| /* |
| * linux/arch/sh/kernel/signal.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| * |
| * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson |
| * |
| * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima |
| * |
| */ |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/smp_lock.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/stddef.h> |
| #include <linux/tty.h> |
| #include <linux/elf.h> |
| #include <linux/personality.h> |
| #include <linux/binfmts.h> |
| #include <linux/freezer.h> |
| |
| #include <asm/ucontext.h> |
| #include <asm/uaccess.h> |
| #include <asm/pgtable.h> |
| #include <asm/cacheflush.h> |
| |
| #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| |
| /* |
| * Atomically swap in the new signal mask, and wait for a signal. |
| */ |
| asmlinkage int |
| sys_sigsuspend(old_sigset_t mask, |
| unsigned long r5, unsigned long r6, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| mask &= _BLOCKABLE; |
| spin_lock_irq(¤t->sighand->siglock); |
| current->saved_sigmask = current->blocked; |
| siginitset(¤t->blocked, mask); |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| current->state = TASK_INTERRUPTIBLE; |
| schedule(); |
| set_thread_flag(TIF_RESTORE_SIGMASK); |
| return -ERESTARTNOHAND; |
| } |
| |
| asmlinkage int |
| sys_sigaction(int sig, const struct old_sigaction __user *act, |
| struct old_sigaction __user *oact) |
| { |
| struct k_sigaction new_ka, old_ka; |
| int ret; |
| |
| if (act) { |
| old_sigset_t mask; |
| if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
| __get_user(new_ka.sa.sa_handler, &act->sa_handler) || |
| __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) |
| return -EFAULT; |
| __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
| __get_user(mask, &act->sa_mask); |
| 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)) || |
| __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || |
| __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) |
| return -EFAULT; |
| __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
| __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); |
| } |
| |
| return ret; |
| } |
| |
| asmlinkage int |
| sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, |
| unsigned long r6, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| |
| return do_sigaltstack(uss, uoss, regs->regs[15]); |
| } |
| |
| |
| /* |
| * Do a signal return; undo the signal stack. |
| */ |
| |
| #define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */ |
| #if defined(CONFIG_CPU_SH2) |
| #define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */ |
| #else |
| #define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */ |
| #endif |
| #define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */ |
| |
| struct sigframe |
| { |
| struct sigcontext sc; |
| unsigned long extramask[_NSIG_WORDS-1]; |
| u16 retcode[8]; |
| }; |
| |
| struct rt_sigframe |
| { |
| struct siginfo info; |
| struct ucontext uc; |
| u16 retcode[8]; |
| }; |
| |
| #ifdef CONFIG_SH_FPU |
| static inline int restore_sigcontext_fpu(struct sigcontext __user *sc) |
| { |
| struct task_struct *tsk = current; |
| |
| if (!(cpu_data->flags & CPU_HAS_FPU)) |
| return 0; |
| |
| set_used_math(); |
| return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0], |
| sizeof(long)*(16*2+2)); |
| } |
| |
| static inline int save_sigcontext_fpu(struct sigcontext __user *sc, |
| struct pt_regs *regs) |
| { |
| struct task_struct *tsk = current; |
| |
| if (!(cpu_data->flags & CPU_HAS_FPU)) |
| return 0; |
| |
| if (!used_math()) { |
| __put_user(0, &sc->sc_ownedfp); |
| return 0; |
| } |
| |
| __put_user(1, &sc->sc_ownedfp); |
| |
| /* This will cause a "finit" to be triggered by the next |
| attempted FPU operation by the 'current' process. |
| */ |
| clear_used_math(); |
| |
| unlazy_fpu(tsk, regs); |
| return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard, |
| sizeof(long)*(16*2+2)); |
| } |
| #endif /* CONFIG_SH_FPU */ |
| |
| static int |
| restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p) |
| { |
| unsigned int err = 0; |
| |
| #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) |
| COPY(regs[1]); |
