1  /* ELF program property for Intel CET.
       2     Copyright (C) 2017-2023 Free Software Foundation, Inc.
       3  
       4     This file is free software; you can redistribute it and/or modify it
       5     under the terms of the GNU General Public License as published by the
       6     Free Software Foundation; either version 3, or (at your option) any
       7     later version.
       8  
       9     This file is distributed in the hope that it will be useful, but
      10     WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     General Public License for more details.
      13  
      14     Under Section 7 of GPL version 3, you are granted additional
      15     permissions described in the GCC Runtime Library Exception, version
      16     3.1, as published by the Free Software Foundation.
      17  
      18     You should have received a copy of the GNU General Public License and
      19     a copy of the GCC Runtime Library Exception along with this program;
      20     see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      21     <http://www.gnu.org/licenses/>.
      22   */
      23  
      24  /* Add x86 feature with IBT and/or SHSTK bits to ELF program property
      25     if they are enabled.  Otherwise, contents in this header file are
      26     unused.  Define _CET_ENDBR for assembly codes.  _CET_ENDBR should be
      27     placed unconditionally at the entrance of a function whose address
      28     may be taken.  */
      29  
      30  #ifndef _CET_H_INCLUDED
      31  #define _CET_H_INCLUDED
      32  
      33  #ifdef __ASSEMBLER__
      34  
      35  # if defined __CET__ && (__CET__ & 1) != 0
      36  #  ifdef __x86_64__
      37  #   define _CET_ENDBR endbr64
      38  #  else
      39  #   define _CET_ENDBR endbr32
      40  #  endif
      41  # else
      42  #  define _CET_ENDBR
      43  # endif
      44  
      45  # ifdef __ELF__
      46  #  ifdef __CET__
      47  #   if (__CET__ & 1) != 0
      48  /* GNU_PROPERTY_X86_FEATURE_1_IBT.  */
      49  #    define __PROPERTY_IBT 0x1
      50  #   else
      51  #    define __PROPERTY_IBT 0x0
      52  #   endif
      53  
      54  #   if (__CET__ & 2) != 0
      55  /* GNU_PROPERTY_X86_FEATURE_1_SHSTK.  */
      56  #    define __PROPERTY_SHSTK 0x2
      57  #   else
      58  #    define __PROPERTY_SHSTK 0x0
      59  #   endif
      60  
      61  #   define __PROPERTY_BITS (__PROPERTY_IBT | __PROPERTY_SHSTK)
      62  
      63  #   ifdef __LP64__
      64  #    define __PROPERTY_ALIGN 3
      65  #   else
      66  #    define __PROPERTY_ALIGN 2
      67  #   endif
      68  
      69  	.pushsection ".note.gnu.property", "a"
      70  	.p2align __PROPERTY_ALIGN
      71  	.long 1f - 0f		/* name length.  */
      72  	.long 4f - 1f		/* data length.  */
      73  	/* NT_GNU_PROPERTY_TYPE_0.   */
      74  	.long 5			/* note type.  */
      75  0:
      76  	.asciz "GNU"		/* vendor name.  */
      77  1:
      78  	.p2align __PROPERTY_ALIGN
      79  	/* GNU_PROPERTY_X86_FEATURE_1_AND.  */
      80  	.long 0xc0000002	/* pr_type.  */
      81  	.long 3f - 2f		/* pr_datasz.  */
      82  2:
      83  	/* GNU_PROPERTY_X86_FEATURE_1_XXX.  */
      84  	.long __PROPERTY_BITS
      85  3:
      86  	.p2align __PROPERTY_ALIGN
      87  4:
      88  	.popsection
      89  #  endif /* __CET__ */
      90  # endif /* __ELF__ */
      91  #endif /* __ASSEMBLER__ */
      92  
      93  #endif /* _CET_H_INCLUDED */