signal32.c

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/*
 * 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.
 *
 * Copyright (C) 1991, 1992  Linus Torvalds
 * Copyright (C) 1994 - 2000, 2006  Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 */
#include <linux/cache.h>
#include <linux/compat.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.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/suspend.h>
#include <linux/compiler.h>
#include <linux/uaccess.h>

#include <asm/abi.h>
#include <asm/asm.h>
#include <asm/compat-signal.h>
#include <linux/bitops.h>
#include <asm/cacheflush.h>
#include <asm/sim.h>
#include <asm/ucontext.h>
#include <asm/fpu.h>
#include <asm/war.h>
#include <asm/vdso.h>
#include <asm/dsp.h>

#include "signal-common.h"

static int (*save_fp_context32)(struct sigcontext32 __user *sc);
static int (*restore_fp_context32)(struct sigcontext32 __user *sc);

extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);

extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);

/*
 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
 */
#define __NR_O32_restart_syscall        4253

/* 32-bit compatibility types */

typedef unsigned int __sighandler32_t;
typedef void (*vfptr_t)(void);

struct sigaction32 {
    unsigned int        sa_flags;
    __sighandler32_t    sa_handler;
    compat_sigset_t     sa_mask;
};

/* IRIX compatible stack_t  */
typedef struct sigaltstack32 {
    s32 ss_sp;
    compat_size_t ss_size;
    int ss_flags;
} stack32_t;

struct ucontext32 {
    u32                 uc_flags;
    s32                 uc_link;
    stack32_t           uc_stack;
    struct sigcontext32 uc_mcontext;
    compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
};

struct sigframe32 {
    u32 sf_ass[4];      /* argument save space for o32 */
    u32 sf_pad[2];      /* Was: signal trampoline */
    struct sigcontext32 sf_sc;
    compat_sigset_t sf_mask;
};

struct rt_sigframe32 {
    u32 rs_ass[4];          /* argument save space for o32 */
    u32 rs_pad[2];          /* Was: signal trampoline */
    compat_siginfo_t rs_info;
    struct ucontext32 rs_uc;
};

/*
 * sigcontext handlers
 */
static int protected_save_fp_context32(struct sigcontext32 __user *sc)
{
    int err;
    while (1) {
        lock_fpu_owner();
        own_fpu_inatomic(1);
        err = save_fp_context32(sc); /* this might fail */
        unlock_fpu_owner();
        if (likely(!err))
            break;
        /* touch the sigcontext and try again */
        err = __put_user(0, &sc->sc_fpregs[0]) |
            __put_user(0, &sc->sc_fpregs[31]) |
            __put_user(0, &sc->sc_fpc_csr);
        if (err)
            break;  /* really bad sigcontext */
    }
    return err;
}

static int protected_restore_fp_context32(struct sigcontext32 __user *sc)
{
    int err, tmp __maybe_unused;
    while (1) {
        lock_fpu_owner();
        own_fpu_inatomic(0);
        err = restore_fp_context32(sc); /* this might fail */
        unlock_fpu_owner();
        if (likely(!err))
            break;
        /* touch the sigcontext and try again */
        err = __get_user(tmp, &sc->sc_fpregs[0]) |
            __get_user(tmp, &sc->sc_fpregs[31]) |
            __get_user(tmp, &sc->sc_fpc_csr);
        if (err)
            break;  /* really bad sigcontext */
    }
    return err;
}

static int setup_sigcontext32(struct pt_regs *regs,
                  struct sigcontext32 __user *sc)
{
    int err = 0;
    int i;
    u32 used_math;

    err |= __put_user(regs->cp0_epc, &sc->sc_pc);

    err |= __put_user(0, &sc->sc_regs[0]);
    for (i = 1; i < 32; i++)
        err |= __put_user(regs->regs[i], &sc->sc_regs[i]);

