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/unistd.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)))
104 * For ARM syscalls, the syscall number has to be loaded into r7.
105 * We do not support an OABI userspace.
107 #define MOV_R7_NR_SIGRETURN (0xe3a07000 | __NR_compat_sigreturn)
108 #define SVC_SYS_SIGRETURN (0xef000000 | __NR_compat_sigreturn)
109 #define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | __NR_compat_rt_sigreturn)
110 #define SVC_SYS_RT_SIGRETURN (0xef000000 | __NR_compat_rt_sigreturn)
113 * For Thumb syscalls, we also pass the syscall number via r7. We therefore
114 * need two 16-bit instructions.
116 #define SVC_THUMB_SIGRETURN (((0xdf00 | __NR_compat_sigreturn) << 16) | \
117 0x2700 | __NR_compat_sigreturn)
118 #define SVC_THUMB_RT_SIGRETURN (((0xdf00 | __NR_compat_rt_sigreturn) << 16) | \
119 0x2700 | __NR_compat_rt_sigreturn)
121 const compat_ulong_t aarch32_sigret_code[6] = {
123 * AArch32 sigreturn code.
124 * We don't construct an OABI SWI - instead we just set the imm24 field
125 * to the EABI syscall number so that we create a sane disassembly.
127 MOV_R7_NR_SIGRETURN, SVC_SYS_SIGRETURN, SVC_THUMB_SIGRETURN,
128 MOV_R7_NR_RT_SIGRETURN, SVC_SYS_RT_SIGRETURN, SVC_THUMB_RT_SIGRETURN,
131 static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
133 compat_sigset_t cset;
135 cset.sig[0] = set->sig[0] & 0xffffffffull;
136 cset.sig[1] = set->sig[0] >> 32;
138 return copy_to_user(uset, &cset, sizeof(*uset));
141 static inline int get_sigset_t(sigset_t *set,
142 const compat_sigset_t __user *uset)
146 if (copy_from_user(&s32, uset, sizeof(*uset)))
149 set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
153 int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
157 if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
160 /* If you change siginfo_t structure, please be sure
161 * this code is fixed accordingly.
162 * It should never copy any pad contained in the structure
163 * to avoid security leaks, but must copy the generic
164 * 3 ints plus the relevant union member.
165 * This routine must convert siginfo from 64bit to 32bit as well
168 err = __put_user(from->si_signo, &to->si_signo);
169 err |= __put_user(from->si_errno, &to->si_errno);
170 err |= __put_user((short)from->si_code, &to->si_code);
171 if (from->si_code < 0)
172 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
174 else switch (from->si_code & __SI_MASK) {
176 err |= __put_user(from->si_pid, &to->si_pid);
177 err |= __put_user(from->si_uid, &to->si_uid);
180 err |= __put_user(from->si_tid, &to->si_tid);
181 err |= __put_user(from->si_overrun, &to->si_overrun);
182 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
186 err |= __put_user(from->si_band, &to->si_band);
187 err |= __put_user(from->si_fd, &to->si_fd);
190 err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
194 * Other callers might not initialize the si_lsb field,
195 * so check explicitely for the right codes here.
197 if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
198 err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
202 err |= __put_user(from->si_pid, &to->si_pid);
203 err |= __put_user(from->si_uid, &to->si_uid);
204 err |= __put_user(from->si_status, &to->si_status);
205 err |= __put_user(from->si_utime, &to->si_utime);
206 err |= __put_user(from->si_stime, &to->si_stime);
208 case __SI_RT: /* This is not generated by the kernel as of now. */
209 case __SI_MESGQ: /* But this is */
210 err |= __put_user(from->si_pid, &to->si_pid);
211 err |= __put_user(from->si_uid, &to->si_uid);
212 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
214 default: /* this is just in case for now ... */
215 err |= __put_user(from->si_pid, &to->si_pid);
216 err |= __put_user(from->si_uid, &to->si_uid);
222 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
224 memset(to, 0, sizeof *to);
226 if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
227 copy_from_user(to->_sifields._pad,
228 from->_sifields._pad, SI_PAD_SIZE))
235 * VFP save/restore code.
