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>
27 #include <asm/fpsimd.h>
28 #include <asm/signal32.h>
29 #include <asm/uaccess.h>
30 #include <asm/unistd32.h>
32 struct compat_sigcontext {
33 /* We always set these two fields to 0 */
34 compat_ulong_t trap_no;
35 compat_ulong_t error_code;
37 compat_ulong_t oldmask;
38 compat_ulong_t arm_r0;
39 compat_ulong_t arm_r1;
40 compat_ulong_t arm_r2;
41 compat_ulong_t arm_r3;
42 compat_ulong_t arm_r4;
43 compat_ulong_t arm_r5;
44 compat_ulong_t arm_r6;
45 compat_ulong_t arm_r7;
46 compat_ulong_t arm_r8;
47 compat_ulong_t arm_r9;
48 compat_ulong_t arm_r10;
49 compat_ulong_t arm_fp;
50 compat_ulong_t arm_ip;
51 compat_ulong_t arm_sp;
52 compat_ulong_t arm_lr;
53 compat_ulong_t arm_pc;
54 compat_ulong_t arm_cpsr;
55 compat_ulong_t fault_address;
58 struct compat_ucontext {
59 compat_ulong_t uc_flags;
60 compat_uptr_t uc_link;
61 compat_stack_t uc_stack;
62 struct compat_sigcontext uc_mcontext;
63 compat_sigset_t uc_sigmask;
64 int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
65 compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
68 struct compat_vfp_sigframe {
71 struct compat_user_vfp {
72 compat_u64 fpregs[32];
75 struct compat_user_vfp_exc {
77 compat_ulong_t fpinst;
78 compat_ulong_t fpinst2;
80 } __attribute__((__aligned__(8)));
82 #define VFP_MAGIC 0x56465001
83 #define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
85 #define FSR_WRITE_SHIFT (11)
87 struct compat_aux_sigframe {
88 struct compat_vfp_sigframe vfp;
90 /* Something that isn't a valid magic number for any coprocessor. */
91 unsigned long end_magic;
92 } __attribute__((__aligned__(8)));
94 struct compat_sigframe {
95 struct compat_ucontext uc;
96 compat_ulong_t retcode[2];
99 struct compat_rt_sigframe {
100 struct compat_siginfo info;
101 struct compat_sigframe sig;
104 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
106 static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
108 compat_sigset_t cset;
110 cset.sig[0] = set->sig[0] & 0xffffffffull;
111 cset.sig[1] = set->sig[0] >> 32;
113 return copy_to_user(uset, &cset, sizeof(*uset));
116 static inline int get_sigset_t(sigset_t *set,
117 const compat_sigset_t __user *uset)
121 if (copy_from_user(&s32, uset, sizeof(*uset)))
124 set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
128 int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
132 if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
135 /* If you change siginfo_t structure, please be sure
136 * this code is fixed accordingly.
137 * It should never copy any pad contained in the structure
138 * to avoid security leaks, but must copy the generic
139 * 3 ints plus the relevant union member.
140 * This routine must convert siginfo from 64bit to 32bit as well
143 err = __put_user(from->si_signo, &to->si_signo);
144 err |= __put_user(from->si_errno, &to->si_errno);
145 err |= __put_user((short)from->si_code, &to->si_code);
146 if (from->si_code < 0)
147 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
149 else switch (from->si_code & __SI_MASK) {
151 err |= __put_user(from->si_pid, &to->si_pid);
152 err |= __put_user(from->si_uid, &to->si_uid);
155 err |= __put_user(from->si_tid, &to->si_tid);
156 err |= __put_user(from->si_overrun, &to->si_overrun);
157 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
161 err |= __put_user(from->si_band, &to->si_band);
162 err |= __put_user(from->si_fd, &to->si_fd);
165 err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
169 * Other callers might not initialize the si_lsb field,
170 * so check explicitely for the right codes here.
