diff mbox series

[v2,4/4] i386: Remove CET support bits

Message ID 20240109200618.1508659-5-hjl.tools@gmail.com
State New
Headers show
Series i386: Remove remaining CET bits | expand

Commit Message

H.J. Lu Jan. 9, 2024, 8:06 p.m. UTC
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.
---
 sysdeps/i386/dl-machine.h                     | 11 +--
 sysdeps/i386/dl-trampoline.S                  | 69 -------------------
 sysdeps/unix/sysv/linux/x86_64/dl-cet.h       |  2 +-
 sysdeps/x86/cpu-features-offsets.sym          |  2 -
 sysdeps/x86/cpu-features.c                    |  4 +-
 sysdeps/x86/ldsodefs.h                        |  1 -
 sysdeps/x86_64/Makefile                       |  2 +-
 sysdeps/{x86 => x86_64}/dl-procruntime.c      |  2 +-
 sysdeps/x86_64/dl-trampoline.S                |  1 +
 .../feature-control.h}                        |  8 +--
 sysdeps/x86_64/features-offsets.sym           |  6 ++
 sysdeps/x86_64/ldsodefs.h                     | 26 +++++++
 12 files changed, 45 insertions(+), 89 deletions(-)
 rename sysdeps/{x86 => x86_64}/dl-procruntime.c (97%)
 rename sysdeps/{x86/cet-control.h => x86_64/feature-control.h} (92%)
 create mode 100644 sysdeps/x86_64/features-offsets.sym
 create mode 100644 sysdeps/x86_64/ldsodefs.h
diff mbox series

Patch

diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index c69ae165ac..fc1ef96587 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -65,9 +65,6 @@  elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
   extern void _dl_runtime_profile (Elf32_Word) attribute_hidden;
   extern void _dl_runtime_resolve_shstk (Elf32_Word) attribute_hidden;
   extern void _dl_runtime_profile_shstk (Elf32_Word) attribute_hidden;
-  /* Check if SHSTK is enabled by kernel.  */
-  bool shstk_enabled
-    = (GL(dl_x86_feature_1) & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0;
 
   if (l->l_info[DT_JMPREL] && lazy)
     {
@@ -95,9 +92,7 @@  elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
 #ifdef SHARED
       if (__glibc_unlikely (profile))
 	{
-	  got[2] = (shstk_enabled
-		    ? (Elf32_Addr) &_dl_runtime_profile_shstk
-		    : (Elf32_Addr) &_dl_runtime_profile);
+	  got[2] = (Elf32_Addr) &_dl_runtime_profile;
 
 	  if (GLRO(dl_profile) != NULL
 	      && _dl_name_match_p (GLRO(dl_profile), l))
@@ -109,9 +104,7 @@  elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
 #endif
 	/* This function will get called to fix up the GOT entry indicated by
 	   the offset on the stack, and then jump to the resolved address.  */
-	got[2] = (shstk_enabled
-		  ? (Elf32_Addr) &_dl_runtime_resolve_shstk
-		  : (Elf32_Addr) &_dl_runtime_resolve);
+	got[2] = (Elf32_Addr) &_dl_runtime_resolve;
     }
 
   return lazy;
diff --git a/sysdeps/i386/dl-trampoline.S b/sysdeps/i386/dl-trampoline.S
index 2632020145..6c14d463b6 100644
--- a/sysdeps/i386/dl-trampoline.S
+++ b/sysdeps/i386/dl-trampoline.S
@@ -44,76 +44,7 @@  _dl_runtime_resolve:
 	cfi_endproc
 	.size _dl_runtime_resolve, .-_dl_runtime_resolve
 
