1/* $OpenBSD: sendsig.c,v 1.36 2023/03/08 04:43:07 guenther Exp $ */ 2 3/* 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * William Jolitz and Don Ahn. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 */ 39/* 40 * Copyright (c) 2001 Opsycon AB (www.opsycon.se) 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 51 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 52 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 53 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 54 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 55 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 56 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 57 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 59 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 60 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 61 * SUCH DAMAGE. 62 * 63 */ 64 65#include <sys/param.h> 66#include <sys/systm.h> 67#include <sys/signalvar.h> 68#include <sys/proc.h> 69#include <sys/exec.h> 70#include <sys/mount.h> 71#include <sys/syscallargs.h> 72 73#include <uvm/uvm_extern.h> 74 75#include <machine/regnum.h> 76#include <mips64/mips_cpu.h> 77 78/* 79 * WARNING: code in locore.s assumes the layout shown for sf_signum 80 * thru sf_handler so... don't screw with them! 81 */ 82struct sigframe { 83 int sf_signum; /* signo for handler */ 84 siginfo_t *sf_sip; /* pointer to siginfo_t */ 85 struct sigcontext *sf_scp; /* context ptr for handler */ 86 sig_t sf_handler; /* handler addr for u_sigc */ 87 struct sigcontext sf_sc; /* actual context */ 88 siginfo_t sf_si; 89}; 90 91/* 92 * Send an interrupt to process. 93 */ 94int 95sendsig(sig_t catcher, int sig, sigset_t mask, const siginfo_t *ksip, 96 int info, int onstack) 97{ 98 struct cpu_info *ci = curcpu(); 99 struct proc *p = ci->ci_curproc; 100 struct sigframe *fp; 101 struct trapframe *regs; 102 int fsize; 103 struct sigcontext ksc; 104 105 regs = p->p_md.md_regs; 106 107 /* 108 * Allocate space for the signal handler context. 109 */ 110 fsize = sizeof(struct sigframe); 111 if (!info) 112 fsize -= sizeof(siginfo_t); 113 if ((p->p_sigstk.ss_flags & SS_DISABLE) == 0 && 114 !sigonstack(regs->sp) && onstack) 115 fp = (struct sigframe *) 116 (trunc_page((vaddr_t)p->p_sigstk.ss_sp + p->p_sigstk.ss_size) 117 - fsize); 118 else 119 fp = (struct sigframe *)(regs->sp - fsize); 120 /* 121 * Build the signal context to be used by sigreturn. 122 */ 123 bzero(&ksc, sizeof(ksc)); 124 ksc.sc_mask = mask; 125 ksc.sc_pc = regs->pc; 126 ksc.mullo = regs->mullo; 127 ksc.mulhi = regs->mulhi; 128 bcopy((caddr_t)®s->ast, (caddr_t)&ksc.sc_regs[1], 129 sizeof(ksc.sc_regs) - sizeof(register_t)); 130 ksc.sc_fpused = p->p_md.md_flags & MDP_FPUSED; 131 if (ksc.sc_fpused) { 132 /* if FPU has current state, save it first */ 133 if (p == ci->ci_fpuproc) 134 save_fpu(); 135 136 bcopy((caddr_t)&p->p_md.md_regs->f0, (caddr_t)ksc.sc_fpregs, 137 sizeof(ksc.sc_fpregs)); 138 } 139 140 if (info) { 141 if (copyout(ksip, (caddr_t)&fp->sf_si, sizeof *ksip)) 142 return 1; 143 } 144 145 ksc.sc_cookie = (long)&fp->sf_sc ^ p->p_p->ps_sigcookie; 146 if (copyout((caddr_t)&ksc, (caddr_t)&fp->sf_sc, sizeof(ksc))) 147 return 1; 148 149 /* 150 * Build the argument list for the signal handler. 151 */ 152 regs->a0 = sig; 153 regs->a1 = info ? (register_t)&fp->sf_si : 0; 154 regs->a2 = (register_t)&fp->sf_sc; 155 regs->a3 = (register_t)catcher; 156 157 regs->pc = (register_t)catcher; 158 regs->t9 = (register_t)catcher; 159 regs->sp = (register_t)fp; 160 161 regs->ra = p->p_p->ps_sigcode; 162 163 return 0; 164} 165 166/* 167 * System call to cleanup state after a signal 168 * has been taken. Reset signal mask and 169 * stack state from context left by sendsig (above). 170 * Return to previous pc and psl as specified by 171 * context left by sendsig. Check carefully to 172 * make sure that the user has not modified the 173 * psl to gain improper privileges or to cause 174 * a machine fault. 175 */ 176int 177sys_sigreturn(struct proc *p, void *v, register_t *retval) 178{ 179 struct cpu_info *ci = curcpu(); 180 struct sys_sigreturn_args /* { 181 syscallarg(struct sigcontext *) sigcntxp; 182 } */ *uap = v; 183 struct sigcontext ksc, *scp = SCARG(uap, sigcntxp); 184 struct trapframe *regs = p->p_md.md_regs; 185 int error; 186 187 if (PROC_PC(p) != p->p_p->ps_sigcoderet) { 188 sigexit(p, SIGILL); 189 return (EPERM); 190 } 191 192 /* 193 * Test and fetch the context structure. 194 * We grab it all at once for speed. 195 */ 196 error = copyin((caddr_t)scp, (caddr_t)&ksc, sizeof(ksc)); 197 if (error) 198 return (error); 199 200 if (ksc.sc_cookie != ((long)scp ^ p->p_p->ps_sigcookie)) { 201 sigexit(p, SIGILL); 202 return (EFAULT); 203 } 204 205 /* Prevent reuse of the sigcontext cookie */ 206 ksc.sc_cookie = 0; 207 (void)copyout(&ksc.sc_cookie, (caddr_t)scp + 208 offsetof(struct sigcontext, sc_cookie), sizeof (ksc.sc_cookie)); 209 210 /* 211 * Restore the user supplied information 212 */ 213 p->p_sigmask = ksc.sc_mask &~ sigcantmask; 214 regs->pc = ksc.sc_pc; 215 regs->mullo = ksc.mullo; 216 regs->mulhi = ksc.mulhi; 217 regs->sr &= ~SR_COP_1_BIT; /* Zap current FP state */ 218 if (p == ci->ci_fpuproc) 219 ci->ci_fpuproc = NULL; 220 bcopy((caddr_t)&ksc.sc_regs[1], (caddr_t)®s->ast, 221 sizeof(ksc.sc_regs) - sizeof(register_t)); 222 if (ksc.sc_fpused) 223 bcopy((caddr_t)ksc.sc_fpregs, (caddr_t)&p->p_md.md_regs->f0, 224 sizeof(ksc.sc_fpregs)); 225 return (EJUSTRETURN); 226} 227 228void 229signotify(struct proc *p) 230{ 231 /* 232 * Ensure that preceding stores are visible to other CPUs 233 * before setting the AST flag. 234 */ 235 membar_producer(); 236 237 aston(p); 238 cpu_unidle(p->p_cpu); 239} 240