Revision bb143f814ea488769ca2e79e0b376139cb5f134b authored by Vineet Gupta on 23 February 2016, 06:25:16 UTC, committed by Vineet Gupta on 24 February 2016, 05:37:28 UTC
ARConnect/MCIP Inter-Core-Interrupt module can't send interrupt to local core. So use core intc capability to trigger software interrupt to self, using an unsued IRQ #21. This showed up as csd deadlock with LTP trace_sched on a dual core system. This test acts as scheduler fuzzer, triggering all sorts of schedulting activity. Trouble starts with IPI to self, which doesn't get delivered (effectively lost due to H/w capability), but the msg intended to be sent remain enqueued in per-cpu @ipi_data. All subsequent IPIs to this core from other cores get elided due to the IPI coalescing optimization in ipi_send_msg_one() where a pending msg implies an IPI already sent and assumes other core is yet to ack it. After the elided IPI, other core simply goes into csd_lock_wait() but never comes out as this core never sees the interrupt. Fixes STAR 9001008624 Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> [4.2] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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debug.c
/* SCTP kernel implementation
* (C) Copyright IBM Corp. 2001, 2004
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001 Intel Corp.
*
* This file is part of the SCTP kernel implementation
*
* This file converts numerical ID value to alphabetical names for SCTP
* terms such as chunk type, parameter time, event type, etc.
*
* This SCTP implementation 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, or (at your option)
* any later version.
*
* This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* Written or modified by:
* La Monte H.P. Yarroll <piggy@acm.org>
* Karl Knutson <karl@athena.chicago.il.us>
* Xingang Guo <xingang.guo@intel.com>
* Jon Grimm <jgrimm@us.ibm.com>
* Daisy Chang <daisyc@us.ibm.com>
* Sridhar Samudrala <sri@us.ibm.com>
*/
#include <net/sctp/sctp.h>
/* These are printable forms of Chunk ID's from section 3.1. */
static const char *const sctp_cid_tbl[SCTP_NUM_BASE_CHUNK_TYPES] = {
"DATA",
"INIT",
"INIT_ACK",
"SACK",
"HEARTBEAT",
"HEARTBEAT_ACK",
"ABORT",
"SHUTDOWN",
"SHUTDOWN_ACK",
"ERROR",
"COOKIE_ECHO",
"COOKIE_ACK",
"ECN_ECNE",
"ECN_CWR",
"SHUTDOWN_COMPLETE",
};
/* Lookup "chunk type" debug name. */
const char *sctp_cname(const sctp_subtype_t cid)
{
if (cid.chunk <= SCTP_CID_BASE_MAX)
return sctp_cid_tbl[cid.chunk];
switch (cid.chunk) {
case SCTP_CID_ASCONF:
return "ASCONF";
case SCTP_CID_ASCONF_ACK:
return "ASCONF_ACK";
case SCTP_CID_FWD_TSN:
return "FWD_TSN";
case SCTP_CID_AUTH:
return "AUTH";
default:
break;
}
return "unknown chunk";
}
/* These are printable forms of the states. */
const char *const sctp_state_tbl[SCTP_STATE_NUM_STATES] = {
"STATE_CLOSED",
"STATE_COOKIE_WAIT",
"STATE_COOKIE_ECHOED",
"STATE_ESTABLISHED",
"STATE_SHUTDOWN_PENDING",
"STATE_SHUTDOWN_SENT",
"STATE_SHUTDOWN_RECEIVED",
"STATE_SHUTDOWN_ACK_SENT",
};
/* Events that could change the state of an association. */
const char *const sctp_evttype_tbl[] = {
"EVENT_T_unknown",
"EVENT_T_CHUNK",
"EVENT_T_TIMEOUT",
"EVENT_T_OTHER",
"EVENT_T_PRIMITIVE"
};
/* Return value of a state function */
const char *const sctp_status_tbl[] = {
"DISPOSITION_DISCARD",
"DISPOSITION_CONSUME",
"DISPOSITION_NOMEM",
"DISPOSITION_DELETE_TCB",
"DISPOSITION_ABORT",
"DISPOSITION_VIOLATION",
"DISPOSITION_NOT_IMPL",
"DISPOSITION_ERROR",
"DISPOSITION_BUG"
};
/* Printable forms of primitives */
static const char *const sctp_primitive_tbl[SCTP_NUM_PRIMITIVE_TYPES] = {
"PRIMITIVE_ASSOCIATE",
"PRIMITIVE_SHUTDOWN",
"PRIMITIVE_ABORT",
"PRIMITIVE_SEND",
"PRIMITIVE_REQUESTHEARTBEAT",
"PRIMITIVE_ASCONF",
};
/* Lookup primitive debug name. */
const char *sctp_pname(const sctp_subtype_t id)
{
if (id.primitive <= SCTP_EVENT_PRIMITIVE_MAX)
return sctp_primitive_tbl[id.primitive];
return "unknown_primitive";
}
static const char *const sctp_other_tbl[] = {
"NO_PENDING_TSN",
"ICMP_PROTO_UNREACH",
};
/* Lookup "other" debug name. */
const char *sctp_oname(const sctp_subtype_t id)
{
if (id.other <= SCTP_EVENT_OTHER_MAX)
return sctp_other_tbl[id.other];
return "unknown 'other' event";
}
static const char *const sctp_timer_tbl[] = {
"TIMEOUT_NONE",
"TIMEOUT_T1_COOKIE",
"TIMEOUT_T1_INIT",
"TIMEOUT_T2_SHUTDOWN",
"TIMEOUT_T3_RTX",
"TIMEOUT_T4_RTO",
"TIMEOUT_T5_SHUTDOWN_GUARD",
"TIMEOUT_HEARTBEAT",
"TIMEOUT_SACK",
"TIMEOUT_AUTOCLOSE",
};
/* Lookup timer debug name. */
const char *sctp_tname(const sctp_subtype_t id)
{
if (id.timeout <= SCTP_EVENT_TIMEOUT_MAX)
return sctp_timer_tbl[id.timeout];
return "unknown_timer";
}
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