diff options
Diffstat (limited to 'arch/m68knommu/kernel/signal.c')
| -rw-r--r-- | arch/m68knommu/kernel/signal.c | 788 |
1 files changed, 788 insertions, 0 deletions
diff --git a/arch/m68knommu/kernel/signal.c b/arch/m68knommu/kernel/signal.c new file mode 100644 index 00000000000..30dceb59a46 --- /dev/null +++ b/arch/m68knommu/kernel/signal.c @@ -0,0 +1,788 @@ +/* + * linux/arch/m68knommu/kernel/signal.c + * + * 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. + */ + +/* + * Linux/m68k support by Hamish Macdonald + * + * 68060 fixes by Jesper Skov + * + * 1997-12-01 Modified for POSIX.1b signals by Andreas Schwab + * + * mathemu support by Roman Zippel + * (Note: fpstate in the signal context is completely ignored for the emulator + * and the internal floating point format is put on stack) + */ + +/* + * ++roman (07/09/96): implemented signal stacks (specially for tosemu on + * Atari :-) Current limitation: Only one sigstack can be active at one time. + * If a second signal with SA_ONSTACK set arrives while working on a sigstack, + * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested + * signal handlers! + */ + +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/kernel.h> +#include <linux/signal.h> +#include <linux/syscalls.h> +#include <linux/errno.h> +#include <linux/wait.h> +#include <linux/ptrace.h> +#include <linux/unistd.h> +#include <linux/stddef.h> +#include <linux/highuid.h> +#include <linux/tty.h> +#include <linux/personality.h> +#include <linux/binfmts.h> + +#include <asm/setup.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/traps.h> +#include <asm/ucontext.h> + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs); + +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ +asmlinkage int do_sigsuspend(struct pt_regs *regs) +{ + old_sigset_t mask = regs->d3; + 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->d0 = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(&saveset, regs)) + return -EINTR; + } +} + +asmlinkage int +do_rt_sigsuspend(struct pt_regs *regs) +{ + sigset_t *unewset = (sigset_t *)regs->d1; + size_t sigsetsize = (size_t)regs->d2; + 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->d0 = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(&saveset, regs)) + 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) +{ + return do_sigaltstack(uss, uoss, rdusp()); +} + + +/* + * Do a signal return; undo the signal stack. + * + * Keep the return code on the stack quadword aligned! + * That makes the cache flush below easier. + */ + +struct sigframe +{ + char *pretcode; + int sig; + int code; + struct sigcontext *psc; + char retcode[8]; + unsigned long extramask[_NSIG_WORDS-1]; + struct sigcontext sc; +}; + +struct rt_sigframe +{ + char *pretcode; + int sig; + struct siginfo *pinfo; + void *puc; + char retcode[8]; + struct siginfo info; + struct ucontext uc; +}; + +#ifdef CONFIG_FPU + +static unsigned char fpu_version = 0; /* version number of fpu, set by setup_frame */ + +static inline int restore_fpu_state(struct sigcontext *sc) +{ + int err = 1; + + if (FPU_IS_EMU) { + /* restore registers */ + memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12); + memcpy(current->thread.fp, sc->sc_fpregs, 24); + return 0; + } + + if (sc->sc_fpstate[0]) { + /* Verify the frame format. */ + if (sc->sc_fpstate[0] != fpu_version) + goto out; + + __asm__ volatile (".chip 68k/68881\n\t" + "fmovemx %0,%/fp0-%/fp1\n\t" + "fmoveml %1,%/fpcr/%/fpsr/%/fpiar\n\t" + ".chip 68k" + : /* no outputs */ + : "m" (*sc->sc_fpregs), "m" (*sc->sc_fpcntl)); + } + __asm__ volatile (".chip 68k/68881\n\t" + "frestore %0\n\t" + ".chip 68k" : : "m" (*sc->sc_fpstate)); + err = 0; + +out: + return err; +} + +#define FPCONTEXT_SIZE 216 +#define uc_fpstate uc_filler[0] +#define uc_formatvec uc_filler[FPCONTEXT_SIZE/4] +#define uc_extra uc_filler[FPCONTEXT_SIZE/4+1] + +static inline int rt_restore_fpu_state(struct ucontext *uc) +{ + unsigned char fpstate[FPCONTEXT_SIZE]; + int context_size = 0; + fpregset_t fpregs; + int err = 1; + + if (FPU_IS_EMU) { + /* restore fpu control register */ + if (__copy_from_user(current->thread.fpcntl, + &uc->uc_mcontext.fpregs.f_pcr, 12)) + goto out; + /* restore all other fpu register */ + if (__copy_from_user(current->thread.fp, + uc->uc_mcontext.fpregs.f_fpregs, 