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 */
88 void
linux_setregs(struct lwp * l,struct exec_package * pack,vaddr_t stack)89 linux_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
104 void
linux_sendsig(const ksiginfo_t * ksi,const sigset_t * mask)105 linux_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 */
268 int
linux_sys_rt_sigreturn(struct lwp * l,const struct linux_sys_rt_sigreturn_args * uap,register_t * retval)269 linux_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 */
363 int
linux_sys_sigreturn(struct lwp * l,const struct linux_sys_sigreturn_args * uap,register_t * retval)364 linux_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 */
455 dev_t
linux_fakedev(dev_t dev,int raw)456 linux_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 */
465 int
linux_machdepioctl(struct lwp * l,const struct linux_sys_ioctl_args * uap,register_t * retval)466 linux_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 */
493 int
linux_sys_new_uname(struct lwp * l,const struct linux_sys_new_uname_args * uap,register_t * retval)494 linux_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 */
502 int
linux_sys_new_select(struct lwp * l,const struct linux_sys_new_select_args * uap,register_t * retval)503 linux_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
508 int
linux_usertrap(struct lwp * l,vaddr_t trapaddr,void * arg)509 linux_usertrap(struct lwp *l, vaddr_t trapaddr, void *arg)
510 {
511 return 0;
512 }
513