/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2012, 2013, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * libcfs/libcfs/linux/linux-debug.c
 *
 * Author: Phil Schwan <phil@clusterfs.com>
 */

#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/notifier.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#ifdef HAVE_KERNEL_LOCKED
#include <linux/smp_lock.h>
#endif
#include <linux/unistd.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <linux/completion.h>

#include <linux/fs.h>
#include <linux/stat.h>
#include <asm/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/version.h>

# define DEBUG_SUBSYSTEM S_LNET

#include <libcfs/libcfs.h>

#include "tracefile.h"

#include <linux/kallsyms.h>

char lnet_upcall[1024] = "/usr/lib/lustre/lnet_upcall";
char lnet_debug_log_upcall[1024] = "/usr/lib/lustre/lnet_debug_log_upcall";

/**
 * Upcall function once a Lustre log has been dumped.
 *
 * \param file  path of the dumped log
 */
void libcfs_run_debug_log_upcall(char *file)
{
        char *argv[3];
        int   rc;
        char *envp[] = {
                "HOME=/",
                "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
                NULL};
        ENTRY;

        argv[0] = lnet_debug_log_upcall;

        LASSERTF(file != NULL, "called on a null filename\n");
        argv[1] = file; //only need to pass the path of the file

        argv[2] = NULL;

        rc = call_usermodehelper(argv[0], argv, envp, 1);
        if (rc < 0 && rc != -ENOENT) {
                CERROR("Error %d invoking LNET debug log upcall %s %s; "
                       "check /proc/sys/lnet/debug_log_upcall\n",
                       rc, argv[0], argv[1]);
        } else {
                CDEBUG(D_HA, "Invoked LNET debug log upcall %s %s\n",
                       argv[0], argv[1]);
        }

        EXIT;
}

void libcfs_run_upcall(char **argv)
{
        int   rc;
        int   argc;
        char *envp[] = {
                "HOME=/",
                "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
                NULL};
        ENTRY;

        argv[0] = lnet_upcall;
        argc = 1;
        while (argv[argc] != NULL)
                argc++;

        LASSERT(argc >= 2);

        rc = call_usermodehelper(argv[0], argv, envp, 1);
        if (rc < 0 && rc != -ENOENT) {
                CERROR("Error %d invoking LNET upcall %s %s%s%s%s%s%s%s%s; "
                       "check /proc/sys/lnet/upcall\n",
                       rc, argv[0], argv[1],
                       argc < 3 ? "" : ",", argc < 3 ? "" : argv[2],
                       argc < 4 ? "" : ",", argc < 4 ? "" : argv[3],
                       argc < 5 ? "" : ",", argc < 5 ? "" : argv[4],
                       argc < 6 ? "" : ",...");
        } else {
                CDEBUG(D_HA, "Invoked LNET upcall %s %s%s%s%s%s%s%s%s\n",
                       argv[0], argv[1],
                       argc < 3 ? "" : ",", argc < 3 ? "" : argv[2],
                       argc < 4 ? "" : ",", argc < 4 ? "" : argv[3],
                       argc < 5 ? "" : ",", argc < 5 ? "" : argv[4],
                       argc < 6 ? "" : ",...");
        }
}

void libcfs_run_lbug_upcall(struct libcfs_debug_msg_data *msgdata)
{
        char *argv[6];
        char buf[32];

        ENTRY;
        snprintf (buf, sizeof buf, "%d", msgdata->msg_line);

        argv[1] = "LBUG";
        argv[2] = (char *)msgdata->msg_file;
        argv[3] = (char *)msgdata->msg_fn;
        argv[4] = buf;
        argv[5] = NULL;

        libcfs_run_upcall (argv);
}
EXPORT_SYMBOL(libcfs_run_lbug_upcall);

