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)(struct sigcontext __user *sc);
45 static int (*restore_fp_context)(struct sigcontext __user *sc);
47 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
48 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
51 u32 sf_ass[4]; /* argument save space for o32 */
52 u32 sf_pad[2]; /* Was: signal trampoline */
53 struct sigcontext sf_sc;
58 u32 rs_ass[4]; /* argument save space for o32 */
59 u32 rs_pad[2]; /* Was: signal trampoline */
60 struct siginfo rs_info;
61 struct ucontext rs_uc;
65 * Thread saved context copy to/from a signal context presumed to be on the
66 * user stack, and therefore accessed with appropriate macros from uaccess.h.
68 static int copy_fp_to_sigcontext(struct sigcontext __user *sc)
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, &sc->sc_fpc_csr);
83 static int copy_fp_from_sigcontext(struct sigcontext __user *sc)
89 for (i = 0; i < NUM_FPU_REGS; i++) {
90 err |= __get_user(fpr_val, &sc->sc_fpregs[i]);
91 set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
93 err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
101 static int protected_save_fp_context(struct sigcontext __user *sc)
106 * EVA does not have userland equivalents of ldc1 or sdc1, so
107 * save to the kernel FP context & copy that to userland below.
109 if (config_enabled(CONFIG_EVA))
114 if (is_fpu_owner()) {
115 err = save_fp_context(sc);
119 err = copy_fp_to_sigcontext(sc);
123 /* touch the sigcontext and try again */
124 err = __put_user(0, &sc->sc_fpregs[0]) |
125 __put_user(0, &sc->sc_fpregs[31]) |
126 __put_user(0, &sc->sc_fpc_csr);
128 break; /* really bad sigcontext */
134 static int protected_restore_fp_context(struct sigcontext __user *sc)
136 int err, tmp __maybe_unused;
139 * EVA does not have userland equivalents of ldc1 or sdc1, so we
140 * disable the FPU here such that the code below simply copies to
141 * the kernel FP context.
143 if (config_enabled(CONFIG_EVA))
148 if (is_fpu_owner()) {
149 err = restore_fp_context(sc);
153 err = copy_fp_from_sigcontext(sc);
157 /* touch the sigcontext and try again */
158 err = __get_user(tmp, &sc->sc_fpregs[0]) |
159 __get_user(tmp, &sc->sc_fpregs[31]) |
160 __get_user(tmp, &sc->sc_fpc_csr);
162 break; /* really bad sigcontext */
168 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
172 unsigned int used_math;
174 err |= __put_user(regs->cp0_epc, &sc->sc_pc);
176 err |= __put_user(0, &sc->sc_regs[0]);
177 for (i = 1; i < 32; i++)
178 err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
180 #ifdef CONFIG_CPU_HAS_SMARTMIPS
181 err |= __put_user(regs->acx, &sc->sc_acx);
183 err |= __put_user(regs->hi, &sc->sc_mdhi);
184 err |= __put_user(regs->lo, &sc->sc_mdlo);
186 err |= __put_user(mfhi1(), &sc->sc_hi1);
187 err |= __put_user(mflo1(), &sc->sc_lo1);
188 err |= __put_user(mfhi2(), &sc->sc_hi2);
189 err |= __put_user(mflo2(), &sc->sc_lo2);
190 err |= __put_user(mfhi3(), &sc->sc_hi3);
191 err |= __put_user(mflo3(), &sc->sc_lo3);
192 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
195 used_math = !!used_math();
196 err |= __put_user(used_math, &sc->sc_used_math);
200 * Save FPU state to signal context. Signal handler
201 * will "inherit" current FPU state.
