diff options
Diffstat (limited to 'arch/v850/kernel/signal.c')
| -rw-r--r-- | arch/v850/kernel/signal.c | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/arch/v850/kernel/signal.c b/arch/v850/kernel/signal.c new file mode 100644 index 00000000000..37061e32e1a --- /dev/null +++ b/arch/v850/kernel/signal.c @@ -0,0 +1,525 @@ +/* + * arch/v850/kernel/signal.c -- Signal handling + * + * Copyright (C) 2001,02,03 NEC Electronics Corporation + * Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org> + * Copyright (C) 1999,2000,2002 Niibe Yutaka & Kaz Kojima + * Copyright (C) 1991,1992 Linus Torvalds + * + * 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. + * + * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson + * + * This file was derived from the sh version, arch/sh/kernel/signal.c + */ + +#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/personality.h> +#include <linux/tty.h> + +#include <asm/ucontext.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/thread_info.h> +#include <asm/cacheflush.h> + +#define DEBUG_SIG 0 + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +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(old_sigset_t mask, struct pt_regs *regs) +{ + 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); + + regs->gpr[GPR_RVAL] = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(regs, &saveset)) + return -EINTR; + } +} + +asmlinkage int +sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, + struct pt_regs *regs) +{ + 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); + + regs->gpr[GPR_RVAL] = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(regs, &saveset)) + return -EINTR; + } +} + +asmlinkage int +sys_sigaction(int sig, const struct old_sigaction *act, + struct old_sigaction *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 *uss, stack_t *uoss, + struct pt_regs *regs) +{ + return do_sigaltstack(uss, uoss, regs->gpr[GPR_SP]); +} + + +/* + * Do a signal return; undo the signal stack. + */ + +struct sigframe +{ + struct sigcontext sc; + unsigned long extramask[_NSIG_WORDS-1]; + unsigned long tramp[2]; /* signal trampoline */ +}; + +struct rt_sigframe +{ + struct siginfo info; + struct ucontext uc; + unsigned long tramp[2]; /* signal trampoline */ +}; + +static int +restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p) +{ + unsigned int err = 0; + +#define COPY(x) err |= __get_user(regs->x, &sc->regs.x) + COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]); + COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]); + COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]); + COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]); + COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]); + COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]); + COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]); + COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]); + COPY(pc); COPY(psw); + COPY(ctpc); COPY(ctpsw); COPY(ctbp); +#undef COPY + + return err; +} + +asmlinkage int sys_sigreturn(struct pt_regs *regs) +{ + struct sigframe *frame = (struct sigframe *)regs->gpr[GPR_SP]; + sigset_t set; + int rval; + + 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, &rval)) + goto badframe; + return rval; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) +{ + struct rt_sigframe *frame = (struct rt_sigframe *)regs->gpr[GPR_SP]; + sigset_t set; + stack_t st; + int rval; + + 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, &rval)) + 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->gpr[GPR_SP]); + + return rval; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +/* + * Set up a signal frame. + */ + +static int +setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, + unsigned long mask) +{ + int err = 0; + +#define COPY(x) err |= __put_user(regs->x, &sc->regs.x) + COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]); + COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]); + COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]); + COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]); + COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]); + COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]); + COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]); + COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]); + COPY(pc); COPY(psw); + COPY(ctpc); COPY(ctpsw); COPY(ctbp); +#undef COPY + + err |= __put_user(mask, &sc->oldmask); + + return err; +} + +/* + * Determine which stack to use.. + */ +static inline