2 * Copyright (c) 2006 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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.
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,
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31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * $DragonFly: src/lib/libc/i386/sys/getcontext.S,v 1.2 2007/02/04 20:28:21 corecode Exp $
37 #include <machine/asm.h>
38 #include <asmcontext.h>
41 * This function is special-cased because the context it saves
42 * includes a stale stack context (because it returns before the
43 * caller presumably makes the call to setcontext()).
46 .set getcontext,_getcontext
49 * Retrieve the current signal mask and save it in &ucp->uc_sigmask.
51 movl 4(%esp),%eax /* ucontext_t pointer */
52 addl $UC_SIGMASK,%eax /* pointer to signal mask */
57 call PIC_PLT(_sigprocmask) /* retrieve & save signal mask */
62 * Save what we need because our stack context is going stale.
65 movl %eax,%ecx /* save ucontext_t in %ecx */
66 movl (%esp),%edx /* save return PC in %edx */
67 addl $UC_MCONTEXT,%eax
69 call get_mcontext /* returns non-zero on resume */
74 * On resume, resave the stale return pc and restore the signal
75 * mask (signals are blocked right now from the setcontext call).
77 movl %edx,(%esp) /* re-save the return PC */
83 call PIC_PLT(_sigprocmask) /* retrieve & save signal mask */
87 movl $0,%eax /* return success */
92 jmp PIC_PLT(HIDENAME(cerror))