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;
72 int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
74 for (i = 0; i < NUM_FPU_REGS; i += inc) {
76 __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
79 err |= __put_user(current->thread.fpu.fcr31, csr);
84 static int copy_fp_from_sigcontext(void __user *sc)
86 struct mips_abi *abi = current->thread.abi;
87 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
88 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
91 int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
94 for (i = 0; i < NUM_FPU_REGS; i += inc) {
95 err |= __get_user(fpr_val, &fpregs[i]);
96 set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
98 err |= __get_user(current->thread.fpu.fcr31, csr);
104 * Wrappers for the assembly _{save,restore}_fp_context functions.
106 static int save_hw_fp_context(void __user *sc)
108 struct mips_abi *abi = current->thread.abi;
109 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
110 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
112 return _save_fp_context(fpregs, csr);
115 static int restore_hw_fp_context(void __user *sc)
117 struct mips_abi *abi = current->thread.abi;
118 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
119 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
121 return _restore_fp_context(fpregs, csr);
127 int protected_save_fp_context(void __user *sc)
129 struct mips_abi *abi = current->thread.abi;
130 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
131 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
132 uint32_t __user *used_math = sc + abi->off_sc_used_math;
136 used = !!used_math();
137 err = __put_user(used, used_math);
142 * EVA does not have userland equivalents of ldc1 or sdc1, so
143 * save to the kernel FP context & copy that to userland below.
145 if (config_enabled(CONFIG_EVA))
150 if (is_fpu_owner()) {
151 err = save_fp_context(sc);
155 err = copy_fp_to_sigcontext(sc);
159 /* touch the sigcontext and try again */
160 err = __put_user(0, &fpregs[0]) |
161 __put_user(0, &fpregs[31]) |
164 break; /* really bad sigcontext */
170 int protected_restore_fp_context(void __user *sc)
172 struct mips_abi *abi = current->thread.abi;
173 uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
174 uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
175 uint32_t __user *used_math = sc + abi->off_sc_used_math;
177 int err, sig, tmp __maybe_unused;
179 err = __get_user(used, used_math);
180 conditional_used_math(used);
183 * The signal handler may have used FPU; give it up if the program
184 * doesn't want it following sigreturn.
191 err = sig = fpcsr_pending(csr);
196 * EVA does not have userland equivalents of ldc1 or sdc1, so we
197 * disable the FPU here such that the code below simply copies to
198 * the kernel FP context.
200 if (config_enabled(CONFIG_EVA))
205 if (is_fpu_owner()) {
206 err = restore_fp_context(sc);
210 err = copy_fp_from_sigcontext(sc);
214 /* touch the sigcontext and try again */
215 err = __get_user(tmp, &fpregs[0]) |
216 __get_user(tmp, &fpregs[31]) |
217 __get_user(tmp, csr);
219 break; /* really bad sigcontext */
225 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
230 err |= __put_user(regs->cp0_epc, &sc->sc_pc);
232 err |= __put_user(0, &sc->sc_regs[0]);
233 for (i = 1; i < 32; i++)
234 err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
236 #ifdef CONFIG_CPU_HAS_SMARTMIPS
237 err |= __put_user(regs->acx, &sc->sc_acx);
239 err |= __put_user(regs->hi, &sc->sc_mdhi);
240 err |= __put_user(regs->lo, &sc->sc_mdlo);
242 err |= __put_user(mfhi1(), &sc->sc_hi1);
243 err |= __put_user(mflo1(), &sc->sc_lo1);
244 err |= __put_user(mfhi2(), &sc->sc_hi2);
245 err |= __put_user(mflo2(), &sc->sc_lo2);
246 err |= __put_user(mfhi3(), &sc->sc_hi3);
247 err |= __put_user(mflo3(), &sc->sc_lo3);
248 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
253 * Save FPU state to signal context. Signal handler
254 * will "inherit" current FPU state.