void * +get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) +{ + /* Default to using normal stack */ + unsigned long sp = regs->gpr[GPR_SP]; + + if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) + sp = current->sas_ss_sp + current->sas_ss_size; + + return (void *)((sp - frame_size) & -8UL); +} + +static void setup_frame(int sig, struct k_sigaction *ka, + sigset_t *set, struct pt_regs *regs) +{ + struct sigframe *frame; + int err = 0; + int signal; + + frame = get_sigframe(ka, regs, 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->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer; + } else { + /* Note, these encodings are _little endian_! */ + + /* addi __NR_sigreturn, r0, r12 */ + err |= __put_user(0x6600 | (__NR_sigreturn << 16), + frame->tramp + 0); + /* trap 0 */ + err |= __put_user(0x010007e0, + frame->tramp + 1); + + regs->gpr[GPR_LP] = (unsigned long)frame->tramp; + + flush_cache_sigtramp (regs->gpr[GPR_LP]); + } + + if (err) + goto give_sigsegv; + + /* Set up registers for signal handler. */ + regs->pc = (v850_reg_t) ka->sa.sa_handler; + regs->gpr[GPR_SP] = (v850_reg_t)frame; + /* Signal handler args: */ + regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */ + regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->sc;/* arg 1: sigcontext */ + + set_fs(USER_DS); + +#if DEBUG_SIG + printk("SIG deliver (%s:%d): sp=%p pc=%08lx ra=%08lx\n", + current->comm, current->pid, frame, regs->pc, ); +#endif + + return; + +give_sigsegv: + force_sigsegv(sig, current); +} + +static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, + sigset_t *set, struct pt_regs *regs) +{ + struct rt_sigframe *frame; + int err = 0; + int signal; + + frame = get_sigframe(ka, regs, 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->gpr[GPR_SP]), + &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->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer; + } else { + /* Note, these encodings are _little endian_! */ + + /* addi __NR_sigreturn, r0, r12 */ + err |= __put_user(0x6600 | (__NR_sigreturn << 16), + frame->tramp + 0); + /* trap 0 */ + err |= __put_user(0x010007e0, + frame->tramp + 1); + + regs->gpr[GPR_LP] = (unsigned long)frame->tramp; + + flush_cache_sigtramp (regs->gpr[GPR_LP]); + } + + if (err) + goto give_sigsegv; + + /* Set up registers for signal handler. */ + regs->pc = (v850_reg_t) ka->sa.sa_handler; + regs->gpr[GPR_SP] = (v850_reg_t)frame; + /* Signal handler args: */ + regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */ + regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->info; /* arg 1: siginfo */ + regs->gpr[GPR_ARG2] = (v850_reg_t)&frame->uc; /* arg 2: ucontext */ + + set_fs(USER_DS); + +#if DEBUG_SIG + printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", + current->comm, current->pid, frame, regs->pc, regs->pr); +#endif + + return; + +give_sigsegv: + force_sigsegv(sig, current); +} + +/* + * 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 (PT_REGS_SYSCALL (regs)) { + /* If so, check system call restarting.. */ + switch (regs->gpr[GPR_RVAL]) { + case -ERESTART_RESTARTBLOCK: + current_thread_info()->restart_block.fn = + do_no_restart_syscall; + /* fall through */ + case -ERESTARTNOHAND: + regs->gpr[GPR_RVAL] = -EINTR; + break; + + case -ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->gpr[GPR_RVAL] = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: + regs->gpr[12] = PT_REGS_SYSCALL (regs); + regs->pc -= 4; /* Size of `trap 0' insn. */ + } + + PT_REGS_SET_SYSCALL (regs, 0); + } + + /* 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); + } +} + +/* + * 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. + */ +int do_signal(struct pt_regs *regs, sigset_t *oldset) +{ + siginfo_t info; + int signr; + struct k_sigaction ka; + + /* + * 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 (!oldset) + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + /* Whee! Actually deliver the signal. */ + handle_signal(signr, &info, &ka, oldset, regs); + return 1; + } + + /* Did we come from a system call? */ + if (PT_REGS_SYSCALL (regs)) { + int rval = (int)regs->gpr[GPR_RVAL]; + /* Restart the system call - no handlers present */ + if (rval == -ERESTARTNOHAND + || rval == -ERESTARTSYS + || rval == -ERESTARTNOINTR) + { + regs->gpr[12] = PT_REGS_SYSCALL (regs); + regs->pc -= 4; /* Size of `trap 0' insn. */ + } + else if (rval == -ERESTART_RESTARTBLOCK) { + regs->gpr[12] = __NR_restart_syscall; + regs->pc -= 4; /* Size of `trap 0' insn. */ + } + } + return 0; +} |