/* Install given context. Copyright (C) 2002-2012 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, see <http://www.gnu.org/licenses/>. */ #include <sysdep.h> #include "ucontext_i.h" /* int __setcontext (const ucontext_t *ucp) 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 restore anything other than the PRESERVED state. */ ENTRY(__setcontext) /* Save argument since syscall will destroy it. */ pushq %rdi cfi_adjust_cfa_offset(8) /* Set the signal mask with rt_sigprocmask (SIG_SETMASK, mask, NULL, _NSIG/8). */ leaq oSIGMASK(%rdi), %rsi xorl %edx, %edx movl $SIG_SETMASK, %edi movl $_NSIG8,%r10d movl $__NR_rt_sigprocmask, %eax syscall popq %rdi /* Reload %rdi, adjust stack. */ cfi_adjust_cfa_offset(-8) cmpq $-4095, %rax /* Check %rax for error. */ jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */ /* Restore the floating-point context. Not the registers, only the rest. */ movq oFPREGS(%rdi), %rcx fldenv (%rcx) ldmxcsr oMXCSR(%rdi) /* Load the new stack pointer, the preserved registers and registers used for passing args. */ cfi_def_cfa(%rdi, 0) cfi_offset(%rbx,oRBX) cfi_offset(%rbp,oRBP) cfi_offset(%r12,oR12) cfi_offset(%r13,oR13) cfi_offset(%r14,oR14) cfi_offset(%r15,oR15) cfi_offset(%rsp,oRSP) cfi_offset(%rip,oRIP) movq oRSP(%rdi), %rsp movq oRBX(%rdi), %rbx movq oRBP(%rdi), %rbp movq oR12(%rdi), %r12 movq oR13(%rdi), %r13 movq oR14(%rdi), %r14 movq oR15(%rdi), %r15 /* The following ret should return to the address set with getcontext. Therefore push the address on the stack. */ movq oRIP(%rdi), %rcx pushq %rcx movq oRSI(%rdi), %rsi movq oRDX(%rdi), %rdx movq oRCX(%rdi), %rcx movq oR8(%rdi), %r8 movq oR9(%rdi), %r9 /* Setup finally %rdi. */ movq oRDI(%rdi), %rdi /* End FDE here, we fall into another context. */ cfi_endproc cfi_startproc /* Clear rax to indicate success. */ xorl %eax, %eax L(pseudo_end): ret PSEUDO_END(__setcontext) weak_alias (__setcontext, setcontext)