1 /*-
2 * Copyright (c) 2014 Andrew Turner
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/exec.h>
31 #include <sys/imgact.h>
32 #include <sys/kdb.h>
33 #include <sys/kernel.h>
34 #include <sys/ktr.h>
35 #include <sys/limits.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/proc.h>
39 #include <sys/ptrace.h>
40 #include <sys/reg.h>
41 #include <sys/rwlock.h>
42 #include <sys/signalvar.h>
43 #include <sys/syscallsubr.h>
44 #include <sys/sysent.h>
45 #include <sys/sysproto.h>
46 #include <sys/ucontext.h>
47
48 #include <vm/vm.h>
49 #include <vm/vm_param.h>
50 #include <vm/pmap.h>
51 #include <vm/vm_map.h>
52
53 #include <machine/armreg.h>
54 #include <machine/kdb.h>
55 #include <machine/md_var.h>
56 #include <machine/pcb.h>
57
58 #ifdef VFP
59 #include <machine/vfp.h>
60 #endif
61
62 _Static_assert(sizeof(mcontext_t) == 880, "mcontext_t size incorrect");
63 _Static_assert(sizeof(ucontext_t) == 960, "ucontext_t size incorrect");
64 _Static_assert(sizeof(siginfo_t) == 80, "siginfo_t size incorrect");
65
66 static void get_fpcontext(struct thread *td, mcontext_t *mcp);
67 static void set_fpcontext(struct thread *td, mcontext_t *mcp);
68
69 int
fill_regs(struct thread * td,struct reg * regs)70 fill_regs(struct thread *td, struct reg *regs)
71 {
72 struct trapframe *frame;
73
74 frame = td->td_frame;
75 regs->sp = frame->tf_sp;
76 regs->lr = frame->tf_lr;
77 regs->elr = frame->tf_elr;
78 regs->spsr = frame->tf_spsr;
79
80 memcpy(regs->x, frame->tf_x, sizeof(regs->x));
81
82 #ifdef COMPAT_FREEBSD32
83 /*
84 * We may be called here for a 32bits process, if we're using a
85 * 64bits debugger. If so, put PC and SPSR where it expects it.
86 */
87 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
88 regs->x[15] = frame->tf_elr;
89 regs->x[16] = frame->tf_spsr;
90 }
91 #endif
92 return (0);
93 }
94
95 int
set_regs(struct thread * td,struct reg * regs)96 set_regs(struct thread *td, struct reg *regs)
97 {
98 struct trapframe *frame;
99
100 frame = td->td_frame;
101 frame->tf_sp = regs->sp;
102 frame->tf_lr = regs->lr;
103
104 memcpy(frame->tf_x, regs->x, sizeof(frame->tf_x));
105
106 #ifdef COMPAT_FREEBSD32
107 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
108 /*
109 * We may be called for a 32bits process if we're using
110 * a 64bits debugger. If so, get PC and SPSR from where
111 * it put it.
112 */
113 frame->tf_elr = regs->x[15];
114 frame->tf_spsr &= ~PSR_SETTABLE_32;
115 frame->tf_spsr |= regs->x[16] & PSR_SETTABLE_32;
116 /* Don't allow userspace to ask to continue single stepping.
117 * The SPSR.SS field doesn't exist when the EL1 is AArch32.
118 * As the SPSR.DIT field has moved in its place don't
119 * allow userspace to set the SPSR.SS field.
120 */
121 } else
122 #endif
123 {
124 frame->tf_elr = regs->elr;
125 /*
126 * frame->tf_spsr and regs->spsr on FreeBSD 13 was 32-bit
127 * where from 14 they are 64 bit. As PSR_SETTABLE_64 clears
128 * the upper 32 bits no compatibility handling is needed,
129 * however if this is ever not the case we will need to add
130 * these, similar to how it is done in set_mcontext.
131 */
132 frame->tf_spsr &= ~PSR_SETTABLE_64;
133 frame->tf_spsr |= regs->spsr & PSR_SETTABLE_64;
134 /* Enable single stepping if userspace asked fot it */
135 if ((frame->tf_spsr & PSR_SS) != 0) {
136 td->td_pcb->pcb_flags |= PCB_SINGLE_STEP;
137
138 WRITE_SPECIALREG(mdscr_el1,
139 READ_SPECIALREG(mdscr_el1) | MDSCR_SS);
140 isb();
141 }
142 }
143 return (0);
144 }
145
146 int
fill_fpregs(struct thread * td,struct fpreg * regs)147 fill_fpregs(struct thread *td, struct fpreg *regs)
148 {
149 #ifdef VFP
150 struct pcb *pcb;
151
152 pcb = td->td_pcb;
153 if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
154 /*
155 * If we have just been running VFP instructions we will
156 * need to save the state to memcpy it below.
