libcfs/libcfs/linux/linux-debug.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * libcfs/libcfs/linux/linux-debug.c
  33  *
  34  * Author: Phil Schwan <phil@clusterfs.com>
  35  */
  36
  37 #include <linux/errno.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/kallsyms.h>
  40 #include <linux/kmod.h>
  41 #include <linux/module.h>
  42 #include <linux/notifier.h>
  43 #ifdef HAVE_KERNEL_LOCKED
  44 #include <linux/smp_lock.h>
  45 #endif
  46 #include <linux/string.h>
  47 #include <linux/unistd.h>
  48 #include <linux/stacktrace.h>
  49 #include <linux/utsname.h>
  50
  51 # define DEBUG_SUBSYSTEM S_LNET
  52
  53 #include <libcfs/libcfs.h>
  54
  55 #include "tracefile.h"
  56
  57 char lnet_debug_log_upcall[1024] = "/usr/lib/lustre/lnet_debug_log_upcall";
  58
  59 /**
  60  * Upcall function once a Lustre log has been dumped.
  61  *
  62  * \param file  path of the dumped log
  63  */
  64 void libcfs_run_debug_log_upcall(char *file)
  65 {
  66         char *argv[3];
  67         int   rc;
  68         char *envp[] = {
  69                 "HOME=/",
  70                 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
  71                 NULL};
  72         ENTRY;
  73
  74         argv[0] = lnet_debug_log_upcall;
  75
  76         LASSERTF(file != NULL, "called on a null filename\n");
  77         argv[1] = file; //only need to pass the path of the file
  78
  79         argv[2] = NULL;
  80
  81         rc = call_usermodehelper(argv[0], argv, envp, 1);
  82         if (rc < 0 && rc != -ENOENT) {
  83                 CERROR("Error %d invoking LNET debug log upcall %s %s; "
  84                        "check /proc/sys/lnet/debug_log_upcall\n",
  85                        rc, argv[0], argv[1]);
  86         } else {
  87                 CDEBUG(D_HA, "Invoked LNET debug log upcall %s %s\n",
  88                        argv[0], argv[1]);
  89         }
  90
  91         EXIT;
  92 }
  93
  94 /* coverity[+kill] */
  95 void lbug_with_loc(struct libcfs_debug_msg_data *msgdata)
  96 {
  97         libcfs_catastrophe = 1;
  98         libcfs_debug_msg(msgdata, "LBUG\n");
  99
 100         if (in_interrupt()) {
 101                 panic("LBUG in interrupt.\n");
 102                 /* not reached */
 103         }
 104
 105         libcfs_debug_dumpstack(NULL);
 106         if (libcfs_panic_on_lbug)
 107                 panic("LBUG");
 108         else
 109                 libcfs_debug_dumplog();
 110         set_current_state(TASK_UNINTERRUPTIBLE);
 111         while (1)
 112                 schedule();
 113 }
 114 EXPORT_SYMBOL(lbug_with_loc);
 115
 116 #ifdef CONFIG_STACKTRACE
 117
 118 #ifndef HAVE_SAVE_STACK_TRACE_TSK
 119 #define save_stack_trace_tsk(tsk, trace)                                       \
 120 do {                                                                           \
 121         if (tsk == current)                                                    \
 122                 save_stack_trace(trace);                                       \
 123         else                                                                   \
 124                 pr_info("No stack, save_stack_trace_tsk() not exported\n");    \
 125 } while (0)
 126 #endif
 127
 128 #define MAX_ST_ENTRIES  100
 129 static DEFINE_SPINLOCK(st_lock);
 130
 131 static void libcfs_call_trace(struct task_struct *tsk)
 132 {
 133         struct stack_trace trace;
 134         static unsigned long entries[MAX_ST_ENTRIES];
 135
 136         trace.nr_entries = 0;
 137         trace.max_entries = MAX_ST_ENTRIES;
 138         trace.entries = entries;
 139         trace.skip = 0;
 140
 141         spin_lock(&st_lock);
 142         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 143                init_utsname()->release, init_utsname()->version);
 144         pr_info("Call Trace:\n");
 145         save_stack_trace_tsk(tsk, &trace);
 146         print_stack_trace(&trace, 0);
