1/* $NetBSD: linux_machdep.c,v 1.51 2021/09/07 11:43:04 riastradh Exp $ */ 2 3/*- 4 * Copyright (c) 1995, 2000, 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Frank van der Linden and Emmanuel Dreyfus. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33__KERNEL_RCSID(0, "$NetBSD: linux_machdep.c,v 1.51 2021/09/07 11:43:04 riastradh Exp $"); 34 35#include <sys/param.h> 36#include <sys/systm.h> 37#include <sys/signalvar.h> 38#include <sys/kernel.h> 39#include <sys/proc.h> 40#include <sys/buf.h> 41#include <sys/reboot.h> 42#include <sys/conf.h> 43#include <sys/exec.h> 44#include <sys/file.h> 45#include <sys/callout.h> 46#include <sys/mbuf.h> 47#include <sys/msgbuf.h> 48#include <sys/mount.h> 49#include <sys/vnode.h> 50#include <sys/device.h> 51#include <sys/syscallargs.h> 52#include <sys/filedesc.h> 53#include <sys/exec_elf.h> 54#include <sys/disklabel.h> 55#include <sys/ioctl.h> 56#include <miscfs/specfs/specdev.h> 57 58#include <compat/linux/common/linux_types.h> 59#include <compat/linux/common/linux_signal.h> 60#include <compat/linux/common/linux_util.h> 61#include <compat/linux/common/linux_ioctl.h> 62#include <compat/linux/common/linux_hdio.h> 63#include <compat/linux/common/linux_exec.h> 64#include <compat/linux/common/linux_machdep.h> 65 66#include <compat/linux/linux_syscallargs.h> 67 68#include <sys/cpu.h> 69#include <machine/fpu.h> 70#include <machine/psl.h> 71#include <machine/pcb.h> 72#include <machine/vmparam.h> 73 74/* 75 * To see whether wscons is configured (for virtual console ioctl calls). 76 */ 77#if defined(_KERNEL_OPT) 78#include "wsdisplay.h" 79#endif 80#if (NWSDISPLAY > 0) 81#include <dev/wscons/wsconsio.h> 82#include <dev/wscons/wsdisplay_usl_io.h> 83#endif 84 85/* 86 * Set set up registers on exec. 87 */ 88void 89linux_setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack) 90{ 91 setregs(l, pack, stack); 92} 93 94/* 95 * Send an interrupt to process. 96 * 97 * Adapted from arch/powerpc/powerpc/sig_machdep.c:sendsig and 98 * compat/linux/arch/i386/linux_machdep.c:linux_sendsig 99 * 100 * XXX Does not work well yet with RT signals 101 * 102 */ 103 104void 105linux_sendsig(const ksiginfo_t *ksi, const sigset_t *mask) 106{ 107 const int sig = ksi->ksi_signo; 108 struct lwp *l = curlwp; 109 struct proc *p = l->l_proc; 110 struct trapframe *tf; 111 sig_t catcher = SIGACTION(p, sig).sa_handler; 112 struct linux_sigregs frame; 113 struct linux_pt_regs linux_regs; 114 struct linux_sigcontext sc; 115 register_t fp; 116 int onstack, error; 117 int i; 118 119 tf = trapframe(l); 120 121 /* 122 * Do we need to jump onto the signal stack? 123 */ 124 onstack = 125 (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 && 126 (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; 127 128 /* 129 * Signal stack is broken (see at the end of linux_sigreturn), so we do 130 * not use it yet. XXX fix this. 131 */ 132 onstack=0; 133 134 /* 135 * Allocate space for the signal handler context. 136 */ 137 if (onstack) { 138 fp = (register_t) 139 ((char *)l->l_sigstk.ss_sp + 140 l->l_sigstk.ss_size); 141 } else { 142 fp = tf->tf_fixreg[1]; 143 } 144#ifdef DEBUG_LINUX 145 printf("fp at start of linux_sendsig = %x\n", fp); 146#endif 147 fp -= sizeof(struct linux_sigregs); 148 fp &= ~0xf; 149 150 /* 151 * Prepare a sigcontext for later. 