157 */
158 if (td == curthread)
159 vfp_save_state(td, pcb);
160 }
161
162 KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
163 ("Called fill_fpregs while the kernel is using the VFP"));
164 memcpy(regs->fp_q, pcb->pcb_fpustate.vfp_regs,
165 sizeof(regs->fp_q));
166 regs->fp_cr = pcb->pcb_fpustate.vfp_fpcr;
167 regs->fp_sr = pcb->pcb_fpustate.vfp_fpsr;
168 #else
169 memset(regs, 0, sizeof(*regs));
170 #endif
171 return (0);
172 }
173
174 int
set_fpregs(struct thread * td,struct fpreg * regs)175 set_fpregs(struct thread *td, struct fpreg *regs)
176 {
177 #ifdef VFP
178 struct pcb *pcb;
179
180 pcb = td->td_pcb;
181 KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
182 ("Called set_fpregs while the kernel is using the VFP"));
183 memcpy(pcb->pcb_fpustate.vfp_regs, regs->fp_q, sizeof(regs->fp_q));
184 pcb->pcb_fpustate.vfp_fpcr = regs->fp_cr;
185 pcb->pcb_fpustate.vfp_fpsr = regs->fp_sr;
186 #endif
187 return (0);
188 }
189
190 int
fill_dbregs(struct thread * td,struct dbreg * regs)191 fill_dbregs(struct thread *td, struct dbreg *regs)
192 {
193 struct debug_monitor_state *monitor;
194 int i;
195 uint8_t debug_ver, nbkpts, nwtpts;
196
197 memset(regs, 0, sizeof(*regs));
198
199 extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_DebugVer_SHIFT,
200 &debug_ver);
201 extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_BRPs_SHIFT,
202 &nbkpts);
203 extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_WRPs_SHIFT,
204 &nwtpts);
205
206 /*
207 * The BRPs field contains the number of breakpoints - 1. Armv8-A
208 * allows the hardware to provide 2-16 breakpoints so this won't
209 * overflow an 8 bit value. The same applies to the WRPs field.
210 */
211 nbkpts++;
212 nwtpts++;
213
214 regs->db_debug_ver = debug_ver;
215 regs->db_nbkpts = nbkpts;
216 regs->db_nwtpts = nwtpts;
217
218 monitor = &td->td_pcb->pcb_dbg_regs;
219 if ((monitor->dbg_flags & DBGMON_ENABLED) != 0) {
220 for (i = 0; i < nbkpts; i++) {
221 regs->db_breakregs[i].dbr_addr = monitor->dbg_bvr[i];
222 regs->db_breakregs[i].dbr_ctrl = monitor->dbg_bcr[i];
223 }
224 for (i = 0; i < nwtpts; i++) {
225 regs->db_watchregs[i].dbw_addr = monitor->dbg_wvr[i];
226 regs->db_watchregs[i].dbw_ctrl = monitor->dbg_wcr[i];
227 }
228 }
229
230 return (0);
231 }
232
233 int
set_dbregs(struct thread * td,struct dbreg * regs)234 set_dbregs(struct thread *td, struct dbreg *regs)
235 {
236 struct debug_monitor_state *monitor;
237 uint64_t addr;
238 uint32_t ctrl;
239 int i;
240
241 monitor = &td->td_pcb->pcb_dbg_regs;
242 monitor->dbg_enable_count = 0;
243
244 for (i = 0; i < DBG_BRP_MAX; i++) {
245 addr = regs->db_breakregs[i].dbr_addr;
246 ctrl = regs->db_breakregs[i].dbr_ctrl;
247
248 /*
249 * Don't let the user set a breakpoint on a kernel or
250 * non-canonical user address.
251 */
252 if (addr >= VM_MAXUSER_ADDRESS)
253 return (EINVAL);
254
255 /*
256 * The lowest 2 bits are ignored, so record the effective
257 * address.
258 */
259 addr = rounddown2(addr, 4);
260
261 /*
262 * Some control fields are ignored, and other bits reserved.
263 * Only unlinked, address-matching breakpoints are supported.
264 *
265 * XXX: fields that appear unvalidated, such as BAS, have
266 * constrained undefined behaviour. If the user mis-programs
267 * these, there is no risk to the system.
