2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 * Copyright (C) 1994 - 2000 Ralf Baechle
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 * Copyright (C) 2014, Imagination Technologies Ltd.
11 #include <linux/cache.h>
12 #include <linux/context_tracking.h>
13 #include <linux/irqflags.h>
14 #include <linux/sched.h>
16 #include <linux/personality.h>
17 #include <linux/smp.h>
18 #include <linux/kernel.h>
19 #include <linux/signal.h>
20 #include <linux/errno.h>
21 #include <linux/wait.h>
22 #include <linux/ptrace.h>
23 #include <linux/unistd.h>
24 #include <linux/compiler.h>
25 #include <linux/syscalls.h>
26 #include <linux/uaccess.h>
27 #include <linux/tracehook.h>
31 #include <linux/bitops.h>
32 #include <asm/cacheflush.h>
35 #include <asm/ucontext.h>
36 #include <asm/cpu-features.h>
42 #include "signal-common.h"
44 static int (*save_fp_context)(void __user *sc);
45 static int (*restore_fp_context)(void __user *sc);
48 u32 sf_ass[4]; /* argument save space for o32 */
49 u32 sf_pad[2]; /* Was: signal trampoline */
50 struct sigcontext sf_sc;
55 u32 rs_ass[4]; /* argument save space for o32 */
56 u32 rs_pad[2]; /* Was: signal trampoline */
57 struct siginfo rs_info;
58 struct ucontext rs_uc;
62 * Thread saved context copy to/from a signal context presumed to be on the
63 * user stack, and therefore accessed with appropriate macros from uaccess.h.
65 static int copy_fp_to_sigcontext(void __user *sc)
67 struct mips_abi *abi = current->thread.abi;
68 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
69 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
73 for (i = 0; i < NUM_FPU_REGS; i++) {
75 __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
78 err |= __put_user(current->thread.fpu.fcr31, csr);
83 static int copy_fp_from_sigcontext(void __user *sc)
85 struct mips_abi *abi = current->thread.abi;
86 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
87 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
92 for (i = 0; i < NUM_FPU_REGS; i++) {
93 err |= __get_user(fpr_val, &fpregs[i]);
94 set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
96 err |= __get_user(current->thread.fpu.fcr31, csr);
102 * Wrappers for the assembly _{save,restore}_fp_context functions.
104 static int save_hw_fp_context(void __user *sc)
106 struct mips_abi *abi = current->thread.abi;
107 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
108 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
110 return _save_fp_context(fpregs, csr);
113 static int restore_hw_fp_context(void __user *sc)
115 struct mips_abi *abi = current->thread.abi;
116 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
117 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
119 return _restore_fp_context(fpregs, csr);
125 static int protected_save_fp_context(void __user *sc)
127 struct mips_abi *abi = current->thread.abi;
128 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
129 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
133 * EVA does not have userland equivalents of ldc1 or sdc1, so
134 * save to the kernel FP context & copy that to userland below.
136 if (config_enabled(CONFIG_EVA))
141 if (is_fpu_owner()) {
142 err = save_fp_context(sc);
146 err = copy_fp_to_sigcontext(sc);
150 /* touch the sigcontext and try again */
151 err = __put_user(0, &fpregs[0]) |
152 __put_user(0, &fpregs[31]) |
155 break; /* really bad sigcontext */
161 static int protected_restore_fp_context(void __user *sc)
163 struct mips_abi *abi = current->thread.abi;
164 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
165 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
166 int err, tmp __maybe_unused;
169 * EVA does not have userland equivalents of ldc1 or sdc1, so we
170 * disable the FPU here such that the code below simply copies to
171 * the kernel FP context.
173 if (config_enabled(CONFIG_EVA))
178 if (is_fpu_owner()) {
179 err = restore_fp_context(sc);
183 err = copy_fp_from_sigcontext(sc);
187 /* touch the sigcontext and try again */
188 err = __get_user(tmp, &fpregs[0]) |
189 __get_user(tmp, &fpregs[31]) |
190 __get_user(tmp, csr);
192 break; /* really bad sigcontext */
198 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
202 unsigned int used_math;
204 err |= __put_user(regs->cp0_epc, &sc->sc_pc);
206 err |= __put_user(0, &sc->sc_regs[0]);
207 for (i = 1; i < 32; i++)
208 err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
210 #ifdef CONFIG_CPU_HAS_SMARTMIPS
211 err |= __put_user(regs->acx, &sc->sc_acx);
213 err |= __put_user(regs->hi, &sc->sc_mdhi);
214 err |= __put_user(regs->lo, &sc->sc_mdlo);
216 err |= __put_user(mfhi1(), &sc->sc_hi1);
217 err |= __put_user(mflo1(), &sc->sc_lo1);
218 err |= __put_user(mfhi2(), &sc->sc_hi2);
219 err |= __put_user(mflo2(), &sc->sc_lo2);
220 err |= __put_user(mfhi3(), &sc->sc_hi3);
221 err |= __put_user(mflo3(), &sc->sc_lo3);
222 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
225 used_math = !!used_math();
226 err |= __put_user(used_math, &sc->sc_used_math);
230 * Save FPU state to signal context. Signal handler
231 * will "inherit" current FPU state.
