1 /* $OpenBSD: syscall_mi.h,v 1.37 2024/12/27 11:57:16 mpi Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)kern_xxx.c 8.2 (Berkeley) 11/14/93 32 */ 33 34 #include <sys/param.h> 35 #include <sys/pledge.h> 36 #include <sys/acct.h> 37 #include <sys/tracepoint.h> 38 #include <sys/syscall.h> 39 #include <sys/signalvar.h> 40 #include <uvm/uvm_extern.h> 41 42 #ifdef KTRACE 43 #include <sys/ktrace.h> 44 #endif 45 46 #include "dt.h" 47 #if NDT > 0 48 #include <dev/dt/dtvar.h> 49 #endif 50 51 /* 52 * Check if a system call is entered from precisely correct location 53 */ 54 static inline int 55 pin_check(struct proc *p, register_t code) 56 { 57 extern char sigcodecall[], sigcoderet[], sigcodecall[]; 58 struct pinsyscall *pin = NULL, *ppin, *plibcpin; 59 struct process *pr = p->p_p; 60 vaddr_t addr; 61 int error = 0; 62 63 /* point at start of syscall instruction */ 64 addr = (vaddr_t)PROC_PC(p) - (vaddr_t)(sigcoderet - sigcodecall); 65 ppin = &pr->ps_pin; 66 plibcpin = &pr->ps_libcpin; 67 68 /* 69 * System calls come from the following places, checks are ordered 70 * by most common case: 71 * 1) dynamic binary: syscalls in libc.so (in the ps_libcpin region) 72 * 2a) static binary: syscalls in main program (in the ps_pin region) 73 * 2b) dynamic binary: syscalls in ld.so (in the ps_pin region) 74 * 3) sigtramp, containing only sigreturn(2) 75 */ 76 if (plibcpin->pn_pins && 77 addr >= plibcpin->pn_start && addr < plibcpin->pn_end) 78 pin = plibcpin; 79 else if (ppin->pn_pins && 80 addr >= ppin->pn_start && addr < ppin->pn_end) 81 pin = ppin; 82 else if (PROC_PC(p) == pr->ps_sigcoderet) { 83 if (code == SYS_sigreturn) 84 return (0); 85 error = EPERM; 86 goto die; 87 } 88 if (pin) { 89 if (code >= pin->pn_npins || pin->pn_pins[code] == 0) 90 error = ENOSYS; 91 else if (pin->pn_pins[code] + pin->pn_start == addr) 92 ; /* correct location */ 93 else if (pin->pn_pins[code] == (u_int)-1) 94 ; /* multiple locations, hopefully a boring operation */ 95 else 96 error = ENOSYS; 97 } else 98 error = ENOSYS; 99 if (error == 0) 100 return (0); 101 die: 102 #ifdef KTRACE 103 if (KTRPOINT(p, KTR_PINSYSCALL)) 104 ktrpinsyscall(p, error, code, addr); 105 #endif 106 KERNEL_LOCK(); 107 /* XXX remove or simplify this uprintf() call after OpenBSD 7.5 release */ 108 uprintf("%s[%d]: pinsyscalls addr %lx code %ld, pinoff 0x%x " 109 "(pin%s %d %lx-%lx %lx) (libcpin%s %d %lx-%lx %lx) error %d\n", 110 p->p_p->ps_comm, p->p_p->ps_pid, addr, code, 111 (pin && code < pin->pn_npins) ? pin->pn_pins[code] : -1, 112 pin == ppin ? "(Y)" : "", ppin->pn_npins, 113 ppin->pn_start, ppin->pn_end, ppin->pn_end - ppin->pn_start, 114 pin == plibcpin ? "(Y)" : "", plibcpin->pn_npins, 115 plibcpin->pn_start, plibcpin->pn_end, plibcpin->pn_end - plibcpin->pn_start, 116 error); 117 p->p_p->ps_acflag |= APINSYS; 118 119 /* Try to stop threads immediately, because this process is suspect */ 120 if (P_HASSIBLING(p)) 121 single_thread_set(p, SINGLE_UNWIND | SINGLE_DEEP); 122 /* Send uncatchable SIGABRT for coredump */ 123 sigabort(p); 124 KERNEL_UNLOCK(); 125 return (error); 126 } 127 128 /* 129 * The MD setup for a system call has been done; here's the MI part. 130 */ 131 static inline int 132 mi_syscall(struct proc *p, register_t code, const struct sysent *callp, 133 register_t *argp, register_t retval[2]) 134 { 135 uint64_t tval; 136 int lock = !