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-rw-r--r--arch/arm64/kernel/signal32.c876
1 files changed, 876 insertions, 0 deletions
diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
new file mode 100644
index 000000000000..ac74c2f261e3
--- /dev/null
+++ b/arch/arm64/kernel/signal32.c
@@ -0,0 +1,876 @@
1/*
2 * Based on arch/arm/kernel/signal.c
3 *
4 * Copyright (C) 1995-2009 Russell King
5 * Copyright (C) 2012 ARM Ltd.
6 * Modified by Will Deacon <will.deacon@arm.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21#define __SYSCALL_COMPAT
22
23#include <linux/compat.h>
24#include <linux/signal.h>
25#include <linux/syscalls.h>
26#include <linux/ratelimit.h>
27
28#include <asm/fpsimd.h>
29#include <asm/signal32.h>
30#include <asm/uaccess.h>
31#include <asm/unistd.h>
32
33typedef struct compat_siginfo {
34 int si_signo;
35 int si_errno;
36 int si_code;
37
38 union {
39 /* The padding is the same size as AArch64. */
40 int _pad[SI_PAD_SIZE];
41
42 /* kill() */
43 struct {
44 compat_pid_t _pid; /* sender's pid */
45 __compat_uid32_t _uid; /* sender's uid */
46 } _kill;
47
48 /* POSIX.1b timers */
49 struct {
50 compat_timer_t _tid; /* timer id */
51 int _overrun; /* overrun count */
52 compat_sigval_t _sigval; /* same as below */
53 int _sys_private; /* not to be passed to user */
54 } _timer;
55
56 /* POSIX.1b signals */
57 struct {
58 compat_pid_t _pid; /* sender's pid */
59 __compat_uid32_t _uid; /* sender's uid */
60 compat_sigval_t _sigval;
61 } _rt;
62
63 /* SIGCHLD */
64 struct {
65 compat_pid_t _pid; /* which child */
66 __compat_uid32_t _uid; /* sender's uid */
67 int _status; /* exit code */
68 compat_clock_t _utime;
69 compat_clock_t _stime;
70 } _sigchld;
71
72 /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
73 struct {
74 compat_uptr_t _addr; /* faulting insn/memory ref. */
75 short _addr_lsb; /* LSB of the reported address */
76 } _sigfault;
77
78 /* SIGPOLL */
79 struct {
80 compat_long_t _band; /* POLL_IN, POLL_OUT, POLL_MSG */
81 int _fd;
82 } _sigpoll;
83 } _sifields;
84} compat_siginfo_t;
85
86struct compat_sigaction {
87 compat_uptr_t sa_handler;
88 compat_ulong_t sa_flags;
89 compat_uptr_t sa_restorer;
90 compat_sigset_t sa_mask;
91};
92
93struct compat_old_sigaction {
94 compat_uptr_t sa_handler;
95 compat_old_sigset_t sa_mask;
96 compat_ulong_t sa_flags;
97 compat_uptr_t sa_restorer;
98};
99
100typedef struct compat_sigaltstack {
101 compat_uptr_t ss_sp;
102 int ss_flags;
103 compat_size_t ss_size;
104} compat_stack_t;
105
106struct compat_sigcontext {
107 /* We always set these two fields to 0 */
108 compat_ulong_t trap_no;
109 compat_ulong_t error_code;
110
111 compat_ulong_t oldmask;
112 compat_ulong_t arm_r0;
113 compat_ulong_t arm_r1;
114 compat_ulong_t arm_r2;
115 compat_ulong_t arm_r3;
116 compat_ulong_t arm_r4;
117 compat_ulong_t arm_r5;
118 compat_ulong_t arm_r6;
119 compat_ulong_t arm_r7;
120 compat_ulong_t arm_r8;
121 compat_ulong_t arm_r9;
122 compat_ulong_t arm_r10;
123 compat_ulong_t arm_fp;
124 compat_ulong_t arm_ip;
125 compat_ulong_t arm_sp;
126 compat_ulong_t arm_lr;
127 compat_ulong_t arm_pc;
128 compat_ulong_t arm_cpsr;
129 compat_ulong_t fault_address;
130};
131
