/* * X.25 Packet Layer release 002 * * This is ALPHA test software. This code may break your machine, * randomly fail to work with new releases, misbehave and/or generally * screw up. It might even work. * * This code REQUIRES 2.1.15 or higher * * This module: * This module 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. * * History * X.25 001 Jonathan Naylor Started coding. * X.25 002 Jonathan Naylor New timer architecture. * 2000-09-04 Henner Eisen Prevented x25_output() skb leakage. * 2000-10-27 Henner Eisen MSG_DONTWAIT for fragment allocation. * 2000-11-10 Henner Eisen x25_send_iframe(): re-queued frames * needed cleaned seq-number fields. */ #include #include #include #include #include #include #include static int x25_pacsize_to_bytes(unsigned int pacsize) { int bytes = 1; if (!pacsize) return 128; while (pacsize-- > 0) bytes *= 2; return bytes; } /* * This is where all X.25 information frames pass. * * Returns the amount of user data bytes sent on success * or a negative error code on failure. */ int x25_output(struct sock *sk, struct sk_buff *skb) { struct sk_buff *skbn; unsigned char header[X25_EXT_MIN_LEN]; int err, frontlen, len; int sent=0, noblock = X25_SKB_CB(skb)->flags & MSG_DONTWAIT; struct x25_sock *x25 = x25_sk(sk); int header_len = x25->neighbour->extended ? X25_EXT_MIN_LEN : X25_STD_MIN_LEN; int max_len = x25_pacsize_to_bytes(x25->facilities.pacsize_out); if (skb->len - header_len > max_len) { /* Save a copy of the Header */ skb_copy_from_linear_data(skb, header, header_len); skb_pull(skb, header_len); frontlen = skb_headroom(skb); while (skb->len > 0) { release_sock(sk); skbn = sock_alloc_send_skb(sk, frontlen + max_len, noblock, &err); lock_sock(sk); if (!skbn) { if (err == -EWOULDBLOCK && noblock){ kfree_skb(skb); return sent; } SOCK_DEBUG(sk, "x25_output: fragment alloc" " failed, err=%d, %d bytes " "sent\n", err, sent); return err; } skb_reserve(skbn, frontlen); len = max_len > skb->len ? skb->len : max_len; /* Copy the user data */ skb_copy_from_linear_data(skb, skb_put(skbn, len), len); skb_pull(skb, len); /* Duplicate the Header */ skb_push(skbn, header_len); skb_copy_to_linear_data(skbn, header, header_len); if (skb->len > 0) { if (x25->neighbour->extended) skbn->data[3] |= X25_EXT_M_BIT; else skbn->data[2] |= X25_STD_M_BIT; } skb_queue_tail(&sk->sk_write_queue, skbn); sent += len; } kfree_skb(skb); } else { skb_queue_tail(&sk->sk_write_queue, skb); sent = skb->len - header_len; } return sent; } /* * This procedure is passed a buffer descriptor for an iframe. It builds * the rest of the control part of the frame and then writes it out. */ static void x25_send_iframe(struct sock *sk, struct sk_buff *skb) { struct x25_sock *x25 = x25_sk(sk); if (!skb) return; if (x25->neighbour->extended) { skb->data[2] = (x25->vs << 1) & 0xFE; skb->data[3] &= X25_EXT_M_BIT; skb->data[3] |= (x25->vr << 1) & 0xFE; } else { skb->data[2] &= X25_STD_M_BIT; skb->data[2] |= (x25->vs << 1) & 0x0E; skb->data[2] |= (x25->vr << 5) & 0xE0; } x25_transmit_link(skb, x25->neighbour); } void x25_kick(struct sock *sk) { struct sk_buff *skb, *skbn; unsigned short start, end; int modulus; struct x25_sock *x25 = x25_sk(sk); if (x25->state != X25_STATE_3) return; /* * Transmit interrupt data. */ if (skb_peek(&x25->interrupt_out_queue) != NULL && !test_and_set_bit(X25_INTERRUPT_FLAG, &x25->flags)) { skb = skb_dequeue(&x25->interrupt_out_queue); x25_transmit_link(skb, x25->neighbour); } if (x25->condition & X25_COND_PEER_RX_BUSY) return; if (!skb_peek(&sk->sk_write_queue)) return; modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS; start = skb_peek(&x25->ack_queue) ? x25->vs : x25->va; end = (x25->va + x25->facilities.winsize_out) % modulus; if (start == end) return; x25->vs = start; /* * Transmit data until either we're out of data to send or * the window is full. */ skb = skb_dequeue(&sk->sk_write_queue); do { if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) { skb_queue_head(&sk->sk_write_queue, skb); break; } skb_set_owner_w(skbn, sk); /* * Transmit the frame copy. */ x25_send_iframe(sk, skbn); x25->vs = (x25->vs + 1) % modulus; /* * Requeue the original data frame. */ skb_queue_tail(&x25->ack_queue, skb); } while (x25->vs != end && (skb = skb_dequeue(&sk->sk_write_queue)) != NULL); x25->vl = x25->vr; x25->condition &= ~X25_COND_ACK_PENDING; x25_stop_timer(sk); } /* * The following routines are taken from page 170 of the 7th ARRL Computer * Networking Conference paper, as is the whole state machine. */ void x25_enquiry_response(struct sock *sk) { struct x25_sock *x25 = x25_sk(sk); if (x25->condition & X25_COND_OWN_RX_BUSY) x25_write_internal(sk, X25_RNR); else x25_write_internal(sk, X25_RR); x25->vl = x25->vr; x25->condition &= ~X25_COND_ACK_PENDING; x25_stop_timer(sk); } '/cgit.cgi/linux/net-next.git/commit/net/ipv6/anycast.c?id=24c2503255d35c269b67162c397a1a1c1e02f6ce'>24c2503255d35c269b67162c397a1a1c1e02f6ce (diff)
x86/mce: Make timer handling more robust
Erik reported that on a preproduction hardware a CMCI storm triggers the BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is started by the CMCI logic before the MCE CPU hotplug callback starts the timer with add_timer_on(). So the timer is already queued which triggers the BUG. Using add_timer_on() is pretty pointless in this code because the timer is strictlty per CPU, initialized as pinned and all operations which arm the timer happen on the CPU to which the timer belongs. Simplify the whole machinery by using mod_timer() instead of add_timer_on() which avoids the problem because mod_timer() can handle already queued timers. Use __start_timer() everywhere so the earliest armed expiry time is preserved. Reported-by: Erik Veijola <erik.veijola@intel.com> Tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'net/ipv6/anycast.c')