    err |= __put_user(regs->hi, &sc->sc_mdhi);
    err |= __put_user(regs->lo, &sc->sc_mdlo);
    if (cpu_has_dsp) {
        err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
        err |= __put_user(mfhi1(), &sc->sc_hi1);
        err |= __put_user(mflo1(), &sc->sc_lo1);
        err |= __put_user(mfhi2(), &sc->sc_hi2);
        err |= __put_user(mflo2(), &sc->sc_lo2);
        err |= __put_user(mfhi3(), &sc->sc_hi3);
        err |= __put_user(mflo3(), &sc->sc_lo3);
    }

    used_math = !!used_math();
    err |= __put_user(used_math, &sc->sc_used_math);

    if (used_math) {
        /*
         * Save FPU state to signal context.  Signal handler
         * will "inherit" current FPU state.
         */
        err |= protected_save_fp_context32(sc);
    }
    return err;
}

static int
check_and_restore_fp_context32(struct sigcontext32 __user *sc)
{
    int err, sig;

    err = sig = fpcsr_pending(&sc->sc_fpc_csr);
    if (err > 0)
        err = 0;
    err |= protected_restore_fp_context32(sc);
    return err ?: sig;
}

static int restore_sigcontext32(struct pt_regs *regs,
                struct sigcontext32 __user *sc)
{
    u32 used_math;
    int err = 0;
    s32 treg;
    int i;

    /* Always make any pending restarted system calls return -EINTR */
    current_thread_info()->restart_block.fn = do_no_restart_syscall;

    err |= __get_user(regs->cp0_epc, &sc->sc_pc);
    err |= __get_user(regs->hi, &sc->sc_mdhi);
    err |= __get_user(regs->lo, &sc->sc_mdlo);
    if (cpu_has_dsp) {
        err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
        err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
        err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
        err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
        err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
        err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
        err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
    }

    for (i = 1; i < 32; i++)
        err |= __get_user(regs->regs[i], &sc->sc_regs[i]);

    err |= __get_user(used_math, &sc->sc_used_math);
    conditional_used_math(used_math);

    if (used_math) {
        /* restore fpu context if we have used it before */
        if (!err)
            err = check_and_restore_fp_context32(sc);
    } else {
        /* signal handler may have used FPU.  Give it up. */
        lose_fpu(0);
    }

    return err;
}

/*
 *
 */
extern void __put_sigset_unknown_nsig(void);
extern void __get_sigset_unknown_nsig(void);

static inline int put_sigset(const sigset_t *kbuf, compat_sigset_t __user *ubuf)
{
    int err = 0;

    if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)))
        return -EFAULT;

    switch (_NSIG_WORDS) {
    default:
        __put_sigset_unknown_nsig();
    case 2:
        err |= __put_user(kbuf->sig[1] >> 32, &ubuf->sig[3]);
        err |= __put_user(kbuf->sig[1] & 0xffffffff, &ubuf->sig[2]);
    case 1:
        err |= __put_user(kbuf->sig[0] >> 32, &ubuf->sig[1]);
        err |= __put_user(kbuf->sig[0] & 0xffffffff, &ubuf->sig[0]);
    }

    return err;
}

static inline int get_sigset(sigset_t *kbuf, const compat_sigset_t __user *ubuf)
{
    int err = 0;
    unsigned long sig[4];

    if (!access_ok(VERIFY_READ, ubuf, sizeof(*ubuf)))
        return -EFAULT;

    switch (_NSIG_WORDS) {
    default:
        __get_sigset_unknown_nsig();
    case 2:
        err |= __get_user(sig[3], &ubuf->sig[3]);
        err |= __get_user(sig[2], &ubuf->sig[2]);
        kbuf->sig[1] = sig[2] | (sig[3] << 32);
    case 1:
        err |= __get_user(sig[1], &ubuf->sig[1]);
        err |= __get_user(sig[0], &ubuf->sig[0]);
        kbuf->sig[0] = sig[0] | (sig[1] << 32);
    }

    return err;
}

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */

asmlinkage int sys32_sigsuspend(nabi_no_regargs struct pt_regs regs)
{
    compat_sigset_t __user *uset;
    sigset_t newset;

    uset = (compat_sigset_t __user *) regs.regs[4];
    if (get_sigset(&newset, uset))
        return -EFAULT;
    return sigsuspend(&newset);
}

asmlinkage int sys32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
{
    compat_sigset_t __user *uset;
    sigset_t newset;
    size_t sigsetsize;

