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 */ 32 33 #ifndef _SYS_SIGNAL2_H_ 34 #define _SYS_SIGNAL2_H_ 35 36 #include <sys/param.h> 37 #include <sys/proc.h> 38 #include <sys/signalvar.h> 39 40 /* 41 * Inline functions: 42 */ 43 /* 44 * Determine which signals are pending for a lwp. 45 * 46 * (Does not need to be interlocked with lwp_spin. If caller holds a 47 * critical section races will be resolved through an AST). 48 */ 49 static __inline sigset_t 50 lwp_sigpend(struct lwp *lp) 51 { 52 sigset_t set; 53 54 set = lp->lwp_proc->p_siglist; 55 SIGSETOR(set, lp->lwp_siglist); 56 57 return (set); 58 } 59 60 /* 61 * Mark a signal as handled by the lwp. 62 * 63 * (p->p_token must be held, lp->lwp_spin must be held) 64 */ 65 static __inline void 66 lwp_delsig(struct lwp *lp, int sig, int fromproc) 67 { 68 SIGDELSET(lp->lwp_siglist, sig); 69 if (fromproc) 70 SIGDELSET_ATOMIC(lp->lwp_proc->p_siglist, sig); 71 } 72 73 #define CURSIG(lp) __cursig(lp, 1, 0, NULL) 74 #define CURSIG_TRACE(lp) __cursig(lp, 1, 1, NULL) 75 #define CURSIG_LCK_TRACE(lp, ptok) __cursig(lp, 1, 1, ptok) 76 #define CURSIG_NOBLOCK(lp) __cursig(lp, 0, 0, NULL) 77 78 /* 79 * This inline checks lpmap->blockallsigs, a user r/w accessible 80 * memory-mapped variable that allows a user thread to instantly 81 * mask and unmask all maskable signals without having to issue a 82 * system call. 83 * 84 * On the unmask count reaching 0, userland can check and clear 85 * bit 31 to determine if any signals arrived, then issue a dummy 86 * system call to ensure delivery. 87 */ 88 static __inline 89 void 90 __sig_condblockallsigs(sigset_t *mask, struct lwp *lp) 91 { 92 struct sys_lpmap *lpmap; 93 uint32_t bas; 94 sigset_t tmp; 95 int trapsig; 96 97 if ((lpmap = lp->lwp_lpmap) == NULL) 98 return; 99 100 bas = lpmap->blockallsigs; 101 while (bas & 0x7FFFFFFFU) { 102 tmp = *mask; /* check maskable signals */ 103 SIG_CANTMASK(tmp); 104 if (SIGISEMPTY(tmp)) /* no unmaskable signals */ 105 return; 106 107 /* 108 * Upon successful update to lpmap->blockallsigs remove 109 * all maskable signals, leaving only unmaskable signals. 110 * 111 * If lwp_sig is non-zero it represents a syncronous 'trap' 112 * signal which, being a synchronous trap, must be allowed. 113 */ 114 if (atomic_fcmpset_int(&lpmap->blockallsigs, &bas, 115 bas | 0x80000000U)) { 116 trapsig = lp->lwp_sig; 117 if (trapsig && SIGISMEMBER(*mask, trapsig)) { 118 SIGSETAND(*mask, sigcantmask_mask); 119 SIGADDSET(*mask, trapsig); 120 } else { 121 SIGSETAND(*mask, sigcantmask_mask); 122 } 123 break; 124 } 125 } 126 } 127 128 /* 129 * Determine signal that should be delivered to process p, the current 130 * process, 0 if none. If there is a pending stop signal with default 131 * action, the process stops in issignal(). 132 * 133 * This function does not interlock pending signals. If the caller needs 134 * to interlock the caller must acquire the per-proc token. 135 * 136 * If ptok is non-NULL this function may return with proc->p_token held, 137 * indicating that the signal came from the process structure. This is 138 * used by postsig to avoid holding p_token when possible. Only applicable 139 * if mayblock is non-zero. 140 */ 141 static __inline 142 int 143 __cursig(struct lwp *lp, int mayblock, int maytrace, int *ptok) 144 { 145 struct proc *p = lp->lwp_proc; 146 sigset_t tmpset; 147 int r; 148 149 tmpset = lwp_sigpend(lp); 150 SIGSETNAND(tmpset, lp->lwp_sigmask); 151 SIG_CONDBLOCKALLSIGS(tmpset, lp); 152 153 /* Nothing interesting happening? */ 154 if (SIGISEMPTY(tmpset)) { 155 /* 156 * Quit here, unless 157 * a) we may block and 158 * b) somebody is tracing us. 159 */ 160 if (mayblock == 0 || (p->p_flags & P_TRACED) == 0) 161 return (0); 162 } 163 164 if (mayblock) 165 r = issignal(lp, maytrace, ptok); 166 else 167 r = TRUE; /* simply state the fact */ 168 169 return(r); 170 } 171 172 #endif /* !_SYS_SIGNAL2_H_ */ 173