2 * Based on arch/arm/kernel/signal.c
4 * Copyright (C) 1995-2009 Russell King
5 * Copyright (C) 2012 ARM Ltd.
6 * Modified by Will Deacon <will.deacon@arm.com>
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.
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.
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/>.
21 #include <linux/compat.h>
22 #include <linux/signal.h>
23 #include <linux/syscalls.h>
24 #include <linux/ratelimit.h>
26 #include <asm/fpsimd.h>
27 #include <asm/signal32.h>
28 #include <asm/uaccess.h>
29 #include <asm/unistd32.h>
31 struct compat_sigcontext {
32 /* We always set these two fields to 0 */
33 compat_ulong_t trap_no;
34 compat_ulong_t error_code;
36 compat_ulong_t oldmask;
37 compat_ulong_t arm_r0;
38 compat_ulong_t arm_r1;
39 compat_ulong_t arm_r2;
40 compat_ulong_t arm_r3;
41 compat_ulong_t arm_r4;
42 compat_ulong_t arm_r5;
43 compat_ulong_t arm_r6;
44 compat_ulong_t arm_r7;
45 compat_ulong_t arm_r8;
46 compat_ulong_t arm_r9;
47 compat_ulong_t arm_r10;
48 compat_ulong_t arm_fp;
49 compat_ulong_t arm_ip;
50 compat_ulong_t arm_sp;
51 compat_ulong_t arm_lr;
52 compat_ulong_t arm_pc;
53 compat_ulong_t arm_cpsr;
54 compat_ulong_t fault_address;
57 struct compat_ucontext {
58 compat_ulong_t uc_flags;
59 compat_uptr_t uc_link;
60 compat_stack_t uc_stack;
61 struct compat_sigcontext uc_mcontext;
62 compat_sigset_t uc_sigmask;
63 int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
64 compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
67 struct compat_vfp_sigframe {
70 struct compat_user_vfp {
71 compat_u64 fpregs[32];
74 struct compat_user_vfp_exc {
76 compat_ulong_t fpinst;
77 compat_ulong_t fpinst2;
79 } __attribute__((__aligned__(8)));
81 #define VFP_MAGIC 0x56465001
82 #define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
84 struct compat_aux_sigframe {
85 struct compat_vfp_sigframe vfp;
87 /* Something that isn't a valid magic number for any coprocessor. */
88 unsigned long end_magic;
89 } __attribute__((__aligned__(8)));
91 struct compat_sigframe {
92 struct compat_ucontext uc;
93 compat_ulong_t retcode[2];
96 struct compat_rt_sigframe {
97 struct compat_siginfo info;
98 struct compat_sigframe sig;
101 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
103 static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
105 compat_sigset_t cset;
107 cset.sig[0] = set->sig[0] & 0xffffffffull;
108 cset.sig[1] = set->sig[0] >> 32;
110 return copy_to_user(uset, &cset, sizeof(*uset));
113 static inline int get_sigset_t(sigset_t *set,
114 const compat_sigset_t __user *uset)
118 if (copy_from_user(&s32, uset, sizeof(*uset)))
121 set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
125 int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
129 if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
132 /* If you change siginfo_t structure, please be sure
133 * this code is fixed accordingly.
134 * It should never copy any pad contained in the structure
135 * to avoid security leaks, but must copy the generic
136 * 3 ints plus the relevant union member.
137 * This routine must convert siginfo from 64bit to 32bit as well
140 err = __put_user(from->si_signo, &to->si_signo);
141 err |= __put_user(from->si_errno, &to->si_errno);
142 err |= __put_user((short)from->si_code, &to->si_code);
143 if (from->si_code < 0)
144 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
146 else switch (from->si_code & __SI_MASK) {
148 err |= __put_user(from->si_pid, &to->si_pid);
149 err |= __put_user(from->si_uid, &to->si_uid);
152 err |= __put_user(from->si_tid, &to->si_tid);
153 err |= __put_user(from->si_overrun, &to->si_overrun);
154 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
158 err |= __put_user(from->si_band, &to->si_band);
159 err |= __put_user(from->si_fd, &to->si_fd);
162 err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
166 * Other callers might not initialize the si_lsb field,
167 * so check explicitely for the right codes here.