    /* XXX Don't preclude handling different sized sigset_t's.  */
    sigsetsize = regs.regs[5];
    if (sigsetsize != sizeof(compat_sigset_t))
        return -EINVAL;

    uset = (compat_sigset_t __user *) regs.regs[4];
    if (get_sigset(&newset, uset))
        return -EFAULT;
    return sigsuspend(&newset);
}

SYSCALL_DEFINE3(32_sigaction, long, sig, const struct sigaction32 __user *, act,
    struct sigaction32 __user *, oact)
{
    struct k_sigaction new_ka, old_ka;
    int ret;
    int err = 0;

    if (act) {
        old_sigset_t mask;
        s32 handler;

        if (!access_ok(VERIFY_READ, act, sizeof(*act)))
            return -EFAULT;
        err |= __get_user(handler, &act->sa_handler);
        new_ka.sa.sa_handler = (void __user *)(s64)handler;
        err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
        err |= __get_user(mask, &act->sa_mask.sig[0]);
        if (err)
            return -EFAULT;

        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)))
            return -EFAULT;
        err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
        err |= __put_user((u32)(u64)old_ka.sa.sa_handler,
                          &oact->sa_handler);
        err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
        err |= __put_user(0, &oact->sa_mask.sig[1]);
        err |= __put_user(0, &oact->sa_mask.sig[2]);
        err |= __put_user(0, &oact->sa_mask.sig[3]);
        if (err)
            return -EFAULT;
    }

    return ret;
}

asmlinkage int sys32_sigaltstack(nabi_no_regargs struct pt_regs regs)
{
    const stack32_t __user *uss = (const stack32_t __user *) regs.regs[4];
    stack32_t __user *uoss = (stack32_t __user *) regs.regs[5];
    unsigned long usp = regs.regs[29];
    stack_t kss, koss;
    int ret, err = 0;
    mm_segment_t old_fs = get_fs();
    s32 sp;

    if (uss) {
        if (!access_ok(VERIFY_READ, uss, sizeof(*uss)))
            return -EFAULT;
        err |= __get_user(sp, &uss->ss_sp);
        kss.ss_sp = (void __user *) (long) sp;
        err |= __get_user(kss.ss_size, &uss->ss_size);
        err |= __get_user(kss.ss_flags, &uss->ss_flags);
        if (err)
            return -EFAULT;
    }

    set_fs(KERNEL_DS);
    ret = do_sigaltstack(uss ? (stack_t __user *)&kss : NULL,
                 uoss ? (stack_t __user *)&koss : NULL, usp);
    set_fs(old_fs);

    if (!ret && uoss) {
        if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
            return -EFAULT;
        sp = (int) (unsigned long) koss.ss_sp;
        err |= __put_user(sp, &uoss->ss_sp);
        err |= __put_user(koss.ss_size, &uoss->ss_size);
        err |= __put_user(koss.ss_flags, &uoss->ss_flags);
        if (err)
            return -EFAULT;
    }
    return ret;
}

int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
    int err;

    if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
        return -EFAULT;

