| /* signal.c: FRV specific bits of signal handling |
| * |
| * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved. |
| * Written by David Howells (dhowells@redhat.com) |
| * - Derived from arch/m68k/kernel/signal.c |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/mm.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/personality.h> |
| #include <linux/freezer.h> |
| #include <linux/tracehook.h> |
| #include <asm/ucontext.h> |
| #include <asm/uaccess.h> |
| #include <asm/cacheflush.h> |
| |
| #define DEBUG_SIG 0 |
| |
| #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| |
| struct fdpic_func_descriptor { |
| unsigned long text; |
| unsigned long GOT; |
| }; |
| |
| /* |
| * Atomically swap in the new signal mask, and wait for a signal. |
| */ |
| asmlinkage int sys_sigsuspend(int history0, int history1, old_sigset_t mask) |
| { |
| 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) |
| { |
| return do_sigaltstack(uss, uoss, __frame->sp); |
| } |
| |
| |
| /* |
| * Do a signal return; undo the signal stack. |
| */ |
| |
| struct sigframe |
| { |
| __sigrestore_t pretcode; |
| int sig; |
| struct sigcontext sc; |
| unsigned long extramask[_NSIG_WORDS-1]; |
| uint32_t retcode[2]; |
| }; |
| |
| struct rt_sigframe |
| { |
| __sigrestore_t pretcode; |
| int sig; |
| struct siginfo __user *pinfo; |
| void __user *puc; |
| struct siginfo info; |
| struct ucontext uc; |
| uint32_t retcode[2]; |
| }; |
| |
| static int restore_sigcontext(struct sigcontext __user *sc, int *_gr8) |
| { |
| struct user_context *user = current->thread.user; |
| unsigned long tbr, psr; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current_thread_info()->restart_block.fn = do_no_restart_syscall; |
| |
| tbr = user->i.tbr; |
| psr = user->i.psr; |
| if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context))) |
| goto badframe; |
| user->i.tbr = tbr; |
| user->i.psr = psr; |
| |
| restore_user_regs(user); |
| |
| user->i.syscallno = -1; /* disable syscall checks */ |
| |
| *_gr8 = user->i.gr[8]; |
| return 0; |
| |
| badframe: |
| return 1; |
| } |
| |
| asmlinkage int sys_sigreturn(void) |
| { |
| struct sigframe __user *frame = (struct sigframe __user *) __frame->sp; |
| sigset_t set; |
| int gr8; |
| |
| if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| if (__get_user(set.sig[0], &frame->sc.sc_oldmask)) |
| goto badframe; |
| |
| if (_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(&frame->sc, &gr8)) |
| goto badframe; |
| return gr8; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| asmlinkage int sys_rt_sigreturn(void) |
| { |
| struct rt_sigframe __user *frame = (struct rt_sigframe __user *) __frame->sp; |
| sigset_t set; |
| int gr8; |
| |
| 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(&frame->uc.uc_mcontext, &gr8)) |
| goto badframe; |
| |
| if (do_sigaltstack(&frame->uc.uc_stack, NULL, __frame->sp) == -EFAULT) |
| goto badframe; |
| |
| return gr8; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| /* |
| * Set up a signal frame |
| */ |
| static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask) |
| { |
| save_user_regs(current->thread.user); |
| |
| if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0) |
| goto badframe; |
| |
| /* non-iBCS2 extensions.. */ |
| if (__put_user(mask, &sc->sc_oldmask) < 0) |
| goto badframe; |
| |
| return 0; |
| |
| badframe: |
| return 1; |
| } |
| |
| /*****************************************************************************/ |
| /* |
| * Determine which stack to use.. |
| */ |
| static inline void __user *get_sigframe(struct k_sigaction *ka, |
| size_t frame_size) |
| { |
| unsigned long sp; |
| |
| /* Default to using normal stack */ |
| sp = __frame->sp; |
| |
| /* This is the X/Open sanctioned signal stack switching. */ |
| if (ka->sa.sa_flags & SA_ONSTACK) { |
| if (! sas_ss_flags(sp)) |
| sp = current->sas_ss_sp + current->sas_ss_size; |
| } |
| |
| return (void __user *) ((sp - frame_size) & ~7UL); |
| |
| } /* end get_sigframe() */ |
| |
| /*****************************************************************************/ |
| /* |
| * |
| */ |
| static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set) |
| { |
| struct sigframe __user *frame; |
| int rsig; |
| |
| set_fs(USER_DS); |
| |
