[v3,1/2] 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>
---
 sysdeps/x86_64/dl-machine.h     | 27 +++++++-----
 sysdeps/x86_64/x32/dl-machine.h | 76 ---------------------------------
 2 files changed, 16 insertions(+), 87 deletions(-)
 delete mode 100644 sysdeps/x86_64/x32/dl-machine.h

On Tue, Jul 23, 2024 at 8:47 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> 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>
> ---
>  sysdeps/x86_64/dl-machine.h     | 27 +++++++-----
>  sysdeps/x86_64/x32/dl-machine.h | 76 ---------------------------------
>  2 files changed, 16 insertions(+), 87 deletions(-)
>  delete mode 100644 sysdeps/x86_64/x32/dl-machine.h
>
> diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h
> index a6de3793e4..4f12955875 100644
> --- a/sysdeps/x86_64/dl-machine.h
> +++ b/sysdeps/x86_64/dl-machine.h
> @@ -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 */
>
> diff --git a/sysdeps/x86_64/x32/dl-machine.h b/sysdeps/x86_64/x32/dl-machine.h
> deleted file mode 100644
> index c35cee9261..0000000000
> --- a/sysdeps/x86_64/x32/dl-machine.h
> +++ /dev/null
> @@ -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 */
> --
> 2.45.2
>

LGTM
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>