1/* Functions for CET/x86.
2   Copyright (C) 2017-2020 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 3, or (at your option)
9any later version.
10
11GCC is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14GNU General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING3.  If not see
18<http://www.gnu.org/licenses/>.  */
19
20#include "config.h"
21#include "system.h"
22#include "coretypes.h"
23#include "tm.h"
24#include "output.h"
25#include "linux-common.h"
26
27void
28file_end_indicate_exec_stack_and_cet (void)
29{
30  file_end_indicate_exec_stack ();
31
32  if (flag_cf_protection == CF_NONE)
33    return;
34
35  unsigned int feature_1 = 0;
36
37  if (flag_cf_protection & CF_BRANCH)
38    /* GNU_PROPERTY_X86_FEATURE_1_IBT.  */
39    feature_1 |= 0x1;
40
41  if (flag_cf_protection & CF_RETURN)
42    /* GNU_PROPERTY_X86_FEATURE_1_SHSTK.  */
43    feature_1 |= 0x2;
44
45  if (feature_1)
46    {
47      int p2align = ptr_mode == SImode ? 2 : 3;
48
49      /* Generate GNU_PROPERTY_X86_FEATURE_1_XXX.  */
50      switch_to_section (get_section (".note.gnu.property",
51				      SECTION_NOTYPE, NULL));
52
53      ASM_OUTPUT_ALIGN (asm_out_file, p2align);
54      /* name length.  */
55      fprintf (asm_out_file, ASM_LONG " 1f - 0f\n");
56      /* data length.  */
57      fprintf (asm_out_file, ASM_LONG " 4f - 1f\n");
58      /* note type: NT_GNU_PROPERTY_TYPE_0.  */
59      fprintf (asm_out_file, ASM_LONG " 5\n");
60      fprintf (asm_out_file, "0:\n");
61      /* vendor name: "GNU".  */
62      fprintf (asm_out_file, STRING_ASM_OP " \"GNU\"\n");
63      fprintf (asm_out_file, "1:\n");
64      ASM_OUTPUT_ALIGN (asm_out_file, p2align);
65      /* pr_type: GNU_PROPERTY_X86_FEATURE_1_AND.  */
66      fprintf (asm_out_file, ASM_LONG " 0xc0000002\n");
67      /* pr_datasz.  */\
68      fprintf (asm_out_file, ASM_LONG " 3f - 2f\n");
69      fprintf (asm_out_file, "2:\n");
70      /* GNU_PROPERTY_X86_FEATURE_1_XXX.  */
71      fprintf (asm_out_file, ASM_LONG " 0x%x\n", feature_1);
72      fprintf (asm_out_file, "3:\n");
73      ASM_OUTPUT_ALIGN (asm_out_file, p2align);
74      fprintf (asm_out_file, "4:\n");
75    }
76}
77