cpu_x86_64.c revision 1.6.2.1
1 /* $NetBSD: cpu_x86_64.c,v 1.6.2.1 2019/06/10 22:06:50 christos 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_x86_64.c,v 1.6.2.1 2019/06/10 22:06:50 christos 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 #if 0 55 static void dump_regs(register_t *reg); 56 57 static void 58 dump_regs(register_t *reg) 59 { 60 int i; 61 62 /* register dump before call */ 63 const char *name[] = {"RDI", "RSI", "RDX", "RCX", "R8", "R9", "R10", 64 "R11", "R12", "R13", "R14", "R15", "RBP", "RAX", 65 "GS", "FS", "ES", "DS", "TRAPNO", "ERR", "RIP", "CS", 66 "RFLAGS", "RSP", "SS"}; 67 68 for (i =0; i < 26; i++) 69 printf("reg[%02d] (%6s) = %"PRIx32"\n", 70 i, name[i], (uint32_t) reg[i]); 71 } 72 #endif 73 74 75 /* from sys/arch/amd64/include/frame.h : KEEP IN SYNC */ 76 77 /* 78 * Signal frame 79 */ 80 struct sigframe_siginfo { 81 uint64_t sf_ra; /* return address for handler */ 82 siginfo_t sf_si; /* actual saved siginfo */ 83 ucontext_t sf_uc; /* actual saved ucontext */ 84 }; 85 86 87 /* 88 * mcontext extensions to handle signal delivery. 89 */ 90 void 91 sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask) 92 { 93 struct lwp *l = curlwp; 94 struct proc *p = l->l_proc; 95 struct pcb *pcb = lwp_getpcb(l); 96 struct sigacts *ps = p->p_sigacts; 97 struct sigframe_siginfo *fp, frame; 98 int sig = ksi->ksi_signo; 99 sig_t catcher = SIGACTION(p, sig).sa_handler; 100 ucontext_t *ucp; 101 register_t *reg; 102 int onstack, error; 103 char *sp; 104 105 KASSERT(mutex_owned(p->p_lock)); 106 107 ucp = &pcb->pcb_userret_ucp; 108 reg = (register_t *) &ucp->uc_mcontext.__gregs; 109 #if 0 110 thunk_printf("%s: ", __func__); 111 thunk_printf("flags %d, ", (int) ksi->ksi_flags); 112 thunk_printf("to lwp %d, signo %d, code %d, errno %d\n", 113 (int) ksi->ksi_lid, 114 ksi->ksi_signo, 115 ksi->ksi_code, 116 ksi->ksi_errno); 117 #endif 118 119 /* do we need to jump onto the signal stack? */ 120 onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 121 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; 122 123 sp = ((char *) reg[24] - 128);/* why -128?*//* RSP */ 124 if (onstack) 125 sp = (char *) l->l_sigstk.ss_sp + l->l_sigstk.ss_size; 126 127 sp -= sizeof(struct sigframe_siginfo); 128 /* 129 * Round down the stackpointer to a multiple of 16 for 130 * fxsave and the ABI 131 */ 132 fp = (struct sigframe_siginfo *) (((unsigned long)sp & ~15) - 8); 133 134 /* set up stack frame */ 135 memset(&frame, 0, sizeof(frame)); 136 frame.sf_ra = (uint64_t) ps->sa_sigdesc[sig].sd_tramp; 137 frame.sf_si._info = ksi->ksi_info; 138 139 /* copy our userret context into sf_uc */ 140 memcpy(&frame.sf_uc, ucp, sizeof(ucontext_t)); 141 frame.sf_uc.uc_sigmask = *mask; 142 frame.sf_uc.uc_link = l->l_ctxlink; 143 frame.sf_uc.uc_flags |= (l->l_sigstk.ss_flags & SS_ONSTACK) 144 ? _UC_SETSTACK : _UC_CLRSTACK; 145 memset(&frame.sf_uc.uc_stack, 0, sizeof(frame.sf_uc.uc_stack)); 146 sendsig_reset(l, sig); 147 148 /* copyout our frame to the stackframe */ 149 mutex_exit(p->p_lock); 150 error = copyout(&frame, fp, sizeof(frame)); 151 mutex_enter(p->p_lock); 152 153 if (error != 0) { 154 /* 155 * Process has trashed its stack; give it an illegal 156 * instruction to halt it in its tracks. 157 */ 158 sigexit(l, SIGILL); 159 /* NOTREACHED */ 160 } 161 162 /* set catcher and the new stack pointer */ 163 reg[24] = (register_t) fp; /* RSP */ 164 reg[21] = (register_t) catcher; /* RIP */ 165 166 reg[ 0] = sig; /* RDI */ 167 reg[ 1] = (uint64_t) &fp->sf_si; /* RSI */ 168 reg[ 2] = (uint64_t) &fp->sf_uc; /* RDX */ 169 reg[11] = reg[ 2]; /* R15 = RDX */ 170 171 /* Remember that we're now on the signal stack. */ 172 if (onstack) 173 l->l_sigstk.ss_flags |= SS_ONSTACK; 174 } 175 176 void 177 setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack) 178 { 179 struct pcb *pcb = lwp_getpcb(l); 180 ucontext_t *ucp; 181 register_t *reg; 182 int i; 183 184 /* set up the user context */ 185 ucp = &pcb->pcb_userret_ucp; 186 reg = (register_t *) &ucp->uc_mcontext.