(callp->sy_flags & SY_NOLOCK); 137 int error, pledged; 138 139 /* refresh the thread's cache of the process's creds */ 140 refreshcreds(p); 141 142 #ifdef SYSCALL_DEBUG 143 KERNEL_LOCK(); 144 scdebug_call(p, code, argp); 145 KERNEL_UNLOCK(); 146 #endif 147 TRACEPOINT(raw_syscalls, sys_enter, code, NULL); 148 #if NDT > 0 149 DT_ENTER(syscall, code, callp->sy_argsize, argp); 150 #endif 151 #ifdef KTRACE 152 if (KTRPOINT(p, KTR_SYSCALL)) { 153 /* convert to mask, then include with code */ 154 ktrsyscall(p, code, callp->sy_argsize, argp); 155 } 156 #endif 157 158 /* SP must be within MAP_STACK space */ 159 if (!uvm_map_inentry(p, &p->p_spinentry, PROC_STACK(p), 160 "[%s]%d/%d sp=%lx inside %lx-%lx: not MAP_STACK\n", 161 uvm_map_inentry_sp, p->p_vmspace->vm_map.sserial)) 162 return (EPERM); 163 164 if ((error = pin_check(p, code))) 165 return (error); 166 167 pledged = (p->p_p->ps_flags & PS_PLEDGE); 168 if (pledged && (error = pledge_syscall(p, code, &tval))) { 169 KERNEL_LOCK(); 170 error = pledge_fail(p, error, tval); 171 KERNEL_UNLOCK(); 172 return (error); 173 } 174 if (lock) 175 KERNEL_LOCK(); 176 error = (*callp->sy_call)(p, argp, retval); 177 if (lock) 178 KERNEL_UNLOCK(); 179 180 return (error); 181 } 182 183 /* 184 * Finish MI stuff on return, after the registers have been set 185 */ 186 static inline void 187 mi_syscall_return(struct proc *p, register_t code, int error, 188 const register_t retval[2]) 189 { 190 #ifdef SYSCALL_DEBUG 191 KERNEL_LOCK(); 192 scdebug_ret(p, code, error, retval); 193 KERNEL_UNLOCK(); 194 #endif 195 #if NDT > 0 196 DT_LEAVE(syscall, code, error, retval[0], retval[1]); 197 #endif 198 TRACEPOINT(raw_syscalls, sys_exit, code, NULL); 199 200 userret(p); 201 202 #ifdef KTRACE 203 if (KTRPOINT(p, KTR_SYSRET)) 204 ktrsysret(p, code, error, retval); 205 #endif 206 } 207 208 /* 209 * Finish MI stuff for a new process/thread to return 210 */ 211 static inline void 212 mi_child_return(struct proc *p) 213 { 214 #if defined(SYSCALL_DEBUG) || defined(KTRACE) || NDT > 0 215 int code = (p->p_flag & P_THREAD) ? SYS___tfork : 216 (p->p_p->ps_flags & PS_PPWAIT) ? SYS_vfork : SYS_fork; 217 const register_t child_retval[2] = { 0, 1 }; 218 #endif 219 220 TRACEPOINT(sched, on__cpu, NULL); 221 222 #ifdef SYSCALL_DEBUG 223 KERNEL_LOCK(); 224 scdebug_ret(p, code, 0, child_retval); 225 KERNEL_UNLOCK(); 226 #endif 227 #if NDT > 0 228 DT_LEAVE(syscall, code, 0, child_retval[0], child_retval[1]); 229 #endif 230 TRACEPOINT(raw_syscalls, sys_exit, code, NULL); 231 232 userret(p); 233 234 #ifdef KTRACE 235 if (KTRPOINT(p, KTR_SYSRET)) 236 ktrsysret(p, code, 0, child_retval); 237 #endif 238 } 239 240 /* 241 * Do the specific processing necessary for an AST 242 */ 243 static inline void 244 mi_ast(struct proc *p, int resched) 245 { 246 if (p->p_flag & P_OWEUPC) { 247 KERNEL_LOCK(); 248 ADDUPROF(p); 249 KERNEL_UNLOCK(); 250 } 251 if (resched) 252 preempt(); 253 254 /* 255 * XXX could move call to userret() here, but 256 * hppa calls ast() in syscall return and sh calls 257 * it after userret() 258 */ 259 } 260