132struct compat_ucontext {
133 compat_ulong_t uc_flags;
134 struct compat_ucontext *uc_link;
135 compat_stack_t uc_stack;
136 struct compat_sigcontext uc_mcontext;
137 compat_sigset_t uc_sigmask;
138 int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
139 compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
140};
141
142struct compat_vfp_sigframe {
143 compat_ulong_t magic;
144 compat_ulong_t size;
145 struct compat_user_vfp {
146 compat_u64 fpregs[32];
147 compat_ulong_t fpscr;
148 } ufp;
149 struct compat_user_vfp_exc {
150 compat_ulong_t fpexc;
151 compat_ulong_t fpinst;
152 compat_ulong_t fpinst2;
153 } ufp_exc;
154} __attribute__((__aligned__(8)));
155
156#define VFP_MAGIC 0x56465001
157#define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
158
159struct compat_aux_sigframe {
160 struct compat_vfp_sigframe vfp;
161
162 /* Something that isn't a valid magic number for any coprocessor. */
163 unsigned long end_magic;
164} __attribute__((__aligned__(8)));
165
166struct compat_sigframe {
167 struct compat_ucontext uc;
168 compat_ulong_t retcode[2];
169};
170
171struct compat_rt_sigframe {
172 struct compat_siginfo info;
173 struct compat_sigframe sig;
174};
175
176#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
177
178/*
179 * For ARM syscalls, the syscall number has to be loaded into r7.
180 * We do not support an OABI userspace.
181 */
182#define MOV_R7_NR_SIGRETURN (0xe3a07000 | __NR_sigreturn)
183#define SVC_SYS_SIGRETURN (0xef000000 | __NR_sigreturn)
184#define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | __NR_rt_sigreturn)
185#define SVC_SYS_RT_SIGRETURN (0xef000000 | __NR_rt_sigreturn)
186
187/*
188 * For Thumb syscalls, we also pass the syscall number via r7. We therefore
189 * need two 16-bit instructions.
190 */
191#define SVC_THUMB_SIGRETURN (((0xdf00 | __NR_sigreturn) << 16) | \
192 0x2700 | __NR_sigreturn)
193#define SVC_THUMB_RT_SIGRETURN (((0xdf00 | __NR_rt_sigreturn) << 16) | \
194 0x2700 | __NR_rt_sigreturn)
195
196const compat_ulong_t aarch32_sigret_code[6] = {
197 /*
198 * AArch32 sigreturn code.
199 * We don't construct an OABI SWI - instead we just set the imm24 field
200 * to the EABI syscall number so that we create a sane disassembly.
201 */
202 MOV_R7_NR_SIGRETURN, SVC_SYS_SIGRETURN, SVC_THUMB_SIGRETURN,
203 MOV_R7_NR_RT_SIGRETURN, SVC_SYS_RT_SIGRETURN, SVC_THUMB_RT_SIGRETURN,
204};
205
206static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
207{
208 compat_sigset_t cset;
209
210 cset.sig[0] = set->sig[0] & 0xffffffffull;
211 cset.sig[1] = set->sig[0] >> 32;
212
213 return copy_to_user(uset, &cset, sizeof(*uset));
214}
215
216static inline int get_sigset_t(sigset_t *set,
217 const compat_sigset_t __user *uset)
218{
219 compat_sigset_t s32;
220
221 if (copy_from_user(&s32, uset, sizeof(*uset)))
222 return -EFAULT;
223
224 set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
225 return 0;
226}
227
228int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
229{
230 int err;
231
232 if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
233 return -EFAULT;
234
235 /* If you change siginfo_t structure, please be sure
236 * this code is fixed accordingly.