    /* If you change siginfo_t structure, please be sure
       this code is fixed accordingly.
       It should never copy any pad contained in the structure
       to avoid security leaks, but must copy the generic
       3 ints plus the relevant union member.
       This routine must convert siginfo from 64bit to 32bit as well
       at the same time.  */
    err = __put_user(from->si_signo, &to->si_signo);
    err |= __put_user(from->si_errno, &to->si_errno);
    err |= __put_user((short)from->si_code, &to->si_code);
    if (from->si_code < 0)
        err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
    else {
        switch (from->si_code >> 16) {
        case __SI_TIMER >> 16:
            err |= __put_user(from->si_tid, &to->si_tid);
            err |= __put_user(from->si_overrun, &to->si_overrun);
            err |= __put_user(from->si_int, &to->si_int);
            break;
        case __SI_CHLD >> 16:
            err |= __put_user(from->si_utime, &to->si_utime);
            err |= __put_user(from->si_stime, &to->si_stime);
            err |= __put_user(from->si_status, &to->si_status);
        default:
            err |= __put_user(from->si_pid, &to->si_pid);
            err |= __put_user(from->si_uid, &to->si_uid);
            break;
        case __SI_FAULT >> 16:
            err |= __put_user((unsigned long)from->si_addr, &to->si_addr);
            break;
        case __SI_POLL >> 16:
            err |= __put_user(from->si_band, &to->si_band);
            err |= __put_user(from->si_fd, &to->si_fd);
            break;
        case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
        case __SI_MESGQ >> 16:
            err |= __put_user(from->si_pid, &to->si_pid);
            err |= __put_user(from->si_uid, &to->si_uid);
            err |= __put_user(from->si_int, &to->si_int);
            break;
        }
    }
    return err;
}

int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
    memset(to, 0, sizeof *to);

    if (copy_from_user(to, from, 3*sizeof(int)) ||
        copy_from_user(to->_sifields._pad,
               from->_sifields._pad, SI_PAD_SIZE32))
        return -EFAULT;

    return 0;
}

asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs)
{
    struct sigframe32 __user *frame;
    sigset_t blocked;
    int sig;

    frame = (struct sigframe32 __user *) regs.regs[29];
    if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
        goto badframe;
    if (__copy_conv_sigset_from_user(&blocked, &frame->sf_mask))
        goto badframe;

    set_current_blocked(&blocked);

    sig = restore_sigcontext32(&regs, &frame->sf_sc);
    if (sig < 0)
        goto badframe;
    else if (sig)
        force_sig(sig, current);

    /*
     * Don't let your children do this ...
     */
    __asm__ __volatile__(
        "move\t$29, %0\n\t"
        "j\tsyscall_exit"
        :/* no outputs */
        :"r" (&regs));
    /* Unreached */

badframe:
    force_sig(SIGSEGV, current);
}

asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
{
    struct rt_sigframe32 __user *frame;
    mm_segment_t old_fs;
    sigset_t set;
    stack_t st;
    s32 sp;
    int sig;

    frame = (struct rt_sigframe32 __user *) regs.regs[29];
    if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
        goto badframe;
    if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
        goto badframe;

    set_current_blocked(&set);

    sig = restore_sigcontext32(&regs, &frame->rs_uc.uc_mcontext);
    if (sig < 0)
        goto badframe;
    else if (sig)
        force_sig(sig, current);

    /* The ucontext contains a stack32_t, so we must convert!  */
    if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
        goto badframe;
    st.ss_sp = (void __user *)(long) sp;
    if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
        goto badframe;
    if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
        goto badframe;

    /* It is more difficult to avoid calling this function than to
       call it and ignore errors.  */
    old_fs = get_fs();
    set_fs(KERNEL_DS);
    do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
    set_fs(old_fs);

    /*
     * Don't let your children do this ...
     */
    __asm__ __volatile__(
        "move\t$29, %0\n\t"
        "j\tsyscall_exit"
        :/* no outputs */
        :"r" (&regs));
    /* Unreached */

badframe:
    force_sig(SIGSEGV, current);
}

static int setup_frame_32(void *sig_return, struct k_sigaction *ka,
              struct pt_regs *regs, int signr, sigset_t *set)
{
    struct sigframe32 __user *frame;
    int err = 0;

    frame = get_sigframe(ka, regs, sizeof(*frame));
    if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
        goto give_sigsegv;

    err |= setup_sigcontext32(regs, &frame->sf_sc);
    err |= __copy_conv_sigset_to_user(&frame->sf_mask, set);

    if (err)
        goto give_sigsegv;

