1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. 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. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)signalvar.h 8.6 (Berkeley) 2/19/95 30 * $FreeBSD: src/sys/sys/signalvar.h,v 1.34.2.1 2000/05/16 06:58:05 dillon Exp $ 31 * $DragonFly: src/sys/sys/signal2.h,v 1.3 2008/10/14 21:25:14 swildner Exp $ 32 */ 33 34 #ifndef _SYS_SIGNAL2_H 35 #define _SYS_SIGNAL2_H 36 37 #include <sys/proc.h> 38 39 /* 40 * Inline functions: 41 */ 42 /* 43 * Determine which signals are pending for a lwp. 44 * 45 * (Does not need to be interlocked with lwp_spin. If caller holds a 46 * critical section races will be resolved through an AST). 47 */ 48 static __inline sigset_t 49 lwp_sigpend(struct lwp *lp) 50 { 51 sigset_t set; 52 53 set = lp->lwp_proc->p_siglist; 54 SIGSETOR(set, lp->lwp_siglist); 55 56 return (set); 57 } 58 59 /* 60 * Mark a signal as handled by the lwp. 61 * 62 * (p->p_token must be held, lp->lwp_spin must be held) 63 */ 64 static __inline void 65 lwp_delsig(struct lwp *lp, int sig, int fromproc) 66 { 67 SIGDELSET(lp->lwp_siglist, sig); 68 if (fromproc) 69 SIGDELSET_ATOMIC(lp->lwp_proc->p_siglist, sig); 70 } 71 72 #define CURSIG(lp) __cursig(lp, 1, 0, NULL) 73 #define CURSIG_TRACE(lp) __cursig(lp, 1, 1, NULL) 74 #define CURSIG_LCK_TRACE(lp, ptok) __cursig(lp, 1, 1, ptok) 75 #define CURSIG_NOBLOCK(lp) __cursig(lp, 0, 0, NULL) 76 77 /* 78 * This inline checks lpmap->blockallsigs, a user r/w accessible 79 * memory-mapped variable that allows a user thread to instantly 80 * mask and unmask all maskable signals without having to issue a 81 * system call. 82 * 83 * On the unmask count reaching 0, userland can check and clear 84 * bit 31 to determine if any signals arrived, then issue a dummy 85 * system call to ensure delivery. 86 */ 87 static __inline 88 void 89 __sig_condblockallsigs(sigset_t *mask, struct lwp *lp) 90 { 91 struct sys_lpmap *lpmap; 92 uint32_t bas; 93 sigset_t tmp; 94 int trapsig; 95 96 if ((lpmap = lp->lwp_lpmap) == NULL) 97 return; 98 99 bas = lpmap->blockallsigs; 100 while (bas & 0x7FFFFFFFU) { 101 tmp = *mask; /* check maskable signals */ 102 SIG_CANTMASK(tmp); 103 if (SIGISEMPTY(tmp)) /* no unmaskable signals */ 104 return; 105 106 /* 107 * Upon successful update to lpmap->blockallsigs remove 108 * all maskable signals, leaving only unmaskable signals. 109 * 110 * If lwp_sig is non-zero it represents a syncronous 'trap' 111 * signal which, being a synchronous trap, must be allowed. 112 */ 113 if (atomic_fcmpset_int(&lpmap->blockallsigs, &bas, 114 bas | 0x80000000U)) { 115 trapsig = lp->lwp_sig; 116 if (trapsig && SIGISMEMBER(*mask, trapsig)) { 117 SIGSETAND(*mask, sigcantmask_mask); 118 SIGADDSET(*mask, trapsig); 119 } else { 120 SIGSETAND(*mask, sigcantmask_mask); 121 } 122 break; 123 } 124 } 125 } 126 127 /* 128 * Determine signal that should be delivered to process p, the current 129 * process, 0 if none. If there is a pending stop signal with default 130 * action, the process stops in issignal(). 131 * 132 * This function does not interlock pending signals. If the caller needs 133 * to interlock the caller must acquire the per-proc token. 134 * 135 * If ptok is non-NULL this function may return with proc->p_token held, 136 * indicating that the signal came from the process structure. This is 137 * used by postsig to avoid holding p_token when possible. Only applicable 138 * if mayblock is non-zero. 139 */ 140 static __inline 141 int 142 __cursig(struct lwp *lp, int mayblock, int maytrace, int *ptok) 143 { 144 struct proc *p = lp->lwp_proc; 145 sigset_t tmpset; 146 int r; 147 148 tmpset = lwp_sigpend(lp); 149 SIGSETNAND(tmpset, lp->lwp_sigmask); 150 SIG_CONDBLOCKALLSIGS(tmpset, lp); 151 152 /* Nothing interesting happening? */ 153 if (SIGISEMPTY(tmpset)) { 154 /* 155 * Quit here, unless 156 * a) we may block and 157 * b) somebody is tracing us. 158 */ 159 if (mayblock == 0 || (p->p_flags & P_TRACED) == 0) 160 return (0); 161 } 162 163 if (mayblock) 164 r = issignal(lp, maytrace, ptok); 165 else 166 r = TRUE; /* simply state the fact */ 167 168 return(r); 169 } 170 171 #endif 172