268 */
269 ctrl &= DBGBCR_EN | DBGBCR_PMC | DBGBCR_BAS;
270 if ((ctrl & DBGBCR_EN) != 0) {
271 /* Only target EL0. */
272 if ((ctrl & DBGBCR_PMC) != DBGBCR_PMC_EL0)
273 return (EINVAL);
274
275 monitor->dbg_enable_count++;
276 }
277
278 monitor->dbg_bvr[i] = addr;
279 monitor->dbg_bcr[i] = ctrl;
280 }
281
282 for (i = 0; i < DBG_WRP_MAX; i++) {
283 addr = regs->db_watchregs[i].dbw_addr;
284 ctrl = regs->db_watchregs[i].dbw_ctrl;
285
286 /*
287 * Don't let the user set a watchpoint on a kernel or
288 * non-canonical user address.
289 */
290 if (addr >= VM_MAXUSER_ADDRESS)
291 return (EINVAL);
292
293 /*
294 * Some control fields are ignored, and other bits reserved.
295 * Only unlinked watchpoints are supported.
296 */
297 ctrl &= DBGWCR_EN | DBGWCR_PAC | DBGWCR_LSC | DBGWCR_BAS |
298 DBGWCR_MASK;
299
300 if ((ctrl & DBGWCR_EN) != 0) {
301 /* Only target EL0. */
302 if ((ctrl & DBGWCR_PAC) != DBGWCR_PAC_EL0)
303 return (EINVAL);
304
305 /* Must set at least one of the load/store bits. */
306 if ((ctrl & DBGWCR_LSC) == 0)
307 return (EINVAL);
308
309 /*
310 * When specifying the address range with BAS, the MASK
311 * field must be zero.
312 */
313 if ((ctrl & DBGWCR_BAS) != DBGWCR_BAS &&
314 (ctrl & DBGWCR_MASK) != 0)
315 return (EINVAL);
316
317 monitor->dbg_enable_count++;
318 }
319 monitor->dbg_wvr[i] = addr;
320 monitor->dbg_wcr[i] = ctrl;
321 }
322
323 if (monitor->dbg_enable_count > 0)
324 monitor->dbg_flags |= DBGMON_ENABLED;
325
326 return (0);
327 }
328
329 #ifdef COMPAT_FREEBSD32
330 int
fill_regs32(struct thread * td,struct reg32 * regs)331 fill_regs32(struct thread *td, struct reg32 *regs)
332 {
333 int i;
334 struct trapframe *tf;
335
336 tf = td->td_frame;
337 for (i = 0; i < 13; i++)
338 regs->r[i] = tf->tf_x[i];
339 /* For arm32, SP is r13 and LR is r14 */
340 regs->r_sp = tf->tf_x[13];
341 regs->r_lr = tf->tf_x[14];
342 regs->r_pc = tf->tf_elr;
343 regs->r_cpsr = tf->tf_spsr;
344
345 return (0);
346 }
347
348 int
set_regs32(struct thread * td,struct reg32 * regs)349 set_regs32(struct thread *td, struct reg32 *regs)
350 {
351 int i;
352 struct trapframe *tf;
353
354 tf = td->td_frame;
355 for (i = 0; i < 13; i++)
356 tf->tf_x[i] = regs->r[i];
357 /* For arm 32, SP is r13 an LR is r14 */
358 tf->tf_x[13] = regs->r_sp;
359 tf->tf_x[14] = regs->r_lr;
360 tf->tf_elr = regs->r_pc;
361 tf->tf_spsr &= ~PSR_SETTABLE_32;
362 tf->tf_spsr |= regs->r_cpsr & PSR_SETTABLE_32;
363
364 return (0);
365 }
366
367 /* XXX fill/set dbregs/fpregs are stubbed on 32-bit arm. */
368 int
fill_fpregs32(struct thread * td,struct fpreg32 * regs)369 fill_fpregs32(struct thread *td, struct fpreg32 *regs)
370 {
371
372 memset(regs, 0, sizeof(*regs));
373 return (0);
374 }
375
376 int
set_fpregs32(struct thread * td,struct fpreg32 * regs)377 set_fpregs32(struct thread *td, struct fpreg32 *regs)
378 {
379
380 return (0);
381 }
382
383 int
fill_dbregs32(struct thread * td,struct dbreg32 * regs)384 fill_dbregs32(struct thread *td, struct dbreg32 *regs)
385 {
386
387 memset(regs, 0, sizeof(*regs));
388 return (0);
389 }
390
391 int
set_dbregs32(struct thread * td,struct dbreg32 * regs)392 set_dbregs32(struct thread *td, struct dbreg32 *regs)
393 {
394
395 return (0);
396 }
397 #endif
398
399 void
exec_setregs(struct thread * td,struct image_params * imgp,uintptr_t stack)400 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
401 {
402 struct trapframe *tf = td->td_frame;
403 struct pcb *pcb = td->td_pcb;
404
405 memset(tf, 0, sizeof(struct trapframe));
406
407 tf->tf_x[0] = stack;
408 tf->tf_sp = STACKALIGN(stack);
409 tf->tf_lr = imgp->entry_addr;
410 tf->tf_elr = imgp->entry_addr;
411
412 td->td_pcb->pcb_tpidr_el0 = 0;
413 td->td_pcb->pcb_tpidrro_el0 = 0;
414 WRITE_SPECIALREG(tpidrro_el0, 0);
415 WRITE_SPECIALREG(tpidr_el0, 0);
416
417 #ifdef VFP
418 vfp_reset_state(td, pcb);
419 #endif
420
421 /*
422 * Clear debug register state. It is not applicable to the new process.