203 err |= protected_save_fp_context(sc);
208 int fpcsr_pending(unsigned int __user *fpcsr)
211 unsigned int csr, enabled;
213 err = __get_user(csr, fpcsr);
214 enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
216 * If the signal handler set some FPU exceptions, clear it and
221 err |= __put_user(csr, fpcsr);
228 check_and_restore_fp_context(struct sigcontext __user *sc)
232 err = sig = fpcsr_pending(&sc->sc_fpc_csr);
235 err |= protected_restore_fp_context(sc);
239 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
241 unsigned int used_math;
246 /* Always make any pending restarted system calls return -EINTR */
247 current->restart_block.fn = do_no_restart_syscall;
249 err |= __get_user(regs->cp0_epc, &sc->sc_pc);
251 #ifdef CONFIG_CPU_HAS_SMARTMIPS
252 err |= __get_user(regs->acx, &sc->sc_acx);
254 err |= __get_user(regs->hi, &sc->sc_mdhi);
255 err |= __get_user(regs->lo, &sc->sc_mdlo);
257 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
258 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
259 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
260 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
261 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
262 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
263 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
266 for (i = 1; i < 32; i++)
267 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
269 err |= __get_user(used_math, &sc->sc_used_math);
270 conditional_used_math(used_math);
273 /* restore fpu context if we have used it before */
275 err = check_and_restore_fp_context(sc);
277 /* signal handler may have used FPU. Give it up. */
284 void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
289 /* Default to using normal stack */
293 * FPU emulator may have it's own trampoline active just
294 * above the user stack, 16-bytes before the next lowest
295 * 16 byte boundary. Try to avoid trashing it.
299 sp = sigsp(sp, ksig);
301 return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
305 * Atomically swap in the new signal mask, and wait for a signal.
308 #ifdef CONFIG_TRAD_SIGNALS
309 SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
311 return sys_rt_sigsuspend(uset, sizeof(sigset_t));
315 #ifdef CONFIG_TRAD_SIGNALS
316 SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
317 struct sigaction __user *, oact)
319 struct k_sigaction new_ka, old_ka;
326 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
328 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
329 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
330 err |= __get_user(mask, &act->sa_mask.sig[0]);
334 siginitset(&new_ka.sa.sa_mask, mask);
337 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
340 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
342 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
343 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
344 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
345 err |= __put_user(0, &oact->sa_mask.sig[1]);
346 err |= __put_user(0, &oact->sa_mask.sig[2]);
347 err |= __put_user(0, &oact->sa_mask.sig[3]);
356 #ifdef CONFIG_TRAD_SIGNALS
357 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
359 struct sigframe __user *frame;
363 frame = (struct sigframe __user *) regs.regs[29];
364 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
366 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
369 set_current_blocked(&blocked);
371 sig = restore_sigcontext(®s, &frame->sf_sc);
375 force_sig(sig, current);
378 * Don't let your children do this ...
380 __asm__ __volatile__(
388 force_sig(SIGSEGV, current);
390 #endif /* CONFIG_TRAD_SIGNALS */
392 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
394 struct rt_sigframe __user *frame;
398 frame = (struct rt_sigframe __user *) regs.regs[29];
399 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
401 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
404 set_current_blocked(&set);
406 sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext);
410 force_sig(sig, current);
412 if (restore_altstack(&frame->rs_uc.uc_stack))
416 * Don't let your children do this ...
418 __asm__ __volatile__(
426 force_sig(SIGSEGV, current);
429 #ifdef CONFIG_TRAD_SIGNALS
430 static int setup_frame(void *sig_return, struct ksignal *ksig,
431 struct pt_regs *regs, sigset_t *set)
433 struct sigframe __user *frame;
436 frame = get_sigframe(ksig, regs, sizeof(*frame));
437 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
440 err |= setup_sigcontext(regs, &frame->sf_sc);
441 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
446 * Arguments to signal handler:
449 * a1 = 0 (should be cause)
450 * a2 = pointer to struct sigcontext
452 * $25 and c0_epc point to the signal handler, $29 points to the
455 regs->regs[ 4] = ksig->sig;
457 regs->regs[ 6] = (unsigned long) &frame->sf_sc;
458 regs->regs[29] = (unsigned long) frame;
459 regs->regs[31] = (unsigned long) sig_return;
460 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
462 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
463 current->comm, current->pid,
464 frame, regs->cp0_epc, regs->regs[31]);
469 static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
470 struct pt_regs *regs, sigset_t *set)
472 struct rt_sigframe __user *frame;
475 frame = get_sigframe(ksig, regs, sizeof(*frame));
476 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
479 /* Create siginfo. */
480 err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
482 /* Create the ucontext. */
483 err |= __put_user(0, &frame->rs_uc.uc_flags);
484 err |= __put_user(NULL, &frame->rs_uc.uc_link);
485 err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
486 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
487 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
493 * Arguments to signal handler:
496 * a1 = 0 (should be cause)
497 * a2 = pointer to ucontext
499 * $25 and c0_epc point to the signal handler, $29 points to
500 * the struct rt_sigframe.
