| /* |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| * Copyright (C) 1994 - 2000 Ralf Baechle |
| * Copyright (C) 1999, 2000 Silicon Graphics, Inc. |
| * Copyright (C) 2014, Imagination Technologies Ltd. |
| */ |
| #include <linux/cache.h> |
| #include <linux/context_tracking.h> |
| #include <linux/irqflags.h> |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/personality.h> |
| #include <linux/smp.h> |
| #include <linux/kernel.h> |
| #include <linux/signal.h> |
| #include <linux/errno.h> |
| #include <linux/wait.h> |
| #include <linux/ptrace.h> |
| #include <linux/unistd.h> |
| #include <linux/compiler.h> |
| #include <linux/syscalls.h> |
| #include <linux/uaccess.h> |
| #include <linux/tracehook.h> |
| |
| #include <asm/abi.h> |
| #include <asm/asm.h> |
| #include <linux/bitops.h> |
| #include <asm/cacheflush.h> |
| #include <asm/fpu.h> |
| #include <asm/sim.h> |
| #include <asm/ucontext.h> |
| #include <asm/cpu-features.h> |
| #include <asm/war.h> |
| #include <asm/vdso.h> |
| #include <asm/dsp.h> |
| #include <asm/inst.h> |
| |
| #include "signal-common.h" |
| |
| static int (*save_fp_context)(struct sigcontext __user *sc); |
| static int (*restore_fp_context)(struct sigcontext __user *sc); |
| |
| extern asmlinkage int _save_fp_context(struct sigcontext __user *sc); |
| extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc); |
| |
| struct sigframe { |
| u32 sf_ass[4]; /* argument save space for o32 */ |
| u32 sf_pad[2]; /* Was: signal trampoline */ |
| struct sigcontext sf_sc; |
| sigset_t sf_mask; |
| }; |
| |
| struct rt_sigframe { |
| u32 rs_ass[4]; /* argument save space for o32 */ |
| u32 rs_pad[2]; /* Was: signal trampoline */ |
| struct siginfo rs_info; |
| struct ucontext rs_uc; |
| }; |
| |
| /* |
| * Thread saved context copy to/from a signal context presumed to be on the |
| * user stack, and therefore accessed with appropriate macros from uaccess.h. |
| */ |
| static int copy_fp_to_sigcontext(struct sigcontext __user *sc) |
| { |
| int i; |
| int err = 0; |
| |
| for (i = 0; i < NUM_FPU_REGS; i++) { |
| err |= |
| __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0), |
| &sc->sc_fpregs[i]); |
| } |
| err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr); |
| |
| return err; |
| } |
| |
| static int copy_fp_from_sigcontext(struct sigcontext __user *sc) |
| { |
| int i; |
| int err = 0; |
| u64 fpr_val; |
| |
| for (i = 0; i < NUM_FPU_REGS; i++) { |
| err |= __get_user(fpr_val, &sc->sc_fpregs[i]); |
| set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val); |
| } |
| err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr); |
| |
| return err; |
| } |
| |
| /* |
| * Helper routines |
| */ |
| static int protected_save_fp_context(struct sigcontext __user *sc) |
| { |
| int err; |
| #ifndef CONFIG_EVA |
| while (1) { |
| lock_fpu_owner(); |
| if (is_fpu_owner()) { |
| err = save_fp_context(sc); |
| unlock_fpu_owner(); |
| } else { |
| unlock_fpu_owner(); |
| err = copy_fp_to_sigcontext(sc); |
| } |
| if (likely(!err)) |
| break; |
| /* touch the sigcontext and try again */ |
| err = __put_user(0, &sc->sc_fpregs[0]) | |
| __put_user(0, &sc->sc_fpregs[31]) | |
| __put_user(0, &sc->sc_fpc_csr); |
| if (err) |
| break; /* really bad sigcontext */ |
| } |
| #else |
| /* |
| * EVA does not have FPU EVA instructions so saving fpu context directly |
| * does not work. |
| */ |
| lose_fpu(1); |
| err = save_fp_context(sc); /* this might fail */ |
| #endif |
| return err; |
| } |
| |
| static int protected_restore_fp_context(struct sigcontext __user *sc) |
