getcontext implementation for Linux/x86.

diff --git a/sysdeps/unix/sysv/linux/i386/getcontext.S b/sysdeps/unix/sysv/linux/i386/getcontext.S
new file mode 100644 (file)
index 0000000..c4dddba
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/i386/getcontext.S
@@ -0,0 +1,79 @@
+/* Save current context.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+
+ENTRY(__getcontext)
+       /* Load address of the context data structure.  */
+       movl    4(%esp), %eax
+
+       /* Return value of getcontext.  EAX is the only register whose
+          value is not preserved.  */
+       movl    $0, oEAX(%eax)
+
+       /* Save the 32-bit register values and the return address.  */
+       movl    %ecx, oECX(%eax)
+       movl    %edx, oEDX(%eax)
+       movl    %edi, oEDI(%eax)
+       movl    %esi, oESI(%eax)
+       movl    %ebp, oEBP(%eax)
+       movl    (%esp), %ecx
+       movl    %ecx, oEIP(%eax)
+       leal    4(%esp), %ecx           /* Exclude the return address.  */
+       movl    %ecx, oESP(%eax)
+       movl    %ebx, oEBX(%eax)
+
+       /* Save the FS and GS segment register.  */
+       xorl    %edx, %edx
+       xorl    %ecx, %ecx
+       movw    %gs, %dx
+       movw    %fs, %cx
+       movl    %edx, oGS(%eax)
+       movl    %ecx, oFS(%eax)
+
+       /* We have separate floating-point register content memory on the
+          stack.  We use the __fpregs_mem block in the context.  Set the
+          links up correctly.  */
+       leal    oFPREGSMEM(%eax), %ecx
+       movl    %ecx, oFPREGS(%eax)
+       /* Save the floating-point context.  */
+       fnstenv (%ecx)
+
+       /* Save the current signal mask.  */
+       pushl   %ebx
+       leal    oSIGMASK(%eax), %edx
+       xorl    %ecx, %ecx
+       movl    $SIG_BLOCK, %ebx
+       movl    $__NR_sigprocmask, %eax
+       int     $0x80
+       popl    %ebx
+       cmpl    $-4095, %eax            /* Check %eax for error.  */
+       jae     SYSCALL_ERROR_LABEL     /* Jump to error handler if error.  */
+
+       /* All done, return 0 for success.  */
+       xorl    %eax, %eax
+L(pseudo_end):
+       ret
+PSEUDO_END(__getcontext)
+
+weak_alias(__getcontext, getcontext)