423 */
424 bzero(&pcb->pcb_dbg_regs, sizeof(pcb->pcb_dbg_regs));
425
426 /* Generate new pointer authentication keys */
427 ptrauth_exec(td);
428 }
429
430 /* Sanity check these are the same size, they will be memcpy'd to and from */
431 CTASSERT(sizeof(((struct trapframe *)0)->tf_x) ==
432 sizeof((struct gpregs *)0)->gp_x);
433 CTASSERT(sizeof(((struct trapframe *)0)->tf_x) ==
434 sizeof((struct reg *)0)->x);
435
436 int
get_mcontext(struct thread * td,mcontext_t * mcp,int clear_ret)437 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret)
438 {
439 struct trapframe *tf = td->td_frame;
440
441 if (clear_ret & GET_MC_CLEAR_RET) {
442 mcp->mc_gpregs.gp_x[0] = 0;
443 mcp->mc_gpregs.gp_spsr = tf->tf_spsr & ~PSR_C;
444 } else {
445 mcp->mc_gpregs.gp_x[0] = tf->tf_x[0];
446 mcp->mc_gpregs.gp_spsr = tf->tf_spsr;
447 }
448
449 memcpy(&mcp->mc_gpregs.gp_x[1], &tf->tf_x[1],
450 sizeof(mcp->mc_gpregs.gp_x[1]) * (nitems(mcp->mc_gpregs.gp_x) - 1));
451
452 mcp->mc_gpregs.gp_sp = tf->tf_sp;
453 mcp->mc_gpregs.gp_lr = tf->tf_lr;
454 mcp->mc_gpregs.gp_elr = tf->tf_elr;
455 get_fpcontext(td, mcp);
456
457 return (0);
458 }
459
460 int
set_mcontext(struct thread * td,mcontext_t * mcp)461 set_mcontext(struct thread *td, mcontext_t *mcp)
462 {
463 #define PSR_13_MASK 0xfffffffful
464 struct arm64_reg_context ctx;
465 struct trapframe *tf = td->td_frame;
466 uint64_t spsr;
467 vm_offset_t addr;
468 int error;
469 bool done;
470
471 spsr = mcp->mc_gpregs.gp_spsr;
472 #ifdef COMPAT_FREEBSD13
473 if (td->td_proc->p_osrel < P_OSREL_ARM64_SPSR) {
474 /*
475 * Before FreeBSD 14 gp_spsr was 32 bit. The size of mc_gpregs
476 * was identical because of padding so mask of the upper bits
477 * that may be invalid on earlier releases.
