cpu_i386.c revision 1.6
1 /* $NetBSD: cpu_i386.c,v 1.6 2018/05/22 14:38:10 reinoud Exp $ */ 2 3 /*- 4 * Copyright (c) 2011 Reinoud Zandijk <reinoud (at) netbsd.org> 5 * Copyright (c) 2007 Jared D. McNeill <jmcneill (at) invisible.ca> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: cpu_i386.c,v 1.6 2018/05/22 14:38:10 reinoud Exp $"); 33 34 #include <sys/types.h> 35 #include <sys/systm.h> 36 #include <sys/param.h> 37 #include <sys/time.h> 38 #include <sys/exec.h> 39 #include <sys/buf.h> 40 #include <sys/boot_flag.h> 41 #include <sys/ucontext.h> 42 #include <sys/utsname.h> 43 #include <machine/pcb.h> 44 #include <machine/psl.h> 45 46 #include <uvm/uvm_extern.h> 47 #include <uvm/uvm_page.h> 48 49 #include <dev/mm.h> 50 #include <machine/machdep.h> 51 #include <machine/thunk.h> 52 #include <machine/mcontext.h> 53 54 #include "opt_exec.h" 55 56 #if 0 57 static void dump_regs(register_t *reg);; 58 59 static void 60 dump_regs(register_t *reg) 61 { 62 int i; 63 64 /* register dump before call */ 65 const char *name[] = {"GS", "FS", "ES", "DS", "EDI", "ESI", "EBP", "ESP", 66 "EBX", "EDX", "ECX", "EAX", "TRAPNO", "ERR", "EIP", "CS", "EFL", 67 "UESP", "SS"}; 68 69 for (i =0; i < 19; i++) 70 printf("reg[%02d] (%6s) = %"PRIx32"\n", i, name[i], (uint32_t) reg[i]); 71 } 72 #endif 73 74 75 /* from sys/arch/i386/include/frame.h : KEEP IN SYNC */ 76 77 /* 78 * New-style signal frame 79 */ 80 struct sigframe_siginfo { 81 int sf_ra; /* return address for handler */ 82 int sf_signum; /* "signum" argument for handler */ 83 siginfo_t *sf_sip; /* "sip" argument for handler */ 84 ucontext_t *sf_ucp; /* "ucp" argument for handler */ 85 siginfo_t sf_si; /* actual saved siginfo */ 86 ucontext_t sf_uc; /* actual saved ucontext */ 87 }; 88 89 90 /* 91 * mcontext extensions to handle signal delivery. 92 */ 93 94 void 95 sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask) 96 { 97 struct lwp *l = curlwp; 98 struct proc *p = l->l_proc; 99 struct pcb *pcb = lwp_getpcb(l); 100 struct sigacts *ps = p->p_sigacts; 101 struct sigframe_siginfo *fp, frame; 102 int sig = ksi->ksi_signo; 103 sig_t catcher = SIGACTION(p, sig).sa_handler; 104 ucontext_t *ucp; 105 register_t *reg; 106 int onstack, error; 107 108 KASSERT(mutex_owned(p->p_lock)); 109 110 ucp = &pcb->pcb_userret_ucp; 111 reg = (register_t *) &ucp->uc_mcontext.__gregs; 112 #if 0 113 thunk_printf("%s: ", __func__); 114 thunk_printf("flags %d, ", (int) ksi->ksi_flags); 115 thunk_printf("to lwp %d, signo %d, code %d, errno %d\n", 116 (int) ksi->ksi_lid, 117 ksi->ksi_signo, 118 ksi->ksi_code, 119 ksi->ksi_errno); 120 #endif 121 122 /* do we need to jump onto the signal stack? */ 123 onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 124 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; 125 126 fp = (void *) reg[17]; /* ESP */ 127 if (onstack) 128 fp = (void *) 129 ((char *) l->l_sigstk.ss_sp + l->l_sigstk.ss_size); 