| /* 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, 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(__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) |
| |
| /* 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) |
| |
| /* 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 |
| popl %ebx |
| cmpl $-4095, %eax /* Check %eax for error. */ |
| jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */ |
| |
| /* 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) |
