1 /* 2 * Copyright (c) 2019 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 #include "namespace.h" 36 #include <sys/cdefs.h> 37 #include <sys/types.h> 38 #include <sys/syscall.h> 39 #include <sys/time.h> 40 #include <machine/cpufunc.h> 41 #include <machine/atomic.h> 42 #include <errno.h> 43 #include <time.h> 44 #include <stdio.h> 45 #include <unistd.h> 46 #include "un-namespace.h" 47 #include "libc_private.h" 48 #include "upmap.h" 49 50 int _sigblockall(void); 51 int _sigunblockall(void); 52 int __getpid(void); 53 pid_t __sys_getpid(void); 54 55 /* 56 * Block all maskable signals to this thread. Does not prevent signal 57 * delivery to the thread's pending signal mask, but does prevent signal 58 * dispatch. 59 * 60 * Reentrant, returns the reentrancy count. First call will thus return 61 * 1. -1 is returned if the feature is not supported. 62 * 63 * The pointer is set-up on program startup and will remain valid on fork() 64 * (the kernel will re-fault the proper page). On vfork(), however, the 65 * pointer points to the parent thread's mapping. 66 */ 67 int 68 _sigblockall(void) 69 { 70 if (__lpmap_blockallsigs) 71 return atomic_fetchadd_int(__lpmap_blockallsigs, 1) + 1; 72 return -1; 73 } 74 75 /* 76 * Reverse the effects of sigblockall(). Returns the reentrancy count 77 * after decrement. -1 is returned if not supported. 78 * 79 * Bit 31 is set on return if signals were received while blocked. Upon 80 * last unblock this bit also indicates that pending service routines ran. 81 * The bit is cumulative until the last unblock occurs. 82 */ 83 int 84 _sigunblockall(void) 85 { 86 uint32_t bas; 87 88 if (__lpmap_blockallsigs) { 89 bas = atomic_fetchadd_int(__lpmap_blockallsigs, -1) - 1; 90 if (bas == 0x80000000U) { 91 (void)__sys_getpid(); /* force signal processing */ 92 atomic_clear_int(__lpmap_blockallsigs, 0x80000000U); 93 } 94 return (int)bas; 95 } 96 return -1; 97 } 98 99 __weak_reference(_sigblockall, sigblockall); 100 __weak_reference(_sigunblockall, sigunblockall); 101