cpu_i386.c revision 1.5
1 /* $NetBSD: cpu_i386.c,v 1.5 2018/05/18 20:21:14 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 1.5 2018/05/18 20:21:14 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 53 #include "opt_exec.h" 54 55 #if 0 56 static void dump_regs(register_t *reg);; 57 58 static void 59 dump_regs(register_t *reg) 60 { 61 int i; 62 63 /* register dump before call */ 64 const char *name[] = {"GS", "FS", "ES", "DS", "EDI", "ESI", "EBP", "ESP", 65 "EBX", "EDX", "ECX", "EAX", "TRAPNO", "ERR", "EIP", "CS", "EFL", 66 "UESP", "SS"}; 67 68 for (i =0; i < 19; i++) 69 printf("reg[%02d] (%6s) = %"PRIx32"\n", i, name[i], (uint32_t) reg[i]); 70 } 71 #endif 72 73 74 /* from sys/arch/i386/include/frame.h : KEEP IN SYNC */ 75 76 /* 77 * New-style signal frame 78 */ 79 struct sigframe_siginfo { 80 int sf_ra; /* return address for handler */ 81 int sf_signum; /* "signum" argument for handler */ 82 siginfo_t *sf_sip; /* "sip" argument for handler */ 83 ucontext_t *sf_ucp; /* "ucp" argument for handler */ 84 siginfo_t sf_si; /* actual saved siginfo */ 85 ucontext_t sf_uc; /* actual saved ucontext */ 86 }; 87 88 89 /* 90 * mcontext extensions to handle signal delivery. 91 */ 92 #define _UC_SETSTACK 0x00010000 93 #define _UC_CLRSTACK 0x00020000 94 #define _UC_VM 0x00040000 95 #define _UC_TLSBASE 0x00080000 96 97 98 void 99 sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask) 100 { 101 struct lwp *l = curlwp; 102 struct proc *p = l->l_proc; 103 struct pcb *pcb = lwp_getpcb(l); 104 struct sigacts *ps = p->p_sigacts; 105 struct sigframe_siginfo *fp, frame; 106 int sig = ksi->ksi_signo; 107 sig_t catcher = SIGACTION(p, sig).sa_handler; 108 ucontext_t *ucp; 109 register_t *reg; 110 int onstack, error; 111 112 KASSERT(mutex_owned(p->p_lock)); 113 114 ucp = &pcb->pcb_userret_ucp; 115 reg = (register_t *) &ucp->uc_mcontext.__gregs; 116 #if 0 117 thunk_printf("%s: ", __func__); 118 thunk_printf("flags %d, ", (int) ksi->ksi_flags); 119 thunk_printf("to lwp %d, signo %d, code %d, errno %d\n", 120 (int) ksi->ksi_lid, 121 ksi->ksi_signo, 122 ksi->ksi_code, 123 ksi->ksi_errno); 124 #endif 125 126 /* do we need to jump onto the signal stack? */ 127 onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 128 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; 129 130 fp = (void *) reg[17]; /* ESP */ 131 if (onstack) 132 fp = (void *) 133 ((char *) l->l_sigstk.ss_sp + l->l_sigstk.ss_size); 134 135 fp--; 136 137 /* set up stack frame */ 138 frame.sf_ra = (int)ps->sa_sigdesc[sig].sd_tramp; 139 frame.sf_signum = sig; 140 frame.sf_sip = &fp->sf_si; 141 frame.sf_ucp = &fp->sf_uc; 142 frame.sf_si._info = ksi->ksi_info; 143 144 /* copy our userret context into sf_uc */ 145 memcpy(&frame.sf_uc, ucp, sizeof(ucontext_t)); 146 frame.sf_uc.uc_sigmask = *mask; 147 frame.sf_uc.uc_link = l->l_ctxlink; /* XXX ??? */ 148 frame.sf_uc.uc_flags |= (l->l_sigstk.ss_flags & SS_ONSTACK) 149 ? _UC_SETSTACK : _UC_CLRSTACK; 150 memset(&frame.sf_uc.uc_stack, 0, sizeof(frame.sf_uc.uc_stack)); 151 152 sendsig_reset(l, sig); 153 154 /* copyout our frame to the stackframe */ 155 mutex_exit(p->p_lock); 156 error = copyout(&frame, fp, sizeof(frame)); 157 mutex_enter(p->p_lock); 158 159 if (error != 0) { 160 /* 161 * Process has trashed its stack; give it an illegal 162 * instruction to halt it in its tracks. 163 */ 164 sigexit(l, SIGILL); 165 /* NOTREACHED */ 166 } 167 168 /* set catcher and the new stack pointer */ 169 reg[17] = (register_t) fp; /* ESP */ 170 reg[14] = (register_t) catcher; /* EIP */ 171 172 /* Remember that we're now on the signal stack. */ 173 if (onstack) 174 l->l_sigstk.ss_flags |= SS_ONSTACK; 175 } 176 177 void 178 setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack) 179 { 180 struct pcb *pcb = lwp_getpcb(l); 181 ucontext_t *ucp; 182 uint *reg, i; 183 184 #ifdef DEBUG_EXEC 185 printf("setregs called: lwp %p, exec package %p, stack %p\n", 186 l, pack, (void *) stack); 187 printf("current stat of pcb %p\n", pcb); 188 printf("\tpcb->pcb_ucp.uc_stack.ss_sp = %p\n", 189 pcb->pcb_ucp.uc_stack.ss_sp); 190 printf("\tpcb->pcb_ucp.uc_stack.ss_size = %d\n", 191 (int) pcb->pcb_ucp.uc_stack.ss_size); 192 #endif 193 194 /* set up the user context */ 195 ucp = &pcb->pcb_userret_ucp; 196 reg = (int *) &ucp->uc_mcontext.