| COPY(regs[2]); COPY(regs[3]); |
| COPY(regs[4]); COPY(regs[5]); |
| COPY(regs[6]); COPY(regs[7]); |
| COPY(regs[8]); COPY(regs[9]); |
| COPY(regs[10]); COPY(regs[11]); |
| COPY(regs[12]); COPY(regs[13]); |
| COPY(regs[14]); COPY(regs[15]); |
| COPY(gbr); COPY(mach); |
| COPY(macl); COPY(pr); |
| COPY(sr); COPY(pc); |
| #undef COPY |
| |
| #ifdef CONFIG_SH_FPU |
| if (cpu_data->flags & CPU_HAS_FPU) { |
| int owned_fp; |
| struct task_struct *tsk = current; |
| |
| regs->sr |= SR_FD; /* Release FPU */ |
| clear_fpu(tsk, regs); |
| clear_used_math(); |
| __get_user (owned_fp, &sc->sc_ownedfp); |
| if (owned_fp) |
| err |= restore_sigcontext_fpu(sc); |
| } |
| #endif |
| |
| regs->tra = -1; /* disable syscall checks */ |
| err |= __get_user(*r0_p, &sc->sc_regs[0]); |
| return err; |
| } |
| |
| asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5, |
| unsigned long r6, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15]; |
| sigset_t set; |
| int r0; |
| |
| if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| |
| if (__get_user(set.sig[0], &frame->sc.oldmask) |
| || (_NSIG_WORDS > 1 |
| && __copy_from_user(&set.sig[1], &frame->extramask, |
| sizeof(frame->extramask)))) |
| goto badframe; |
| |
| sigdelsetmask(&set, ~_BLOCKABLE); |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| current->blocked = set; |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| if (restore_sigcontext(regs, &frame->sc, &r0)) |
| goto badframe; |
| return r0; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5, |
| unsigned long r6, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15]; |
| sigset_t set; |
| stack_t st; |
| int r0; |
| |
| if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| |
| if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) |
| goto badframe; |
| |
| sigdelsetmask(&set, ~_BLOCKABLE); |
| spin_lock_irq(¤t->sighand->siglock); |
| current->blocked = set; |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0)) |
| goto badframe; |
| |
| if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) |
| goto badframe; |
| /* It is more difficult to avoid calling this function than to |
| call it and ignore errors. */ |
| do_sigaltstack(&st, NULL, regs->regs[15]); |
| |
| return r0; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| /* |
| * Set up a signal frame. |
| */ |
| |
| static int |
| setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, |
| unsigned long mask) |
| { |
| int err = 0; |
| |
| #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x) |
| COPY(regs[0]); COPY(regs[1]); |
| COPY(regs[2]); COPY(regs[3]); |
| COPY(regs[4]); COPY(regs[5]); |
| COPY(regs[6]); COPY(regs[7]); |
| COPY(regs[8]); COPY(regs[9]); |
| COPY(regs[10]); COPY(regs[11]); |
| COPY(regs[12]); COPY(regs[13]); |
| COPY(regs[14]); COPY(regs[15]); |
| COPY(gbr); COPY(mach); |
| COPY(macl); COPY(pr); |
| COPY(sr); COPY(pc); |
| #undef COPY |
| |
| #ifdef CONFIG_SH_FPU |
| err |= save_sigcontext_fpu(sc, regs); |
| #endif |
| |
| /* non-iBCS2 extensions.. */ |
| err |= __put_user(mask, &sc->oldmask); |
| |
| return err; |
| } |
| |
| /* |
| * Determine which stack to use.. |
| */ |
| static inline void __user * |
| get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) |
| { |
| if (ka->sa.sa_flags & SA_ONSTACK) { |
| if (sas_ss_flags(sp) == 0) |
| sp = current->sas_ss_sp + current->sas_ss_size; |
| } |
| |
| return (void __user *)((sp - frame_size) & -8ul); |
| } |
| |
| /* These symbols are defined with the addresses in the vsyscall page. |
| See vsyscall-trapa.S. */ |
| extern void __user __kernel_sigreturn; |
| extern void __user __kernel_rt_sigreturn; |
| |
| static int setup_frame(int sig, struct k_sigaction *ka, |
| sigset_t *set, struct pt_regs *regs) |
| { |
| struct sigframe __user *frame; |
| int err = 0; |
| int signal; |
| |
| frame = get_sigframe(ka, regs->regs[15], sizeof(*frame)); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| goto give_sigsegv; |
| |
| signal = current_thread_info()->exec_domain |
| && current_thread_info()->exec_domain->signal_invmap |
| && sig < 32 |
| ? current_thread_info()->exec_domain->signal_invmap[sig] |
| : sig; |
| |