502 regs->regs[ 4] = ksig->sig;
503 regs->regs[ 5] = (unsigned long) &frame->rs_info;
504 regs->regs[ 6] = (unsigned long) &frame->rs_uc;
505 regs->regs[29] = (unsigned long) frame;
506 regs->regs[31] = (unsigned long) sig_return;
507 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
509 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
510 current->comm, current->pid,
511 frame, regs->cp0_epc, regs->regs[31]);
516 struct mips_abi mips_abi = {
517 #ifdef CONFIG_TRAD_SIGNALS
518 .setup_frame = setup_frame,
519 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
521 .setup_rt_frame = setup_rt_frame,
522 .rt_signal_return_offset =
523 offsetof(struct mips_vdso, rt_signal_trampoline),
524 .restart = __NR_restart_syscall,
526 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
527 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
528 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
531 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
533 sigset_t *oldset = sigmask_to_save();
535 struct mips_abi *abi = current->thread.abi;
536 #ifdef CONFIG_CPU_MICROMIPS
538 unsigned long tmp = (unsigned long)current->mm->context.vdso;
543 void *vdso = current->mm->context.vdso;
547 switch(regs->regs[2]) {
548 case ERESTART_RESTARTBLOCK:
550 regs->regs[2] = EINTR;
553 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
554 regs->regs[2] = EINTR;
559 regs->regs[7] = regs->regs[26];
560 regs->regs[2] = regs->regs[0];
564 regs->regs[0] = 0; /* Don't deal with this again. */
567 if (sig_uses_siginfo(&ksig->ka))
568 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
571 ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig,
574 signal_setup_done(ret, ksig, 0);
577 static void do_signal(struct pt_regs *regs)
581 if (get_signal(&ksig)) {
582 /* Whee! Actually deliver the signal. */
583 handle_signal(&ksig, regs);
588 switch (regs->regs[2]) {
592 regs->regs[2] = regs->regs[0];
593 regs->regs[7] = regs->regs[26];
597 case ERESTART_RESTARTBLOCK:
598 regs->regs[2] = current->thread.abi->restart;
599 regs->regs[7] = regs->regs[26];
603 regs->regs[0] = 0; /* Don't deal with this again. */
607 * If there's no signal to deliver, we just put the saved sigmask
610 restore_saved_sigmask();
614 * notification of userspace execution resumption
615 * - triggered by the TIF_WORK_MASK flags
617 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
618 __u32 thread_info_flags)
624 /* deal with pending signal delivery */
625 if (thread_info_flags & _TIF_SIGPENDING)
628 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
629 clear_thread_flag(TIF_NOTIFY_RESUME);
630 tracehook_notify_resume(regs);
637 static int smp_save_fp_context(struct sigcontext __user *sc)
639 return raw_cpu_has_fpu
640 ? _save_fp_context(sc)
641 : copy_fp_to_sigcontext(sc);
644 static int smp_restore_fp_context(struct sigcontext __user *sc)
646 return raw_cpu_has_fpu
647 ? _restore_fp_context(sc)
648 : copy_fp_from_sigcontext(sc);
652 static int signal_setup(void)
655 /* For now just do the cpu_has_fpu check when the functions are invoked */
656 save_fp_context = smp_save_fp_context;
657 restore_fp_context = smp_restore_fp_context;
660 save_fp_context = _save_fp_context;
661 restore_fp_context = _restore_fp_context;
663 save_fp_context = copy_fp_to_sigcontext;
664 restore_fp_context = copy_fp_from_sigcontext;
666 #endif /* CONFIG_SMP */
671 arch_initcall(signal_setup);