237 static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
239 struct fpsimd_state *fpsimd = ¤t->thread.fpsimd_state;
240 compat_ulong_t magic = VFP_MAGIC;
241 compat_ulong_t size = VFP_STORAGE_SIZE;
242 compat_ulong_t fpscr, fpexc;
246 * Save the hardware registers to the fpsimd_state structure.
247 * Note that this also saves V16-31, which aren't visible
250 fpsimd_preserve_current_state();
252 /* Place structure header on the stack */
253 __put_user_error(magic, &frame->magic, err);
254 __put_user_error(size, &frame->size, err);
257 * Now copy the FP registers. Since the registers are packed,
258 * we can copy the prefix we want (V0-V15) as it is.
259 * FIXME: Won't work if big endian.
261 err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
262 sizeof(frame->ufp.fpregs));
264 /* Create an AArch32 fpscr from the fpsr and the fpcr. */
265 fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
266 (fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
267 __put_user_error(fpscr, &frame->ufp.fpscr, err);
270 * The exception register aren't available so we fake up a
271 * basic FPEXC and zero everything else.
274 __put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
275 __put_user_error(0, &frame->ufp_exc.fpinst, err);
276 __put_user_error(0, &frame->ufp_exc.fpinst2, err);
278 return err ? -EFAULT : 0;
281 static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
283 struct fpsimd_state fpsimd;
284 compat_ulong_t magic = VFP_MAGIC;
285 compat_ulong_t size = VFP_STORAGE_SIZE;
286 compat_ulong_t fpscr;
289 __get_user_error(magic, &frame->magic, err);
290 __get_user_error(size, &frame->size, err);
294 if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
298 * Copy the FP registers into the start of the fpsimd_state.
299 * FIXME: Won't work if big endian.
301 err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
302 sizeof(frame->ufp.fpregs));
304 /* Extract the fpsr and the fpcr from the fpscr */
305 __get_user_error(fpscr, &frame->ufp.fpscr, err);
306 fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
307 fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
310 * We don't need to touch the exception register, so
311 * reload the hardware state.
314 fpsimd_update_current_state(&fpsimd);
316 return err ? -EFAULT : 0;
319 static int compat_restore_sigframe(struct pt_regs *regs,
320 struct compat_sigframe __user *sf)
324 struct compat_aux_sigframe __user *aux;
326 err = get_sigset_t(&set, &sf->uc.uc_sigmask);
328 sigdelsetmask(&set, ~_BLOCKABLE);
329 set_current_blocked(&set);
332 __get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
333 __get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
334 __get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
335 __get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
336 __get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
337 __get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
338 __get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
339 __get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
340 __get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
341 __get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
342 __get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
343 __get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
344 __get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
345 __get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
346 __get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
347 __get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
348 __get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
351 * Avoid compat_sys_sigreturn() restarting.
353 regs->syscallno = ~0UL;
355 err |= !valid_user_regs(®s->user_regs);
357 aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
359 err |= compat_restore_vfp_context(&aux->vfp);
364 asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
366 struct compat_sigframe __user *frame;
368 /* Always make any pending restarted system calls return -EINTR */
369 current_thread_info()->restart_block.fn = do_no_restart_syscall;
372 * Since we stacked the signal on a 64-bit boundary,
373 * then 'sp' should be word aligned here. If it's
374 * not, then the user is trying to mess with us.
376 if (regs->compat_sp & 7)
379 frame = (struct compat_sigframe __user *)regs->compat_sp;
381 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
384 if (compat_restore_sigframe(regs, frame))
387 return regs->regs[0];
390 if (show_unhandled_signals)
391 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
392 current->comm, task_pid_nr(current), __func__,
394 force_sig(SIGSEGV, current);
398 asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
400 struct compat_rt_sigframe __user *frame;
402 /* Always make any pending restarted system calls return -EINTR */
403 current_thread_info()->restart_block.fn = do_no_restart_syscall;
406 * Since we stacked the signal on a 64-bit boundary,
407 * then 'sp' should be word aligned here. If it's
408 * not, then the user is trying to mess with us.