256 err |= protected_save_fp_context(sc);
261 int fpcsr_pending(unsigned int __user *fpcsr)
264 unsigned int csr, enabled;
266 err = __get_user(csr, fpcsr);
267 enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
269 * If the signal handler set some FPU exceptions, clear it and
274 err |= __put_user(csr, fpcsr);
280 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
286 /* Always make any pending restarted system calls return -EINTR */
287 current->restart_block.fn = do_no_restart_syscall;
289 err |= __get_user(regs->cp0_epc, &sc->sc_pc);
291 #ifdef CONFIG_CPU_HAS_SMARTMIPS
292 err |= __get_user(regs->acx, &sc->sc_acx);
294 err |= __get_user(regs->hi, &sc->sc_mdhi);
295 err |= __get_user(regs->lo, &sc->sc_mdlo);
297 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
298 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
299 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
300 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
301 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
302 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
303 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
306 for (i = 1; i < 32; i++)
307 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
309 return err ?: protected_restore_fp_context(sc);
312 void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
317 /* Default to using normal stack */
321 * FPU emulator may have it's own trampoline active just
322 * above the user stack, 16-bytes before the next lowest
323 * 16 byte boundary. Try to avoid trashing it.
327 sp = sigsp(sp, ksig);
329 return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
333 * Atomically swap in the new signal mask, and wait for a signal.
336 #ifdef CONFIG_TRAD_SIGNALS
337 SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
339 return sys_rt_sigsuspend(uset, sizeof(sigset_t));
343 #ifdef CONFIG_TRAD_SIGNALS
344 SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
345 struct sigaction __user *, oact)
347 struct k_sigaction new_ka, old_ka;
354 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
356 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
357 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
358 err |= __get_user(mask, &act->sa_mask.sig[0]);
362 siginitset(&new_ka.sa.sa_mask, mask);
365 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
368 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
370 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
371 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
372 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
373 err |= __put_user(0, &oact->sa_mask.sig[1]);
374 err |= __put_user(0, &oact->sa_mask.sig[2]);
375 err |= __put_user(0, &oact->sa_mask.sig[3]);
384 #ifdef CONFIG_TRAD_SIGNALS
385 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
387 struct sigframe __user *frame;
391 frame = (struct sigframe __user *) regs.regs[29];
392 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
394 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
397 set_current_blocked(&blocked);
399 sig = restore_sigcontext(®s, &frame->sf_sc);
403 force_sig(sig, current);
406 * Don't let your children do this ...
408 __asm__ __volatile__(
416 force_sig(SIGSEGV, current);
418 #endif /* CONFIG_TRAD_SIGNALS */
420 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
422 struct rt_sigframe __user *frame;
426 frame = (struct rt_sigframe __user *) regs.regs[29];
427 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
429 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
432 set_current_blocked(&set);
434 sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext);
438 force_sig(sig, current);
440 if (restore_altstack(&frame->rs_uc.uc_stack))
444 * Don't let your children do this ...
446 __asm__ __volatile__(
454 force_sig(SIGSEGV, current);
457 #ifdef CONFIG_TRAD_SIGNALS
458 static int setup_frame(void *sig_return, struct ksignal *ksig,
459 struct pt_regs *regs, sigset_t *set)
461 struct sigframe __user *frame;
464 frame = get_sigframe(ksig, regs, sizeof(*frame));
465 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
468 err |= setup_sigcontext(regs, &frame->sf_sc);
469 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
474 * Arguments to signal handler:
477 * a1 = 0 (should be cause)
478 * a2 = pointer to struct sigcontext
480 * $25 and c0_epc point to the signal handler, $29 points to the
483 regs->regs[ 4] = ksig->sig;
485 regs->regs[ 6] = (unsigned long) &frame->sf_sc;
486 regs->regs[29] = (unsigned long) frame;
487 regs->regs[31] = (unsigned long) sig_return;
488 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
490 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
491 current->comm, current->pid,
492 frame, regs->cp0_epc, regs->regs[31]);
497 static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
498 struct pt_regs *regs, sigset_t *set)
500 struct rt_sigframe __user *frame;
503 frame = get_sigframe(ksig, regs, sizeof(*frame));
504 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
507 /* Create siginfo. */
508 err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
510 /* Create the ucontext. */
511 err |= __put_user(0, &frame->rs_uc.uc_flags);
512 err |= __put_user(NULL, &frame->rs_uc.uc_link);
513 err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
514 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
515 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
521 * Arguments to signal handler:
524 * a1 = 0 (should be cause)
525 * a2 = pointer to ucontext
527 * $25 and c0_epc point to the signal handler, $29 points to
528 * the struct rt_sigframe.