237 * It should never copy any pad contained in the structure
238 * to avoid security leaks, but must copy the generic
239 * 3 ints plus the relevant union member.
240 * This routine must convert siginfo from 64bit to 32bit as well
241 * at the same time.
242 */
243 err = __put_user(from->si_signo, &to->si_signo);
244 err |= __put_user(from->si_errno, &to->si_errno);
245 err |= __put_user((short)from->si_code, &to->si_code);
246 if (from->si_code < 0)
247 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
248 SI_PAD_SIZE);
249 else switch (from->si_code & __SI_MASK) {
250 case __SI_KILL:
251 err |= __put_user(from->si_pid, &to->si_pid);
252 err |= __put_user(from->si_uid, &to->si_uid);
253 break;
254 case __SI_TIMER:
255 err |= __put_user(from->si_tid, &to->si_tid);
256 err |= __put_user(from->si_overrun, &to->si_overrun);
257 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
258 &to->si_ptr);
259 break;
260 case __SI_POLL:
261 err |= __put_user(from->si_band, &to->si_band);
262 err |= __put_user(from->si_fd, &to->si_fd);
263 break;
264 case __SI_FAULT:
265 err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
266 &to->si_addr);
267#ifdef BUS_MCEERR_AO
268 /*
269 * Other callers might not initialize the si_lsb field,
270 * so check explicitely for the right codes here.
271 */
272 if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
273 err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
274#endif
275 break;
276 case __SI_CHLD:
277 err |= __put_user(from->si_pid, &to->si_pid);
278 err |= __put_user(from->si_uid, &to->si_uid);
279 err |= __put_user(from->si_status, &to->si_status);
280 err |= __put_user(from->si_utime, &to->si_utime);
281 err |= __put_user(from->si_stime, &to->si_stime);
282 break;
283 case __SI_RT: /* This is not generated by the kernel as of now. */
284 case __SI_MESGQ: /* But this is */
285 err |= __put_user(from->si_pid, &to->si_pid);
286 err |= __put_user(from->si_uid, &to->si_uid);
287 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
288 break;
289 default: /* this is just in case for now ... */
290 err |= __put_user(from->si_pid, &to->si_pid);
291 err |= __put_user(from->si_uid, &to->si_uid);
292 break;
293 }
294 return err;
295}
296
297int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
298{
299 memset(to, 0, sizeof *to);
300
301 if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
302 copy_from_user(to->_sifields._pad,
303 from->_sifields._pad, SI_PAD_SIZE))
304 return -EFAULT;
305
306 return 0;
307}
308
309/*
310 * VFP save/restore code.
311 */
312static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
313{
314 struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
315 compat_ulong_t magic = VFP_MAGIC;
316 compat_ulong_t size = VFP_STORAGE_SIZE;
317 compat_ulong_t fpscr, fpexc;
318 int err = 0;
319
320 /*
321 * Save the hardware registers to the fpsimd_state structure.
322 * Note that this also saves V16-31, which aren't visible
323 * in AArch32.
324 */
325 fpsimd_save_state(fpsimd);
326
327 /* Place structure header on the stack */
328 __put_user_error(magic, &frame->magic, err);
329 __put_user_error(size, &frame->size, err);
330
331 /*
332 * Now copy the FP registers. Since the registers are packed,
333 * we can copy the prefix we want (V0-V15) as it is.
334 * FIXME: Won't work if big endian.
335 */
336 err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
337 sizeof(frame->ufp.fpregs));
338
339 /* Create an AArch32 fpscr from the fpsr and the fpcr. */
340 fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
341 (fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
342 __put_user_error(fpscr, &frame->ufp.fpscr, err);
343
344 /*
345 * The exception register aren't available so we fake up a
346 * basic FPEXC and zero everything else.
