diff options
Diffstat (limited to 'REORG.TODO/sysdeps/unix/sysv/linux/i386/swapcontext.S')
| -rw-r--r-- | REORG.TODO/sysdeps/unix/sysv/linux/i386/swapcontext.S | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/i386/swapcontext.S b/REORG.TODO/sysdeps/unix/sysv/linux/i386/swapcontext.S new file mode 100644 index 0000000000..cfdb1f0ad1 --- /dev/null +++ b/REORG.TODO/sysdeps/unix/sysv/linux/i386/swapcontext.S @@ -0,0 +1,109 @@ +/* Save current context and install the given one. + Copyright (C) 2001-2017 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) + + /* 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. */ + ret +PSEUDO_END(__swapcontext) + +weak_alias (__swapcontext, swapcontext) |