err = -ENOMEM;
        ap = kzalloc(sizeof(*ap), GFP_KERNEL);
-       if (ap == 0)
+       if (!ap)
                goto out;
 
        /* initialize the asyncppp structure */
        ap = tty->disc_data;
        tty->disc_data = NULL;
        write_unlock_irq(&disc_data_lock);
-       if (ap == 0)
+       if (!ap)
                return;
 
        /*
        tasklet_kill(&ap->tsk);
 
        ppp_unregister_channel(&ap->chan);
-       if (ap->rpkt != 0)
+       if (ap->rpkt)
                kfree_skb(ap->rpkt);
        skb_queue_purge(&ap->rqueue);
-       if (ap->tpkt != 0)
+       if (ap->tpkt)
                kfree_skb(ap->tpkt);
        kfree(ap);
 }
        int err, val;
        int __user *p = (int __user *)arg;
 
-       if (ap == 0)
+       if (!ap)
                return -ENXIO;
        err = -EFAULT;
        switch (cmd) {
        case PPPIOCGCHAN:
                err = -ENXIO;
-               if (ap == 0)
+               if (!ap)
                        break;
                err = -EFAULT;
                if (put_user(ppp_channel_index(&ap->chan), p))
 
        case PPPIOCGUNIT:
                err = -ENXIO;
-               if (ap == 0)
+               if (!ap)
                        break;
                err = -EFAULT;
                if (put_user(ppp_unit_number(&ap->chan), p))
        struct asyncppp *ap = ap_get(tty);
        unsigned long flags;
 
-       if (ap == 0)
+       if (!ap)
                return;
        spin_lock_irqsave(&ap->recv_lock, flags);
        ppp_async_input(ap, buf, cflags, count);
        struct asyncppp *ap = ap_get(tty);
 
        clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
-       if (ap == 0)
+       if (!ap)
                return;
        set_bit(XMIT_WAKEUP, &ap->xmit_flags);
        tasklet_schedule(&ap->tsk);
                                tty_stuffed = 1;
                        continue;
                }
-               if (ap->optr >= ap->olim && ap->tpkt != 0) {
+               if (ap->optr >= ap->olim && ap->tpkt) {
                        if (ppp_async_encode(ap)) {
                                /* finished processing ap->tpkt */
                                clear_bit(XMIT_FULL, &ap->xmit_flags);
                clear_bit(XMIT_BUSY, &ap->xmit_flags);
                /* any more work to do? if not, exit the loop */
                if (!(test_bit(XMIT_WAKEUP, &ap->xmit_flags)
-                     || (!tty_stuffed && ap->tpkt != 0)))
+                     || (!tty_stuffed && ap->tpkt)))
                        break;
                /* more work to do, see if we can do it now */
                if (test_and_set_bit(XMIT_BUSY, &ap->xmit_flags))
 
 flush:
        clear_bit(XMIT_BUSY, &ap->xmit_flags);
-       if (ap->tpkt != 0) {
+       if (ap->tpkt) {
                kfree_skb(ap->tpkt);
                ap->tpkt = NULL;
                clear_bit(XMIT_FULL, &ap->xmit_flags);
                s = 0;
                for (i = 0; i < count; ++i) {
                        c = buf[i];
-                       if (flags != 0 && flags[i] != 0)
+                       if (flags && flags[i] != 0)
                                continue;
                        s |= (c & 0x80)? SC_RCV_B7_1: SC_RCV_B7_0;
                        c = ((c >> 4) ^ c) & 0xf;
                        n = scan_ordinary(ap, buf, count);
 
                f = 0;
-               if (flags != 0 && (ap->state & SC_TOSS) == 0) {
+               if (flags && (ap->state & SC_TOSS) == 0) {
                        /* check the flags to see if any char had an error */
                        for (j = 0; j < n; ++j)
                                if ((f = flags[j]) != 0)
                } else if (n > 0 && (ap->state & SC_TOSS) == 0) {
                        /* stuff the chars in the skb */
                        skb = ap->rpkt;
-                       if (skb == 0) {
+                       if (!skb) {
                                skb = dev_alloc_skb(ap->mru + PPP_HDRLEN + 2);
-                               if (skb == 0)
+                               if (!skb)
                                        goto nomem;
                                ap->rpkt = skb;
                        }
                ++n;
 
                buf += n;
-               if (flags != 0)
+               if (flags)
                        flags += n;
                count -= n;
        }
 
        struct ppp_file *pf = file->private_data;
        struct ppp *ppp;
 