96)) + goto out; + return 0; + } + + if (__get_user(*(long *)fpstate, (long *)&uc->uc_fpstate)) + goto out; + if (fpstate[0]) { + context_size = fpstate[1]; + + /* Verify the frame format. */ + if (fpstate[0] != fpu_version) + goto out; + if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs, + sizeof(fpregs))) + goto out; + __asm__ volatile (".chip 68k/68881\n\t" + "fmovemx %0,%/fp0-%/fp7\n\t" + "fmoveml %1,%/fpcr/%/fpsr/%/fpiar\n\t" + ".chip 68k" + : /* no outputs */ + : "m" (*fpregs.f_fpregs), + "m" (fpregs.f_pcr)); + } + if (context_size && + __copy_from_user(fpstate + 4, (long *)&uc->uc_fpstate + 1, + context_size)) + goto out; + __asm__ volatile (".chip 68k/68881\n\t" + "frestore %0\n\t" + ".chip 68k" : : "m" (*fpstate)); + err = 0; + +out: + return err; +} + +#endif + +static inline int +restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc, void *fp, + int *pd0) +{ + int formatvec; + struct sigcontext context; + int err = 0; + + /* get previous context */ + if (copy_from_user(&context, usc, sizeof(context))) + goto badframe; + + /* restore passed registers */ + regs->d1 = context.sc_d1; + regs->a0 = context.sc_a0; + regs->a1 = context.sc_a1; + regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff); + regs->pc = context.sc_pc; + regs->orig_d0 = -1; /* disable syscall checks */ + wrusp(context.sc_usp); + formatvec = context.sc_formatvec; + regs->format = formatvec >> 12; + regs->vector = formatvec & 0xfff; + +#ifdef CONFIG_FPU + err = restore_fpu_state(&context); +#endif + + *pd0 = context.sc_d0; + return err; + +badframe: + return 1; +} + +static inline int +rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw, + struct ucontext *uc, int *pd0) +{ + int temp; + greg_t *gregs = uc->uc_mcontext.gregs; + unsigned long usp; + int err; + + err = __get_user(temp, &uc->uc_mcontext.version); + if (temp != MCONTEXT_VERSION) + goto badframe; + /* restore passed registers */ + err |= __get_user(regs->d0, &gregs[0]); + err |= __get_user(regs->d1, &gregs[1]); + err |= __get_user(regs->d2, &gregs[2]); + err |= __get_user(regs->d3, &gregs[3]); + err |= __get_user(regs->d4, &gregs[4]); + err |= __get_user(regs->d5, &gregs[5]); + err |= __get_user(sw->d6, &gregs[6]); + err |= __get_user(sw->d7, &gregs[7]); + err |= __get_user(regs->a0, &gregs[8]); + err |= __get_user(regs->a1, &gregs[9]); + err |= __get_user(regs->a2, &gregs[10]); + err |= __get_user(sw->a3, &gregs[11]); + err |= __get_user(sw->a4, &gregs[12]); + err |= __get_user(sw->a5, &gregs[13]); + err |= __get_user(sw->a6, &gregs[14]); + err |= __get_user(usp, &gregs[15]); + wrusp(usp); + err |= __get_user(regs->pc, &gregs[16]); + err |= __get_user(temp, &gregs[17]); + regs->sr = (regs->sr & 0xff00) | (temp & 0xff); + regs->orig_d0 = -1; /* disable syscall checks */ + regs->format = temp >> 12; + regs->vector = temp & 0xfff; + + if (do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT) + goto badframe; + + *pd0 = regs->d0; + return err; + +badframe: + return 1; +} + +asmlinkage int do_sigreturn(unsigned long __unused) +{ + struct switch_stack *sw = (struct switch_stack *) &__unused; + struct pt_regs *regs = (struct pt_regs *) (sw + 1); + unsigned long usp = rdusp(); + struct sigframe *frame = (struct sigframe *)(usp - 4); + sigset_t set; + int d0; + + if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) + goto badframe; + if (__get_user(set.sig[0], &frame->sc.sc_mask) || + (_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, frame + 1, &d0)) + goto badframe; + return d0; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +asmlinkage int do_rt_sigreturn(unsigned long __unused) +{ + struct switch_stack *sw = (struct switch_stack *) &__unused; + struct pt_regs *regs = (struct pt_regs *) (sw + 1); + unsigned long usp = rdusp(); + struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4); + sigset_t set; + int d0; + + 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 (rt_restore_ucontext(regs, sw, &frame->uc, &d0)) + goto badframe; + return d0; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +#ifdef CONFIG_FPU +/* + * Set up a signal frame. + */ + +static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs) +{ + if (FPU_IS_EMU) { + /* save registers */ + memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12); + memcpy(sc->sc_fpregs, current->thread.fp, 