347 */
348 fpexc = (1 << 30);
349 __put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
350 __put_user_error(0, &frame->ufp_exc.fpinst, err);
351 __put_user_error(0, &frame->ufp_exc.fpinst2, err);
352
353 return err ? -EFAULT : 0;
354}
355
356static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
357{
358 struct fpsimd_state fpsimd;
359 compat_ulong_t magic = VFP_MAGIC;
360 compat_ulong_t size = VFP_STORAGE_SIZE;
361 compat_ulong_t fpscr;
362 int err = 0;
363
364 __get_user_error(magic, &frame->magic, err);
365 __get_user_error(size, &frame->size, err);
366
367 if (err)
368 return -EFAULT;
369 if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
370 return -EINVAL;
371
372 /*
373 * Copy the FP registers into the start of the fpsimd_state.
374 * FIXME: Won't work if big endian.
375 */
376 err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
377 sizeof(frame->ufp.fpregs));
378
379 /* Extract the fpsr and the fpcr from the fpscr */
380 __get_user_error(fpscr, &frame->ufp.fpscr, err);
381 fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
382 fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
383
384 /*
385 * We don't need to touch the exception register, so
386 * reload the hardware state.
387 */
388 if (!err) {
389 preempt_disable();
390 fpsimd_load_state(&fpsimd);
391 preempt_enable();
392 }
393
394 return err ? -EFAULT : 0;
395}
396
397/*
398 * atomically swap in the new signal mask, and wait for a signal.
399 */
400asmlinkage int compat_sys_sigsuspend(int restart, compat_ulong_t oldmask,
401 compat_old_sigset_t mask)
402{
403 sigset_t blocked;
404
405 siginitset(&current->blocked, mask);
406 return sigsuspend(&blocked);
407}
408
409asmlinkage int compat_sys_sigaction(int sig,
410 const struct compat_old_sigaction __user *act,
411 struct compat_old_sigaction __user *oact)
412{
413 struct k_sigaction new_ka, old_ka;
414 int ret;
415 compat_old_sigset_t mask;
416 compat_uptr_t handler, restorer;
417
418 if (act) {
419 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
420 __get_user(handler, &act->sa_handler) ||
421 __get_user(restorer, &act->sa_restorer) ||
422 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
423 __get_user(mask, &act->sa_mask))
424 return -EFAULT;
425
426 new_ka.sa.sa_handler = compat_ptr(handler);
427 new_ka.sa.sa_restorer = compat_ptr(restorer);
428 siginitset(&new_ka.sa.sa_mask, mask);
429 }
430
431 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
432
433 if (!ret && oact) {
434 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
435 __put_user(ptr_to_compat(old_ka.sa.sa_handler),
436 &oact->sa_handler) ||
437 __put_user(ptr_to_compat(old_ka.sa.sa_restorer),
438 &oact->sa_restorer) ||
439 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
440 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
441 return -EFAULT;
442 }
443
444 return ret;
445}
446
447asmlinkage int compat_sys_rt_sigaction(int sig,
448 const struct compat_sigaction __user *act,
449 struct compat_sigaction __user *oact,
450 compat_size_t sigsetsize)
451{
452 struct k_sigaction new_ka, old_ka;
453 int ret;
454
455 /* XXX: Don't preclude handling different sized sigset_t's. */
456 if (sigsetsize != sizeof(compat_sigset_t))
457 return -EINVAL;
458
459 if (act) {
460 compat_uptr_t handler, restorer;
461
462 ret = get_user(handler, &act->sa_handler);
463 new_ka.sa.sa_handler = compat_ptr(handler);
464 ret |= get_user(restorer, &act->sa_restorer);
465 new_ka.sa.sa_restorer = compat_ptr(restorer);
466 ret |= get_sigset_t(&new_ka.sa.sa_mask, &act->sa_mask);
467 ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
468 if (ret)
469 return -EFAULT;
470 }
471
472 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
473 if (!ret && oact) {
474 ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), &oact->sa_handler);
475 ret |= put_sigset_t(&oact->sa_mask, &old_ka.sa.sa_mask);
476 ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
477 }
478 return ret;
479}
480
481int compat_do_sigaltstack(compat_uptr_t compat_uss, compat_uptr_t compat_uoss,
482 compat_ulong_t sp)
483{
484 compat_stack_t __user *newstack = compat_ptr(compat_uss);