172 if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
173 err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
177 err |= __put_user(from->si_pid, &to->si_pid);
178 err |= __put_user(from->si_uid, &to->si_uid);
179 err |= __put_user(from->si_status, &to->si_status);
180 err |= __put_user(from->si_utime, &to->si_utime);
181 err |= __put_user(from->si_stime, &to->si_stime);
183 case __SI_RT: /* This is not generated by the kernel as of now. */
184 case __SI_MESGQ: /* But this is */
185 err |= __put_user(from->si_pid, &to->si_pid);
186 err |= __put_user(from->si_uid, &to->si_uid);
187 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
189 default: /* this is just in case for now ... */
190 err |= __put_user(from->si_pid, &to->si_pid);
191 err |= __put_user(from->si_uid, &to->si_uid);
197 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
199 memset(to, 0, sizeof *to);
201 if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
202 copy_from_user(to->_sifields._pad,
203 from->_sifields._pad, SI_PAD_SIZE))
210 * VFP save/restore code.
212 static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
214 struct fpsimd_state *fpsimd = ¤t->thread.fpsimd_state;
215 compat_ulong_t magic = VFP_MAGIC;
216 compat_ulong_t size = VFP_STORAGE_SIZE;
217 compat_ulong_t fpscr, fpexc;
221 * Save the hardware registers to the fpsimd_state structure.
222 * Note that this also saves V16-31, which aren't visible
225 fpsimd_save_state(fpsimd);
227 /* Place structure header on the stack */
228 __put_user_error(magic, &frame->magic, err);
229 __put_user_error(size, &frame->size, err);
232 * Now copy the FP registers. Since the registers are packed,
233 * we can copy the prefix we want (V0-V15) as it is.
234 * FIXME: Won't work if big endian.
236 err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
237 sizeof(frame->ufp.fpregs));
239 /* Create an AArch32 fpscr from the fpsr and the fpcr. */
240 fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
241 (fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
242 __put_user_error(fpscr, &frame->ufp.fpscr, err);
245 * The exception register aren't available so we fake up a
246 * basic FPEXC and zero everything else.
249 __put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
250 __put_user_error(0, &frame->ufp_exc.fpinst, err);
251 __put_user_error(0, &frame->ufp_exc.fpinst2, err);
253 return err ? -EFAULT : 0;
256 static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
258 struct fpsimd_state fpsimd;
259 compat_ulong_t magic = VFP_MAGIC;
260 compat_ulong_t size = VFP_STORAGE_SIZE;
261 compat_ulong_t fpscr;
264 __get_user_error(magic, &frame->magic, err);
265 __get_user_error(size, &frame->size, err);
269 if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
273 * Copy the FP registers into the start of the fpsimd_state.
274 * FIXME: Won't work if big endian.
276 err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
277 sizeof(frame->ufp.fpregs));
279 /* Extract the fpsr and the fpcr from the fpscr */
280 __get_user_error(fpscr, &frame->ufp.fpscr, err);
281 fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
282 fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
285 * We don't need to touch the exception register, so
286 * reload the hardware state.
290 fpsimd_load_state(&fpsimd);
294 return err ? -EFAULT : 0;
297 static int compat_restore_sigframe(struct pt_regs *regs,
298 struct compat_sigframe __user *sf)
302 struct compat_aux_sigframe __user *aux;
304 err = get_sigset_t(&set, &sf->uc.uc_sigmask);
306 sigdelsetmask(&set, ~_BLOCKABLE);
307 set_current_blocked(&set);
310 __get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
311 __get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
312 __get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
313 __get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
314 __get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
315 __get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
316 __get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
317 __get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
318 __get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
319 __get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
320 __get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
321 __get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
322 __get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
323 __get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
324 __get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
325 __get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
326 __get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
329 * Avoid compat_sys_sigreturn() restarting.
331 regs->syscallno = ~0UL;
333 err |= !valid_user_regs(®s->user_regs);
335 aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
337 err |= compat_restore_vfp_context(&aux->vfp);
342 asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
344 struct compat_sigframe __user *frame;
346 /* Always make any pending restarted system calls return -EINTR */
347 current_thread_info()->restart_block.fn = do_no_restart_syscall;
350 * Since we stacked the signal on a 64-bit boundary,
351 * then 'sp' should be word aligned here. If it's
352 * not, then the user is trying to mess with us.
