| /* Save current context and install the given one. |
| Copyright (C) 2002, 2005 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Andreas Jaeger <aj@suse.de>, 2002. |
| |
| 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" |
| |
| |
| /* int __swapcontext (ucontext_t *oucp, const ucontext_t *ucp); |
| |
| Saves the machine context in oucp such that when it is activated, |
| it appears as if __swapcontextt() returned again, restores the |
| machine context in ucp and thereby resumes execution in that |
| context. |
| |
| This implementation is intended to be used for *synchronous* context |
| switches only. Therefore, it does not have to save anything |
| other than the PRESERVED state. */ |
| |
| ENTRY(__swapcontext) |
| /* Save the preserved registers, the registers used for passing args, |
| and the return address. */ |
| movq %rbx, oRBX(%rdi) |
| movq %rbp, oRBP(%rdi) |
| movq %r12, oR12(%rdi) |
| movq %r13, oR13(%rdi) |
| movq %r14, oR14(%rdi) |
| movq %r15, oR15(%rdi) |
| |
| movq %rdi, oRDI(%rdi) |
| movq %rsi, oRSI(%rdi) |
| movq %rdx, oRDX(%rdi) |
| movq %rcx, oRCX(%rdi) |
| movq %r8, oR8(%rdi) |
| movq %r9, oR9(%rdi) |
| |
| movq (%rsp), %rcx |
| movq %rcx, oRIP(%rdi) |
| leaq 8(%rsp), %rcx /* Exclude the return address. */ |
| movq %rcx, oRSP(%rdi) |
| |
| /* 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. */ |
| leaq oFPREGSMEM(%rdi), %rcx |
| movq %rcx, oFPREGS(%rdi) |
| /* Save the floating-point environment. */ |
| fnstenv (%rcx) |
| stmxcsr oMXCSR(%rdi) |
| |
| |
| /* The syscall destroys some registers, save them. */ |
| movq %rsi, %r12 |
| |
| /* Save the current signal mask and install the new one with |
| rt_sigprocmask (SIG_BLOCK, newset, oldset,_NSIG/8). */ |
| leaq oSIGMASK(%rdi), %rdx |
| leaq oSIGMASK(%rsi), %rsi |
| movl $SIG_SETMASK, %edi |
| movl $_NSIG8,%r10d |
| movl $__NR_rt_sigprocmask, %eax |
| syscall |
| cmpq $-4095, %rax /* Check %rax for error. */ |
| jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */ |
| |
| /* Restore destroyed registers. */ |
| movq %r12, %rsi |
| |
| /* Restore the floating-point context. Not the registers, only the |
| rest. */ |
| movq oFPREGS(%rsi), %rcx |
| fldenv (%rcx) |
| ldmxcsr oMXCSR(%rsi) |
| |
| /* Load the new stack pointer and the preserved registers. */ |
| movq oRSP(%rsi), %rsp |
| movq oRBX(%rsi), %rbx |
| movq oRBP(%rsi), %rbp |
| movq oR12(%rsi), %r12 |
| movq oR13(%rsi), %r13 |
| movq oR14(%rsi), %r14 |
| movq oR15(%rsi), %r15 |
| |
| /* The following ret should return to the address set with |
| getcontext. Therefore push the address on the stack. */ |
| movq oRIP(%rsi), %rcx |
| pushq %rcx |
| |
| /* Setup registers used for passing args. */ |
| movq oRDI(%rsi), %rdi |
| movq oRDX(%rsi), %rdx |
| movq oRCX(%rsi), %rcx |
| movq oR8(%rsi), %r8 |
| movq oR9(%rsi), %r9 |
| |
| /* Setup finally %rsi. */ |
| movq oRSI(%rsi), %rsi |
| |
| /* Clear rax to indicate success. */ |
| xorl %eax, %eax |
| |
| L(pseudo_end): |
| ret |
| PSEUDO_END(__swapcontext) |
| |
| weak_alias (__swapcontext, swapcontext) |