| { |
| int err, tmp __maybe_unused; |
| #ifndef CONFIG_EVA |
| while (1) { |
| lock_fpu_owner(); |
| if (is_fpu_owner()) { |
| err = restore_fp_context(sc); |
| unlock_fpu_owner(); |
| } else { |
| unlock_fpu_owner(); |
| err = copy_fp_from_sigcontext(sc); |
| } |
| if (likely(!err)) |
| break; |
| /* touch the sigcontext and try again */ |
| err = __get_user(tmp, &sc->sc_fpregs[0]) | |
| __get_user(tmp, &sc->sc_fpregs[31]) | |
| __get_user(tmp, &sc->sc_fpc_csr); |
| if (err) |
| break; /* really bad sigcontext */ |
| } |
| #else |
| /* |
| * EVA does not have FPU EVA instructions so restoring fpu context |
| * directly does not work. |
| */ |
| lose_fpu(0); |
| err = restore_fp_context(sc); /* this might fail */ |
| #endif |
| return err; |
| } |
| |
| int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) |
| { |
| int err = 0; |
| int i; |
| unsigned int used_math; |
| |
| err |= __put_user(regs->cp0_epc, &sc->sc_pc); |
| |
| err |= __put_user(0, &sc->sc_regs[0]); |
| for (i = 1; i < 32; i++) |
| err |= __put_user(regs->regs[i], &sc->sc_regs[i]); |
| |
| #ifdef CONFIG_CPU_HAS_SMARTMIPS |
| err |= __put_user(regs->acx, &sc->sc_acx); |
| #endif |
| err |= __put_user(regs->hi, &sc->sc_mdhi); |
| err |= __put_user(regs->lo, &sc->sc_mdlo); |
| if (cpu_has_dsp) { |
| err |= __put_user(mfhi1(), &sc->sc_hi1); |
| err |= __put_user(mflo1(), &sc->sc_lo1); |
| err |= __put_user(mfhi2(), &sc->sc_hi2); |
| err |= __put_user(mflo2(), &sc->sc_lo2); |
| err |= __put_user(mfhi3(), &sc->sc_hi3); |
| err |= __put_user(mflo3(), &sc->sc_lo3); |
| err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); |
| } |
| |
| used_math = !!used_math(); |
| err |= __put_user(used_math, &sc->sc_used_math); |
| |
| if (used_math) { |
| /* |
| * Save FPU state to signal context. Signal handler |
| * will "inherit" current FPU state. |
| */ |
| err |= protected_save_fp_context(sc); |
| } |
| return err; |
| } |
| |
| int fpcsr_pending(unsigned int __user *fpcsr) |
| { |
| int err, sig = 0; |
| unsigned int csr, enabled; |
| |
| err = __get_user(csr, fpcsr); |
| enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5); |
| /* |
| * If the signal handler set some FPU exceptions, clear it and |
| * send SIGFPE. |
| */ |
| if (csr & enabled) { |
| csr &= ~enabled; |
| err |= __put_user(csr, fpcsr); |
| sig = SIGFPE; |
| } |
| return err ?: sig; |
| } |
| |
| static int |
| check_and_restore_fp_context(struct sigcontext __user *sc) |
| { |
| int err, sig; |
| |
| err = sig = fpcsr_pending(&sc->sc_fpc_csr); |
| if (err > 0) |
| err = 0; |
| err |= protected_restore_fp_context(sc); |
| return err ?: sig; |
| } |
| |
| int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) |
| { |
| unsigned int used_math; |
| unsigned long treg; |
| int err = 0; |
| int i; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current_thread_info()->restart_block.fn = do_no_restart_syscall; |
| |
| err |= __get_user(regs->cp0_epc, &sc->sc_pc); |
| |
| #ifdef CONFIG_CPU_HAS_SMARTMIPS |
| err |= __get_user(regs->acx, &sc->sc_acx); |
| #endif |
| err |= __get_user(regs->hi, &sc->sc_mdhi); |
| err |= __get_user(regs->lo, &sc->sc_mdlo); |
| if (cpu_has_dsp) { |
| err |= __get_user(treg, &sc->sc_hi1); mthi1(treg); |
| err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg); |
| err |= __get_user(treg, &sc->sc_hi2); mthi2(treg); |
| err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg); |
| err |= __get_user(treg, &sc->sc_hi3); mthi3(treg); |
| err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg); |