130 131 fp--; 132 133 /* set up stack frame */ 134 frame.sf_ra = (int)ps->sa_sigdesc[sig].sd_tramp; 135 frame.sf_signum = sig; 136 frame.sf_sip = &fp->sf_si; 137 frame.sf_ucp = &fp->sf_uc; 138 frame.sf_si._info = ksi->ksi_info; 139 140 /* copy our userret context into sf_uc */ 141 memcpy(&frame.sf_uc, ucp, sizeof(ucontext_t)); 142 frame.sf_uc.uc_sigmask = *mask; 143 frame.sf_uc.uc_link = l->l_ctxlink; /* XXX ??? */ 144 frame.sf_uc.uc_flags |= (l->l_sigstk.ss_flags & SS_ONSTACK) 145 ? _UC_SETSTACK : _UC_CLRSTACK; 146 memset(&frame.sf_uc.uc_stack, 0, sizeof(frame.sf_uc.uc_stack)); 147 148 sendsig_reset(l, sig); 149 150 /* copyout our frame to the stackframe */ 151 mutex_exit(p->p_lock); 152 error = copyout(&frame, fp, sizeof(frame)); 153 mutex_enter(p->p_lock); 154 155 if (error != 0) { 156 /* 157 * Process has trashed its stack; give it an illegal 158 * instruction to halt it in its tracks. 159 */ 160 sigexit(l, SIGILL); 161 /* NOTREACHED */ 162 } 163 164 /* set catcher and the new stack pointer */ 165 reg[17] = (register_t) fp; /* ESP */ 166 reg[14] = (register_t) catcher; /* EIP */ 167 168 /* Remember that we're now on the signal stack. */ 169 if (onstack) 170 l->l_sigstk.ss_flags |= SS_ONSTACK; 171 } 172 173 void 174 setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack) 175 { 176 struct pcb *pcb = lwp_getpcb(l); 177 ucontext_t *ucp; 178 uint *reg, i; 179 180 #ifdef DEBUG_EXEC 181 printf("setregs called: lwp %p, exec package %p, stack %p\n", 182 l, pack, (void *) stack); 183 printf("current stat of pcb %p\n", pcb); 184 printf("\tpcb->pcb_ucp.uc_stack.ss_sp = %p\n", 185 pcb->pcb_ucp.uc_stack.ss_sp); 186 printf("\tpcb->pcb_ucp.uc_stack.ss_size = %d\n", 187 (int) pcb->pcb_ucp.uc_stack.ss_size); 188 #endif 189 190 /* set up the user context */ 191 ucp = &pcb->pcb_userret_ucp; 192 reg = (int *) &ucp->uc_mcontext.__gregs; 193 for (i = 4; i < 11; i++) 194 reg[i] = 0; 195 196 /* use given stack */ 197 ucp->uc_stack.ss_sp = (void *) (stack-4); /* to prevent clearing */ 198 ucp->uc_stack.ss_size = 0; //pack->ep_ssize; 199 thunk_makecontext(ucp, (void *) pack->ep_entry, 200 0, NULL, NULL, NULL, NULL); 201 202 /* patch up */ 203 reg[ 8] = l->l_proc->p_psstrp; /* _REG_EBX */ 204 reg[17] = (stack); /* _REG_UESP */ 205 206 //dump_regs(reg); 207 208 #ifdef DEBUG_EXEC 209 printf("updated pcb %p\n", pcb); 210 printf("\tpcb->pcb_ucp.uc_stack.ss_sp = %p\n", 211 pcb->pcb_ucp.uc_stack.ss_sp); 212 printf("\tpcb->pcb_ucp.uc_stack.ss_size = %d\n", 213 (int) pcb->pcb_ucp.uc_stack.ss_size); 214 printf("\tpack->ep_entry = %p\n", 215 (void *) pack->ep_entry); 216 #endif 217 } 218 219 void 220 md_syscall_get_syscallnumber(ucontext_t *ucp, uint32_t *code) 221 { 222 uint *reg = (int *) &ucp->uc_mcontext.__gregs; 223 *code = reg[11]; /* EAX */ 224 } 225 226 int 227 md_syscall_getargs(lwp_t *l, ucontext_t *ucp, int nargs, int argsize, 228 register_t *args) 229 { 230 uint *reg = (int *) &ucp->uc_mcontext.