152 */ 153 memset(&sc, 0, sizeof sc); 154 sc.lsignal = (int)native_to_linux_signo[sig]; 155 sc.lhandler = (unsigned long)catcher; 156 native_to_linux_old_extra_sigset(&sc.lmask, &sc._unused[3], mask); 157 sc.lregs = (struct linux_pt_regs*)fp; 158 159 /* 160 * Setup the signal stack frame as Linux does it in 161 * arch/ppc/kernel/signal.c:setup_frame() 162 * 163 * Save register context. 164 */ 165 memset(&linux_regs, 0, sizeof(linux_regs)); 166 for (i = 0; i < 32; i++) 167 linux_regs.lgpr[i] = tf->tf_fixreg[i]; 168 linux_regs.lnip = tf->tf_srr0; 169 linux_regs.lmsr = tf->tf_srr1 & PSL_USERSRR1; 170 linux_regs.lorig_gpr3 = tf->tf_fixreg[3]; /* XXX Is that right? */ 171 linux_regs.lctr = tf->tf_ctr; 172 linux_regs.llink = tf->tf_lr; 173 linux_regs.lxer = tf->tf_xer; 174 linux_regs.lccr = tf->tf_cr; 175 linux_regs.lmq = 0; /* Unused, 601 only */ 176 linux_regs.ltrap = tf->tf_exc; 177 linux_regs.ldar = tf->tf_dar; 178 linux_regs.ldsisr = tf->tf_dsisr; 179 linux_regs.lresult = 0; 180 181 memset(&frame, 0, sizeof(frame)); 182 memcpy(&frame.lgp_regs, &linux_regs, sizeof(linux_regs)); 183 184#ifdef PPC_HAVE_FPU 185 fpu_save(l); 186#endif 187 memcpy(&frame.lfp_regs, curpcb->pcb_fpu.fpreg, sizeof(frame.lfp_regs)); 188 189 /* 190 * Copy Linux's signal trampoline on the user stack It should not 191 * be used, but Linux binaries might expect it to be there. 192 */ 193 frame.ltramp[0] = 0x38997777; /* li r0, 0x7777 */ 194 frame.ltramp[1] = 0x44000002; /* sc */ 195 196 /* 197 * Move it to the user stack 198 * There is a little trick here, about the LINUX_ABIGAP: the 199 * linux_sigreg structure has a 56 int gap to support rs6000/xcoff 200 * binaries. But the Linux kernel seems to do without it, and it 201 * just skip it when building the stack frame. Hence the LINUX_ABIGAP. 202 */ 203 sendsig_reset(l, sig); 204 mutex_exit(p->p_lock); 205 error = copyout(&frame, (void *)fp, sizeof (frame) - LINUX_ABIGAP); 206 207 if (error != 0) { 208 /* 209 * Process has trashed its stack; give it an illegal 210 * instruction to halt it in its tracks. 211 */ 212 mutex_enter(p->p_lock); 213 sigexit(l, SIGILL); 214 /* NOTREACHED */ 215 } 216 217 /* 218 * Add a sigcontext on the stack 219 */ 220 fp -= sizeof(struct linux_sigcontext); 221 error = copyout(&sc, (void *)fp, sizeof (struct linux_sigcontext)); 222 mutex_enter(p->p_lock); 223 224 if (error != 0) { 225 /* 226 * Process has trashed its stack; give it an illegal 227 * instruction to halt it in its tracks. 228 */ 229 sigexit(l, SIGILL); 230 /* NOTREACHED */ 231 } 232 233 /* 234 * Set the registers according to how the Linux process expects them. 235 * "Mind the gap" Linux expects a gap here. 236 */ 237 tf->tf_fixreg[1] = fp - LINUX__SIGNAL_FRAMESIZE; 238 tf->tf_lr = (int)catcher; 239 tf->tf_fixreg[3] = (int)native_to_linux_signo[sig]; 240 tf->tf_fixreg[4] = fp; 241 tf->tf_srr0 = (int)p->p_sigctx.ps_sigcode; 242 243#ifdef DEBUG_LINUX 244 printf("fp at end of linux_sendsig = %x\n", fp); 245#endif 246 /* 247 * Remember that we're now on the signal stack. 