.0/crtend.o /lib/../lib64/crtn.o
  ld.lld: warning: /lib/../lib64/crt1.o: --require-cet: file is not compatible with CET
  ld.lld: warning: /lib/../lib64/crti.o: --require-cet: file is not compatible with CET
  ld.lld: warning: /nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../lib/gcc/x86_64-linux-gnu/8.3.0/crtbegin.o: --require-cet: file is not compatible with CET
  ld.lld: warning: /usr/lib64/libc_nonshared.a(elf-init.oS): --require-cet: file is not compatible with CET
  ld.lld: warning: /nfs/sc/proj/icl/rdrive/ref/gcc/8.3.0/rhel70/efi2/bin/../lib/gcc/x86_64-linux-gnu/8.3.0/crtend.o: --require-cet: file is not compatible with CET
  ld.lld: warning: /lib/../lib64/crtn.o: --require-cet: file is not compatible with CET
  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$
  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$./a.out
  Hello llvm!
  [xiangzh1 at scels75 /export/iusers/xiangzh1/LLVM/ORG/test]$


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