-# The SHSTK compatible version.
-	.text
-	.globl _dl_runtime_resolve_shstk
-	.type _dl_runtime_resolve_shstk, @function
-	cfi_startproc
-	.align 16
-_dl_runtime_resolve_shstk:
-	cfi_adjust_cfa_offset (8)
-	pushl %eax		# Preserve registers otherwise clobbered.
-	cfi_adjust_cfa_offset (4)
-	pushl %edx
-	cfi_adjust_cfa_offset (4)
-	movl 12(%esp), %edx	# Copy args pushed by PLT in register.  Note
-	movl 8(%esp), %eax	# that `fixup' takes its parameters in regs.
-	call _dl_fixup		# Call resolver.
-	movl (%esp), %edx	# Get register content back.
-	movl %eax, %ecx		# Store the function address.
-	movl 4(%esp), %eax	# Get register content back.
-	addl $16, %esp		# Adjust stack: PLT1 + PLT2 + %eax + %edx
-	cfi_adjust_cfa_offset (-16)
-	jmp *%ecx		# Jump to function address.
-	cfi_endproc
-	.size _dl_runtime_resolve_shstk, .-_dl_runtime_resolve_shstk
-
 #if !defined PROF && defined SHARED
-# The SHSTK compatible version.
-	.globl _dl_runtime_profile_shstk
-	.type _dl_runtime_profile_shstk, @function
-	cfi_startproc
-	.align 16
-_dl_runtime_profile_shstk:
-	cfi_adjust_cfa_offset (8)
-	pushl %esp
-	cfi_adjust_cfa_offset (4)
-	addl $8, (%esp)		# Account for the pushed PLT data
-	pushl %ebp
-	cfi_adjust_cfa_offset (4)
-	pushl %eax		# Preserve registers otherwise clobbered.
-	cfi_adjust_cfa_offset (4)
-	pushl %ecx
-	cfi_adjust_cfa_offset (4)
-	pushl %edx
-	cfi_adjust_cfa_offset (4)
-	movl %esp, %ecx
-	subl $8, %esp
-	cfi_adjust_cfa_offset (8)
-	movl $-1, 4(%esp)
-	leal 4(%esp), %edx
-	movl %edx, (%esp)
-	pushl %ecx		# Address of the register structure
-	cfi_adjust_cfa_offset (4)
-	movl 40(%esp), %ecx	# Load return address
-	movl 36(%esp), %edx	# Copy args pushed by PLT in register.  Note
-	movl 32(%esp), %eax	# that `fixup' takes its parameters in regs.
-	call _dl_profile_fixup	# Call resolver.
-	cfi_adjust_cfa_offset (-8)
-	movl (%esp), %edx
-	testl %edx, %edx
-	jns 1f
-	movl 4(%esp), %edx	# Get register content back.
-	movl %eax, %ecx		# Store the function address.
-	movl 12(%esp), %eax	# Get register content back.
-	# Adjust stack: PLT1 + PLT2 + %esp + %ebp + %eax + %ecx + %edx
-	# + free.
-	addl $32, %esp
-	cfi_adjust_cfa_offset (-32)
-	jmp *%ecx		# Jump to function address.
-	cfi_endproc
-	.size _dl_runtime_profile_shstk, .-_dl_runtime_profile_shstk
-
 	.globl _dl_runtime_profile
 	.type _dl_runtime_profile, @function
 	cfi_startproc
diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
index 94e9b9aa86..a00c7ee662 100644
--- a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
+++ b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
@@ -17,7 +17,7 @@ 
 
 #include <sys/prctl.h>
 #include <asm/prctl.h>
-#include <cpu-features-offsets.h>
+#include <features-offsets.h>
 
 static __always_inline int
 dl_cet_disable_cet (unsigned int cet_feature)
diff --git a/sysdeps/x86/cpu-features-offsets.sym b/sysdeps/x86/cpu-features-offsets.sym
index 5429f60632..6a8fd29813 100644
--- a/sysdeps/x86/cpu-features-offsets.sym
+++ b/sysdeps/x86/cpu-features-offsets.sym
@@ -2,6 +2,4 @@ 
 
 #include <ldsodefs.h>
 
-RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET offsetof (struct rtld_global_ro, _dl_x86_cpu_features)
 XSAVE_STATE_SIZE_OFFSET	offsetof (struct cpu_features, xsave_state_size)
-RTLD_GLOBAL_DL_X86_FEATURE_1_OFFSET offsetof (struct rtld_global, _dl_x86_feature_1)
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 9ca307f521..46bdaffbc2 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -27,7 +27,7 @@ 
 extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *)
   attribute_hidden;
 
-#ifdef SHARED
+#if defined SHARED && defined __x86_64__
 static void
 TUNABLE_CALLBACK (set_plt_rewrite) (tunable_val_t *valp)
 {
@@ -1125,8 +1125,10 @@  no_cpuid:
 #endif
 