410 if (regs->compat_sp & 7)
413 frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
415 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
418 if (compat_restore_sigframe(regs, &frame->sig))
421 if (compat_restore_altstack(&frame->sig.uc.uc_stack))
424 return regs->regs[0];
427 if (show_unhandled_signals)
428 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
429 current->comm, task_pid_nr(current), __func__,
431 force_sig(SIGSEGV, current);
435 static void __user *compat_get_sigframe(struct k_sigaction *ka,
436 struct pt_regs *regs,
439 compat_ulong_t sp = regs->compat_sp;
443 * This is the X/Open sanctioned signal stack switching.
445 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
446 sp = current->sas_ss_sp + current->sas_ss_size;
449 * ATPCS B01 mandates 8-byte alignment
451 frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
454 * Check that we can actually write to the signal frame.
456 if (!access_ok(VERIFY_WRITE, frame, framesize))
462 static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
463 compat_ulong_t __user *rc, void __user *frame,
466 compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
467 compat_ulong_t retcode;
468 compat_ulong_t spsr = regs->pstate & ~PSR_f;
471 /* Check if the handler is written for ARM or Thumb */
475 spsr |= COMPAT_PSR_T_BIT;
476 spsr &= ~COMPAT_PSR_IT_MASK;
478 spsr &= ~COMPAT_PSR_T_BIT;
481 if (ka->sa.sa_flags & SA_RESTORER) {
482 retcode = ptr_to_compat(ka->sa.sa_restorer);
484 /* Set up sigreturn pointer */
485 unsigned int idx = thumb << 1;
487 if (ka->sa.sa_flags & SA_SIGINFO)
490 retcode = AARCH32_VECTORS_BASE +
491 AARCH32_KERN_SIGRET_CODE_OFFSET +
495 regs->regs[0] = usig;
496 regs->compat_sp = ptr_to_compat(frame);
497 regs->compat_lr = retcode;
502 static int compat_setup_sigframe(struct compat_sigframe __user *sf,
503 struct pt_regs *regs, sigset_t *set)
505 struct compat_aux_sigframe __user *aux;
508 __put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
509 __put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
510 __put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
511 __put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
512 __put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
513 __put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
514 __put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
515 __put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
516 __put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
517 __put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
518 __put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
519 __put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
520 __put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
521 __put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
522 __put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
523 __put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
524 __put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
526 __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
527 __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.error_code, err);
528 __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
529 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
531 err |= put_sigset_t(&sf->uc.uc_sigmask, set);
533 aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
536 err |= compat_preserve_vfp_context(&aux->vfp);
537 __put_user_error(0, &aux->end_magic, err);
543 * 32-bit signal handling routines called from signal.c
545 int compat_setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
546 sigset_t *set, struct pt_regs *regs)
548 struct compat_rt_sigframe __user *frame;
551 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
556 err |= copy_siginfo_to_user32(&frame->info, info);
558 __put_user_error(0, &frame->sig.uc.uc_flags, err);
559 __put_user_error(0, &frame->sig.uc.uc_link, err);
561 err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
563 err |= compat_setup_sigframe(&frame->sig, regs, set);
566 compat_setup_return(regs, ka, frame->sig.retcode, frame, usig);
567 regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
568 regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
574 int compat_setup_frame(int usig, struct k_sigaction *ka, sigset_t *set,
575 struct pt_regs *regs)
577 struct compat_sigframe __user *frame;
580 frame = compat_get_sigframe(ka, regs, sizeof(*frame));
585 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
587 err |= compat_setup_sigframe(frame, regs, set);
589 compat_setup_return(regs, ka, frame->retcode, frame, usig);
594 void compat_setup_restart_syscall(struct pt_regs *regs)
596 regs->regs[7] = __NR_compat_restart_syscall;