-       if (pf != 0) {
+       if (pf) {
                file->private_data = NULL;
                if (pf->kind == INTERFACE) {
                        ppp = PF_TO_PPP(pf);
 
        ret = count;
 
-       if (pf == 0)
+       if (!pf)
                return -ENXIO;
        add_wait_queue(&pf->rwait, &wait);
        for (;;) {
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&pf->rwait, &wait);
 
-       if (skb == 0)
+       if (!skb)
                goto out;
 
        ret = -EOVERFLOW;
        struct sk_buff *skb;
        ssize_t ret;
 
-       if (pf == 0)
+       if (!pf)
                return -ENXIO;
        ret = -ENOMEM;
        skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
-       if (skb == 0)
+       if (!skb)
                goto out;
        skb_reserve(skb, pf->hdrlen);
        ret = -EFAULT;
        struct ppp_file *pf = file->private_data;
        unsigned int mask;
 
-       if (pf == 0)
+       if (!pf)
                return 0;
        poll_wait(file, &pf->rwait, wait);
        mask = POLLOUT | POLLWRNORM;
-       if (skb_peek(&pf->rq) != 0)
+       if (skb_peek(&pf->rq))
                mask |= POLLIN | POLLRDNORM;
        if (pf->dead)
                mask |= POLLHUP;
        void __user *argp = (void __user *)arg;
        int __user *p = argp;
 
-       if (pf == 0)
+       if (!pf)
                return ppp_unattached_ioctl(pf, file, cmd, arg);
 
        if (cmd == PPPIOCDETACH) {
                        val &= 0xffff;
                }
                vj = slhc_init(val2+1, val+1);
-               if (vj == 0) {
+               if (!vj) {
                        printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
                        err = -ENOMEM;
                        break;
                }
                ppp_lock(ppp);
-               if (ppp->vj != 0)
+               if (ppp->vj)
                        slhc_free(ppp->vj);
                ppp->vj = vj;
                ppp_unlock(ppp);
                if (get_user(unit, p))
                        break;
                ppp = ppp_create_interface(unit, &err);
-               if (ppp == 0)
+               if (!ppp)
                        break;
                file->private_data = &ppp->file;
                ppp->owner = file;
                mutex_lock(&all_ppp_mutex);
                err = -ENXIO;
                ppp = ppp_find_unit(unit);
-               if (ppp != 0) {
+               if (ppp) {
                        atomic_inc(&ppp->file.refcnt);
                        file->private_data = &ppp->file;
                        err = 0;
                spin_lock_bh(&all_channels_lock);
                err = -ENXIO;
                chan = ppp_find_channel(unit);
-               if (chan != 0) {
+               if (chan) {
                        atomic_inc(&chan->file.refcnt);
                        file->private_data = &chan->file;
                        err = 0;
 
        case SIOCGPPPCSTATS:
                memset(&cstats, 0, sizeof(cstats));
-               if (ppp->xc_state != 0)
+               if (ppp->xc_state)
                        ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
-               if (ppp->rc_state != 0)
+               if (ppp->rc_state)
                        ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
                if (copy_to_user(addr, &cstats, sizeof(cstats)))
                        break;
        struct sk_buff *skb;
 
        ppp_xmit_lock(ppp);
-       if (ppp->dev != 0) {
+       if (ppp->dev) {
                ppp_push(ppp);
-               while (ppp->xmit_pending == 0
-                      && (skb = skb_dequeue(&ppp->file.xq)) != 0)
+               while (!ppp->xmit_pending
+                      && (skb = skb_dequeue(&ppp->file.xq)))
                        ppp_send_frame(ppp, skb);
                /* If there's no work left to do, tell the core net
                   code that we can accept some more. */
-               if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
+               if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
                        netif_wake_queue(ppp->dev);
        }
        ppp_xmit_unlock(ppp);
 
        switch (proto) {
        case PPP_IP:
-               if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
+               if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
                        break;
                /* try to do VJ TCP header compression */
                new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
                                    GFP_ATOMIC);
-               if (new_skb == 0) {
+               if (!new_skb) {
                        printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
                        goto drop;
                }
        }
 
