diff options
Diffstat (limited to 'arch/frv/kernel/signal.c')
| -rw-r--r-- | arch/frv/kernel/signal.c | 588 |
1 files changed, 588 insertions, 0 deletions
diff --git a/arch/frv/kernel/signal.c b/arch/frv/kernel/signal.c new file mode 100644 index 00000000000..d8d8f3d4304 --- /dev/null +++ b/arch/frv/kernel/signal.c @@ -0,0 +1,588 @@ +/* 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/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/personality.h> +#include <linux/suspend.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; +}; + +asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); + +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ +asmlinkage int sys_sigsuspend(int history0, int history1, old_sigset_t mask) +{ + sigset_t saveset; + + mask &= _BLOCKABLE; + spin_lock_irq(¤t->sighand->siglock); + saveset = current->blocked; + siginitset(¤t->blocked, mask); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + __frame->gr8 = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(__frame, &saveset)) + /* return the signal number as the return value of this function + * - this is an utterly evil hack. syscalls should not invoke do_signal() + * as entry.S sets regs->gr8 to the return value of the system call + * - we can't just use sigpending() as we'd have to discard SIG_IGN signals + * and call waitpid() if SIGCHLD needed discarding + * - this only works on the i386 because it passes arguments to the signal + * handler on the stack, and the return value in EAX is effectively + * discarded + */ + return __frame->gr8; + } +} + +asmlinkage int sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize) +{ + sigset_t saveset, newset; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + + if (copy_from_user(&newset, unewset, sizeof(newset))) + return -EFAULT; + sigdelsetmask(&newset, ~_BLOCKABLE); + + spin_lock_irq(¤t->sighand->siglock); + saveset = current->blocked; + current->blocked = newset; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + __frame->gr8 = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(__frame, &saveset)) + /* return the signal number as the return value of this function + * - this is an utterly evil hack. syscalls should not invoke do_signal() + * as entry.S sets regs->gr8 to the return value of the system call + * - we can't just use sigpending() as we'd have to discard SIG_IGN signals + * and call waitpid() if SIGCHLD needed discarding + * - this only works on the i386 because it passes arguments to the signal + * handler on the stack, and the return value in EAX is effectively + * discarded + */ + return __frame->gr8; + } +} + +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 +{ + void (*pretcode)(void); + int sig; + struct sigcontext sc; + unsigned long extramask[_NSIG_WORDS-1]; + uint32_t retcode[2]; +}; + +struct rt_sigframe +{ + void (*pretcode)(void); + int sig; + struct siginfo *pinfo; + void *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; + + 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, + struct pt_regs *regs, + size_t frame_size) +{ + unsigned long sp; + + /* Default to using normal stack */ + sp = regs->sp; + + /* This is the X/Open sanctioned signal stack switching. */ + if (ka->sa.sa_flags & SA_ONSTACK) { + if (! on_sig_stack(sp)) + sp = current->sas_ss_sp + current->sas_ss_size; + } + + return (void __user *) ((sp - frame_size) & ~7UL); +} /* end get_sigframe() */ + +/*****************************************************************************/ +/* + * + */ +static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs) +{ + struct sigframe __user *frame; + int rsig; + + frame = get_sigframe(ka, regs, 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((void (*)(void))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 signal handler */ + regs->sp = (unsigned long) frame; + regs->lr = (unsigned long) &frame->retcode; + regs->gr8 = sig; + + if (get_personality & FDPIC_FUNCPTRS) { + struct fdpic_func_descriptor __user *funcptr = + (struct fdpic_func_descriptor *) ka->sa.sa_handler; + __get_user(regs->pc, &funcptr->text); + __get_user(regs->gr15, &funcptr->GOT); + } else { + regs->pc = (unsigned long) ka->sa.sa_handler; + regs->gr15 = 0; + } + + set_fs(USER_DS); + +#if DEBUG_SIG + printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", + sig, current->comm, current->pid, frame, regs->pc, frame->pretcode); +#endif + + return; + +give_sigsegv: + if (sig == SIGSEGV) + ka->sa.sa_handler = SIG_DFL; + + force_sig(SIGSEGV, current); +} /* end setup_frame() */ + +/*****************************************************************************/ +/* + * + */ +static void 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 rsig; + + frame = get_sigframe(ka, regs, 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(0, &frame->uc.uc_link) || + __put_user((void*)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp) || + __put_user(sas_ss_flags(regs->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((void (*)(void))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 */ + regs->sp = (unsigned long) frame; + regs->lr = (unsigned long) &frame->retcode; + regs->gr8 = sig; + regs->gr9 = (unsigned long) &frame->info; + + if (get_personality & FDPIC_FUNCPTRS) { + struct fdpic_func_descriptor *funcptr = + (struct fdpic_func_descriptor __user *) ka->sa.sa_handler; + __get_user(regs->pc, &funcptr->text); + __get_user(regs->gr15, &funcptr->GOT); + } else { + regs->pc = (unsigned long) ka->sa.sa_handler; + regs->gr15 = 0; + } + + set_fs(USER_DS); + +#if DEBUG_SIG + printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", + sig, current->comm, current->pid, frame, regs->pc, frame->pretcode); +#endif + + return; + +give_sigsegv: + if (sig == SIGSEGV) + ka->sa.sa_handler = SIG_DFL; + force_sig(SIGSEGV, current); + +} /* end setup_rt_frame() */ + +/*****************************************************************************/ +/* + * OK, we're invoking a handler + */ +static void handle_signal(unsigned long sig, siginfo_t *info, + struct k_sigaction *ka, sigset_t *oldset, + struct pt_regs *regs) +{ + /* Are we from a system call? */ + if (in_syscall(regs)) { + /* If so, check system call restarting.. */ + switch (regs->gr8) { + case -ERESTART_RESTARTBLOCK: + case -ERESTARTNOHAND: + regs->gr8 = -EINTR; + break; + + case -ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->gr8 = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: + regs->gr8 = regs->orig_gr8; + regs->pc -= 4; + } + } + + /* Set up the stack frame */ + if (ka->sa.sa_flags & SA_SIGINFO) + setup_rt_frame(sig, ka, info, oldset, regs); + else + setup_frame(sig, ka, oldset, regs); + + if (!(ka->sa.sa_flags & SA_NODEFER)) { + spin_lock_irq(¤t->sighand->siglock); + sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); + sigaddset(¤t->blocked, sig); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + } +} /* 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. + */ +int do_signal(struct pt_regs *regs, sigset_t *oldset) +{ + struct k_sigaction ka; + siginfo_t info; + 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(regs)) + return 1; + + if (current->flags & PF_FREEZE) { + refrigerator(0); + goto no_signal; + } + + if (!oldset) + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + handle_signal(signr, &info, &ka, oldset, regs); + return 1; + } + + no_signal: + /* Did we come from a system call? */ + if (regs->syscallno >= 0) { + /* Restart the system call - no handlers present */ + if (regs->gr8 == -ERESTARTNOHAND || + regs->gr8 == -ERESTARTSYS || + regs->gr8 == -ERESTARTNOINTR) { + regs->gr8 = regs->orig_gr8; + regs->pc -= 4; + } + + if (regs->gr8 == -ERESTART_RESTARTBLOCK){ + regs->gr8 = __NR_restart_syscall; + regs->pc -= 4; + } + } + + return 0; +} /* end do_signal() */ + +/*****************************************************************************/ +/* + * notification of userspace execution resumption + * - triggered by current->work.notify_resume + */ +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) + do_signal(__frame, NULL); + +} /* end do_notify_resume() */ |