| err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK); |
| } |
| |
| for (i = 1; i < 32; i++) |
| err |= __get_user(regs->regs[i], &sc->sc_regs[i]); |
| |
| err |= __get_user(used_math, &sc->sc_used_math); |
| conditional_used_math(used_math); |
| |
| if (used_math) { |
| /* restore fpu context if we have used it before */ |
| if (!err) |
| err = check_and_restore_fp_context(sc); |
| } else { |
| /* signal handler may have used FPU. Give it up. */ |
| lose_fpu(0); |
| } |
| |
| return err; |
| } |
| |
| void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, |
| size_t frame_size) |
| { |
| unsigned long sp; |
| |
| /* Default to using normal stack */ |
| sp = regs->regs[29]; |
| |
| /* |
| * FPU emulator may have it's own trampoline active just |
| * above the user stack, 16-bytes before the next lowest |
| * 16 byte boundary. Try to avoid trashing it. |
| */ |
| sp -= 32; |
| |
| sp = sigsp(sp, ksig); |
| |
| return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK)); |
| } |
| |
| /* |
| * Atomically swap in the new signal mask, and wait for a signal. |
| */ |
| |
| #ifdef CONFIG_TRAD_SIGNALS |
| SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset) |
| { |
| return sys_rt_sigsuspend(uset, sizeof(sigset_t)); |
| } |
| #endif |
| |
| #ifdef CONFIG_TRAD_SIGNALS |
| SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act, |
| struct sigaction __user *, oact) |
| { |
| struct k_sigaction new_ka, old_ka; |
| int ret; |
| int err = 0; |
| |
| if (act) { |
| old_sigset_t mask; |
| |
| if (!access_ok(VERIFY_READ, act, sizeof(*act))) |
| return -EFAULT; |
| err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler); |
| err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
| err |= __get_user(mask, &act->sa_mask.sig[0]); |
| if (err) |
| return -EFAULT; |
| |
| siginitset(&new_ka.sa.sa_mask, mask); |
| } |
| |
| ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); |
| |
| if (!ret && oact) { |
| if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact))) |
| return -EFAULT; |
| err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
| err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler); |
| err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig); |
| err |= __put_user(0, &oact->sa_mask.sig[1]); |
| err |= __put_user(0, &oact->sa_mask.sig[2]); |
| err |= __put_user(0, &oact->sa_mask.sig[3]); |
| if (err) |
| return -EFAULT; |
| } |
| |
| return ret; |
| } |
| #endif |
| |
| #ifdef CONFIG_TRAD_SIGNALS |
| asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs) |
| { |
| struct sigframe __user *frame; |
| sigset_t blocked; |
| int sig; |
| |
| frame = (struct sigframe __user *) regs.regs[29]; |
| if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked))) |
| goto badframe; |
| |
| set_current_blocked(&blocked); |
| |
| sig = restore_sigcontext(®s, &frame->sf_sc); |
| if (sig < 0) |
| goto badframe; |
| else if (sig) |
| force_sig(sig, current); |
| |
| /* |
| * Don't let your children do this ... |
| */ |
| __asm__ __volatile__( |
| "move\t$29, %0\n\t" |
| "j\tsyscall_exit" |
| :/* no outputs */ |
| :"r" (®s)); |
| /* Unreached */ |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| } |
| #endif /* CONFIG_TRAD_SIGNALS */ |
| |
| asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs) |
| { |
| struct rt_sigframe __user *frame; |
| sigset_t set; |
| int sig; |
| |
| frame = (struct rt_sigframe __user *) regs.regs[29]; |
| if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set))) |
| goto badframe; |
| |
| set_current_blocked(&set); |
| |
| sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext); |
| if (sig < 0) |
| goto badframe; |
| else if (sig) |
| force_sig(sig, current); |
| |
| if (restore_altstack(&frame->rs_uc.uc_stack)) |
| goto badframe; |
| |
| /* |
| * Don't let your children do this ... |
| */ |
| __asm__ __volatile__( |
| "move\t$29, %0\n\t" |
| "j\tsyscall_exit" |
| :/* no outputs */ |
| :"r" (®s)); |
| /* Unreached */ |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| } |
| |
| #ifdef CONFIG_TRAD_SIGNALS |
| static int setup_frame(void *sig_return, struct ksignal *ksig, |
| struct pt_regs *regs, sigset_t *set) |
| { |
| struct sigframe __user *frame; |
| int err = 0; |
| |
| frame = get_sigframe(ksig, regs, sizeof(*frame)); |
| if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) |
| return -EFAULT; |
| |
| err |= setup_sigcontext(regs, &frame->sf_sc); |
| err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set)); |
| if (err) |
| return -EFAULT; |
| |
| /* |
| * Arguments to signal handler: |
| * |
| * a0 = signal number |
| * a1 = 0 (should be cause) |
| * a2 = pointer to struct sigcontext |
| * |
| * $25 and c0_epc point to the signal handler, $29 points to the |
| * struct sigframe. |
| */ |
| regs->regs[ 4] = ksig->sig; |
| regs->regs[ 5] = 0; |
| regs->regs[ 6] = (unsigned long) &frame->sf_sc; |
| regs->regs[29] = (unsigned long) frame; |
| regs->regs[31] = (unsigned long) sig_return; |
| regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; |
| |
| DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", |
| current->comm, current->pid, |
| frame, regs->cp0_epc, regs->regs[31]); |
| return 0; |
| } |
| #endif |
| |
| static int setup_rt_frame(void *sig_return, struct ksignal *ksig, |
| struct pt_regs *regs, sigset_t *set) |
| { |
| struct rt_sigframe __user *frame; |
| int err = 0; |
| |
| frame = get_sigframe(ksig, regs, sizeof(*frame)); |
| if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) |
| return -EFAULT; |
| |
| /* Create siginfo. */ |
| err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info); |
| |
| /* Create the ucontext. */ |
| err |= __put_user(0, &frame->rs_uc.uc_flags); |
| err |= __put_user(NULL, &frame->rs_uc.uc_link); |
| err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); |
| err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); |
| err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set)); |
| |
| if (err) |
| return -EFAULT; |
| |
| /* |
| * Arguments to signal handler: |
| * |
| * a0 = signal number |
| * a1 = 0 (should be cause) |
| * a2 = pointer to ucontext |
| * |
| * $25 and c0_epc point to the signal handler, $29 points to |
| * the struct rt_sigframe. |
| */ |
| regs->regs[ 4] = ksig->sig; |
| regs->regs[ 5] = (unsigned long) &frame->rs_info; |
| regs->regs[ 6] = (unsigned long) &frame->rs_uc; |
| regs->regs[29] = (unsigned long) frame; |
| regs->regs[31] = (unsigned long) sig_return; |
| regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; |
| |
| DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", |
| current->comm, current->pid, |
| frame, regs->cp0_epc, regs->regs[31]); |
| |
| return 0; |
| } |
| |
| struct mips_abi mips_abi = { |
| #ifdef CONFIG_TRAD_SIGNALS |
| .setup_frame = setup_frame, |
| .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline), |
| #endif |
| .setup_rt_frame = setup_rt_frame, |
| .rt_signal_return_offset = |
| offsetof(struct mips_vdso, rt_signal_trampoline), |
| .restart = __NR_restart_syscall |
| }; |
| |
| static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
| { |
