cpu_i386.c revision 1.1
1 /* $NetBSD: cpu_i386.c,v 1.1 2012/01/07 20:07:01 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 * Note that this machdep.c uses the `dummy' mcontext_t defined for usermode. 32 * This is basicly a blob of PAGE_SIZE big. We might want to switch over to 33 * non-generic mcontext_t's one day, but will this break non-NetBSD hosts? 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: cpu_i386.c,v 1.1 2012/01/07 20:07:01 reinoud Exp $"); 38 39 #include <sys/types.h> 40 #include <sys/systm.h> 41 #include <sys/param.h> 42 #include <sys/time.h> 43 #include <sys/exec.h> 44 #include <sys/buf.h> 45 #include <sys/boot_flag.h> 46 #include <sys/ucontext.h> 47 #include <sys/utsname.h> 48 #include <machine/pcb.h> 49 #include <machine/psl.h> 50 51 #include <uvm/uvm_extern.h> 52 #include <uvm/uvm_page.h> 53 54 #include <dev/mm.h> 55 #include <machine/machdep.h> 56 #include <machine/thunk.h> 57 58 #if 0 59 static void dump_regs(register_t *reg);; 60 61 static void 62 dump_regs(register_t *reg) 63 { 64 int i; 65 66 /* register dump before call */ 67 const char *name[] = {"GS", "FS", "ES", "DS", "EDI", "ESI", "EBP", "ESP", 68 "EBX", "EDX", "ECX", "EAX", "TRAPNO", "ERR", "EIP", "CS", "EFL", 69 "UESP", "SS"}; 70 71 for (i =0; i < 19; i++) 72 printf("reg[%02d] (%6s) = %"PRIx32"\n", i, name[i], (uint32_t) reg[i]); 73 } 74 #endif 75 76 77 /* from sys/arch/i386/include/frame.h : KEEP IN SYNC */ 78 79 /* 80 * New-style signal frame 81 */ 82 struct sigframe_siginfo { 83 int sf_ra; /* return address for handler */ 84 int sf_signum; /* "signum" argument for handler */ 85 siginfo_t *sf_sip; /* "sip" argument for handler */ 86 ucontext_t *sf_ucp; /* "ucp" argument for handler */ 87 siginfo_t sf_si; /* actual saved siginfo */ 88 ucontext_t sf_uc; /* actual saved ucontext */ 89 }; 90 91 92 /* 93 * mcontext extensions to handle signal delivery. 94 */ 95 #define _UC_SETSTACK 0x00010000 96 #define _UC_CLRSTACK 0x00020000 97 #define _UC_VM 0x00040000 98 #define _UC_TLSBASE 0x00080000 99 100 101 void 102 sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask) 103 { 104 struct lwp *l = curlwp; 105 struct proc *p = l->l_proc; 106 struct pcb *pcb = lwp_getpcb(l); 107 struct sigacts *ps = p->p_sigacts; 108 struct sigframe_siginfo *fp, frame; 109 int sig = ksi->ksi_signo; 110 sig_t catcher = SIGACTION(p, sig).sa_handler; 111 ucontext_t *ucp = &pcb->pcb_userret_ucp; 112 register_t *reg = (register_t *) &ucp->uc_mcontext; 113 int onstack, error; 114 115 KASSERT(mutex_owned(p->p_lock)); 116 117 #if 0 118 printf("%s: ", __func__); 119 printf("flags %d, ", (int) ksi->ksi_flags); 120 printf("to lwp %d, signo %d, code %d, errno %d\n", 121 (int) ksi->ksi_lid, 122 ksi->ksi_signo, 123 ksi->ksi_code, 124 ksi->ksi_errno); 125 #endif 126 127 /* do we need to jump onto the signal stack? */ 128 onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 129 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; 130 131 fp = (void *) reg[17]; /* ESP */ 132 if (onstack) 133 fp = (void *) 134 ((char *) l->l_sigstk.ss_sp + l->l_sigstk.ss_size); 135 136 fp--; 137 138 /* set up stack frame */ 139 frame.sf_ra = (int)ps->sa_sigdesc[sig].sd_tramp; 140 frame.sf_signum = sig; 141 frame.sf_sip = &fp->sf_si; 142 frame.sf_ucp = &fp->sf_uc; 143 frame.sf_si._info = ksi->ksi_info; 144 145 /* copy our userret context into sf_uc */ 146 memcpy(&frame.sf_uc, ucp, sizeof(ucontext_t)); 147 frame.sf_uc.uc_sigmask = *mask; 148 frame.sf_uc.uc_link = l->l_ctxlink; /* XXX ??? */ 149 frame.sf_uc.uc_flags |= (l->l_sigstk.ss_flags & SS_ONSTACK) 150 ? _UC_SETSTACK : _UC_CLRSTACK; 151 memset(&frame.sf_uc.uc_stack, 0, sizeof(frame.sf_uc.uc_stack)); 152 153 sendsig_reset(l, sig); 154 155 /* copyout our frame to the stackframe */ 156 mutex_exit(p->p_lock); 157 error = copyout(&frame, fp, sizeof(frame)); 158 mutex_enter(p->p_lock); 159 160 if (error != 0) { 161 /* 162 * Process has trashed its stack; give it an illegal 163 * instruction to halt it in its tracks. 164 */ 165 sigexit(l, SIGILL); 166 /* NOTREACHED */ 167 } 168 169 /* set catcher and the new stack pointer */ 170 reg[17] = (register_t) fp; /* ESP */ 171 reg[14] = (register_t) catcher; /* EIP */ 172 173 /* Remember that we're now on the signal stack. */ 174 if (onstack) 175 l->l_sigstk.ss_flags |= SS_ONSTACK; 176 } 177 178 void 179 setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack) 180 { 181 struct pcb *pcb = lwp_getpcb(l); 182 ucontext_t *ucp = &pcb->pcb_userret_ucp; 183 uint *reg, i; 184 185 #ifdef DEBUG_EXEC 186 printf("setregs called: lwp %p, exec package %p, stack %p\n", 187 l, pack, (void *) stack); 188 printf("current stat of pcb %p\n", pcb); 189 printf("\tpcb->pcb_ucp.uc_stack.ss_sp = %p\n", 190 pcb->pcb_ucp.uc_stack.ss_sp); 191 printf("\tpcb->pcb_ucp.uc_stack.ss_size = %d\n", 192 (int) pcb->pcb_ucp.uc_stack.ss_size); 193 printf("\tpcb->pcb_userret_ucp.uc_stack.ss_sp = %p\n", 194 pcb->pcb_userret_ucp.uc_stack.ss_sp); 195 printf("\tpcb->pcb_userret_ucp.uc_stack.ss_size = %d\n", 196 (int) pcb->pcb_userret_ucp.uc_stack.ss_size); 197 #endif 198 199 reg = (int *) &ucp->uc_mcontext; 200 for (i = 4; i < 11; i++) 201 reg[i] = 0; 202 203 ucp->uc_stack.ss_sp = (void *) (stack-4); /* to prevent clearing */ 204 ucp->uc_stack.ss_size = 0; //pack->ep_ssize; 205 thunk_makecontext(ucp, (void *) pack->ep_entry, 0, NULL, NULL, NULL); 206 207 /* patch up */ 208 reg[ 8] = l->l_proc->p_psstrp; /* _REG_EBX */ 209 reg[17] = (stack); /* _REG_UESP */ 210 211 //dump_regs(reg); 212 213 #ifdef DEBUG_EXEC 214 printf("updated pcb %p\n", pcb); 215 printf("\tpcb->pcb_ucp.uc_stack.ss_sp = %p\n", 216 pcb->pcb_ucp.uc_stack.ss_sp); 217 printf("\tpcb->pcb_ucp.uc_stack.ss_size = %d\n", 218 (int) pcb->pcb_ucp.uc_stack.ss_size); 219 printf("\tpcb->pcb_userret_ucp.uc_stack.ss_sp = %p\n", 220 pcb->pcb_userret_ucp.uc_stack.ss_sp); 221 printf("\tpcb->pcb_userret_ucp.uc_stack.ss_size = %d\n", 222 (int) pcb->pcb_userret_ucp.uc_stack.ss_size); 223 