24); + return; + } + + __asm__ volatile (".chip 68k/68881\n\t" + "fsave %0\n\t" + ".chip 68k" + : : "m" (*sc->sc_fpstate) : "memory"); + + if (sc->sc_fpstate[0]) { + fpu_version = sc->sc_fpstate[0]; + __asm__ volatile (".chip 68k/68881\n\t" + "fmovemx %/fp0-%/fp1,%0\n\t" + "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t" + ".chip 68k" + : /* no outputs */ + : "m" (*sc->sc_fpregs), + "m" (*sc->sc_fpcntl) + : "memory"); + } +} + +static inline int rt_save_fpu_state(struct ucontext *uc, struct pt_regs *regs) +{ + unsigned char fpstate[FPCONTEXT_SIZE]; + int context_size = 0; + int err = 0; + + if (FPU_IS_EMU) { + /* save fpu control register */ + err |= copy_to_user(&uc->uc_mcontext.fpregs.f_pcr, + current->thread.fpcntl, 12); + /* save all other fpu register */ + err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs, + current->thread.fp, 96); + return err; + } + + __asm__ volatile (".chip 68k/68881\n\t" + "fsave %0\n\t" + ".chip 68k" + : : "m" (*fpstate) : "memory"); + + err |= __put_user(*(long *)fpstate, (long *)&uc->uc_fpstate); + if (fpstate[0]) { + fpregset_t fpregs; + context_size = fpstate[1]; + fpu_version = fpstate[0]; + __asm__ volatile (".chip 68k/68881\n\t" + "fmovemx %/fp0-%/fp7,%0\n\t" + "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t" + ".chip 68k" + : /* no outputs */ + : "m" (*fpregs.f_fpregs), + "m" (fpregs.f_pcr) + : "memory"); + err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs, + sizeof(fpregs)); + } + if (context_size) + err |= copy_to_user((long *)&uc->uc_fpstate + 1, fpstate + 4, + context_size); + return err; +} + +#endif + +static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, + unsigned long mask) +{ + sc->sc_mask = mask; + sc->sc_usp = rdusp(); + sc->sc_d0 = regs->d0; + sc->sc_d1 = regs->d1; + sc->sc_a0 = regs->a0; + sc->sc_a1 = regs->a1; + sc->sc_sr = regs->sr; + sc->sc_pc = regs->pc; + sc->sc_formatvec = regs->format << 12 | regs->vector; +#ifdef CONFIG_FPU + save_fpu_state(sc, regs); +#endif +} + +static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs) +{ + struct switch_stack *sw = (struct switch_stack *)regs - 1; + greg_t *gregs = uc->uc_mcontext.gregs; + int err = 0; + + err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version); + err |= __put_user(regs->d0, &gregs[0]); + err |= __put_user(regs->d1, &gregs[1]); + err |= __put_user(regs->d2, &gregs[2]); + err |= __put_user(regs->d3, &gregs[3]); + err |= __put_user(regs->d4, &gregs[4]); + err |= __put_user(regs->d5, &gregs[5]); + err |= __put_user(sw->d6, &gregs[6]); + err |= __put_user(sw->d7, &gregs[7]); + err |= __put_user(regs->a0, &gregs[8]); + err |= __put_user(regs->a1, &gregs[9]); + err |= __put_user(regs->a2, &gregs[10]); + err |= __put_user(sw->a3, &gregs[11]); + err |= __put_user(sw->a4, &gregs[12]); + err |= __put_user(sw->a5, &gregs[13]); + err |= __put_user(sw->a6, &gregs[14]); + err |= __put_user(rdusp(), &gregs[15]); + err |= __put_user(regs->pc, &gregs[16]); + err |= __put_user(regs->sr, &gregs[17]); +#ifdef CONFIG_FPU + err |= rt_save_fpu_state(uc, regs); +#endif + return err; +} + +static inline void push_cache (unsigned long vaddr) +{ +} + +static inline void * +get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) +{ + unsigned long usp; + + /* Default to using normal stack. */ + usp = rdusp(); + + /* This is the X/Open sanctioned signal stack switching. */ + if (ka->sa.sa_flags & SA_ONSTACK) { + if (!on_sig_stack(usp)) + usp = current->sas_ss_sp + current->sas_ss_size; + } + return (void *)((usp - frame_size) & -8UL); +} + +static void setup_frame (int sig, struct k_sigaction *ka, + sigset_t *set, struct pt_regs *regs) +{ + struct sigframe *frame; + struct sigcontext context; + int err = 0; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + err |= __put_user((current_thread_info()->exec_domain + && current_thread_info()->exec_domain->signal_invmap + && sig < 32 + ? current_thread_info()->exec_domain->signal_invmap[sig] + : sig), + &frame->sig); + + err |= __put_user(regs->vector, &frame->code); + err |= __put_user(&frame->sc, &frame->psc); + + if (_NSIG_WORDS > 1) + err |= copy_to_user(frame->extramask, &set->sig[1], + sizeof(frame->extramask)); + + setup_sigcontext(&context, regs, set->sig[0]); + err |= copy_to_user (&frame->sc, &context, sizeof(context)); + + /* Set up to return from userspace. */ + err |= __put_user(frame->retcode, &frame->pretcode); + /* moveq #,d0; trap #0 */ + err |= __put_user(0x70004e40 + (__NR_sigreturn << 16), + (long *)(frame->retcode)); + + if (err) + goto give_sigsegv; + + push_cache ((unsigned long) &frame->retcode); + + /* Set up registers for signal handler */ + wrusp ((unsigned long) frame); + regs->pc = (unsigned long) ka->sa.sa_handler; + +adjust_stack: + /* Prepare to skip over the extra stuff in the exception frame. */ + if (regs->stkadj) { + struct pt_regs *tregs = + (struct pt_regs *)((ulong)regs + regs->stkadj); +#if DEBUG + printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj); +#endif + /* This must be copied with decreasing addresses to + handle overlaps. */ + tregs->vector = 0; + tregs->format = 0; + tregs->pc = regs->pc; + tregs->sr = regs->sr; + } + return; + +give_sigsegv: + force_sigsegv(sig, current); + goto adjust_stack; +} + +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; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + err |= __put_user((current_thread_info()->exec_domain + && current_thread_info()->exec_domain->signal_invmap + && sig < 32 + ? current_thread_info()->exec_domain->signal_invmap[sig] + : sig), + &frame->sig); + err |= __put_user(&frame->info, &frame->pinfo); + err |= __put_user(&frame->uc, &frame->puc); + 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(rdusp()), + &frame->uc.uc_stack.ss_flags); + err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); + err |= rt_setup_ucontext(&frame->uc, regs); + err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set)); + + /* Set up to return from userspace. */ + err |= __put_user(frame->retcode, &frame->pretcode); + /* moveq #,d0; notb d0; trap #0 */ + err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16), + (long *)(frame->retcode + 0)); + err |= __put_user(0x4e40, (short *)(frame->retcode + 4)); + + if (err) + goto give_sigsegv; + + push_cache ((unsigned long) &frame->retcode); + + /* Set up registers for signal handler */ + wrusp ((unsigned long) frame); + regs->pc = (unsigned long) ka->sa.sa_handler; + +adjust_stack: + /* Prepare to skip over the extra stuff in the exception frame. */ + if (regs->stkadj) { + struct pt_regs *tregs = + (struct pt_regs *)((ulong)regs + regs->stkadj); +#if DEBUG + printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj); +#endif + /* This must be copied with decreasing addresses to + handle overlaps. */ + tregs->vector = 0; + tregs->format = 0; + tregs->pc = regs->pc; + tregs->sr = regs->sr; + } + return; + +give_sigsegv: + force_sigsegv(sig, current); + goto adjust_stack; +} + +static inline void +handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) +{ + switch (regs->d0) { + case -ERESTARTNOHAND: + if (!has_handler) + goto do_restart; + regs->d0 = -EINTR; + break; + + case -ERESTARTSYS: + if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { + regs->d0 = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: + do_restart: + regs->d0 = regs->orig_d0; + regs->pc -= 2; + break; + } +} + +/* + * OK, we're invoking a handler + */ +static void +handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, + sigset_t *oldset, struct pt_regs *regs) +{ + /* are we from a system call? */ + if (regs->orig_d0 >= 0) + /* If so, check system call restarting.. */ + handle_restart(regs, ka, 1); + + /* 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_ONESHOT) + ka->sa.sa_handler = SIG_DFL; + + 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. + */ +asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs) +{ + 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 (!oldset) + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + /* Whee! Actually deliver the signal. */ + handle_signal(signr, &ka, &info, oldset, regs); + return 1; + } + + /* Did we come from a system call? */ + if (regs->orig_d0 >= 0) { + /* Restart the system call - no handlers present */ + if (regs->d0 == -ERESTARTNOHAND + || regs->d0 == -ERESTARTSYS + || regs->d0 == -ERESTARTNOINTR) { + regs->d0 = regs->orig_d0; + regs->pc -= 2; + } else if (regs->d0 == -ERESTART_RESTARTBLOCK) { + regs->d0 = __NR_restart_syscall; + regs->pc -= 2; + } + } + return 0; +} |