| err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); |
| |
| if (_NSIG_WORDS > 1) |
| err |= __copy_to_user(frame->extramask, &set->sig[1], |
| sizeof(frame->extramask)); |
| |
| /* Set up to return from userspace. If provided, use a stub |
| already in userspace. */ |
| if (ka->sa.sa_flags & SA_RESTORER) { |
| regs->pr = (unsigned long) ka->sa.sa_restorer; |
| #ifdef CONFIG_VSYSCALL |
| } else if (likely(current->mm->context.vdso)) { |
| regs->pr = VDSO_SYM(&__kernel_sigreturn); |
| #endif |
| } else { |
| /* Generate return code (system call to sigreturn) */ |
| err |= __put_user(MOVW(7), &frame->retcode[0]); |
| err |= __put_user(TRAP_NOARG, &frame->retcode[1]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[2]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[3]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[4]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[5]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[6]); |
| err |= __put_user((__NR_sigreturn), &frame->retcode[7]); |
| regs->pr = (unsigned long) frame->retcode; |
| } |
| |
| if (err) |
| goto give_sigsegv; |
| |
| /* Set up registers for signal handler */ |
| regs->regs[15] = (unsigned long) frame; |
| regs->regs[4] = signal; /* Arg for signal handler */ |
| regs->regs[5] = 0; |
| regs->regs[6] = (unsigned long) &frame->sc; |
| regs->pc = (unsigned long) ka->sa.sa_handler; |
| |
| set_fs(USER_DS); |
| |
| pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", |
| current->comm, current->pid, frame, regs->pc, regs->pr); |
| |
| flush_cache_sigtramp(regs->pr); |
| |
| if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode)) |
| flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES); |
| |
| return 0; |
| |
| give_sigsegv: |
| force_sigsegv(sig, current); |
| return -EFAULT; |
| } |
| |
| static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
| sigset_t *set, struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| int err = 0; |
| int signal; |
| |
| frame = get_sigframe(ka, regs->regs[15], sizeof(*frame)); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| goto give_sigsegv; |
| |
| signal = current_thread_info()->exec_domain |
| && current_thread_info()->exec_domain->signal_invmap |
| && sig < 32 |
| ? current_thread_info()->exec_domain->signal_invmap[sig] |
| : sig; |
| |
| err |= copy_siginfo_to_user(&frame->info, info); |
| |
| /* Create the ucontext. */ |
| err |= __put_user(0, &frame->uc.uc_flags); |
| err |= __put_user(0, &frame->uc.uc_link); |
| err |= __put_user((void *)current->sas_ss_sp, |
| &frame->uc.uc_stack.ss_sp); |
| err |= __put_user(sas_ss_flags(regs->regs[15]), |
| &frame->uc.uc_stack.ss_flags); |
| err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); |
| err |= setup_sigcontext(&frame->uc.uc_mcontext, |
| regs, set->sig[0]); |
| err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
| |
| /* Set up to return from userspace. If provided, use a stub |
| already in userspace. */ |
| if (ka->sa.sa_flags & SA_RESTORER) { |
| regs->pr = (unsigned long) ka->sa.sa_restorer; |
| #ifdef CONFIG_VSYSCALL |
| } else if (likely(current->mm->context.vdso)) { |
| regs->pr = VDSO_SYM(&__kernel_rt_sigreturn); |
| #endif |
| } else { |
| /* Generate return code (system call to rt_sigreturn) */ |
| err |= __put_user(MOVW(7), &frame->retcode[0]); |
| err |= __put_user(TRAP_NOARG, &frame->retcode[1]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[2]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[3]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[4]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[5]); |
| err |= __put_user(OR_R0_R0, &frame->retcode[6]); |
| err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]); |
| regs->pr = (unsigned long) frame->retcode; |
| } |
| |
| if (err) |
| goto give_sigsegv; |
| |
| /* Set up registers for signal handler */ |
| regs->regs[15] = (unsigned long) frame; |
| regs->regs[4] = signal; /* Arg for signal handler */ |
| regs->regs[5] = (unsigned long) &frame->info; |
| regs->regs[6] = (unsigned long) &frame->uc; |
| regs->pc = (unsigned long) ka->sa.sa_handler; |
| |
| set_fs(USER_DS); |
| |
| pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", |