| frame = get_sigframe(ka, sizeof(*frame)); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| goto give_sigsegv; |
| |
| rsig = sig; |
| if (sig < 32 && |
| __current_thread_info->exec_domain && |
| __current_thread_info->exec_domain->signal_invmap) |
| rsig = __current_thread_info->exec_domain->signal_invmap[sig]; |
| |
| if (__put_user(rsig, &frame->sig) < 0) |
| goto give_sigsegv; |
| |
| if (setup_sigcontext(&frame->sc, set->sig[0])) |
| goto give_sigsegv; |
| |
| if (_NSIG_WORDS > 1) { |
| if (__copy_to_user(frame->extramask, &set->sig[1], |
| sizeof(frame->extramask))) |
| goto give_sigsegv; |
| } |
| |
| /* Set up to return from userspace. If provided, use a stub |
| * already in userspace. */ |
| if (ka->sa.sa_flags & SA_RESTORER) { |
| if (__put_user(ka->sa.sa_restorer, &frame->pretcode) < 0) |
| goto give_sigsegv; |
| } |
| else { |
| /* Set up the following code on the stack: |
| * setlos #__NR_sigreturn,gr7 |
| * tira gr0,0 |
| */ |
| if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) || |
| __put_user(0x8efc0000|__NR_sigreturn, &frame->retcode[0]) || |
| __put_user(0xc0700000, &frame->retcode[1])) |
| goto give_sigsegv; |
| |
| flush_icache_range((unsigned long) frame->retcode, |
| (unsigned long) (frame->retcode + 2)); |
| } |
| |
| /* Set up registers for the signal handler */ |
| if (current->personality & FDPIC_FUNCPTRS) { |
| struct fdpic_func_descriptor __user *funcptr = |
| (struct fdpic_func_descriptor __user *) ka->sa.sa_handler; |
| struct fdpic_func_descriptor desc; |
| if (copy_from_user(&desc, funcptr, sizeof(desc))) |
| goto give_sigsegv; |
| __frame->pc = desc.text; |
| __frame->gr15 = desc.GOT; |
| } else { |
| __frame->pc = (unsigned long) ka->sa.sa_handler; |
| __frame->gr15 = 0; |
| } |
| |
| __frame->sp = (unsigned long) frame; |
| __frame->lr = (unsigned long) &frame->retcode; |
| __frame->gr8 = sig; |
| |
| /* the tracer may want to single-step inside the handler */ |
| if (test_thread_flag(TIF_SINGLESTEP)) |
| ptrace_notify(SIGTRAP); |
| |
| #if DEBUG_SIG |
| printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", |
| sig, current->comm, current->pid, frame, __frame->pc, |
| frame->pretcode); |
| #endif |
| |
| return 0; |
| |
| give_sigsegv: |
| force_sigsegv(sig, current); |
| return -EFAULT; |
| |
| } /* end setup_frame() */ |
| |
| /*****************************************************************************/ |
| /* |
| * |
| */ |
| static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
| sigset_t *set) |
| { |
| struct rt_sigframe __user *frame; |
| int rsig; |
| |
| set_fs(USER_DS); |
| |
| frame = get_sigframe(ka, sizeof(*frame)); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| goto give_sigsegv; |
| |
| rsig = sig; |
| if (sig < 32 && |
| __current_thread_info->exec_domain && |
| __current_thread_info->exec_domain->signal_invmap) |
| rsig = __current_thread_info->exec_domain->signal_invmap[sig]; |
| |
| if (__put_user(rsig, &frame->sig) || |
| __put_user(&frame->info, &frame->pinfo) || |
| __put_user(&frame->uc, &frame->puc)) |
| goto give_sigsegv; |
| |
| if (copy_siginfo_to_user(&frame->info, info)) |
| goto give_sigsegv; |
| |
| /* Create the ucontext. */ |
| if (__put_user(0, &frame->uc.uc_flags) || |
| __put_user(NULL, &frame->uc.uc_link) || |
| __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp) || |
| __put_user(sas_ss_flags(__frame->sp), &frame->uc.uc_stack.ss_flags) || |
| __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size)) |
| goto give_sigsegv; |
| |
| if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0])) |
| goto give_sigsegv; |
| |
| if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set))) |
| goto give_sigsegv; |
| |
| /* Set up to return from userspace. If provided, use a stub |
| * already in userspace. */ |
| if (ka->sa.sa_flags & SA_RESTORER) { |
| if (__put_user(ka->sa.sa_restorer, &frame->pretcode)) |
| goto give_sigsegv; |
| } |
| else { |
| /* Set up the following code on the stack: |
| * setlos #__NR_sigreturn,gr7 |
| * tira gr0,0 |
| */ |
| if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) || |
| __put_user(0x8efc0000|__NR_rt_sigreturn, &frame->retcode[0]) || |
| __put_user(0xc0700000, &frame->retcode[1])) |
| goto give_sigsegv; |
| |
| flush_icache_range((unsigned long) frame->retcode, |