485 compat_stack_t __user *oldstack = compat_ptr(compat_uoss);
486 compat_uptr_t ss_sp;
487 int ret;
488 mm_segment_t old_fs;
489 stack_t uss, uoss;
490
491 /* Marshall the compat new stack into a stack_t */
492 if (newstack) {
493 if (get_user(ss_sp, &newstack->ss_sp) ||
494 __get_user(uss.ss_flags, &newstack->ss_flags) ||
495 __get_user(uss.ss_size, &newstack->ss_size))
496 return -EFAULT;
497 uss.ss_sp = compat_ptr(ss_sp);
498 }
499
500 old_fs = get_fs();
501 set_fs(KERNEL_DS);
502 /* The __user pointer casts are valid because of the set_fs() */
503 ret = do_sigaltstack(
504 newstack ? (stack_t __user *) &uss : NULL,
505 oldstack ? (stack_t __user *) &uoss : NULL,
506 (unsigned long)sp);
507 set_fs(old_fs);
508
509 /* Convert the old stack_t into a compat stack. */
510 if (!ret && oldstack &&
511 (put_user(ptr_to_compat(uoss.ss_sp), &oldstack->ss_sp) ||
512 __put_user(uoss.ss_flags, &oldstack->ss_flags) ||
513 __put_user(uoss.ss_size, &oldstack->ss_size)))
514 return -EFAULT;
515 return ret;
516}
517
518static int compat_restore_sigframe(struct pt_regs *regs,
519 struct compat_sigframe __user *sf)
520{
521 int err;
522 sigset_t set;
523 struct compat_aux_sigframe __user *aux;
524
525 err = get_sigset_t(&set, &sf->uc.uc_sigmask);
526 if (err == 0) {
527 sigdelsetmask(&set, ~_BLOCKABLE);
528 set_current_blocked(&set);
529 }
530
531 __get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
532 __get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
533 __get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
534 __get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
535 __get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
536 __get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
537 __get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
538 __get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
539 __get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
540 __get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
541 __get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
542 __get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
543 __get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
544 __get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
545 __get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
546 __get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
547 __get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
548
549 /*
550 * Avoid compat_sys_sigreturn() restarting.
551 */
552 regs->syscallno = ~0UL;
553
554 err |= !valid_user_regs(&regs->user_regs);
555
556 aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
557 if (err == 0)
558 err |= compat_restore_vfp_context(&aux->vfp);
559
560 return err;
561}
562
563asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
564{
565 struct compat_sigframe __user *frame;
566
567 /* Always make any pending restarted system calls return -EINTR */
568 current_thread_info()->restart_block.fn = do_no_restart_syscall;
569
570 /*
571 * Since we stacked the signal on a 64-bit boundary,
572 * then 'sp' should be word aligned here. If it's
573 * not, then the user is trying to mess with us.
574 */
575 if (regs->compat_sp & 7)
576 goto badframe;
577
578 frame = (struct compat_sigframe __user *)regs->compat_sp;
579
580 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
581 goto badframe;
582
583 if (compat_restore_sigframe(regs, frame))
584 goto badframe;
585
586 return regs->regs[0];
587
588badframe:
589 if (show_unhandled_signals)
590 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
591 current->comm, task_pid_nr(current), __func__,
592 regs->pc, regs->sp);
593 force_sig(SIGSEGV, current);
594 return 0;
595}
596
597asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
598{
599 struct compat_rt_sigframe __user *frame;
600
601 /* Always make any pending restarted system calls return -EINTR */
602 current_thread_info()->restart_block.fn = do_no_restart_syscall;
603
604 /*
605 * Since we stacked the signal on a 64-bit boundary,
606 * then 'sp' should be word aligned here. If it's
607 * not, then the user is trying to mess with us.