 #ifdef SHARED
+# ifdef __x86_64__
   TUNABLE_GET (plt_rewrite, tunable_val_t *,
 	       TUNABLE_CALLBACK (set_plt_rewrite));
+# endif
 #else
   /* NB: In libc.a, call init_cacheinfo.  */
   init_cacheinfo ();
diff --git a/sysdeps/x86/ldsodefs.h b/sysdeps/x86/ldsodefs.h
index b2a6d71513..50dc81c022 100644
--- a/sysdeps/x86/ldsodefs.h
+++ b/sysdeps/x86/ldsodefs.h
@@ -61,7 +61,6 @@  struct La_x32_retval;
 				     struct La_x86_64_retval *,		\
 				     const char *)
 
-#include <cet-control.h>
 #include_next <ldsodefs.h>
 
 #endif
diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index abb8b354af..10a253e4f1 100644
--- a/sysdeps/x86_64/Makefile
+++ b/sysdeps/x86_64/Makefile
@@ -10,7 +10,7 @@  LDFLAGS-rtld += -Wl,-z,nomark-plt
 endif
 
 ifeq ($(subdir),csu)
-gen-as-const-headers += link-defines.sym
+gen-as-const-headers += features-offsets.sym link-defines.sym
 endif
 
 ifeq ($(subdir),gmon)
diff --git a/sysdeps/x86/dl-procruntime.c b/sysdeps/x86_64/dl-procruntime.c
similarity index 97%
rename from sysdeps/x86/dl-procruntime.c
rename to sysdeps/x86_64/dl-procruntime.c
index 15b3d0d878..7078581778 100644
--- a/sysdeps/x86/dl-procruntime.c
+++ b/sysdeps/x86_64/dl-procruntime.c
@@ -1,4 +1,4 @@ 
-/* Data for processor runtime information.  x86 version.
+/* Data for processor runtime information.  x86-64 version.
    Copyright (C) 2018-2024 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
diff --git a/sysdeps/x86_64/dl-trampoline.S b/sysdeps/x86_64/dl-trampoline.S
index 4c1ba5c9af..b2e7e0f69b 100644
--- a/sysdeps/x86_64/dl-trampoline.S
+++ b/sysdeps/x86_64/dl-trampoline.S
@@ -19,6 +19,7 @@ 
 #include <config.h>
 #include <sysdep.h>
 #include <cpu-features-offsets.h>
+#include <features-offsets.h>
 #include <link-defines.h>
 #include <isa-level.h>
 
diff --git a/sysdeps/x86/cet-control.h b/sysdeps/x86_64/feature-control.h
similarity index 92%
rename from sysdeps/x86/cet-control.h
rename to sysdeps/x86_64/feature-control.h
index f09f193e9b..4c8727e844 100644
--- a/sysdeps/x86/cet-control.h
+++ b/sysdeps/x86_64/feature-control.h
@@ -1,4 +1,4 @@ 
-/* x86 CET tuning.
+/* x86-64 feature tuning.
    This file is part of the GNU C Library.
    Copyright (C) 2018-2024 Free Software Foundation, Inc.
 
@@ -16,8 +16,8 @@ 
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#ifndef _CET_CONTROL_H
-#define _CET_CONTROL_H
+#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
@@ -50,4 +50,4 @@  struct dl_x86_feature_control
   enum dl_plt_rewrite_control plt_rewrite : 2;
 };
 
-#endif /* cet-control.h */
+#endif /* feature-control.h */
diff --git a/sysdeps/x86_64/features-offsets.sym b/sysdeps/x86_64/features-offsets.sym
new file mode 100644
index 0000000000..9e4be3393a
--- /dev/null
+++ b/sysdeps/x86_64/features-offsets.sym
@@ -0,0 +1,6 @@ 
+#define SHARED 1
+
+#include <ldsodefs.h>
+
+RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET offsetof (struct rtld_global_ro, _dl_x86_cpu_features)
+RTLD_GLOBAL_DL_X86_FEATURE_1_OFFSET offsetof (struct rtld_global, _dl_x86_feature_1)
diff --git a/sysdeps/x86_64/ldsodefs.h b/sysdeps/x86_64/ldsodefs.h
new file mode 100644
index 0000000000..0f468ddf5b
--- /dev/null
+++ b/sysdeps/x86_64/ldsodefs.h
@@ -0,0 +1,26 @@ 
+/* Run-time dynamic linker data structures for loaded ELF shared objects.
+   x86-64 version.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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_LDSODEFS_H
+#define	_X86_64_LDSODEFS_H	1
+
+#include <feature-control.h>
+#include_next <ldsodefs.h>
+
+#endif