248 */ 249 if (onstack) 250 l->l_sigstk.ss_flags |= SS_ONSTACK; 251#ifdef DEBUG_LINUX 252 printf("linux_sendsig: exiting. fp=0x%lx\n",(long)fp); 253#endif 254} 255 256/* 257 * System call to cleanup state after a signal 258 * has been taken. Reset signal mask and 259 * stack state from context left by sendsig (above). 260 * Return to previous pc and psl as specified by 261 * context left by sendsig. Check carefully to 262 * make sure that the user has not modified the 263 * psl to gain improper privileges or to cause 264 * a machine fault. 265 * 266 * XXX not tested 267 */ 268int 269linux_sys_rt_sigreturn(struct lwp *l, const struct linux_sys_rt_sigreturn_args *uap, register_t *retval) 270{ 271 /* { 272 syscallarg(struct linux_rt_sigframe *) sfp; 273 } */ 274 struct proc *p = l->l_proc; 275 struct linux_rt_sigframe *scp, sigframe; 276 struct linux_sigregs sregs; 277 struct linux_pt_regs *lregs; 278 struct trapframe *tf; 279 sigset_t mask; 280 int i; 281 282 /* 283 * The trampoline code hands us the context. 284 * It is unsafe to keep track of it ourselves, in the event that a 285 * program jumps out of a signal handler. 286 */ 287 scp = SCARG(uap, sfp); 288 289 /* 290 * Get the context from user stack 291 */ 292 if (copyin((void *)scp, &sigframe, sizeof(*scp))) 293 return (EFAULT); 294 295 /* 296 * Restore register context. 297 */ 298 if (copyin((void *)sigframe.luc.luc_context.lregs, 299 &sregs, sizeof(sregs))) 300 return (EFAULT); 301 lregs = (struct linux_pt_regs *)&sregs.lgp_regs; 302 303 tf = trapframe(l); 304#ifdef DEBUG_LINUX 305 printf("linux_sys_rt_sigreturn: trapframe=0x%lx scp=0x%lx\n", 306 (unsigned long)tf, (unsigned long)scp); 307#endif 308 309 if (!PSL_USEROK_P(lregs->lmsr)) 310 return (EINVAL); 311 312 for (i = 0; i < 32; i++) 313 tf->tf_fixreg[i] = lregs->lgpr[i]; 314 tf->tf_lr = lregs->llink; 315 tf->tf_cr = lregs->lccr; 316 tf->tf_xer = lregs->lxer; 317 tf->tf_ctr = lregs->lctr; 318 tf->tf_srr0 = lregs->lnip; 319 tf->tf_srr1 = lregs->lmsr; 320 321 /* 322 * Make sure the fpu state is discarded 323 */ 324#ifdef PPC_HAVE_FPU 325 fpu_discard(l); 326#endif 327 328 memcpy(curpcb->pcb_fpu.fpreg, (void *)&sregs.lfp_regs, 329 sizeof(curpcb->pcb_fpu.fpreg)); 330 331 fpu_mark_used(l); 332 333 mutex_enter(p->p_lock); 334 335 /* 336 * Restore signal stack. 337 * 338 * XXX cannot find the onstack information in Linux sig context. 339 * Is signal stack really supported on Linux? 340 * 341 * It seems to be supported in libc6... 342 */ 343 /* if (sc.sc_onstack & SS_ONSTACK) 344 l->l_sigstk.ss_flags |= SS_ONSTACK; 345 else */ 346 l->l_sigstk.ss_flags &= ~SS_ONSTACK; 347 348 /* 349 * Grab the signal mask 350 */ 351 linux_to_native_sigset(&mask, &sigframe.luc.luc_sigmask); 352 (void) sigprocmask1(l, SIG_SETMASK, &mask, 0); 353 354 mutex_exit(p->p_lock); 355 356 return (EJUSTRETURN); 357} 358 359 360/* 361 * The following needs code review for potential security issues 362 */ 363int 364linux_sys_sigreturn(struct lwp *l, const struct linux_sys_sigreturn_args *uap, register_t *retval) 365{ 366 /* { 367 syscallarg(struct linux_sigcontext *) scp; 368 } */ 369 struct proc *p = l->l_proc; 370 struct linux_sigcontext *scp, context; 371 struct linux_sigregs sregs; 372 struct linux_pt_regs *lregs; 373 struct trapframe *tf; 374 sigset_t mask; 375 int i; 376 377 /* 378 * The trampoline code hands us the context. 