478 */
479 spsr &= PSR_13_MASK;
480 }
481 #endif
482
483 if ((spsr & PSR_M_MASK) != PSR_M_EL0t ||
484 (spsr & PSR_AARCH32) != 0 ||
485 (spsr & PSR_DAIF) != (td->td_frame->tf_spsr & PSR_DAIF))
486 return (EINVAL);
487
488 memcpy(tf->tf_x, mcp->mc_gpregs.gp_x, sizeof(tf->tf_x));
489
490 tf->tf_sp = mcp->mc_gpregs.gp_sp;
491 tf->tf_lr = mcp->mc_gpregs.gp_lr;
492 tf->tf_elr = mcp->mc_gpregs.gp_elr;
493 #ifdef COMPAT_FREEBSD13
494 if (td->td_proc->p_osrel < P_OSREL_ARM64_SPSR) {
495 /* Keep the upper 32 bits of spsr on older releases */
496 tf->tf_spsr &= ~PSR_13_MASK;
497 tf->tf_spsr |= spsr;
498 } else
499 #endif
500 tf->tf_spsr = spsr;
501 if ((tf->tf_spsr & PSR_SS) != 0) {
502 td->td_pcb->pcb_flags |= PCB_SINGLE_STEP;
503
504 WRITE_SPECIALREG(mdscr_el1,
505 READ_SPECIALREG(mdscr_el1) | MDSCR_SS);
506 isb();
507 }
508
509 set_fpcontext(td, mcp);
510
511 /* Read any register contexts we find */
512 if (mcp->mc_ptr != 0) {
513 addr = mcp->mc_ptr;
514
515 done = false;
516 do {
517 if (!__is_aligned(addr,
518 _Alignof(struct arm64_reg_context)))
519 return (EINVAL);
520
521 error = copyin((const void *)addr, &ctx, sizeof(ctx));
522 if (error != 0)
523 return (error);
524
525 switch (ctx.ctx_id) {
526 case ARM64_CTX_END:
527 done = true;
528 break;
529 default:
530 return (EINVAL);
531 }
532
533 addr += ctx.ctx_size;
534 } while (!done);
535 }
536
537 return (0);
538 #undef PSR_13_MASK
539 }
540
541 static void
get_fpcontext(struct thread * td,mcontext_t * mcp)542 get_fpcontext(struct thread *td, mcontext_t *mcp)
543 {
544 #ifdef VFP
545 struct pcb *curpcb;
546
547 MPASS(td == curthread);
548
549 curpcb = curthread->td_pcb;
550 if ((curpcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
551 /*
552 * If we have just been running VFP instructions we will
553 * need to save the state to memcpy it below.
554 */
555 vfp_save_state(td, curpcb);
556 }
557
558 KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate,
559 ("Called get_fpcontext while the kernel is using the VFP"));
560 KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
561 ("Non-userspace FPU flags set in get_fpcontext"));
562 memcpy(mcp->mc_fpregs.fp_q, curpcb->pcb_fpustate.vfp_regs,
563 sizeof(mcp->mc_fpregs.fp_q));
564 mcp->mc_fpregs.fp_cr = curpcb->pcb_fpustate.vfp_fpcr;
565 mcp->mc_fpregs.fp_sr = curpcb->pcb_fpustate.vfp_fpsr;
566 mcp->mc_fpregs.fp_flags = curpcb->pcb_fpflags;
567 mcp->mc_flags |= _MC_FP_VALID;
568 #endif
569 }
570
571 static void
set_fpcontext(struct thread * td,mcontext_t * mcp)572 set_fpcontext(struct thread *td, mcontext_t *mcp)
573 {
574 #ifdef VFP
575 struct pcb *curpcb;
576
577 MPASS(td == curthread);
578 if ((mcp->mc_flags & _MC_FP_VALID) != 0) {
579 curpcb = curthread->td_pcb;
580
581 /*
582 * Discard any vfp state for the current thread, we
583 * are about to override it.