233 err |= protected_save_fp_context(sc);
238 int fpcsr_pending(unsigned int __user *fpcsr)
241 unsigned int csr, enabled;
243 err = __get_user(csr, fpcsr);
244 enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
246 * If the signal handler set some FPU exceptions, clear it and
251 err |= __put_user(csr, fpcsr);
258 check_and_restore_fp_context(void __user *sc)
260 struct mips_abi *abi = current->thread.abi;
263 err = sig = fpcsr_pending(sc + abi->off_sc_fpc_csr);
266 err |= protected_restore_fp_context(sc);
270 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
272 unsigned int used_math;
277 /* Always make any pending restarted system calls return -EINTR */
278 current->restart_block.fn = do_no_restart_syscall;
280 err |= __get_user(regs->cp0_epc, &sc->sc_pc);
282 #ifdef CONFIG_CPU_HAS_SMARTMIPS
283 err |= __get_user(regs->acx, &sc->sc_acx);
285 err |= __get_user(regs->hi, &sc->sc_mdhi);
286 err |= __get_user(regs->lo, &sc->sc_mdlo);
288 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
289 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
290 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
291 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
292 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
293 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
294 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
297 for (i = 1; i < 32; i++)
298 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
300 err |= __get_user(used_math, &sc->sc_used_math);
301 conditional_used_math(used_math);
304 /* restore fpu context if we have used it before */
306 err = check_and_restore_fp_context(sc);
308 /* signal handler may have used FPU. Give it up. */
315 void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
320 /* Default to using normal stack */
324 * FPU emulator may have it's own trampoline active just
325 * above the user stack, 16-bytes before the next lowest
326 * 16 byte boundary. Try to avoid trashing it.
330 sp = sigsp(sp, ksig);
332 return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
336 * Atomically swap in the new signal mask, and wait for a signal.
339 #ifdef CONFIG_TRAD_SIGNALS
340 SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
342 return sys_rt_sigsuspend(uset, sizeof(sigset_t));
346 #ifdef CONFIG_TRAD_SIGNALS
347 SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
348 struct sigaction __user *, oact)
350 struct k_sigaction new_ka, old_ka;
357 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
359 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
360 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
361 err |= __get_user(mask, &act->sa_mask.sig[0]);
365 siginitset(&new_ka.sa.sa_mask, mask);
368 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
371 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
373 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
374 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
375 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
376 err |= __put_user(0, &oact->sa_mask.sig[1]);
377 err |= __put_user(0, &oact->sa_mask.sig[2]);
378 err |= __put_user(0, &oact->sa_mask.sig[3]);
387 #ifdef CONFIG_TRAD_SIGNALS
388 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
390 struct sigframe __user *frame;
394 frame = (struct sigframe __user *) regs.regs[29];
395 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
397 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
400 set_current_blocked(&blocked);
402 sig = restore_sigcontext(®s, &frame->sf_sc);
406 force_sig(sig, current);
409 * Don't let your children do this ...
411 __asm__ __volatile__(
419 force_sig(SIGSEGV, current);
421 #endif /* CONFIG_TRAD_SIGNALS */
423 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
425 struct rt_sigframe __user *frame;
429 frame = (struct rt_sigframe __user *) regs.regs[29];
430 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
432 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
435 set_current_blocked(&set);
437 sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext);
441 force_sig(sig, current);
443 if (restore_altstack(&frame->rs_uc.uc_stack))
447 * Don't let your children do this ...