169 if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
170 err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
174 err |= __put_user(from->si_pid, &to->si_pid);
175 err |= __put_user(from->si_uid, &to->si_uid);
176 err |= __put_user(from->si_status, &to->si_status);
177 err |= __put_user(from->si_utime, &to->si_utime);
178 err |= __put_user(from->si_stime, &to->si_stime);
180 case __SI_RT: /* This is not generated by the kernel as of now. */
181 case __SI_MESGQ: /* But this is */
182 err |= __put_user(from->si_pid, &to->si_pid);
183 err |= __put_user(from->si_uid, &to->si_uid);
184 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
186 default: /* this is just in case for now ... */
187 err |= __put_user(from->si_pid, &to->si_pid);
188 err |= __put_user(from->si_uid, &to->si_uid);
194 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
196 memset(to, 0, sizeof *to);
198 if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
199 copy_from_user(to->_sifields._pad,
200 from->_sifields._pad, SI_PAD_SIZE))
207 * VFP save/restore code.
209 static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
211 struct fpsimd_state *fpsimd = ¤t->thread.fpsimd_state;
212 compat_ulong_t magic = VFP_MAGIC;
213 compat_ulong_t size = VFP_STORAGE_SIZE;
214 compat_ulong_t fpscr, fpexc;
218 * Save the hardware registers to the fpsimd_state structure.
219 * Note that this also saves V16-31, which aren't visible
222 fpsimd_save_state(fpsimd);
224 /* Place structure header on the stack */
225 __put_user_error(magic, &frame->magic, err);
226 __put_user_error(size, &frame->size, err);
229 * Now copy the FP registers. Since the registers are packed,
230 * we can copy the prefix we want (V0-V15) as it is.
231 * FIXME: Won't work if big endian.
233 err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
234 sizeof(frame->ufp.fpregs));
236 /* Create an AArch32 fpscr from the fpsr and the fpcr. */
237 fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
238 (fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
239 __put_user_error(fpscr, &frame->ufp.fpscr, err);
242 * The exception register aren't available so we fake up a
243 * basic FPEXC and zero everything else.
246 __put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
247 __put_user_error(0, &frame->ufp_exc.fpinst, err);
248 __put_user_error(0, &frame->ufp_exc.fpinst2, err);
250 return err ? -EFAULT : 0;
253 static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
255 struct fpsimd_state fpsimd;
256 compat_ulong_t magic = VFP_MAGIC;
257 compat_ulong_t size = VFP_STORAGE_SIZE;
258 compat_ulong_t fpscr;
261 __get_user_error(magic, &frame->magic, err);
262 __get_user_error(size, &frame->size, err);
266 if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
270 * Copy the FP registers into the start of the fpsimd_state.
271 * FIXME: Won't work if big endian.
273 err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
274 sizeof(frame->ufp.fpregs));
276 /* Extract the fpsr and the fpcr from the fpscr */
277 __get_user_error(fpscr, &frame->ufp.fpscr, err);
278 fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
279 fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
282 * We don't need to touch the exception register, so
283 * reload the hardware state.
287 fpsimd_load_state(&fpsimd);
291 return err ? -EFAULT : 0;
294 static int compat_restore_sigframe(struct pt_regs *regs,
295 struct compat_sigframe __user *sf)
299 struct compat_aux_sigframe __user *aux;
301 err = get_sigset_t(&set, &sf->uc.uc_sigmask);
303 sigdelsetmask(&set, ~_BLOCKABLE);
304 set_current_blocked(&set);
307 __get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
308 __get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
309 __get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
310 __get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
311 __get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
312 __get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
313 __get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
314 __get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
315 __get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
316 __get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
317 __get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
318 __get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
319 __get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
320 __get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
321 __get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
322 __get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
323 __get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
326 * Avoid compat_sys_sigreturn() restarting.
328 regs->syscallno = ~0UL;
330 err |= !valid_user_regs(®s->user_regs);
332 aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
334 err |= compat_restore_vfp_context(&aux->vfp);
339 asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
341 struct compat_sigframe __user *frame;
343 /* Always make any pending restarted system calls return -EINTR */
344 current_thread_info()->restart_block.fn = do_no_restart_syscall;
347 * Since we stacked the signal on a 64-bit boundary,
348 * then 'sp' should be word aligned here. If it's
349 * not, then the user is trying to mess with us.