printf("\tpack->ep_entry = %p\n", 224 (void *) pack->ep_entry); 225 #endif 226 } 227 228 void 229 md_syscall_get_syscallnumber(ucontext_t *ucp, uint32_t *code) 230 { 231 uint *reg = (int *) &ucp->uc_mcontext; 232 *code = reg[11]; /* EAX */ 233 } 234 235 int 236 md_syscall_getargs(lwp_t *l, ucontext_t *ucp, int nargs, int argsize, 237 register_t *args) 238 { 239 uint *reg = (int *) &ucp->uc_mcontext; 240 register_t *sp = (register_t *) reg[17];/* ESP */ 241 int ret; 242 243 //dump_regs(reg); 244 ret = copyin(sp + 1, args, argsize); 245 246 return ret; 247 } 248 249 void 250 md_syscall_set_returnargs(lwp_t *l, ucontext_t *ucp, 251 int error, register_t *rval) 252 { 253 register_t *reg = (register_t *) &ucp->uc_mcontext; 254 255 reg[16] &= ~PSL_C; /* EFL */ 256 if (error > 0) { 257 rval[0] = error; 258 reg[16] |= PSL_C; /* EFL */ 259 } 260 261 /* set return parameters */ 262 reg[11] = rval[0]; /* EAX */ 263 if (error == 0) 264 reg[ 9] = rval[1]; /* EDX */ 265 266 //dump_regs(reg); 267 } 268 269 register_t 270 md_get_pc(ucontext_t *ucp) 271 { 272 register_t *reg = (register_t *) &ucp->uc_mcontext; 273 274 return reg[14]; /* EIP */ 275 } 276 277 int 278 md_syscall_check_opcode(ucontext_t *ucp) 279 { 280 uint32_t opcode; 281 282 md_syscall_get_opcode(ucp, &opcode); 283 284 switch (opcode) { 285 case 0xff0f: /* UD1 */ 286 case 0xff0b: /* UD2 */ 287 case 0x80cd: /* int $80 */ 288 case 0x340f: /* sysenter */ 289 case 0x050f: /* syscall */ 290 return 1; 291 default: 292 return 0; 293 } 294 } 295 296 void 297 md_syscall_get_opcode(ucontext_t *ucp, uint32_t *opcode) 298 { 299 register_t *reg = (register_t *) &ucp->uc_mcontext; 300 // uint8_t *p8 = (uint8_t *) (reg[14]); 301 uint16_t *p16 = (uint16_t*) (reg[14]); /* EIP */ 302 303 switch (*p16) { 304 case 0xff0f: /* UD1 */ 305 case 0xff0b: /* UD2 */ 306 case 0x80cd: /* int $80 */ 307 case 0x340f: /* sysenter */ 308 case 0x050f: /* syscall */ 309 *opcode = *p16; 310 break; 311 default: 312 *opcode = 0; 313 } 314 } 315 316 void 317 md_syscall_inc_pc(ucontext_t *ucp, uint32_t opcode) 318 { 319 uint *reg = (int *) &ucp->uc_mcontext; 320 321 /* advance program counter */ 322 switch (opcode) { 323 case 0xff0f: /* UD1 */ 324 case 0xff0b: /* UD2 */ 325 case 0x80cd: /* int $80 */ 326 case 0x340f: /* sysenter */ 327 case 0x050f: /* syscall */ 328 reg[14] += 2; /* EIP */ 329 break; 330 default: 331 panic("%s, unknown illegal instruction: opcode = %x\n", 332 __func__, (uint32_t) opcode); 333 } 334 } 335 336 void 337 md_syscall_dec_pc(ucontext_t *ucp, uint32_t opcode) 338 { 339 uint *reg = (int *) &ucp->uc_mcontext; 340 341 switch (opcode) { 342 case 0xff0f: /* UD1 */ 343 case 0xff0b: /* UD2 */ 344 case 0x80cd: /* int $80 */ 345 case 0x340f: /* sysenter */ 346 case 0x050f: /* syscall */ 347 reg[14] -= 2; /* EIP */ 348 break; 349 default: 350 panic("%s, unknown illegal instruction: opcode = %x\n", 351 __func__, (uint32_t) opcode); 352 } 353 } 354 355
Indexes created Mon Sep 29 15:09:53 GMT 2025