530 regs->regs[ 4] = ksig->sig;
531 regs->regs[ 5] = (unsigned long) &frame->rs_info;
532 regs->regs[ 6] = (unsigned long) &frame->rs_uc;
533 regs->regs[29] = (unsigned long) frame;
534 regs->regs[31] = (unsigned long) sig_return;
535 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
537 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
538 current->comm, current->pid,
539 frame, regs->cp0_epc, regs->regs[31]);
544 struct mips_abi mips_abi = {
545 #ifdef CONFIG_TRAD_SIGNALS
546 .setup_frame = setup_frame,
547 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
549 .setup_rt_frame = setup_rt_frame,
550 .rt_signal_return_offset =
551 offsetof(struct mips_vdso, rt_signal_trampoline),
552 .restart = __NR_restart_syscall,
554 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
555 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
556 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
559 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
561 sigset_t *oldset = sigmask_to_save();
563 struct mips_abi *abi = current->thread.abi;
564 #ifdef CONFIG_CPU_MICROMIPS
566 unsigned long tmp = (unsigned long)current->mm->context.vdso;
571 void *vdso = current->mm->context.vdso;
575 switch(regs->regs[2]) {
576 case ERESTART_RESTARTBLOCK:
578 regs->regs[2] = EINTR;
581 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
582 regs->regs[2] = EINTR;
587 regs->regs[7] = regs->regs[26];
588 regs->regs[2] = regs->regs[0];
592 regs->regs[0] = 0; /* Don't deal with this again. */
595 if (sig_uses_siginfo(&ksig->ka))
596 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
599 ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig,
602 signal_setup_done(ret, ksig, 0);
605 static void do_signal(struct pt_regs *regs)
609 if (get_signal(&ksig)) {
610 /* Whee! Actually deliver the signal. */
611 handle_signal(&ksig, regs);
616 switch (regs->regs[2]) {
620 regs->regs[2] = regs->regs[0];
621 regs->regs[7] = regs->regs[26];
625 case ERESTART_RESTARTBLOCK:
626 regs->regs[2] = current->thread.abi->restart;
627 regs->regs[7] = regs->regs[26];
631 regs->regs[0] = 0; /* Don't deal with this again. */
635 * If there's no signal to deliver, we just put the saved sigmask
638 restore_saved_sigmask();
642 * notification of userspace execution resumption
643 * - triggered by the TIF_WORK_MASK flags
645 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
646 __u32 thread_info_flags)
652 /* deal with pending signal delivery */
653 if (thread_info_flags & _TIF_SIGPENDING)
656 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
657 clear_thread_flag(TIF_NOTIFY_RESUME);
658 tracehook_notify_resume(regs);
665 static int smp_save_fp_context(void __user *sc)
667 return raw_cpu_has_fpu
668 ? save_hw_fp_context(sc)
669 : copy_fp_to_sigcontext(sc);
672 static int smp_restore_fp_context(void __user *sc)
674 return raw_cpu_has_fpu
675 ? restore_hw_fp_context(sc)
676 : copy_fp_from_sigcontext(sc);
680 static int signal_setup(void)
683 /* For now just do the cpu_has_fpu check when the functions are invoked */
684 save_fp_context = smp_save_fp_context;
685 restore_fp_context = smp_restore_fp_context;
688 save_fp_context = save_hw_fp_context;
689 restore_fp_context = restore_hw_fp_context;
691 save_fp_context = copy_fp_to_sigcontext;
692 restore_fp_context = copy_fp_from_sigcontext;
694 #endif /* CONFIG_SMP */
699 arch_initcall(signal_setup);