/* coverity[+kill] */
void lbug_with_loc(struct libcfs_debug_msg_data *msgdata)
{
        libcfs_catastrophe = 1;
        libcfs_debug_msg(msgdata, "LBUG\n");

        if (in_interrupt()) {
                panic("LBUG in interrupt.\n");
                /* not reached */
        }

        libcfs_debug_dumpstack(NULL);
        if (!libcfs_panic_on_lbug)
                libcfs_debug_dumplog();
        libcfs_run_lbug_upcall(msgdata);
        if (libcfs_panic_on_lbug)
                panic("LBUG");
        set_task_state(current, TASK_UNINTERRUPTIBLE);
        while (1)
                schedule();
}
EXPORT_SYMBOL(lbug_with_loc);

#ifdef CONFIG_X86
#include <linux/nmi.h>
#include <asm/stacktrace.h>

#ifdef HAVE_STACKTRACE_WARNING
static void
print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
{
        printk("%s", (char *)data);
	print_symbol(msg, symbol);
	printk("\n");
}

static void print_trace_warning(void *data, char *msg)
{
	printk("%s%s\n", (char *)data, msg);
}
#endif

static int print_trace_stack(void *data, char *name)
{
	printk(" <%s> ", name);
	return 0;
}

#ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
static int
#else
static void
#endif
print_trace_address(void *data, unsigned long addr, int reliable)
{
	char fmt[32];

	touch_nmi_watchdog();
	sprintf(fmt, " [<%016lx>] %s%%s\n", addr, reliable ? "": "? ");
	__print_symbol(fmt, addr);
#ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
	return 0;
#endif
}

static const struct stacktrace_ops print_trace_ops = {
#ifdef HAVE_STACKTRACE_WARNING
	.warning = print_trace_warning,
	.warning_symbol = print_trace_warning_symbol,
#endif
	.stack = print_trace_stack,
	.address = print_trace_address,
#ifdef STACKTRACE_OPS_HAVE_WALK_STACK
	.walk_stack = print_context_stack,
#endif
};

static void libcfs_call_trace(struct task_struct *tsk)
{
	dump_trace(tsk, NULL, NULL,
#ifdef HAVE_DUMP_TRACE_ADDRESS
		   0,
#endif /* HAVE_DUMP_TRACE_ADDRESS */
		   &print_trace_ops, NULL);
	printk("\n");
}

#else /* !CONFIG_X86 */

static void libcfs_call_trace(struct task_struct *tsk)
{
	if ((tsk == NULL) || (tsk == current))
		dump_stack();
	else
		CWARN("can't show stack: kernel doesn't export show_task\n");
}

#endif /* CONFIG_X86 */

void libcfs_debug_dumpstack(struct task_struct *tsk)
{
        /* dump_stack() */
        /* show_trace() */
        if (tsk == NULL)
                tsk = current;
	printk("Pid: %d, comm: %.20s\n", tsk->pid, tsk->comm);
        /* show_trace_log_lvl() */
	printk("\nCall Trace:\n");
	libcfs_call_trace(tsk);
}
EXPORT_SYMBOL(libcfs_debug_dumpstack);

struct task_struct *libcfs_current(void)
{
        CWARN("current task struct is %p\n", current);
        return current;
}

static int panic_notifier(struct notifier_block *self, unsigned long unused1,
                         void *unused2)
{
        if (libcfs_panic_in_progress)
                return 0;

        libcfs_panic_in_progress = 1;
        mb();

#ifdef LNET_DUMP_ON_PANIC
        /* This is currently disabled because it spews far too much to the
         * console on the rare cases it is ever triggered. */

        if (in_interrupt()) {
                cfs_trace_debug_print();
        } else {
#ifdef HAVE_KERNEL_LOCKED
		while (kernel_locked())
			unlock_kernel();
#endif
		libcfs_debug_dumplog_internal((void *)(long)current_pid());
        }
#endif
        return 0;
}

static struct notifier_block libcfs_panic_notifier = {
        notifier_call :     panic_notifier,
        next :              NULL,
        priority :          10000
};

void libcfs_register_panic_notifier(void)
{
        atomic_notifier_chain_register(&panic_notifier_list, &libcfs_panic_notifier);
}

void libcfs_unregister_panic_notifier(void)
{
        atomic_notifier_chain_unregister(&panic_notifier_list, &libcfs_panic_notifier);
}