584 */
585 critical_enter();
586 vfp_discard(td);
587 critical_exit();
588
589 KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate,
590 ("Called set_fpcontext while the kernel is using the VFP"));
591 memcpy(curpcb->pcb_fpustate.vfp_regs, mcp->mc_fpregs.fp_q,
592 sizeof(mcp->mc_fpregs.fp_q));
593 curpcb->pcb_fpustate.vfp_fpcr = mcp->mc_fpregs.fp_cr;
594 curpcb->pcb_fpustate.vfp_fpsr = mcp->mc_fpregs.fp_sr;
595 curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK;
596 }
597 #endif
598 }
599
600 int
sys_sigreturn(struct thread * td,struct sigreturn_args * uap)601 sys_sigreturn(struct thread *td, struct sigreturn_args *uap)
602 {
603 ucontext_t uc;
604 int error;
605
606 if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
607 return (EFAULT);
608
609 error = set_mcontext(td, &uc.uc_mcontext);
610 if (error != 0)
611 return (error);
612
613 /* Restore signal mask. */
614 kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
615
616 return (EJUSTRETURN);
617 }
618
619 static bool
sendsig_ctx_end(struct thread * td,vm_offset_t * addrp)620 sendsig_ctx_end(struct thread *td, vm_offset_t *addrp)
621 {
622 struct arm64_reg_context end_ctx;
623 vm_offset_t ctx_addr;
624
625 *addrp -= sizeof(end_ctx);
626 ctx_addr = *addrp;
627
628 memset(&end_ctx, 0, sizeof(end_ctx));
629 end_ctx.ctx_id = ARM64_CTX_END;
630 end_ctx.ctx_size = sizeof(end_ctx);
631
632 if (copyout(&end_ctx, (void *)ctx_addr, sizeof(end_ctx)) != 0)
633 return (false);
634
635 return (true);
636 }
637
638 typedef bool(*ctx_func)(struct thread *, vm_offset_t *);
639 static const ctx_func ctx_funcs[] = {
640 sendsig_ctx_end, /* Must be first to end the linked list */
641 NULL,
642 };
643
644 void
sendsig(sig_t catcher,ksiginfo_t * ksi,sigset_t * mask)645 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
646 {
647 struct thread *td;
648 struct proc *p;
649 struct trapframe *tf;
650 struct sigframe *fp, frame;
651 struct sigacts *psp;
652 vm_offset_t addr;
653 int onstack, sig;
654
655 td = curthread;
656 p = td->td_proc;
657 PROC_LOCK_ASSERT(p, MA_OWNED);
658
659 sig = ksi->ksi_signo;
660 psp = p->p_sigacts;
661 mtx_assert(&psp->ps_mtx, MA_OWNED);
662
663 tf = td->td_frame;
664 onstack = sigonstack(tf->tf_sp);
665
666 CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
667 catcher, sig);
668
669 /* Allocate and validate space for the signal handler context. */
670 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack &&
671 SIGISMEMBER(psp->ps_sigonstack, sig)) {
672 addr = ((uintptr_t)td->td_sigstk.ss_sp +
673 td->td_sigstk.ss_size);
674 #if defined(COMPAT_43)
675 td->td_sigstk.ss_flags |= SS_ONSTACK;
676 #endif
677 } else {
678 addr = td->td_frame->tf_sp;
679 }
680
681 /* Fill in the frame to copy out */
682 bzero(&frame, sizeof(frame));
683 get_mcontext(td, &frame.sf_uc.uc_mcontext, 0);
684 frame.sf_si = ksi->ksi_info;
685 frame.sf_uc.uc_sigmask = *mask;
686 frame.sf_uc.uc_stack = td->td_sigstk;
687 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
688 (onstack ? SS_ONSTACK : 0) : SS_DISABLE;
689 mtx_unlock(&psp->ps_mtx);
690 PROC_UNLOCK(td->td_proc);
691
692 for (int i = 0; ctx_funcs[i] != NULL; i++) {
693 if (!ctx_funcs[i](td, &addr)) {
694 /* Process has trashed its stack. Kill it. */
695 CTR4(KTR_SIG,
696 "sendsig: frame sigexit td=%p fp=%#lx func[%d]=%p",
697 td, addr, i, ctx_funcs[i]);
698 PROC_LOCK(p);
699 sigexit(td, SIGILL);
700 /* NOTREACHED */
701 }
702 }
703
704 /* Point at the first context */
705 frame.sf_uc.uc_mcontext.mc_ptr = addr;
706
707 /* Make room, keeping the stack aligned */
708 fp = (struct sigframe *)addr;
709 fp--;
710 fp = (struct sigframe *)STACKALIGN(fp);
711
712 /* Copy the sigframe out to the user's stack. */
713 if (copyout(&frame, fp, sizeof(*fp)) != 0) {
714 /* Process has trashed its stack. Kill it. */
715 CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
716 PROC_LOCK(p);
717 sigexit(td, SIGILL);
718 }
719
720 tf->tf_x[0] = sig;
721 tf->tf_x[1] = (register_t)&fp->sf_si;
722 tf->tf_x[2] = (register_t)&fp->sf_uc;
723 tf->tf_x[8] = (register_t)catcher;
724 tf->tf_sp = (register_t)fp;
725 tf->tf_elr = (register_t)PROC_SIGCODE(p);
726
727 /* Clear the single step flag while in the signal handler */
728 if ((td->td_pcb->pcb_flags & PCB_SINGLE_STEP) != 0) {
729 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP;
730 WRITE_SPECIALREG(mdscr_el1,
731 READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS);
732 isb();
733 }
734
735 CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_elr,
736 tf->tf_sp);
737
738 PROC_LOCK(p);
739 mtx_lock(&psp->ps_mtx);
740 }
741