__gregs; 231 register_t *sp = (register_t *) reg[17];/* ESP */ 232 int ret; 233 234 //dump_regs(reg); 235 ret = copyin(sp + 1, args, argsize); 236 237 return ret; 238 } 239 240 void 241 md_syscall_set_returnargs(lwp_t *l, ucontext_t *ucp, 242 int error, register_t *rval) 243 { 244 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 245 246 reg[16] &= ~PSL_C; /* EFL */ 247 if (error > 0) { 248 rval[0] = error; 249 reg[16] |= PSL_C; /* EFL */ 250 } 251 252 /* set return parameters */ 253 reg[11] = rval[0]; /* EAX */ 254 if (error == 0) 255 reg[ 9] = rval[1]; /* EDX */ 256 257 //dump_regs(reg); 258 } 259 260 register_t 261 md_get_pc(ucontext_t *ucp) 262 { 263 KASSERT(ucp); 264 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 265 266 return reg[14]; /* EIP */ 267 } 268 269 register_t 270 md_get_sp(ucontext_t *ucp) 271 { 272 KASSERT(ucp); 273 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 274 275 return reg[17]; /* ESP */ 276 } 277 278 int 279 md_syscall_check_opcode(ucontext_t *ucp) 280 { 281 uint32_t opcode; 282 283 md_syscall_get_opcode(ucp, &opcode); 284 285 switch (opcode) { 286 case 0xff0f: /* UD1 */ 287 case 0xff0b: /* UD2 */ 288 case 0x80cd: /* int $80 */ 289 case 0x340f: /* sysenter */ 290 case 0x050f: /* syscall */ 291 return 1; 292 default: 293 return 0; 294 } 295 } 296 297 void 298 md_syscall_get_opcode(ucontext_t *ucp, uint32_t *opcode) 299 { 300 KASSERT(ucp); 301 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 302 // uint8_t *p8 = (uint8_t *) (reg[14]); 303 uint16_t *p16 = (uint16_t*) (reg[14]); /* EIP */ 304 305 switch (*p16) { 306 case 0xff0f: /* UD1 */ 307 case 0xff0b: /* UD2 */ 308 case 0x80cd: /* int $80 */ 309 case 0x340f: /* sysenter */ 310 case 0x050f: /* syscall */ 311 *opcode = *p16; 312 break; 313 default: 314 *opcode = 0; 315 } 316 } 317 318 void 319 md_syscall_inc_pc(ucontext_t *ucp, uint32_t opcode) 320 { 321 KASSERT(ucp); 322 uint *reg = (int *) &ucp->uc_mcontext.__gregs; 323 324 /* advance program counter */ 325 switch (opcode) { 326 case 0xff0f: /* UD1 */ 327 case 0xff0b: /* UD2 */ 328 case 0x80cd: /* int $80 */ 329 case 0x340f: /* sysenter */ 330 case 0x050f: /* syscall */ 331 reg[14] += 2; /* EIP */ 332 break; 333 default: 334 panic("%s, unknown illegal instruction: opcode = %x\n", 335 __func__, (uint32_t) opcode); 336 } 337 } 338 339 void 340 md_syscall_dec_pc(ucontext_t *ucp, uint32_t opcode) 341 { 342 KASSERT(ucp); 343 uint *reg = (int *) &ucp->uc_mcontext.__gregs; 344 345 switch (opcode) { 346 case 0xff0f: /* UD1 */ 347 case 0xff0b: /* UD2 */ 348 case 0x80cd: /* int $80 */ 349 case 0x340f: /* sysenter */ 350 case 0x050f: /* syscall */ 351 reg[14] -= 2; /* EIP */ 352 break; 353 default: 354 panic("%s, unknown illegal instruction: opcode = %x\n", 355 __func__, (uint32_t) opcode); 356 } 357 } 358 359
Indexes created Sat Sep 27 14:09:57 GMT 2025