351 if (regs->compat_sp & 7)
354 frame = (struct compat_sigframe __user *)regs->compat_sp;
356 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
359 if (compat_restore_sigframe(regs, frame))
362 return regs->regs[0];
365 if (show_unhandled_signals)
366 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
367 current->comm, task_pid_nr(current), __func__,
369 force_sig(SIGSEGV, current);
373 asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
375 struct compat_rt_sigframe __user *frame;
377 /* Always make any pending restarted system calls return -EINTR */
378 current_thread_info()->restart_block.fn = do_no_restart_syscall;
381 * Since we stacked the signal on a 64-bit boundary,
382 * then 'sp' should be word aligned here. If it's
383 * not, then the user is trying to mess with us.
385 if (regs->compat_sp & 7)
388 frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
390 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
393 if (compat_restore_sigframe(regs, &frame->sig))
396 if (compat_restore_altstack(&frame->sig.uc.uc_stack))
399 return regs->regs[0];
402 if (show_unhandled_signals)
403 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
404 current->comm, task_pid_nr(current), __func__,
406 force_sig(SIGSEGV, current);
410 static void __user *compat_get_sigframe(struct k_sigaction *ka,
411 struct pt_regs *regs,
414 compat_ulong_t sp = regs->compat_sp;
418 * This is the X/Open sanctioned signal stack switching.
420 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
421 sp = current->sas_ss_sp + current->sas_ss_size;
424 * ATPCS B01 mandates 8-byte alignment
426 frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
429 * Check that we can actually write to the signal frame.
431 if (!access_ok(VERIFY_WRITE, frame, framesize))
437 static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
438 compat_ulong_t __user *rc, void __user *frame,
441 compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
442 compat_ulong_t retcode;
443 compat_ulong_t spsr = regs->pstate & ~PSR_f;
446 /* Check if the handler is written for ARM or Thumb */
450 spsr |= COMPAT_PSR_T_BIT;
452 spsr &= ~COMPAT_PSR_T_BIT;
454 /* The IT state must be cleared for both ARM and Thumb-2 */
455 spsr &= ~COMPAT_PSR_IT_MASK;
457 if (ka->sa.sa_flags & SA_RESTORER) {
458 retcode = ptr_to_compat(ka->sa.sa_restorer);
460 /* Set up sigreturn pointer */
461 unsigned int idx = thumb << 1;
463 if (ka->sa.sa_flags & SA_SIGINFO)
466 retcode = AARCH32_VECTORS_BASE +
467 AARCH32_KERN_SIGRET_CODE_OFFSET +
471 regs->regs[0] = usig;
472 regs->compat_sp = ptr_to_compat(frame);
473 regs->compat_lr = retcode;
478 static int compat_setup_sigframe(struct compat_sigframe __user *sf,
479 struct pt_regs *regs, sigset_t *set)
481 struct compat_aux_sigframe __user *aux;
484 __put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
485 __put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
486 __put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
487 __put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
488 __put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
489 __put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
490 __put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
491 __put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
492 __put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
493 __put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
494 __put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
495 __put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
496 __put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
497 __put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
498 __put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
499 __put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
500 __put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
502 __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
503 __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.error_code, err);
504 __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
505 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
507 err |= put_sigset_t(&sf->uc.uc_sigmask, set);
509 aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
512 err |= compat_preserve_vfp_context(&aux->vfp);
513 __put_user_error(0, &aux->end_magic, err);
519 * 32-bit signal handling routines called from signal.c
521 int compat_setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
522 sigset_t *set, struct pt_regs *regs)
524 struct compat_rt_sigframe __user *frame;
527 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
532 err |= copy_siginfo_to_user32(&frame->info, info);
534 __put_user_error(0, &frame->sig.uc.uc_flags, err);
535 __put_user_error(0, &frame->sig.uc.uc_link, err);
537 err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
539 err |= compat_setup_sigframe(&frame->sig, regs, set);
542 compat_setup_return(regs, ka, frame->sig.retcode, frame, usig);
543 regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
544 regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
550 int compat_setup_frame(int usig, struct k_sigaction *ka, sigset_t *set,
551 struct pt_regs *regs)
553 struct compat_sigframe __user *frame;
556 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
561 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
563 err |= compat_setup_sigframe(frame, regs, set);
565 compat_setup_return(regs, ka, frame->retcode, frame, usig);
570 void compat_setup_restart_syscall(struct pt_regs *regs)
572 regs->regs[7] = __NR_compat_restart_syscall;