        /* try to do packet compression */
-       if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
+       if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
            && proto != PPP_LCP && proto != PPP_CCP) {
                if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
                        if (net_ratelimit())
        struct channel *pch;
        struct sk_buff *skb = ppp->xmit_pending;
 
-       if (skb == 0)
+       if (!skb)
                return;
 
        list = &ppp->channels;
                if (flen == len && nfree == 0)
                        bits |= E;
                frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
-               if (frag == 0)
+               if (!frag)
                        goto noskb;
                q = skb_put(frag, flen + hdrlen);
 
        struct ppp *ppp;
 
        spin_lock_bh(&pch->downl);
-       if (pch->chan != 0) {
+       if (pch->chan) {
                while (!skb_queue_empty(&pch->file.xq)) {
                        skb = skb_dequeue(&pch->file.xq);
                        if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
        if (skb_queue_empty(&pch->file.xq)) {
                read_lock_bh(&pch->upl);
                ppp = pch->ppp;
-               if (ppp != 0)
+               if (ppp)
                        ppp_xmit_process(ppp);
                read_unlock_bh(&pch->upl);
        }
 {
        ppp_recv_lock(ppp);
        /* ppp->dev == 0 means interface is closing down */
-       if (ppp->dev != 0)
+       if (ppp->dev)
                ppp_receive_frame(ppp, skb, pch);
        else
                kfree_skb(skb);
        struct channel *pch = chan->ppp;
        int proto;
 
-       if (pch == 0 || skb->len == 0) {
+       if (!pch || skb->len == 0) {
                kfree_skb(skb);
                return;
        }
 
        proto = PPP_PROTO(skb);
        read_lock_bh(&pch->upl);
-       if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
+       if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
                /* put it on the channel queue */
                skb_queue_tail(&pch->file.rq, skb);
                /* drop old frames if queue too long */
                while (pch->file.rq.qlen > PPP_MAX_RQLEN
-                      && (skb = skb_dequeue(&pch->file.rq)) != 0)
+                      && (skb = skb_dequeue(&pch->file.rq)))
                        kfree_skb(skb);
                wake_up_interruptible(&pch->file.rwait);
        } else {
        struct channel *pch = chan->ppp;
        struct sk_buff *skb;
 
-       if (pch == 0)
+       if (!pch)
                return;
 
        read_lock_bh(&pch->upl);
-       if (pch->ppp != 0) {
+       if (pch->ppp) {
                skb = alloc_skb(0, GFP_ATOMIC);
-               if (skb != 0) {
+               if (skb) {
                        skb->len = 0;           /* probably unnecessary */
                        skb->cb[0] = code;
                        ppp_do_recv(pch->ppp, skb, pch);
 ppp_receive_error(struct ppp *ppp)
 {
        ++ppp->stats.rx_errors;
-       if (ppp->vj != 0)
+       if (ppp->vj)
                slhc_toss(ppp->vj);
 }
 
         * Note that some decompressors need to see uncompressed frames
         * that come in as well as compressed frames.
         */
-       if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
+       if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
            && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
                skb = ppp_decompress_frame(ppp, skb);
 
        switch (proto) {
        case PPP_VJC_COMP:
                /* decompress VJ compressed packets */
-               if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
+               if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
                        goto err;
 
                if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
                        /* copy to a new sk_buff with more tailroom */
                        ns = dev_alloc_skb(skb->len + 128);
-                       if (ns == 0) {
+                       if (!ns) {
                                printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
                                goto err;
                        }
                break;
 
        case PPP_VJC_UNCOMP:
-               if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
+               if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
                        goto err;
 
                /* Until we fix the decompressor need to make sure
                skb_queue_tail(&ppp->file.rq, skb);
                /* limit queue length by dropping old frames */
                while (ppp->file.rq.qlen > PPP_MAX_RQLEN
-                      && (skb = skb_dequeue(&ppp->file.rq)) != 0)
+                      && (skb = skb_dequeue(&ppp->file.rq)))
                        kfree_skb(skb);
                /* wake up any process polling or blocking on read */
                wake_up_interruptible(&ppp->file.rwait);
                }
 
                ns = dev_alloc_skb(obuff_size);
-               if (ns == 0) {
+               if (!ns) {
                        printk(KERN_ERR "ppp_decompress_frame: no memory\n");
                        goto err;
                }
                ppp->minseq = ppp->mrq.next->sequence;
 
