1/* 2 * Copyright (c) 2006 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 */ 35 36#include <machine/asm.h> 37#include <asmcontext.h> 38 39 /* 40 * This function is special-cased because the context it saves 41 * includes a stale stack context (because it returns before the 42 * caller presumably makes the call to setcontext()). 43 */ 44 .weak getcontext 45 .set getcontext,_getcontext 46ENTRY(_getcontext) 47 /* 48 * Retrieve the current signal mask and save it in &ucp->uc_sigmask. 49 */ 50 pushq %rdi /* save ucontext_t pointer passed */ 51 movq %rdi,%rdx 52 addq $UC_SIGMASK,%rdx /* pointer to signal mask */ 53 movq $0,%rsi 54 movq $SIG_BLOCK,%rdi 55 call PIC_PLT(CNAME(_sigprocmask)) 56 /* 57 * Save what we need because our stack context is going stale. 58 */ 59 popq %rdi 60 movq %rdi,%r9 61 movq (%rsp),%r8 /* save return PC in %r9 */ 62 addq $UC_MCONTEXT,%rdi 63 call PIC_PLT(CNAME(get_mcontext)) /* returns non-zero on resume */ 64 cmpl $0,%eax /* return type is int */ 65 je 2f 66 /* 67 * On resume, resave the stale return pc and restore the signal 68 * mask (signals are blocked right now from the setcontext call). 69 */ 70 movq %r8,(%rsp) /* re-save the return PC */ 71 movq %r9,%rsi 72 addq $UC_SIGMASK,%rsi 73 movq $0,%rdx 74 movq $SIG_SETMASK,%rdi 75 call PIC_PLT(CNAME(_sigprocmask)) /* retrieve & save signal mask */ 762: 77 movl $0,%eax /* return success */ 78 ret 791: 80 pushq %rsi 81#ifdef PIC 82 movq PIC_GOT(HIDENAME(cerror)),%rdx 83 jmp *%rdx 84#else 85 jmp HIDENAME(cerror) 86#endif 87END(_getcontext) 88