i386: Remove CET support bits

1. Remove _dl_runtime_resolve_shstk and _dl_runtime_profile_shstk.
2. Move CET offsets from x86 cpu-features-offsets.sym to x86-64
features-offsets.sym.
3. Rename x86 cet-control.h to x86-64 feature-control.h since it is only
for x86-64 and also used for PLT rewrite.
4. Add x86-64 ldsodefs.h to include feature-control.h.
5. Change TUNABLE_CALLBACK (set_plt_rewrite) to x86-64 only.
6. Move x86 dl-procruntime.c to x86-64.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/sysdeps/x86_64/feature-control.h b/sysdeps/x86_64/feature-control.h
new file mode 100644
index 0000000000..4c8727e844
--- /dev/null
+++ b/sysdeps/x86_64/feature-control.h
@@ -0,0 +1,53 @@
+/* x86-64 feature tuning.
+   This file is part of the GNU C Library.
+   Copyright (C) 2018-2024 Free Software Foundation, Inc.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _X86_64_FEATURE_CONTROL_H
+#define _X86_64_FEATURE_CONTROL_H
+
+/* For each CET feature, IBT and SHSTK, valid control values.  */
+enum dl_x86_cet_control
+{
+  /* Enable CET features based on ELF property note.  */
+  cet_elf_property = 0,
+  /* Always enable CET features.  */
+  cet_always_on,
+  /* Always disable CET features.  */
+  cet_always_off,
+  /* Enable CET features permissively.  */
+  cet_permissive
+};
+
+/* PLT rewrite control.  */
+enum dl_plt_rewrite_control
+{
+  /* No PLT rewrite.  */
+  plt_rewrite_none,
+  /* Rewrite PLT with JMP at run-time.  */
+  plt_rewrite_jmp,
+  /* Rewrite PLT with JMP and JMPABS at run-time.  */
+  plt_rewrite_jmpabs
+};
+
+struct dl_x86_feature_control
+{
+  enum dl_x86_cet_control ibt : 2;
+  enum dl_x86_cet_control shstk : 2;
+  enum dl_plt_rewrite_control plt_rewrite : 2;
+};
+
+#endif /* feature-control.h */