__gregs; 187 for (i = 0; i < 15; i++) 188 reg[i] = 0; 189 190 reg[13] = l->l_proc->p_psstrp; /* RBX */ 191 reg[21] = pack->ep_entry; /* RIP */ 192 reg[24] = (register_t) stack; /* RSP */ 193 194 /* use given stack */ 195 ucp->uc_stack.ss_sp = (void *) stack; 196 ucp->uc_stack.ss_size = pack->ep_ssize; 197 198 //dump_regs(reg); 199 } 200 201 void 202 md_syscall_get_syscallnumber(ucontext_t *ucp, uint32_t *code) 203 { 204 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 205 *code = reg[14]; /* RAX */ 206 } 207 208 int 209 md_syscall_getargs(lwp_t *l, ucontext_t *ucp, int nargs, int argsize, 210 register_t *args) 211 { 212 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 213 register_t *sp = (register_t *) reg[24];/* RSP */ 214 int ret; 215 216 //dump_regs(reg); 217 218 /* 219 * 1st 6 syscall args are passed in 220 * rdi, rsi, rdx, r10, r8 and r9 221 */ 222 args[0] = reg[ 0]; /* RDI */ 223 args[1] = reg[ 1]; /* RSI */ 224 args[2] = reg[ 2]; /* RDX */ 225 args[3] = reg[ 6]; /* R10 (RCX got clobbered) */ 226 args[4] = reg[ 4]; /* R8 */ 227 args[5] = reg[ 5]; /* R9 */ 228 229 ret = 0; 230 if (argsize > 6 * 8) { 231 ret = copyin(sp + 1, 232 args + 6, argsize - 6 * 8); 233 } 234 235 return ret; 236 } 237 238 void 239 md_syscall_set_returnargs(lwp_t *l, ucontext_t *ucp, 240 int error, register_t *rval) 241 { 242 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 243 244 reg[23] &= ~PSL_C; /* RFLAGS */ 245 if (error > 0) { 246 rval[0] = error; 247 reg[23] |= PSL_C; /* RFLAGS */ 248 } 249 250 /* set return parameters */ 251 reg[14] = rval[0]; /* RAX */ 252 if (error == 0) 253 reg[ 2] = rval[1]; /* RDX */ 254 255 //dump_regs(reg); 256 } 257 258 register_t 259 md_get_pc(ucontext_t *ucp) 260 { 261 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 262 263 return reg[21]; /* RIP */ 264 } 265 266 register_t 267 md_get_sp(ucontext_t *ucp) 268 { 269 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 270 271 return reg[24]; /* RSP */ 272 } 273 274 int 275 md_syscall_check_opcode(ucontext_t *ucp) 276 { 277 uint32_t opcode; 278 279 md_syscall_get_opcode(ucp, &opcode); 280 281 switch (opcode) { 282 case 0xff0f: /* UD1 */ 283 case 0xff0b: /* UD2 */ 284 case 0x80cd: /* int $80 */ 285 case 0x340f: /* sysenter */ 286 case 0x050f: /* syscall */ 287 return 1; 288 default: 289 return 0; 290 } 291 } 292 293 294 void 295 md_syscall_get_opcode(ucontext_t *ucp, uint32_t *opcode) 296 { 297 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 298 // uint8_t *p8 = (uint8_t *) (reg[21]); 299 uint16_t *p16 = (uint16_t*) (reg[21]); /* RIP */ 300 301 switch (*p16) { 302 case 0xff0f: /* UD1 */ 303 case 0xff0b: /* UD2 */ 304 case 0x80cd: /* int $80 */ 305 case 0x340f: /* sysenter */ 306 case 0x050f: /* syscall */ 307 *opcode = *p16; 308 break; 309 default: 310 *opcode = 0; 311 } 312 } 313 314 void 315 md_syscall_inc_pc(ucontext_t *ucp, uint32_t opcode) 316 { 317 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 318 319 /* advance program counter */ 320 switch (opcode) { 321 case 0xff0f: /* UD1 */ 322 case 0xff0b: /* UD2 */ 323 case 0x80cd: /* int $80 */ 324 case 0x340f: /* sysenter */ 325 case 0x050f: /* syscall */ 326 reg[21] += 2; /* RIP */ 327 break; 328 default: 329 panic("%s, unknown illegal instruction: opcode = %x\n", 330 __func__, (uint32_t) opcode); 331 } 332 } 333 334 void 335 md_syscall_dec_pc(ucontext_t *ucp, uint32_t opcode) 336 { 337 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs; 338 339 switch (opcode) { 340 case 0xff0f: /* UD1 */ 341 case 0xff0b: /* UD2 */ 342 case 0x80cd: /* int $80 */ 343 case 0x340f: /* sysenter */ 344 case 0x050f: /* syscall */ 345 reg[21] -= 2; /* RIP */ 346 break; 347 default: 348 panic("%s, unknown illegal instruction: opcode = %x\n", 349 __func__, (uint32_t) opcode); 350 } 351 } 352 353
Indexes created Thu Oct 30 03:10:01 GMT 2025