| current->comm, current->pid, frame, regs->pc, regs->pr); |
| |
| flush_cache_sigtramp(regs->pr); |
| |
| if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode)) |
| flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES); |
| |
| return 0; |
| |
| give_sigsegv: |
| force_sigsegv(sig, current); |
| return -EFAULT; |
| } |
| |
| /* |
| * OK, we're invoking a handler |
| */ |
| |
| static int |
| handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, |
| sigset_t *oldset, struct pt_regs *regs) |
| { |
| int ret; |
| |
| /* Are we from a system call? */ |
| if (regs->tra >= 0) { |
| /* If so, check system call restarting.. */ |
| switch (regs->regs[0]) { |
| case -ERESTARTNOHAND: |
| regs->regs[0] = -EINTR; |
| break; |
| |
| case -ERESTARTSYS: |
| if (!(ka->sa.sa_flags & SA_RESTART)) { |
| regs->regs[0] = -EINTR; |
| break; |
| } |
| /* fallthrough */ |
| case -ERESTARTNOINTR: |
| regs->pc -= 2; |
| } |
| } else { |
| /* gUSA handling */ |
| #ifdef CONFIG_PREEMPT |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| #endif |
| if (regs->regs[15] >= 0xc0000000) { |
| int offset = (int)regs->regs[15]; |
| |
| /* Reset stack pointer: clear critical region mark */ |
| regs->regs[15] = regs->regs[1]; |
| if (regs->pc < regs->regs[0]) |
| /* Go to rewind point #1 */ |
| regs->pc = regs->regs[0] + offset - 2; |
| } |
| #ifdef CONFIG_PREEMPT |
| local_irq_restore(flags); |
| #endif |
| } |
| |
| /* Set up the stack frame */ |
| if (ka->sa.sa_flags & SA_SIGINFO) |
| ret = setup_rt_frame(sig, ka, info, oldset, regs); |
| else |
| ret = setup_frame(sig, ka, oldset, regs); |
| |
| if (ka->sa.sa_flags & SA_ONESHOT) |
| ka->sa.sa_handler = SIG_DFL; |
| |
| if (ret == 0) { |
| spin_lock_irq(¤t->sighand->siglock); |
| sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); |
| if (!(ka->sa.sa_flags & SA_NODEFER)) |
| sigaddset(¤t->blocked,sig); |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Note that 'init' is a special process: it doesn't get signals it doesn't |
| * want to handle. Thus you cannot kill init even with a SIGKILL even by |
| * mistake. |
| * |
| * Note that we go through the signals twice: once to check the signals that |
| * the kernel can handle, and then we build all the user-level signal handling |
| * stack-frames in one go after that. |
| */ |
| static void do_signal(struct pt_regs *regs, unsigned int save_r0) |
| { |
| siginfo_t info; |
| int signr; |
| struct k_sigaction ka; |
| sigset_t *oldset; |
| |
| /* |
| * We want the common case to go fast, which |
| * is why we may in certain cases get here from |
| * kernel mode. Just return without doing anything |
| * if so. |
| */ |
| if (!user_mode(regs)) |
| return; |
| |
| if (try_to_freeze()) |
| goto no_signal; |
| |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| oldset = ¤t->saved_sigmask; |
| else |
| oldset = ¤t->blocked; |
| |
| signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| if (signr > 0) { |
| /* Whee! Actually deliver the signal. */ |
| if (handle_signal(signr, &ka, &info, oldset, regs) == 0) { |
| /* a signal was successfully delivered; the saved |
| * sigmask will have been stored in the signal frame, |
| * and will be restored by sigreturn, so we can simply |
| * clear the TIF_RESTORE_SIGMASK flag */ |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| } |
| } |
| |
| no_signal: |
| /* Did we come from a system call? */ |
| if (regs->tra >= 0) { |
| /* Restart the system call - no handlers present */ |
| if (regs->regs[0] == -ERESTARTNOHAND || |
| regs->regs[0] == -ERESTARTSYS || |
| regs->regs[0] == -ERESTARTNOINTR) { |
| regs->regs[0] = save_r0; |
| regs->pc -= 2; |
| } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) { |
| regs->pc -= 2; |
| regs->regs[3] = __NR_restart_syscall; |
| } |
| } |
| |
| /* if there's no signal to deliver, we just put the saved sigmask |
| * back */ |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
| } |
| } |
| |
| asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0, |
| __u32 thread_info_flags) |
| { |
| /* deal with pending signal delivery */ |
| if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) |
| do_signal(regs, save_r0); |
| } |