__gregs; 197 for (i = 4; i < 11; i++) 198 reg[i] = 0; 199 200 /* use given stack */ 201 ucp->uc_stack.ss_sp = (void *) (stack-4); /* to prevent clearing */ 202 ucp->uc_stack.ss_size = 0; //pack->ep_ssize; 203 thunk_makecontext(ucp, (void *) pack->ep_entry, 204 0, NULL, NULL, NULL, NULL); 205 206 /* patch up */ 207 reg[ 8] = l->l_proc->p_psstrp; /* _REG_EBX */ 208 reg[17] = (stack); /* _REG_UESP */ 209 210 //dump_regs(reg); 211 212 #ifdef DEBUG_EXEC 213 printf("updated pcb %p\n", pcb); 214 printf("\tpcb->pcb_ucp.uc_stack.ss_sp = %p\n", 215 pcb->pcb_ucp.uc_stack.ss_sp); 216 printf("\tpcb->pcb_ucp.uc_stack.ss_size = %d\n", 217 (int) pcb->pcb_ucp.uc_stack.ss_size); 218 printf("\tpack->ep_entry = %p\n", 219 (void *) pack->ep_entry); 220 #endif 221 } 222 223 void 224 md_syscall_get_syscallnumber(ucontext_t *ucp, uint32_t *code) 225 { 226 uint *reg = (int *) &ucp->uc_mcontext.__gregs; 227 *code = reg[11]; /* EAX */ 228 } 229 230 int 231 md_syscall_getargs(lwp_t *l, ucontext_t *ucp, int nargs, int argsize, 232 register_t *args) 233 { 234 uint *reg = (int *) &ucp->uc_mcontext.__gregs; 235 register_t *sp = (register_t *) reg[17];/* ESP */ 236 int ret; 237 238 //dump_regs(reg); 239 ret = copyin(sp + 1, args, argsize); 240 241 return ret; 242 } 243 244 void 245 md_syscall_set_returnargs(lwp_t *l, ucontext_t *ucp, 246 int error, register_t *rval) 247 { 248 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 249 250 reg[16] &= ~PSL_C; /* EFL */ 251 if (error > 0) { 252 rval[0] = error; 253 reg[16] |= PSL_C; /* EFL */ 254 } 255 256 /* set return parameters */ 257 reg[11] = rval[0]; /* EAX */ 258 if (error == 0) 259 reg[ 9] = rval[1]; /* EDX */ 260 261 //dump_regs(reg); 262 } 263 264 register_t 265 md_get_pc(ucontext_t *ucp) 266 { 267 KASSERT(ucp); 268 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 269 270 return reg[14]; /* EIP */ 271 } 272 273 register_t 274 md_get_sp(ucontext_t *ucp) 275 { 276 KASSERT(ucp); 277 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 278 279 return reg[17]; /* ESP */ 280 } 281 282 int 283 md_syscall_check_opcode(ucontext_t *ucp) 284 { 285 uint32_t opcode; 286 287 md_syscall_get_opcode(ucp, &opcode); 288 289 switch (opcode) { 290 case 0xff0f: /* UD1 */ 291 case 0xff0b: /* UD2 */ 292 case 0x80cd: /* int $80 */ 293 case 0x340f: /* sysenter */ 294 case 0x050f: /* syscall */ 295 return 1; 296 default: 297 return 0; 298 } 299 } 300 301 void 302 md_syscall_get_opcode(ucontext_t *ucp, uint32_t *opcode) 303 { 304 KASSERT(ucp); 305 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 306 // uint8_t *p8 = (uint8_t *) (reg[14]); 307 uint16_t *p16 = (uint16_t*) (reg[14]); /* EIP */ 308 309 switch (*p16) { 310 case 0xff0f: /* UD1 */ 311 case 0xff0b: /* UD2 */ 312 case 0x80cd: /* int $80 */ 313 case 0x340f: /* sysenter */ 314 case 0x050f: /* syscall */ 315 *opcode = *p16; 316 break; 317 default: 318 *opcode = 0; 319 } 320 } 321 322 void 323 md_syscall_inc_pc(ucontext_t *ucp, uint32_t opcode) 324 { 325 KASSERT(ucp); 326 uint *reg = (int *) &ucp->uc_mcontext.__gregs; 327 328 /* advance program counter */ 329 switch (opcode) { 330 case 0xff0f: /* UD1 */ 331 case 0xff0b: /* UD2 */ 332 case 0x80cd: /* int $80 */ 333 case 0x340f: /* sysenter */ 334 case 0x050f: /* syscall */ 335 reg[14] += 2; /* EIP */ 336 break; 337 default: 338 panic("%s, unknown illegal instruction: opcode = %x\n", 339 __func__, (uint32_t) opcode); 340 } 341 } 342 343 void 344 md_syscall_dec_pc(ucontext_t *ucp, uint32_t opcode) 345 { 346 KASSERT(ucp); 347 uint *reg = (int *) &ucp->uc_mcontext.__gregs; 348 349 switch (opcode) { 350 case 0xff0f: /* UD1 */ 351 case 0xff0b: /* UD2 */ 352 case 0x80cd: /* int $80 */ 353 case 0x340f: /* sysenter */ 354 case 0x050f: /* syscall */ 355 reg[14] -= 2; /* EIP */ 356 break; 357 default: 358 panic("%s, unknown illegal instruction: opcode = %x\n", 359 __func__, (uint32_t) opcode); 360 } 361 } 362 363
Indexes created Fri Sep 26 20:09:58 GMT 2025