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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 $
34 #ifndef _SYS_SIGNAL2_H
35 #define _SYS_SIGNAL2_H
43 * Determine which signals are pending for a lwp.
45 * (Does not need to be interlocked with lwp_spin. If caller holds a
46 * critical section races will be resolved through an AST).
48 static __inline sigset_t
49 lwp_sigpend(struct lwp *lp)
53 set = lp->lwp_proc->p_siglist;
54 SIGSETOR(set, lp->lwp_siglist);
60 * Mark a signal as handled by the lwp.
62 * (p->p_token must be held, lp->lwp_spin must be held)
65 lwp_delsig(struct lwp *lp, int sig, int fromproc)
67 SIGDELSET(lp->lwp_siglist, sig);
69 SIGDELSET_ATOMIC(lp->lwp_proc->p_siglist, sig);
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)
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
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.
89 __sig_condblockallsigs(sigset_t *mask, struct lwp *lp)
91 struct sys_lpmap *lpmap;
96 if ((lpmap = lp->lwp_lpmap) == NULL)
99 bas = lpmap->blockallsigs;
100 while (bas & 0x7FFFFFFFU) {
101 tmp = *mask; /* check maskable signals */
103 if (SIGISEMPTY(tmp)) /* no unmaskable signals */
107 * Upon successful update to lpmap->blockallsigs remove
108 * all maskable signals, leaving only unmaskable signals.
110 * If lwp_sig is non-zero it represents a syncronous 'trap'
111 * signal which, being a synchronous trap, must be allowed.
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);
120 SIGSETAND(*mask, sigcantmask_mask);
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().
132 * This function does not interlock pending signals. If the caller needs
133 * to interlock the caller must acquire the per-proc token.
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.
142 __cursig(struct lwp *lp, int mayblock, int maytrace, int *ptok)
144 struct proc *p = lp->lwp_proc;
148 tmpset = lwp_sigpend(lp);
149 SIGSETNAND(tmpset, lp->lwp_sigmask);
150 SIG_CONDBLOCKALLSIGS(tmpset, lp);
152 /* Nothing interesting happening? */
153 if (SIGISEMPTY(tmpset)) {
156 * a) we may block and
157 * b) somebody is tracing us.
159 if (mayblock == 0 || (p->p_flags & P_TRACED) == 0)
164 r = issignal(lp, maytrace, ptok);
166 r = TRUE; /* simply state the fact */