x86-64: Remove sysdeps/x86_64/x32/dl-machine.h

Remove sysdeps/x86_64/x32/dl-machine.h by folding x32 ARCH_LA_PLTENTER,
ARCH_LA_PLTEXIT and RTLD_START into sysdeps/x86_64/dl-machine.h.  There
are no regressions on x86-64 nor x32.  There are no changes in x86-64
_dl_start_user.  On x32, _dl_start_user changes are

 <_dl_start_user>:
 	mov    %eax,%r12d
+	mov    %esp,%r13d
 	mov    (%rsp),%edx
 	mov    %edx,%esi
-	mov    %esp,%r13d
 	and    $0xfffffff0,%esp
 	mov    0x0(%rip),%edi        # <_dl_start_user+0x14>
 	lea    0x8(%r13,%rdx,4),%ecx

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit is contained in:
H.J. Lu 2024-07-22 17:47:21 -07:00
parent 431c1be28e
commit 652c6cf269
2 changed files with 16 additions and 87 deletions

View File

@ -139,37 +139,37 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
.globl _start\n\
.globl _dl_start_user\n\
_start:\n\
movq %rsp, %rdi\n\
mov %" RSP_LP ", %" RDI_LP "\n\
call _dl_start\n\
_dl_start_user:\n\
# Save the user entry point address in %r12.\n\
movq %rax, %r12\n\
mov %" RAX_LP ", %" R12_LP "\n\
# Save %rsp value in %r13.\n\
movq %rsp, %r13\n\
mov %" RSP_LP ", % " R13_LP "\n\
"\
RTLD_START_ENABLE_X86_FEATURES \
"\
# Read the original argument count.\n\
movq (%rsp), %rdx\n\
mov (%rsp), %" RDX_LP "\n\
# Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\
# argc -> rsi\n\
movq %rdx, %rsi\n\
mov %" RDX_LP ", %" RSI_LP "\n\
# And align stack for the _dl_init call. \n\
andq $-16, %rsp\n\
and $-16, %" RSP_LP "\n\
# _dl_loaded -> rdi\n\
movq _rtld_local(%rip), %rdi\n\
mov _rtld_local(%rip), %" RDI_LP "\n\
# env -> rcx\n\
leaq 16(%r13,%rdx,8), %rcx\n\
lea 2*" LP_SIZE "(%r13,%rdx," LP_SIZE "), %" RCX_LP "\n\
# argv -> rdx\n\
leaq 8(%r13), %rdx\n\
lea " LP_SIZE "(%r13), %" RDX_LP "\n\
# Clear %rbp to mark outermost frame obviously even for constructors.\n\
xorl %ebp, %ebp\n\
# Call the function to run the initializers.\n\
call _dl_init\n\
# Pass our finalizer function to the user in %rdx, as per ELF ABI.\n\
leaq _dl_fini(%rip), %rdx\n\
lea _dl_fini(%rip), %" RDX_LP "\n\
# And make sure %rsp points to argc stored on the stack.\n\
movq %r13, %rsp\n\
mov %" R13_LP ", %" RSP_LP "\n\
# Jump to the user's entry point.\n\
jmp *%r12\n\
.previous\n\
@ -234,8 +234,13 @@ elf_machine_plt_value (struct link_map *map, const ElfW(Rela) *reloc,
/* Names of the architecture-specific auditing callback functions. */
#ifdef __LP64__
#define ARCH_LA_PLTENTER x86_64_gnu_pltenter
#define ARCH_LA_PLTEXIT x86_64_gnu_pltexit
#else
#define ARCH_LA_PLTENTER x32_gnu_pltenter
#define ARCH_LA_PLTEXIT x32_gnu_pltexit
#endif
#endif /* !dl_machine_h */

View File

@ -1,76 +0,0 @@
/* Machine-dependent ELF dynamic relocation inline functions. x32 version.
Copyright (C) 2012-2024 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/>. */
/* Must allow <sysdeps/x86_64/dl-machine.h> to be included more than once.
See #ifdef RESOLVE_MAP in sysdeps/x86_64/dl-machine.h. */
#include <sysdeps/x86_64/dl-machine.h>
#ifndef _X32_DL_MACHINE_H
#define _X32_DL_MACHINE_H
#undef ARCH_LA_PLTENTER
#undef ARCH_LA_PLTEXIT
#undef RTLD_START
/* Names of the architecture-specific auditing callback functions. */
#define ARCH_LA_PLTENTER x32_gnu_pltenter
#define ARCH_LA_PLTEXIT x32_gnu_pltexit
/* Initial entry point code for the dynamic linker.
The C function `_dl_start' is the real entry point;
its return value is the user program's entry point. */
#define RTLD_START asm ("\n\
.text\n\
.p2align 4\n\
.globl _start\n\
.globl _dl_start_user\n\
_start:\n\
movl %esp, %edi\n\
call _dl_start\n\
_dl_start_user:\n\
# Save the user entry point address in %r12.\n\
movl %eax, %r12d\n\
# Read the original argument count.\n\
movl (%rsp), %edx\n\
# Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\
# argc -> rsi\n\
movl %edx, %esi\n\
# Save %rsp value in %r13.\n\
movl %esp, %r13d\n\
# And align stack for the _dl_init call.\n\
and $-16, %esp\n\
# _dl_loaded -> rdi\n\
movl _rtld_local(%rip), %edi\n\
# env -> rcx\n\
lea 8(%r13,%rdx,4), %ecx\n\
# argv -> rdx\n\
lea 4(%r13), %edx\n\
# Clear %rbp to mark outermost frame obviously even for constructors.\n\
xorl %ebp, %ebp\n\
# Call the function to run the initializers.\n\
call _dl_init\n\
# Pass our finalizer function to the user in %rdx, as per ELF ABI.\n\
lea _dl_fini(%rip), %edx\n\
# And make sure %rsp points to argc stored on the stack.\n\
movl %r13d, %esp\n\
# Jump to the user's entry point.\n\
jmp *%r12\n\
.previous\n\
");
#endif /* !_X32_DL_MACHINE_H */