/* $OpenBSD: sig_machdep.c,v 1.18 2006/06/11 20:48:13 miod Exp $ */ /* $NetBSD: sig_machdep.c,v 1.3 1997/04/30 23:28:03 gwr Exp $ */ /* * Copyright (c) 1997 Theo de Raadt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * Copyright (c) 1988 University of Utah. * Copyright (c) 1982, 1986, 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: Utah Hdr: machdep.c 1.74 92/12/20 * from: @(#)machdep.c 8.10 (Berkeley) 4/20/94 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern short exframesize[]; #define SS_RTEFRAME 1 #define SS_FPSTATE 2 #define SS_USERREGS 4 struct sigstate { int ss_flags; /* which of the following are valid */ struct frame ss_frame; /* original exception frame */ struct fpframe ss_fpstate; /* 68881/68882 state info */ }; /* * WARNING: code in locore.s assumes the layout shown for sf_signum * thru sf_handler so... don't screw with them! */ struct sigframe { int sf_signum; /* signo for handler */ siginfo_t *sf_sip; /* pointer to siginfo_t */ struct sigcontext *sf_scp; /* context ptr for handler */ sig_t sf_handler; /* handler addr for u_sigc */ struct sigstate sf_state; /* state of the hardware */ struct sigcontext sf_sc; /* actual context */ siginfo_t sf_si; }; #ifdef DEBUG int sigdebug = 0; int sigpid = 0; #define SDB_FOLLOW 0x01 #define SDB_KSTACK 0x02 #define SDB_FPSTATE 0x04 #endif /* * Send an interrupt to process. */ void sendsig(catcher, sig, mask, code, type, val) sig_t catcher; int sig, mask; u_long code; int type; union sigval val; { struct proc *p = curproc; struct sigframe *fp, *kfp; struct frame *frame; struct sigacts *psp = p->p_sigacts; short ft; int oonstack, fsize; frame = (struct frame *)p->p_md.md_regs; ft = frame->f_format; oonstack = psp->ps_sigstk.ss_flags & SS_ONSTACK; /* * Allocate and validate space for the signal handler * context. Note that if the stack is in P0 space, the * call to grow() is a nop, and the useracc() check * will fail if the process has not already allocated * the space with a `brk'. */ fsize = sizeof(struct sigframe); if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack && (psp->ps_sigonstack & sigmask(sig))) { fp = (struct sigframe *)(psp->ps_sigstk.ss_sp + psp->ps_sigstk.ss_size - fsize); psp->ps_sigstk.ss_flags |= SS_ONSTACK; } else fp = (struct sigframe *)(frame->f_regs[SP] - fsize); if ((unsigned)fp <= USRSTACK - ctob(p->p_vmspace->vm_ssize)) (void)uvm_grow(p, (unsigned)fp); #ifdef DEBUG if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid) printf("sendsig(%d): sig %d ssp %p usp %p scp %p ft %d\n", p->p_pid, sig, &oonstack, fp, &fp->sf_sc, ft); #endif kfp = (struct sigframe *)malloc((u_long)fsize, M_TEMP, M_WAITOK | M_CANFAIL); if (kfp == NULL) { /* Better halt the process in its track than panicing */ sigexit(p, SIGILL); /* NOTREACHED */ } /* * Build the argument list for the signal handler. */ kfp->sf_signum = sig; kfp->sf_sip = NULL; kfp->sf_scp = &fp->sf_sc; kfp->sf_handler = catcher; /* * Save necessary hardware state. Currently this includes: * - general registers * - original exception frame (if not a "normal" frame) * - FP coprocessor state */ kfp->sf_state.ss_flags = SS_USERREGS; bcopy((caddr_t)frame->f_regs, (caddr_t)kfp->sf_state.ss_frame.f_regs, sizeof frame->f_regs); if (ft >= FMT7) { #ifdef DEBUG if (ft > 15 || exframesize[ft] < 0) panic("sendsig: bogus frame type"); #endif kfp->sf_state.ss_flags |= SS_RTEFRAME; kfp->sf_state.ss_frame.f_format = frame->f_format; kfp->sf_state.ss_frame.f_vector = frame->f_vector; bcopy((caddr_t)&frame->F_u, (caddr_t)&kfp->sf_state.ss_frame.F_u, exframesize[ft]); /* * Leave an indicator that we need to clean up the kernel * stack. We do this by setting the "pad word" above the * hardware stack frame to the amount the stack must be * adjusted by. * * N.B. we increment rather than just set f_stackadj in * case we are called from syscall when processing a * sigreturn. In that case, f_stackadj may be non-zero. */ frame->f_stackadj += exframesize[ft]; frame->f_format = frame->f_vector = 0; #ifdef DEBUG if (sigdebug & SDB_FOLLOW) printf("sendsig(%d): copy out %d of frame %d\n", p->p_pid, exframesize[ft], ft); #endif } if (fputype) { kfp->sf_state.ss_flags |= SS_FPSTATE; m68881_save(&kfp->sf_state.ss_fpstate); } #ifdef DEBUG if ((sigdebug & SDB_FPSTATE) && *(char *)&kfp->sf_state.ss_fpstate) printf("sendsig(%d): copy out FP state (%x) to %p\n", p->p_pid, *(u_int *)&kfp->sf_state.ss_fpstate, &kfp->sf_state.ss_fpstate); #endif /* * Build the signal context to be used by sigreturn. */ kfp->sf_sc.sc_onstack = oonstack; kfp->sf_sc.sc_mask = mask; kfp->sf_sc.sc_sp = frame->f_regs[SP]; kfp->sf_sc.sc_fp = frame->f_regs[A6]; kfp->sf_sc.sc_ap = (int)&fp->sf_state; kfp->sf_sc.sc_pc = frame->f_pc; kfp->sf_sc.sc_ps = frame->f_sr; if (psp->ps_siginfo & sigmask(sig)) { kfp->sf_sip = &fp->sf_si; initsiginfo(&kfp->sf_si, sig, code, type, val); } /* XXX do not copy out siginfo if not needed */ if (copyout((caddr_t)kfp, (caddr_t)fp, fsize) != 0) { #ifdef DEBUG if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid) printf("sendsig(%d): copyout failed on sig %d\n", p->p_pid, sig); #endif /* * Process has trashed its stack; give it an illegal * instruction to halt it in its tracks. */ free((caddr_t)kfp, M_TEMP); sigexit(p, SIGILL); /* NOTREACHED */ } frame->f_regs[SP] = (int)fp; #ifdef DEBUG if (sigdebug & SDB_FOLLOW) printf("sendsig(%d): sig %d scp %p fp %p sc_sp %x sc_ap %x\n", p->p_pid, sig, kfp->sf_scp, fp, kfp->sf_sc.sc_sp, kfp->sf_sc.sc_ap); #endif /* * Signal trampoline code is at base of user stack. */ frame->f_pc = p->p_sigcode; #ifdef DEBUG if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid) printf("sendsig(%d): sig %d returns\n", p->p_pid, sig); #endif free((caddr_t)kfp, M_TEMP); } /* * System call to cleanup state after a signal * has been taken. Reset signal mask and * stack state from context left by sendsig (above). * Return to previous pc and psl as specified by * context left by sendsig. Check carefully to * make sure that the user has not modified the * psl to gain improper privileges or to cause * a machine fault. */ int sys_sigreturn(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_sigreturn_args /* { syscallarg(struct sigcontext *) sigcntxp; } */ *uap = v; register struct sigcontext *scp; register struct frame *frame; register int rf; struct sigcontext tsigc; struct sigstate tstate; int flags; scp = SCARG(uap, sigcntxp); #ifdef DEBUG if (sigdebug & SDB_FOLLOW) printf("sigreturn: pid %d, scp %p\n", p->p_pid, scp); #endif if ((int)scp & 1) return (EINVAL); /* * Test and fetch the context structure. * We grab it all at once for speed. */ if (copyin((caddr_t)scp, (caddr_t)&tsigc, sizeof tsigc)) return (EINVAL); scp = &tsigc; if ((scp->sc_ps & PSL_USERCLR) != 0 || (scp->sc_ps & PSL_USERSET) != PSL_USERSET) return (EINVAL); /* * Restore the user supplied information */ if (scp->sc_onstack & 1) p->p_sigacts->ps_sigstk.ss_flags |= SS_ONSTACK; else p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK; p->p_sigmask = scp->sc_mask &~ sigcantmask; frame = (struct frame *) p->p_md.md_regs; frame->f_regs[SP] = scp->sc_sp; frame->f_regs[A6] = scp->sc_fp; frame->f_pc = scp->sc_pc; frame->f_sr = scp->sc_ps; /* * Grab pointer to hardware state information. * If zero, the user is probably doing a longjmp. */ if ((rf = scp->sc_ap) == 0) return (EJUSTRETURN); /* * See if there is anything to do before we go to the * expense of copying in close to 1/2K of data */ if (copyin((caddr_t)rf, &flags, sizeof(int)) != 0) return (EINVAL); #ifdef DEBUG if (sigdebug & SDB_FOLLOW) printf("sigreturn(%d): sc_ap %x flags %x\n", p->p_pid, rf, flags); #endif if (flags == 0 || copyin((caddr_t)rf, (caddr_t)&tstate, sizeof tstate)) return (EJUSTRETURN); #ifdef DEBUG if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid) printf("sigreturn(%d): ssp %p usp %x scp %p ft %d\n", p->p_pid, &flags, scp->sc_sp, SCARG(uap, sigcntxp), (flags&SS_RTEFRAME) ? tstate.ss_frame.f_format : -1); #endif /* * Restore most of the users registers except for A6 and SP * which were handled above. */ if (flags & SS_USERREGS) bcopy((caddr_t)tstate.ss_frame.f_regs, (caddr_t)frame->f_regs, sizeof(frame->f_regs)-2*NBPW); /* * Restore long stack frames. Note that we do not copy * back the saved SR or PC, they were picked up above from * the sigcontext structure. */ if (flags & SS_RTEFRAME) { register int sz; /* grab frame type and validate */ sz = tstate.ss_frame.f_format; if (sz > 15 || (sz = exframesize[sz]) < 0) return (EINVAL); frame->f_stackadj -= sz; frame->f_format = tstate.ss_frame.f_format; frame->f_vector = tstate.ss_frame.f_vector; bcopy((caddr_t)&tstate.ss_frame.F_u, (caddr_t)&frame->F_u, sz); #ifdef DEBUG if (sigdebug & SDB_FOLLOW) printf("sigreturn(%d): copy in %d of frame type %d\n", p->p_pid, sz, tstate.ss_frame.f_format); #endif } /* * Finally we restore the original FP context */ if (fputype && (flags & SS_FPSTATE)) m68881_restore(&tstate.ss_fpstate); #ifdef DEBUG if ((sigdebug & SDB_FPSTATE) && *(char *)&tstate.ss_fpstate) printf("sigreturn(%d): copied in FP state (%x) at %p\n", p->p_pid, *(u_int *)&tstate.ss_fpstate, &tstate.ss_fpstate); if ((sigdebug & SDB_FOLLOW) || ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)) printf("sigreturn(%d): returns\n", p->p_pid); #endif return (EJUSTRETURN); }