449 __asm__ __volatile__(
457 force_sig(SIGSEGV, current);
460 #ifdef CONFIG_TRAD_SIGNALS
461 static int setup_frame(void *sig_return, struct ksignal *ksig,
462 struct pt_regs *regs, sigset_t *set)
464 struct sigframe __user *frame;
467 frame = get_sigframe(ksig, regs, sizeof(*frame));
468 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
471 err |= setup_sigcontext(regs, &frame->sf_sc);
472 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
477 * Arguments to signal handler:
480 * a1 = 0 (should be cause)
481 * a2 = pointer to struct sigcontext
483 * $25 and c0_epc point to the signal handler, $29 points to the
486 regs->regs[ 4] = ksig->sig;
488 regs->regs[ 6] = (unsigned long) &frame->sf_sc;
489 regs->regs[29] = (unsigned long) frame;
490 regs->regs[31] = (unsigned long) sig_return;
491 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
493 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
494 current->comm, current->pid,
495 frame, regs->cp0_epc, regs->regs[31]);
500 static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
501 struct pt_regs *regs, sigset_t *set)
503 struct rt_sigframe __user *frame;
506 frame = get_sigframe(ksig, regs, sizeof(*frame));
507 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
510 /* Create siginfo. */
511 err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
513 /* Create the ucontext. */
514 err |= __put_user(0, &frame->rs_uc.uc_flags);
515 err |= __put_user(NULL, &frame->rs_uc.uc_link);
516 err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
517 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
518 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
524 * Arguments to signal handler:
527 * a1 = 0 (should be cause)
528 * a2 = pointer to ucontext
530 * $25 and c0_epc point to the signal handler, $29 points to
531 * the struct rt_sigframe.
533 regs->regs[ 4] = ksig->sig;
534 regs->regs[ 5] = (unsigned long) &frame->rs_info;
535 regs->regs[ 6] = (unsigned long) &frame->rs_uc;
536 regs->regs[29] = (unsigned long) frame;
537 regs->regs[31] = (unsigned long) sig_return;
538 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
540 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
541 current->comm, current->pid,
542 frame, regs->cp0_epc, regs->regs[31]);
547 struct mips_abi mips_abi = {
548 #ifdef CONFIG_TRAD_SIGNALS
549 .setup_frame = setup_frame,
550 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
552 .setup_rt_frame = setup_rt_frame,
553 .rt_signal_return_offset =
554 offsetof(struct mips_vdso, rt_signal_trampoline),
555 .restart = __NR_restart_syscall,
557 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
558 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
559 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
562 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
564 sigset_t *oldset = sigmask_to_save();
566 struct mips_abi *abi = current->thread.abi;
567 #ifdef CONFIG_CPU_MICROMIPS
569 unsigned long tmp = (unsigned long)current->mm->context.vdso;
574 void *vdso = current->mm->context.vdso;
578 switch(regs->regs[2]) {
579 case ERESTART_RESTARTBLOCK:
581 regs->regs[2] = EINTR;
584 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
585 regs->regs[2] = EINTR;
590 regs->regs[7] = regs->regs[26];
591 regs->regs[2] = regs->regs[0];
595 regs->regs[0] = 0; /* Don't deal with this again. */
598 if (sig_uses_siginfo(&ksig->ka))
599 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
602 ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig,
605 signal_setup_done(ret, ksig, 0);
608 static void do_signal(struct pt_regs *regs)
612 if (get_signal(&ksig)) {
613 /* Whee! Actually deliver the signal. */
614 handle_signal(&ksig, regs);
619 switch (regs->regs[2]) {
623 regs->regs[2] = regs->regs[0];
624 regs->regs[7] = regs->regs[26];
628 case ERESTART_RESTARTBLOCK:
629 regs->regs[2] = current->thread.abi->restart;
630 regs->regs[7] = regs->regs[26];
634 regs->regs[0] = 0; /* Don't deal with this again. */
638 * If there's no signal to deliver, we just put the saved sigmask
641 restore_saved_sigmask();
645 * notification of userspace execution resumption
646 * - triggered by the TIF_WORK_MASK flags
648 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
649 __u32 thread_info_flags)
655 /* deal with pending signal delivery */
656 if (thread_info_flags & _TIF_SIGPENDING)
659 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
660 clear_thread_flag(TIF_NOTIFY_RESUME);
661 tracehook_notify_resume(regs);
668 static int smp_save_fp_context(void __user *sc)
670 return raw_cpu_has_fpu
671 ? save_hw_fp_context(sc)
672 : copy_fp_to_sigcontext(sc);
675 static int smp_restore_fp_context(void __user *sc)
677 return raw_cpu_has_fpu
678 ? restore_hw_fp_context(sc)
679 : copy_fp_from_sigcontext(sc);
683 static int signal_setup(void)
686 /* For now just do the cpu_has_fpu check when the functions are invoked */
687 save_fp_context = smp_save_fp_context;
688 restore_fp_context = smp_restore_fp_context;
691 save_fp_context = save_hw_fp_context;
692 restore_fp_context = restore_hw_fp_context;
694 save_fp_context = copy_fp_to_sigcontext;
695 restore_fp_context = copy_fp_from_sigcontext;
697 #endif /* CONFIG_SMP */
702 arch_initcall(signal_setup);