| /* Copyright (C) 2002-2018 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> |
| |
| /* This is the helper code which gets called if a function which is |
| registered with 'makecontext' returns. In this case we have to |
| install the context listed in the uc_link element of the context |
| 'makecontext' manipulated at the time of the 'makecontext' call. |
| If the pointer is NULL the process must terminate. */ |
| |
| |
| ENTRY(__start_context) |
| /* This removes the parameters passed to the function given to |
| 'makecontext' from the stack. RBX contains the address |
| on the stack pointer for the next context. */ |
| movq %rbx, %rsp |
| |
| /* Don't use pop here so that stack is aligned to 16 bytes. */ |
| movq (%rsp), %rdi /* This is the next context. */ |
| testq %rdi, %rdi |
| je 2f /* If it is zero exit. */ |
| |
| call __setcontext |
| /* If this returns (which can happen if the syscall fails) we'll |
| exit the program with the return error value (-1). */ |
| movq %rax,%rdi |
| |
| 2: |
| call HIDDEN_JUMPTARGET(exit) |
| /* The 'exit' call should never return. In case it does cause |
| the process to terminate. */ |
| hlt |
| END(__start_context) |