| (unsigned long) (frame->retcode + 2)); |
| } |
| |
| /* Set up registers for signal handler */ |
| if (current->personality & FDPIC_FUNCPTRS) { |
| struct fdpic_func_descriptor __user *funcptr = |
| (struct fdpic_func_descriptor __user *) ka->sa.sa_handler; |
| struct fdpic_func_descriptor desc; |
| if (copy_from_user(&desc, funcptr, sizeof(desc))) |
| goto give_sigsegv; |
| __frame->pc = desc.text; |
| __frame->gr15 = desc.GOT; |
| } else { |
| __frame->pc = (unsigned long) ka->sa.sa_handler; |
| __frame->gr15 = 0; |
| } |
| |
| __frame->sp = (unsigned long) frame; |
| __frame->lr = (unsigned long) &frame->retcode; |
| __frame->gr8 = sig; |
| __frame->gr9 = (unsigned long) &frame->info; |
| |
| /* the tracer may want to single-step inside the handler */ |
| if (test_thread_flag(TIF_SINGLESTEP)) |
| ptrace_notify(SIGTRAP); |
| |
| #if DEBUG_SIG |
| printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", |
| sig, current->comm, current->pid, frame, __frame->pc, |
| frame->pretcode); |
| #endif |
| |
| return 0; |
| |
| give_sigsegv: |
| force_sigsegv(sig, current); |
| return -EFAULT; |
| |
| } /* end setup_rt_frame() */ |
| |
| /*****************************************************************************/ |
| /* |
| * OK, we're invoking a handler |
| */ |
| static int handle_signal(unsigned long sig, siginfo_t *info, |
| struct k_sigaction *ka, sigset_t *oldset) |
| { |
| int ret; |
| |
| /* Are we from a system call? */ |
| if (in_syscall(__frame)) { |
| /* If so, check system call restarting.. */ |
| switch (__frame->gr8) { |
| case -ERESTART_RESTARTBLOCK: |
| case -ERESTARTNOHAND: |
| __frame->gr8 = -EINTR; |
| break; |
| |
| case -ERESTARTSYS: |
| if (!(ka->sa.sa_flags & SA_RESTART)) { |
| __frame->gr8 = -EINTR; |
| break; |
| } |
| |
| /* fallthrough */ |
| case -ERESTARTNOINTR: |
| __frame->gr8 = __frame->orig_gr8; |
| __frame->pc -= 4; |
| } |
| } |
| |
| /* Set up the stack frame */ |
| if (ka->sa.sa_flags & SA_SIGINFO) |
| ret = setup_rt_frame(sig, ka, info, oldset); |
| else |
| ret = setup_frame(sig, ka, oldset); |
| |
| 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; |
| |
| } /* end handle_signal() */ |
| |
| /*****************************************************************************/ |
| /* |
| * 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. |
| */ |
| static void do_signal(void) |
| { |
| struct k_sigaction ka; |
| siginfo_t info; |
| sigset_t *oldset; |
| int signr; |
| |
| /* |
| * 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(__frame)) |
| 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, __frame, NULL); |
| if (signr > 0) { |
| if (handle_signal(signr, &info, &ka, oldset) == 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); |
| |
| tracehook_signal_handler(signr, &info, &ka, __frame, |
| test_thread_flag(TIF_SINGLESTEP)); |
| } |
| |
| return; |
| } |
| |
| no_signal: |
| /* Did we come from a system call? */ |
| if (__frame->syscallno != -1) { |
| /* Restart the system call - no handlers present */ |
| switch (__frame->gr8) { |
| case -ERESTARTNOHAND: |
| case -ERESTARTSYS: |
| case -ERESTARTNOINTR: |
| __frame->gr8 = __frame->orig_gr8; |
| __frame->pc -= 4; |
| break; |
| |
| case -ERESTART_RESTARTBLOCK: |
| __frame->gr7 = __NR_restart_syscall; |
| __frame->pc -= 4; |
| break; |
| } |
| } |
| |
| /* 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); |
| } |
| |
| } /* end do_signal() */ |
| |
| /*****************************************************************************/ |
| /* |
| * notification of userspace execution resumption |
| * - triggered by the TIF_WORK_MASK flags |
| */ |
| asmlinkage void do_notify_resume(__u32 thread_info_flags) |
| { |
| /* pending single-step? */ |
| if (thread_info_flags & _TIF_SINGLESTEP) |
| clear_thread_flag(TIF_SINGLESTEP); |
| |
| /* deal with pending signal delivery */ |
| if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) |
| do_signal(); |
| |
| /* deal with notification on about to resume userspace execution */ |
| if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
| clear_thread_flag(TIF_NOTIFY_RESUME); |
| tracehook_notify_resume(__frame); |
| if (current->replacement_session_keyring) |
| key_replace_session_keyring(); |
| } |
| |
| } /* end do_notify_resume() */ |