379 * It is unsafe to keep track of it ourselves, in the event that a 380 * program jumps out of a signal handler. 381 */ 382 scp = SCARG(uap, scp); 383 384 /* 385 * Get the context from user stack 386 */ 387 if (copyin(scp, &context, sizeof(*scp))) 388 return (EFAULT); 389 390 /* 391 * Restore register context. 392 */ 393 if (copyin((void *)context.lregs, &sregs, sizeof(sregs))) 394 return (EFAULT); 395 lregs = (struct linux_pt_regs *)&sregs.lgp_regs; 396 397 tf = trapframe(l); 398#ifdef DEBUG_LINUX 399 printf("linux_sys_sigreturn: trapframe=0x%lx scp=0x%lx\n", 400 (unsigned long)tf, (unsigned long)scp); 401#endif 402 403 if (!PSL_USEROK_P(lregs->lmsr)) 404 return (EINVAL); 405 406 for (i = 0; i < 32; i++) 407 tf->tf_fixreg[i] = lregs->lgpr[i]; 408 tf->tf_lr = lregs->llink; 409 tf->tf_cr = lregs->lccr; 410 tf->tf_xer = lregs->lxer; 411 tf->tf_ctr = lregs->lctr; 412 tf->tf_srr0 = lregs->lnip; 413 tf->tf_srr1 = lregs->lmsr; 414 415 /* 416 * Make sure the fpu state is discarded 417 */ 418#ifdef PPC_HAVE_FPU 419 fpu_discard(l); 420#endif 421 422 memcpy(curpcb->pcb_fpu.fpreg, (void *)&sregs.lfp_regs, 423 sizeof(curpcb->pcb_fpu.fpreg)); 424 425 fpu_mark_used(l); 426 427 mutex_enter(p->p_lock); 428 429 /* 430 * Restore signal stack. 431 * 432 * XXX cannot find the onstack information in Linux sig context. 433 * Is signal stack really supported on Linux? 434 */ 435#if 0 436 if (sc.sc_onstack & SS_ONSTACK) 437 l->l_sigstk.ss_flags |= SS_ONSTACK; 438 else 439#endif 440 l->l_sigstk.ss_flags &= ~SS_ONSTACK; 441 442 /* Restore signal mask. */ 443 linux_old_extra_to_native_sigset(&mask, &context.lmask, 444 &context._unused[3]); 445 (void) sigprocmask1(l, SIG_SETMASK, &mask, 0); 446 447 mutex_exit(p->p_lock); 448 449 return (EJUSTRETURN); 450} 451 452/* 453 * major device numbers remapping 454 */ 455dev_t 456linux_fakedev(dev_t dev, int raw) 457{ 458 /* XXX write me */ 459 return dev; 460} 461 462/* 463 * We come here in a last attempt to satisfy a Linux ioctl() call 464 */ 465int 466linux_machdepioctl(struct lwp *l, const struct linux_sys_ioctl_args *uap, register_t *retval) 467{ 468 /* { 469 syscallarg(int) fd; 470 syscallarg(u_long) com; 471 syscallarg(void *) data; 472 } */ 473 struct sys_ioctl_args bia; 474 u_long com; 475 476 SCARG(&bia, fd) = SCARG(uap, fd); 477 SCARG(&bia, data) = SCARG(uap, data); 478 com = SCARG(uap, com); 479 480 switch (com) { 481 default: 482 printf("linux_machdepioctl: invalid ioctl %08lx\n", com); 483 return EINVAL; 484 } 485 SCARG(&bia, com) = com; 486 /* XXX NJWLWP */ 487 return sys_ioctl(curlwp, &bia, retval); 488} 489 490/* 491 * wrapper linux_sys_new_uname() -> linux_sys_uname() 492 */ 493int 494linux_sys_new_uname(struct lwp *l, const struct linux_sys_new_uname_args *uap, register_t *retval) 495{ 496 return linux_sys_uname(l, (const void *)uap, retval); 497} 498 499/* 500 * wrapper linux_sys_new_select() -> linux_sys_select() 501 */ 502int 503linux_sys_new_select(struct lwp *l, const struct linux_sys_new_select_args *uap, register_t *retval) 504{ 505 return linux_sys_select(l, (const void *)uap, retval); 506} 507 508int 509linux_usertrap(struct lwp *l, vaddr_t trapaddr, void *arg) 510{ 511 return 0; 512} 513