tuxillo's projects / dragonfly.git / blame
| Commit | Line | Data |
|---|---|---|
| e2742650 MD |
1 | /* |
| 2 | * Copyright (c) 2007 Matthew T. Emmerton <matt@gsicomp.on.ca> | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * Redistribution and use in source and binary forms, with or without | |
| 6 | * modification, are permitted provided that the following conditions | |
| 7 | * are met: | |
| 8 | * 1. Redistributions of source code must retain the above copyright | |
| 9 | * notice, this list of conditions and the following disclaimer. | |
| 10 | * 2. Neither the name of the author nor the names of its contributors | |
| 11 | * may be used to endorse or promote products derived from this software | |
| 12 | * without specific prior written permission. | |
| 13 | * | |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |
| 15 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
| 18 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 19 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 20 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 24 | * SUCH DAMAGE. | |
| e2742650 MD |
25 | */ |
| 26 | ||
| e2b7bcae | 27 | #include "namespace.h" |
| e2742650 MD |
28 | #include <sys/param.h> |
| 29 | #include <sys/signal.h> | |
| 30 | #include <sys/ucontext.h> | |
| 31 | ||
| 32 | #include <errno.h> | |
| 33 | #include <stdarg.h> | |
| 34 | #include <stdlib.h> | |
| 35 | #include <unistd.h> | |
| 36 | #include <signal.h> | |
| e2b7bcae | 37 | #include "un-namespace.h" |
| e2742650 MD |
38 | |
| 39 | /* Prototypes */ | |
| 40 | __weak_reference(_swapcontext, swapcontext); | |
| 41 | __weak_reference(_setcontext, setcontext); | |
| 42 | ||
| e2742650 MD |
43 | /* |
| 44 | * We need to block most signals during a context switch so we do not | |
| 45 | * dispatch a signal vector during a context switch. | |
| 46 | */ | |
| 63261abb | 47 | #if 0 |
| e2742650 MD |
48 | static sigset_t sigset_block_all; |
| 49 | ||
| 50 | static void __sigset_block_all_setup(void) __attribute__ ((constructor)); | |
| 51 | ||
| 52 | static void | |
| 53 | __sigset_block_all_setup(void) | |
| 54 | { | |
| 55 | sigfillset(&sigset_block_all); | |
| 56 | sigdelset(&sigset_block_all, SIGSEGV); | |
| 57 | sigdelset(&sigset_block_all, SIGBUS); | |
| 58 | sigdelset(&sigset_block_all, SIGILL); | |
| 59 | } | |
| 63261abb | 60 | #endif |
| e2742650 MD |
61 | |
| 62 | /* | |
| 63 | * Save the calling context in (oucp) then switch to (ucp). | |
| e2742650 MD |
64 | */ |
| 65 | int | |
| 66 | _swapcontext(ucontext_t *oucp, const ucontext_t *ucp) | |
| 67 | { | |
| 68 | int ret; | |
| 69 | ||
| 63261abb MD |
70 | if (getcontext(oucp) == 0) { |
| 71 | ret = sigreturn(__DECONST(ucontext_t *, ucp)); | |
| 72 | } else { | |
| 73 | ret = 0; | |
| e2742650 MD |
74 | } |
| 75 | return(ret); | |
| 76 | } | |
| 77 | ||
| 78 | /* | |
| 63261abb MD |
79 | * Switch to the target context, use sigreturn() to properly restore |
| 80 | * everything, including rflags and to avoid scribbling over the | |
| 81 | * target stack's red-zone. | |
| e2742650 | 82 | * |
| 63261abb MD |
83 | * Note that setcontext() can be called with a ucontext from a signal, |
| 84 | * so the signal state must be restored and there is really no way to | |
| 85 | * avoid making a system call :-( | |
| e2742650 MD |
86 | */ |
| 87 | int | |
| 88 | _setcontext(ucontext_t *ucp) | |
| 89 | { | |
| 90 | int ret; | |
| 91 | ||
| 63261abb | 92 | ret = sigreturn(ucp); |
| 819d0c16 | 93 | |
| e2742650 MD |
94 | return(ret); |
| 95 | } |