[glibc] hurd: Generalize init-first.c to support x86_64

[Samuel Thibault <sthibaul@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=91689649656314b04f3dbee0415a9254eb1424dd

commit 91689649656314b04f3dbee0415a9254eb1424dd
Author: Sergey Bugaev <bugaevc@gmail.com>
Date:   Thu Feb 23 18:14:36 2023 +0300

    hurd: Generalize init-first.c to support x86_64
    
    Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
    Message-Id: <20230223151436.49180-2-bugaevc@gmail.com>

Diff:
---
 sysdeps/mach/hurd/{i386 => x86}/init-first.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sysdeps/mach/hurd/i386/init-first.c b/sysdeps/mach/hurd/x86/init-first.c
similarity index 97%
rename from sysdeps/mach/hurd/i386/init-first.c
rename to sysdeps/mach/hurd/x86/init-first.c
index 05424563bf..2fccaefdd2 100644
--- a/sysdeps/mach/hurd/i386/init-first.c
+++ b/sysdeps/mach/hurd/x86/init-first.c
@@ -225,9 +225,15 @@ _hurd_stack_setup (void)
   void doinit (intptr_t *data)
     {
       init ((void **) data);
+# ifdef __x86_64__
+      asm volatile ("movq %0, %%rsp\n" /* Switch to new outermost stack.  */
+                    "xorq %%rbp, %%rbp\n" /* Clear outermost frame pointer.  */
+                    "jmp *%1" : : "r" (data), "r" (caller));
+# else
       asm volatile ("movl %0, %%esp\n" /* Switch to new outermost stack.  */
 		    "xorl %%ebp, %%ebp\n" /* Clear outermost frame pointer.  */
 		    "jmp *%1" : : "r" (data), "r" (caller));
+# endif
       __builtin_unreachable ();
     }