        /* Pull completed packets off the queue and receive them. */
-       while ((skb = ppp_mp_reconstruct(ppp)) != 0)
+       while ((skb = ppp_mp_reconstruct(ppp)))
                ppp_receive_nonmp_frame(ppp, skb);
 
        return;
        struct channel *pch;
 
        pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
-       if (pch == 0)
+       if (!pch)
                return -ENOMEM;
        pch->ppp = NULL;
        pch->chan = chan;
 {
        struct channel *pch = chan->ppp;
 
-       if (pch != 0)
+       if (pch)
                return pch->file.index;
        return -1;
 }
        struct channel *pch = chan->ppp;
        int unit = -1;
 
-       if (pch != 0) {
+       if (pch) {
                read_lock_bh(&pch->upl);
-               if (pch->ppp != 0)
+               if (pch->ppp)
                        unit = pch->ppp->file.index;
                read_unlock_bh(&pch->upl);
        }
 {
        struct channel *pch = chan->ppp;
 
-       if (pch == 0)
+       if (!pch)
                return;         /* should never happen */
        chan->ppp = NULL;
 
 {
        struct channel *pch = chan->ppp;
 
-       if (pch == 0)
+       if (!pch)
                return;
        ppp_channel_push(pch);
 }
 
        cp = find_compressor(ccp_option[0]);
 #ifdef CONFIG_KMOD
-       if (cp == 0) {
+       if (!cp) {
                request_module("ppp-compress-%d", ccp_option[0]);
                cp = find_compressor(ccp_option[0]);
        }
 #endif /* CONFIG_KMOD */
-       if (cp == 0)
+       if (!cp)
                goto out;
 
        err = -ENOBUFS;
        if (data.transmit) {
                state = cp->comp_alloc(ccp_option, data.length);
-               if (state != 0) {
+               if (state) {
                        ppp_xmit_lock(ppp);
                        ppp->xstate &= ~SC_COMP_RUN;
                        ocomp = ppp->xcomp;
                        ppp->xcomp = cp;
                        ppp->xc_state = state;
                        ppp_xmit_unlock(ppp);
-                       if (ostate != 0) {
+                       if (ostate) {
                                ocomp->comp_free(ostate);
                                module_put(ocomp->owner);
                        }
 
        } else {
                state = cp->decomp_alloc(ccp_option, data.length);
-               if (state != 0) {
+               if (state) {
                        ppp_recv_lock(ppp);
                        ppp->rstate &= ~SC_DECOMP_RUN;
                        ocomp = ppp->rcomp;
                        ppp->rcomp = cp;
                        ppp->rc_state = state;
                        ppp_recv_unlock(ppp);
-                       if (ostate != 0) {
+                       if (ostate) {
                                ocomp->decomp_free(ostate);
                                module_put(ocomp->owner);
                        }
                        break;
                if (inbound) {
                        /* we will start receiving compressed packets */
-                       if (ppp->rc_state == 0)
+                       if (!ppp->rc_state)
                                break;
                        if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
                                        ppp->file.index, 0, ppp->mru, ppp->debug)) {
                        }
                } else {
                        /* we will soon start sending compressed packets */
-                       if (ppp->xc_state == 0)
+                       if (!ppp->xc_state)
                                break;
                        if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
                                        ppp->file.index, 0, ppp->debug))
        int ret;
        spin_lock(&compressor_list_lock);
        ret = -EEXIST;
-       if (find_comp_entry(cp->compress_proto) != 0)
+       if (find_comp_entry(cp->compress_proto))
                goto out;
        ret = -ENOMEM;
        ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
-       if (ce == 0)
+       if (!ce)
                goto out;
        ret = 0;
        ce->comp = cp;
 
        spin_lock(&compressor_list_lock);
        ce = find_comp_entry(cp->compress_proto);
-       if (ce != 0 && ce->comp == cp) {
+       if (ce && ce->comp == cp) {
                list_del(&ce->list);
                kfree(ce);
        }
 
        spin_lock(&compressor_list_lock);
        ce = find_comp_entry(type);
-       if (ce != 0) {
+       if (ce) {
                cp = ce->comp;
                if (!try_module_get(cp->owner))
                        cp = NULL;
        st->p.ppp_opackets = ppp->stats.tx_packets;
        st->p.ppp_oerrors = ppp->stats.tx_errors;
        st->p.ppp_obytes = ppp->stats.tx_bytes;
-       if (vj == 0)
+       if (!vj)
                return;
        st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
        st->vj.vjs_compressed = vj->sls_o_compressed;
 