354 if (regs->compat_sp & 7)
357 frame = (struct compat_sigframe __user *)regs->compat_sp;
359 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
362 if (compat_restore_sigframe(regs, frame))
365 return regs->regs[0];
368 if (show_unhandled_signals)
369 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
370 current->comm, task_pid_nr(current), __func__,
372 force_sig(SIGSEGV, current);
376 asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
378 struct compat_rt_sigframe __user *frame;
380 /* Always make any pending restarted system calls return -EINTR */
381 current_thread_info()->restart_block.fn = do_no_restart_syscall;
384 * Since we stacked the signal on a 64-bit boundary,
385 * then 'sp' should be word aligned here. If it's
386 * not, then the user is trying to mess with us.
388 if (regs->compat_sp & 7)
391 frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
393 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
396 if (compat_restore_sigframe(regs, &frame->sig))
399 if (compat_restore_altstack(&frame->sig.uc.uc_stack))
402 return regs->regs[0];
405 if (show_unhandled_signals)
406 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
407 current->comm, task_pid_nr(current), __func__,
409 force_sig(SIGSEGV, current);
413 static void __user *compat_get_sigframe(struct k_sigaction *ka,
414 struct pt_regs *regs,
417 compat_ulong_t sp = regs->compat_sp;
421 * This is the X/Open sanctioned signal stack switching.
423 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
424 sp = current->sas_ss_sp + current->sas_ss_size;
427 * ATPCS B01 mandates 8-byte alignment
429 frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
432 * Check that we can actually write to the signal frame.
434 if (!access_ok(VERIFY_WRITE, frame, framesize))
440 static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
441 compat_ulong_t __user *rc, void __user *frame,
444 compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
445 compat_ulong_t retcode;
446 compat_ulong_t spsr = regs->pstate & ~PSR_f;
449 /* Check if the handler is written for ARM or Thumb */
453 spsr |= COMPAT_PSR_T_BIT;
455 spsr &= ~COMPAT_PSR_T_BIT;
457 /* The IT state must be cleared for both ARM and Thumb-2 */
458 spsr &= ~COMPAT_PSR_IT_MASK;
460 if (ka->sa.sa_flags & SA_RESTORER) {
461 retcode = ptr_to_compat(ka->sa.sa_restorer);
463 /* Set up sigreturn pointer */
464 unsigned int idx = thumb << 1;
466 if (ka->sa.sa_flags & SA_SIGINFO)
469 retcode = AARCH32_VECTORS_BASE +
470 AARCH32_KERN_SIGRET_CODE_OFFSET +
474 regs->regs[0] = usig;
475 regs->compat_sp = ptr_to_compat(frame);
476 regs->compat_lr = retcode;
481 static int compat_setup_sigframe(struct compat_sigframe __user *sf,
482 struct pt_regs *regs, sigset_t *set)
484 struct compat_aux_sigframe __user *aux;
487 __put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
488 __put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
489 __put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
490 __put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
491 __put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
492 __put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
493 __put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
494 __put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
495 __put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
496 __put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
497 __put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
498 __put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
499 __put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
500 __put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
501 __put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
502 __put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
503 __put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
505 __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
506 /* set the compat FSR WnR */
507 __put_user_error(!!(current->thread.fault_code & ESR_EL1_WRITE) <<
508 FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
509 __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
510 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
512 err |= put_sigset_t(&sf->uc.uc_sigmask, set);
514 aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
517 err |= compat_preserve_vfp_context(&aux->vfp);
518 __put_user_error(0, &aux->end_magic, err);
524 * 32-bit signal handling routines called from signal.c
526 int compat_setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
527 sigset_t *set, struct pt_regs *regs)
529 struct compat_rt_sigframe __user *frame;
532 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
537 err |= copy_siginfo_to_user32(&frame->info, info);
539 __put_user_error(0, &frame->sig.uc.uc_flags, err);
540 __put_user_error(0, &frame->sig.uc.uc_link, err);
542 err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
544 err |= compat_setup_sigframe(&frame->sig, regs, set);
547 compat_setup_return(regs, ka, frame->sig.retcode, frame, usig);
548 regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
549 regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
555 int compat_setup_frame(int usig, struct k_sigaction *ka, sigset_t *set,
556 struct pt_regs *regs)
558 struct compat_sigframe __user *frame;
561 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
566 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
568 err |= compat_setup_sigframe(frame, regs, set);
570 compat_setup_return(regs, ka, frame->retcode, frame, usig);
575 void compat_setup_restart_syscall(struct pt_regs *regs)
577 regs->regs[7] = __NR_compat_restart_syscall;