    /*
     * Arguments to signal handler:
     *
     *   a0 = signal number
     *   a1 = 0 (should be cause)
     *   a2 = pointer to struct sigcontext
     *
     * $25 and c0_epc point to the signal handler, $29 points to the
     * struct sigframe.
     */
    regs->regs[ 4] = signr;
    regs->regs[ 5] = 0;
    regs->regs[ 6] = (unsigned long) &frame->sf_sc;
    regs->regs[29] = (unsigned long) frame;
    regs->regs[31] = (unsigned long) sig_return;
    regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;

    DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
           current->comm, current->pid,
           frame, regs->cp0_epc, regs->regs[31]);

    return 0;

give_sigsegv:
    force_sigsegv(signr, current);
    return -EFAULT;
}

static int setup_rt_frame_32(void *sig_return, struct k_sigaction *ka,
                 struct pt_regs *regs, int signr, sigset_t *set,
                 siginfo_t *info)
{
    struct rt_sigframe32 __user *frame;
    int err = 0;
    s32 sp;

    frame = get_sigframe(ka, regs, sizeof(*frame));
    if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
        goto give_sigsegv;

    /* Convert (siginfo_t -> compat_siginfo_t) and copy to user. */
    err |= copy_siginfo_to_user32(&frame->rs_info, info);

    /* Create the ucontext.  */
    err |= __put_user(0, &frame->rs_uc.uc_flags);
    err |= __put_user(0, &frame->rs_uc.uc_link);
    sp = (int) (long) current->sas_ss_sp;
    err |= __put_user(sp,
                      &frame->rs_uc.uc_stack.ss_sp);
    err |= __put_user(sas_ss_flags(regs->regs[29]),
                      &frame->rs_uc.uc_stack.ss_flags);
    err |= __put_user(current->sas_ss_size,
                      &frame->rs_uc.uc_stack.ss_size);
    err |= setup_sigcontext32(regs, &frame->rs_uc.uc_mcontext);
    err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);

    if (err)
        goto give_sigsegv;

    /*
     * Arguments to signal handler:
     *
     *   a0 = signal number
     *   a1 = 0 (should be cause)
     *   a2 = pointer to ucontext
     *
     * $25 and c0_epc point to the signal handler, $29 points to
     * the struct rt_sigframe32.
     */
    regs->regs[ 4] = signr;
    regs->regs[ 5] = (unsigned long) &frame->rs_info;
    regs->regs[ 6] = (unsigned long) &frame->rs_uc;
    regs->regs[29] = (unsigned long) frame;
    regs->regs[31] = (unsigned long) sig_return;
    regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;

    DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
           current->comm, current->pid,
           frame, regs->cp0_epc, regs->regs[31]);

    return 0;

give_sigsegv:
    force_sigsegv(signr, current);
    return -EFAULT;
}

/*
 * o32 compatibility on 64-bit kernels, without DSP ASE
 */
struct mips_abi mips_abi_32 = {
    .setup_frame    = setup_frame_32,
    .signal_return_offset =
        offsetof(struct mips_vdso, o32_signal_trampoline),
    .setup_rt_frame = setup_rt_frame_32,
    .rt_signal_return_offset =
        offsetof(struct mips_vdso, o32_rt_signal_trampoline),
    .restart    = __NR_O32_restart_syscall
};

SYSCALL_DEFINE4(32_rt_sigaction, int, sig,
    const struct sigaction32 __user *, act,
    struct sigaction32 __user *, oact, unsigned int, sigsetsize)
{
    struct k_sigaction new_sa, old_sa;
    int ret = -EINVAL;