608 */
609 if (regs->compat_sp & 7)
610 goto badframe;
611
612 frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
613
614 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
615 goto badframe;
616
617 if (compat_restore_sigframe(regs, &frame->sig))
618 goto badframe;
619
620 if (compat_do_sigaltstack(ptr_to_compat(&frame->sig.uc.uc_stack),
621 ptr_to_compat((void __user *)NULL),
622 regs->compat_sp) == -EFAULT)
623 goto badframe;
624
625 return regs->regs[0];
626
627badframe:
628 if (show_unhandled_signals)
629 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
630 current->comm, task_pid_nr(current), __func__,
631 regs->pc, regs->sp);
632 force_sig(SIGSEGV, current);
633 return 0;
634}
635
636static inline void __user *compat_get_sigframe(struct k_sigaction *ka,
637 struct pt_regs *regs,
638 int framesize)
639{
640 compat_ulong_t sp = regs->compat_sp;
641 void __user *frame;
642
643 /*
644 * This is the X/Open sanctioned signal stack switching.
645 */
646 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
647 sp = current->sas_ss_sp + current->sas_ss_size;
648
649 /*
650 * ATPCS B01 mandates 8-byte alignment
651 */
652 frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
653
654 /*
655 * Check that we can actually write to the signal frame.
656 */
657 if (!access_ok(VERIFY_WRITE, frame, framesize))
658 frame = NULL;
659
660 return frame;
661}
662
663static int compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
664 compat_ulong_t __user *rc, void __user *frame,
665 int usig)
666{
667 compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
668 compat_ulong_t retcode;
669 compat_ulong_t spsr = regs->pstate & ~PSR_f;
670 int thumb;
671
672 /* Check if the handler is written for ARM or Thumb */
673 thumb = handler & 1;
674
675 if (thumb) {
676 spsr |= COMPAT_PSR_T_BIT;
677 spsr &= ~COMPAT_PSR_IT_MASK;
678 } else {
679 spsr &= ~COMPAT_PSR_T_BIT;
680 }
681
682 if (ka->sa.sa_flags & SA_RESTORER) {
683 retcode = ptr_to_compat(ka->sa.sa_restorer);
684 } else {
685 /* Set up sigreturn pointer */
686 unsigned int idx = thumb << 1;
687
688 if (ka->sa.sa_flags & SA_SIGINFO)
689 idx += 3;
690
691 retcode = AARCH32_VECTORS_BASE +
692 AARCH32_KERN_SIGRET_CODE_OFFSET +
693 (idx << 2) + thumb;
694 }
695
696 regs->regs[0] = usig;
697 regs->compat_sp = ptr_to_compat(frame);
698 regs->compat_lr = retcode;
699 regs->pc = handler;
700 regs->pstate = spsr;
701
702 return 0;
703}
704
705static int compat_setup_sigframe(struct compat_sigframe __user *sf,
706 struct pt_regs *regs, sigset_t *set)
707{
708 struct compat_aux_sigframe __user *aux;
709 int err = 0;
710
711 __put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
712 __put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
713 __put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
714 __put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
715 __put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
716 __put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
717 __put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
718 __put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
719 __put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
720 __put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
721 __put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
722 __put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
723 __put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
724 __put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
725 __put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
726 __put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
727 __put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
728
729 __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
730 __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.error_code, err);
731 __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
