diff options
Diffstat (limited to 'sysdeps/mach/hurd/i386/swapcontext.S')
-rw-r--r-- | sysdeps/mach/hurd/i386/swapcontext.S | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/i386/swapcontext.S b/sysdeps/mach/hurd/i386/swapcontext.S new file mode 100644 index 0000000000..3479a299fb --- /dev/null +++ b/sysdeps/mach/hurd/i386/swapcontext.S @@ -0,0 +1,120 @@ +/* Save current context and install the given one. + Copyright (C) 2001, 2002, 2003 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 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 + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#include "ucontext_i.h" + + +ENTRY(__swapcontext) + /* Load address of the context data structure we save in. */ + movl 4(%esp), %eax + + /* Return value of swapcontext. 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 + movl %ecx, oESP(%eax) + movl %ebx, oEBX(%eax) + + /* Save the FS segment register. */ + xorl %edx, %edx + movw %fs, %dx + movl %edx, oFS(%eax) + + leal oFPREGS(%eax), %ecx + /* Save the floating-point context. */ + fnstenv (%ecx) + + /* Load address of the context data structure we have to load. */ + movl 8(%esp), %ecx + + /* Save the current signal mask and install the new one. */ +// pushl %ebx +// leal oSIGMASK(%eax), %edx +// leal oSIGMASK(%ecx), %ecx +// movl $SIG_SETMASK, %ebx +// movl $__NR_sigprocmask, %eax +// ENTER_KERNEL + subl $16, %esp + cfi_adjust_cfa_offset (16) + leal oSIGMASK(%eax), %eax + movl %eax, 8(%esp) + leal oSIGMASK(%ecx), %eax + movl %eax, 4(%esp) + movl $SIG_SETMASK, (%esp) + call sigprocmask +// popl %ebx + addl $16, %esp + cfi_adjust_cfa_offset (-16) + +// cmpl $-4095, %eax /* Check %eax for error. */ +// jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */ + testl %eax, %eax + jne L(pseudo_end) + + /* EAX was modified, reload it. */ + movl 8(%esp), %eax + + /* Restore the floating-point context. Not the registers, only the + rest. */ + movl oFPREGS(%eax), %ecx + fldenv (%ecx) + + /* Restore the FS segment register. We don't touch the GS register + since it is used for threads. */ + movl oFS(%eax), %edx + movw %dx, %fs + + /* Fetch the address to return to. */ + movl oEIP(%eax), %ecx + + /* Load the new stack pointer. */ + movl oESP(%eax), %esp + + /* Push the return address on the new stack so we can return there. */ + pushl %ecx + + /* Load the values of all the 32-bit registers (except ESP). + Since we are loading from EAX, it must be last. */ + movl oEDI(%eax), %edi + movl oESI(%eax), %esi + movl oEBP(%eax), %ebp + movl oEBX(%eax), %ebx + movl oEDX(%eax), %edx + movl oECX(%eax), %ecx + movl oEAX(%eax), %eax + + /* The following 'ret' will pop the address of the code and jump + to it. */ + +L(pseudo_end): + ret +PSEUDO_END(__swapcontext) + +weak_alias (__swapcontext, swapcontext) |