| sigset_t *oldset = sigmask_to_save(); |
| int ret; |
| struct mips_abi *abi = current->thread.abi; |
| #ifdef CONFIG_CPU_MICROMIPS |
| void *vdso; |
| unsigned int tmp = (unsigned int)current->mm->context.vdso; |
| |
| set_isa16_mode(tmp); |
| vdso = (void *)tmp; |
| #else |
| void *vdso = current->mm->context.vdso; |
| #endif |
| |
| if (regs->regs[0]) { |
| switch(regs->regs[2]) { |
| case ERESTART_RESTARTBLOCK: |
| case ERESTARTNOHAND: |
| regs->regs[2] = EINTR; |
| break; |
| case ERESTARTSYS: |
| if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
| regs->regs[2] = EINTR; |
| break; |
| } |
| /* fallthrough */ |
| case ERESTARTNOINTR: |
| regs->regs[7] = regs->regs[26]; |
| regs->regs[2] = regs->regs[0]; |
| regs->cp0_epc -= 4; |
| } |
| |
| regs->regs[0] = 0; /* Don't deal with this again. */ |
| } |
| |
| if (sig_uses_siginfo(&ksig->ka)) |
| ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset, |
| ksig, regs, oldset); |
| else |
| ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig, |
| regs, oldset); |
| |
| signal_setup_done(ret, ksig, 0); |
| } |
| |
| static void do_signal(struct pt_regs *regs) |
| { |
| struct ksignal ksig; |
| |
| if (get_signal(&ksig)) { |
| /* Whee! Actually deliver the signal. */ |
| handle_signal(&ksig, regs); |
| return; |
| } |
| |
| if (regs->regs[0]) { |
| switch (regs->regs[2]) { |
| case ERESTARTNOHAND: |
| case ERESTARTSYS: |
| case ERESTARTNOINTR: |
| regs->regs[2] = regs->regs[0]; |
| regs->regs[7] = regs->regs[26]; |
| regs->cp0_epc -= 4; |
| break; |
| |
| case ERESTART_RESTARTBLOCK: |
| regs->regs[2] = current->thread.abi->restart; |
| regs->regs[7] = regs->regs[26]; |
| regs->cp0_epc -= 4; |
| break; |
| } |
| regs->regs[0] = 0; /* Don't deal with this again. */ |
| } |
| |
| /* |
| * If there's no signal to deliver, we just put the saved sigmask |
| * back |
| */ |
| restore_saved_sigmask(); |
| } |
| |
| /* |
| * notification of userspace execution resumption |
| * - triggered by the TIF_WORK_MASK flags |
| */ |
| asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, |
| __u32 thread_info_flags) |
| { |
| local_irq_enable(); |
| |
| user_exit(); |
| |
| /* deal with pending signal delivery */ |
| if (thread_info_flags & _TIF_SIGPENDING) |
| do_signal(regs); |
| |
| if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
| clear_thread_flag(TIF_NOTIFY_RESUME); |
| tracehook_notify_resume(regs); |
| } |
| |
| user_enter(); |
| } |
| |
| #ifdef CONFIG_SMP |
| #ifndef CONFIG_EVA |
| static int smp_save_fp_context(struct sigcontext __user *sc) |
| { |
| return raw_cpu_has_fpu |
| ? _save_fp_context(sc) |
| : copy_fp_to_sigcontext(sc); |
| } |
| |
| static int smp_restore_fp_context(struct sigcontext __user *sc) |
| { |
| return raw_cpu_has_fpu |
| ? _restore_fp_context(sc) |
| : copy_fp_from_sigcontext(sc); |
| } |
| #endif /* CONFIG_EVA */ |
| #endif |
| |
| static int signal_setup(void) |
| { |
| #ifndef CONFIG_EVA |
| #ifdef CONFIG_SMP |
| /* For now just do the cpu_has_fpu check when the functions are invoked */ |
| save_fp_context = smp_save_fp_context; |
| restore_fp_context = smp_restore_fp_context; |
| #else |
| if (cpu_has_fpu) { |
| save_fp_context = _save_fp_context; |
| restore_fp_context = _restore_fp_context; |
| } else { |
| save_fp_context = copy_fp_to_sigcontext; |
| restore_fp_context = copy_fp_from_sigcontext; |
| } |
| #endif /* CONFIG_SMP */ |
| #else |
| save_fp_context = copy_fp_to_sigcontext; |
| restore_fp_context = copy_fp_from_sigcontext; |
| #endif |
| |
| return 0; |
| } |
| |
| arch_initcall(signal_setup); |