732 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
733
734 err |= put_sigset_t(&sf->uc.uc_sigmask, set);
735
736 aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
737
738 if (err == 0)
739 err |= compat_preserve_vfp_context(&aux->vfp);
740 __put_user_error(0, &aux->end_magic, err);
741
742 return err;
743}
744
745/*
746 * 32-bit signal handling routines called from signal.c
747 */
748int compat_setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
749 sigset_t *set, struct pt_regs *regs)
750{
751 struct compat_rt_sigframe __user *frame;
752 compat_stack_t stack;
753 int err = 0;
754
755 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
756
757 if (!frame)
758 return 1;
759
760 err |= copy_siginfo_to_user32(&frame->info, info);
761
762 __put_user_error(0, &frame->sig.uc.uc_flags, err);
763 __put_user_error(NULL, &frame->sig.uc.uc_link, err);
764
765 memset(&stack, 0, sizeof(stack));
766 stack.ss_sp = (compat_uptr_t)current->sas_ss_sp;
767 stack.ss_flags = sas_ss_flags(regs->compat_sp);
768 stack.ss_size = current->sas_ss_size;
769 err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
770
771 err |= compat_setup_sigframe(&frame->sig, regs, set);
772 if (err == 0)
773 err = compat_setup_return(regs, ka, frame->sig.retcode, frame,
774 usig);
775
776 if (err == 0) {
777 regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
778 regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
779 }
780
781 return err;
782}
783
784int compat_setup_frame(int usig, struct k_sigaction *ka, sigset_t *set,
785 struct pt_regs *regs)
786{
787 struct compat_sigframe __user *frame;
788 int err = 0;
789
790 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
791
792 if (!frame)
793 return 1;
794
795 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
796
797 err |= compat_setup_sigframe(frame, regs, set);
798 if (err == 0)
799 err = compat_setup_return(regs, ka, frame->retcode, frame, usig);
800
801 return err;
802}
803
804/*
805 * RT signals don't have generic compat wrappers.
806 * See arch/powerpc/kernel/signal_32.c
807 */
808asmlinkage int compat_sys_rt_sigprocmask(int how, compat_sigset_t __user *set,
809 compat_sigset_t __user *oset,
810 compat_size_t sigsetsize)
811{
812 sigset_t s;
813 sigset_t __user *up;
814 int ret;
815 mm_segment_t old_fs = get_fs();
816
817 if (set) {
818 if (get_sigset_t(&s, set))
819 return -EFAULT;
820 }
821
822 set_fs(KERNEL_DS);
823 /* This is valid because of the set_fs() */
824 up = (sigset_t __user *) &s;
825 ret = sys_rt_sigprocmask(how, set ? up : NULL, oset ? up : NULL,
826 sigsetsize);
827 set_fs(old_fs);
828 if (ret)
829 return ret;
830 if (oset) {
831 if (put_sigset_t(oset, &s))
832 return -EFAULT;
833 }
834 return 0;
835}
836
837asmlinkage int compat_sys_rt_sigpending(compat_sigset_t __user *set,
838 compat_size_t sigsetsize)
839{
840 sigset_t s;
841 int ret;
842 mm_segment_t old_fs = get_fs();
843
844 set_fs(KERNEL_DS);
845 /* The __user pointer cast is valid because of the set_fs() */
846 ret = sys_rt_sigpending((sigset_t __user *) &s, sigsetsize);
847 set_fs(old_fs);
848 if (!ret) {
849 if (put_sigset_t(set, &s))
850 return -EFAULT;
851 }
852 return ret;
853}
854
855asmlinkage int compat_sys_rt_sigqueueinfo(int pid, int sig,
856 compat_siginfo_t __user *uinfo)
857{
858 siginfo_t info;
859 int ret;
860 mm_segment_t old_fs = get_fs();
861
862 ret = copy_siginfo_from_user32(&info, uinfo);
863 if (unlikely(ret))
864 return ret;
865
866 set_fs (KERNEL_DS);
867 /* The __user pointer cast is valid because of the set_fs() */
868 ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __user *) &info);
869 set_fs (old_fs);
870 return ret;
871}
872
873void compat_setup_restart_syscall(struct pt_regs *regs)
874{
875 regs->regs[7] = __NR_restart_syscall;
876}
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-07 22:09:44 -0500