    /* XXX: Don't preclude handling different sized sigset_t's.  */
    if (sigsetsize != sizeof(sigset_t))
        goto out;

    if (act) {
        s32 handler;
        int err = 0;

        if (!access_ok(VERIFY_READ, act, sizeof(*act)))
            return -EFAULT;
        err |= __get_user(handler, &act->sa_handler);
        new_sa.sa.sa_handler = (void __user *)(s64)handler;
        err |= __get_user(new_sa.sa.sa_flags, &act->sa_flags);
        err |= get_sigset(&new_sa.sa.sa_mask, &act->sa_mask);
        if (err)
            return -EFAULT;
    }

    ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL);

    if (!ret && oact) {
        int err = 0;

        if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
            return -EFAULT;

        err |= __put_user((u32)(u64)old_sa.sa.sa_handler,
                           &oact->sa_handler);
        err |= __put_user(old_sa.sa.sa_flags, &oact->sa_flags);
        err |= put_sigset(&old_sa.sa.sa_mask, &oact->sa_mask);
        if (err)
            return -EFAULT;
    }
out:
    return ret;
}

SYSCALL_DEFINE4(32_rt_sigprocmask, int, how, compat_sigset_t __user *, set,
    compat_sigset_t __user *, oset, unsigned int, sigsetsize)
{
    sigset_t old_set, new_set;
    int ret;
    mm_segment_t old_fs = get_fs();

    if (set && get_sigset(&new_set, set))
        return -EFAULT;

    set_fs(KERNEL_DS);
    ret = sys_rt_sigprocmask(how, set ? (sigset_t __user *)&new_set : NULL,
                 oset ? (sigset_t __user *)&old_set : NULL,
                 sigsetsize);
    set_fs(old_fs);

    if (!ret && oset && put_sigset(&old_set, oset))
        return -EFAULT;

    return ret;
}

SYSCALL_DEFINE2(32_rt_sigpending, compat_sigset_t __user *, uset,
    unsigned int, sigsetsize)
{
    int ret;
    sigset_t set;
    mm_segment_t old_fs = get_fs();

    set_fs(KERNEL_DS);
    ret = sys_rt_sigpending((sigset_t __user *)&set, sigsetsize);
    set_fs(old_fs);

    if (!ret && put_sigset(&set, uset))
        return -EFAULT;

    return ret;
}

SYSCALL_DEFINE3(32_rt_sigqueueinfo, int, pid, int, sig,
    compat_siginfo_t __user *, uinfo)
{
    siginfo_t info;
    int ret;
    mm_segment_t old_fs = get_fs();

    if (copy_from_user(&info, uinfo, 3*sizeof(int)) ||
        copy_from_user(info._sifields._pad, uinfo->_sifields._pad, SI_PAD_SIZE))
        return -EFAULT;
    set_fs(KERNEL_DS);
    ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __user *)&info);
    set_fs(old_fs);
    return ret;
}

SYSCALL_DEFINE5(32_waitid, int, which, compat_pid_t, pid,
         compat_siginfo_t __user *, uinfo, int, options,
         struct compat_rusage __user *, uru)
{
    siginfo_t info;
    struct rusage ru;
    long ret;
    mm_segment_t old_fs = get_fs();

    info.si_signo = 0;
    set_fs(KERNEL_DS);
    ret = sys_waitid(which, pid, (siginfo_t __user *) &info, options,
             uru ? (struct rusage __user *) &ru : NULL);
    set_fs(old_fs);

    if (ret < 0 || info.si_signo == 0)
        return ret;

    if (uru && (ret = put_compat_rusage(&ru, uru)))
        return ret;

    BUG_ON(info.si_code & __SI_MASK);
    info.si_code |= __SI_CHLD;
    return copy_siginfo_to_user32(uinfo, &info);
}

static int signal32_init(void)
{
    if (cpu_has_fpu) {
        save_fp_context32 = _save_fp_context32;
        restore_fp_context32 = _restore_fp_context32;
    } else {
        save_fp_context32 = fpu_emulator_save_context32;
        restore_fp_context32 = fpu_emulator_restore_context32;
    }

    return 0;
}

arch_initcall(signal32_init);