        mutex_lock(&all_ppp_mutex);
        ppp = ppp_find_unit(unit);
-       if (ppp == 0)
+       if (!ppp)
                goto out;
        write_lock_bh(&pch->upl);
        ret = -EINVAL;
-       if (pch->ppp != 0)
+       if (pch->ppp)
                goto outl;
 
        ppp_lock(ppp);
        ppp = pch->ppp;
        pch->ppp = NULL;
        write_unlock_bh(&pch->upl);
-       if (ppp != 0) {
+       if (ppp) {
                /* remove it from the ppp unit's list */
                ppp_lock(ppp);
                list_del(&pch->clist);
 
 
        ap = kzalloc(sizeof(*ap), GFP_KERNEL);
        err = -ENOMEM;
-       if (ap == 0)
+       if (!ap)
                goto out;
 
        /* initialize the syncppp structure */
        ap = tty->disc_data;
        tty->disc_data = NULL;
        write_unlock_irq(&disc_data_lock);
-       if (ap == 0)
+       if (!ap)
                return;
 
        /*
 
        ppp_unregister_channel(&ap->chan);
        skb_queue_purge(&ap->rqueue);
-       if (ap->tpkt != 0)
+       if (ap->tpkt)
                kfree_skb(ap->tpkt);
        kfree(ap);
 }
        int __user *p = (int __user *)arg;
        int err, val;
 
-       if (ap == 0)
+       if (!ap)
                return -ENXIO;
        err = -EFAULT;
        switch (cmd) {
        case PPPIOCGCHAN:
                err = -ENXIO;
-               if (ap == 0)
+               if (!ap)
                        break;
                err = -EFAULT;
                if (put_user(ppp_channel_index(&ap->chan), p))
 
        case PPPIOCGUNIT:
                err = -ENXIO;
-               if (ap == 0)
+               if (!ap)
                        break;
                err = -EFAULT;
                if (put_user(ppp_unit_number(&ap->chan), p))
        struct syncppp *ap = sp_get(tty);
        unsigned long flags;
 
-       if (ap == 0)
+       if (!ap)
                return;
        spin_lock_irqsave(&ap->recv_lock, flags);
        ppp_sync_input(ap, buf, cflags, count);
        struct syncppp *ap = sp_get(tty);
 
        clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
-       if (ap == 0)
+       if (!ap)
                return;
        set_bit(XMIT_WAKEUP, &ap->xmit_flags);
        tasklet_schedule(&ap->tsk);
        for (;;) {
                if (test_and_clear_bit(XMIT_WAKEUP, &ap->xmit_flags))
                        tty_stuffed = 0;
-               if (!tty_stuffed && ap->tpkt != 0) {
+               if (!tty_stuffed && ap->tpkt) {
                        set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
                        sent = tty->driver->write(tty, ap->tpkt->data, ap->tpkt->len);
                        if (sent < 0)
                /* haven't made any progress */
                spin_unlock_bh(&ap->xmit_lock);
                if (!(test_bit(XMIT_WAKEUP, &ap->xmit_flags)
-                     || (!tty_stuffed && ap->tpkt != 0)))
+                     || (!tty_stuffed && ap->tpkt)))
                        break;
                if (!spin_trylock_bh(&ap->xmit_lock))
                        break;
        return done;
 
 flush:
-       if (ap->tpkt != 0) {
+       if (ap->tpkt) {
                kfree_skb(ap->tpkt);
                ap->tpkt = NULL;
                clear_bit(XMIT_FULL, &ap->xmit_flags);
                ppp_print_buffer ("receive buffer", buf, count);
 
        /* stuff the chars in the skb */
-       if ((skb = dev_alloc_skb(ap->mru + PPP_HDRLEN + 2)) == 0) {
+       skb = dev_alloc_skb(ap->mru + PPP_HDRLEN + 2);
+       if (!skb) {
                printk(KERN_ERR "PPPsync: no memory (input pkt)\n");
                goto err;
        }
        if (buf[0] != PPP_ALLSTATIONS)
                skb_reserve(skb, 2 + (buf[0] & 1));
 
-       if (flags != 0 && *flags) {
+       if (flags && *flags) {
                /* error flag set, ignore frame */
                goto err;
        } else if (count > skb_tailroom(skb)) {