 147         spin_unlock(&st_lock);
 148 }
 149
 150 #else /* !CONFIG_STACKTRACE */
 151
 152 #ifdef CONFIG_X86
 153 #include <linux/nmi.h>
 154 #include <asm/stacktrace.h>
 155
 156 #ifdef HAVE_STACKTRACE_OPS
 157 #ifdef HAVE_STACKTRACE_WARNING
 158 static void
 159 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
 160 {
 161         printk("%s", (char *)data);
 162         print_symbol(msg, symbol);
 163         printk("\n");
 164 }
 165
 166 static void print_trace_warning(void *data, char *msg)
 167 {
 168         printk("%s%s\n", (char *)data, msg);
 169 }
 170 #endif
 171
 172 static int print_trace_stack(void *data, char *name)
 173 {
 174         printk(" <%s> ", name);
 175         return 0;
 176 }
 177
 178 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 179 static int
 180 #else
 181 static void
 182 #endif
 183 print_trace_address(void *data, unsigned long addr, int reliable)
 184 {
 185         char fmt[32];
 186
 187         touch_nmi_watchdog();
 188         sprintf(fmt, " [<%016lx>] %s%%s\n", addr, reliable ? "": "? ");
 189         __print_symbol(fmt, addr);
 190 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 191         return 0;
 192 #endif
 193 }
 194
 195 static const struct stacktrace_ops print_trace_ops = {
 196 #ifdef HAVE_STACKTRACE_WARNING
 197         .warning = print_trace_warning,
 198         .warning_symbol = print_trace_warning_symbol,
 199 #endif
 200         .stack = print_trace_stack,
 201         .address = print_trace_address,
 202 #ifdef STACKTRACE_OPS_HAVE_WALK_STACK
 203         .walk_stack = print_context_stack,
 204 #endif
 205 };
 206 #endif /* HAVE_STACKTRACE_OPS */
 207
 208 static void libcfs_call_trace(struct task_struct *tsk)
 209 {
 210 #ifdef HAVE_STACKTRACE_OPS
 211         printk("Pid: %d, comm: %.20s\n", tsk->pid, tsk->comm);
 212         printk("\nCall Trace:\n");
 213         dump_trace(tsk, NULL, NULL,
 214 #ifdef HAVE_DUMP_TRACE_ADDRESS
 215                    0,
 216 #endif /* HAVE_DUMP_TRACE_ADDRESS */
 217                    &print_trace_ops, NULL);
 218         printk("\n");
 219 #else /* !HAVE_STACKTRACE_OPS */
 220         if (tsk == current)
 221                 dump_stack();
 222         else
 223                 CWARN("can't show stack: kernel doesn't export show_task\n");
 224 #endif /* HAVE_STACKTRACE_OPS */
 225 }
 226
 227 #else /* !CONFIG_X86 */
 228
 229 static void libcfs_call_trace(struct task_struct *tsk)
 230 {
 231         if (tsk == current)
 232                 dump_stack();
 233         else
 234                 CWARN("can't show stack: kernel doesn't export show_task\n");
 235 }
 236
 237 #endif /* CONFIG_X86 */
 238
 239 #endif /* CONFIG_STACKTRACE */
 240
 241 void libcfs_debug_dumpstack(struct task_struct *tsk)
 242 {
 243         libcfs_call_trace(tsk ?: current);
 244 }
 245 EXPORT_SYMBOL(libcfs_debug_dumpstack);
 246
 247 static int panic_notifier(struct notifier_block *self, unsigned long unused1,
 248                          void *unused2)
 249 {
 250         if (libcfs_panic_in_progress)
 251                 return 0;
 252
 253         libcfs_panic_in_progress = 1;
 254         mb();
 255
 256 #ifdef LNET_DUMP_ON_PANIC
 257         /* This is currently disabled because it spews far too much to the
 258          * console on the rare cases it is ever triggered. */
 259
 260         if (in_interrupt()) {
 261                 cfs_trace_debug_print();
 262         } else {
 263 #ifdef HAVE_KERNEL_LOCKED
 264                 while (kernel_locked())
 265                         unlock_kernel();
 266 #endif
 267                 libcfs_debug_dumplog_internal((void *)(long)current_pid());
 268         }
 269 #endif
 270         return 0;
 271 }
 272
 273 static struct notifier_block libcfs_panic_notifier = {
 274         .notifier_call  = panic_notifier,
 275         .next           = NULL,
 276         .priority       = 10000
 277 };
 278
 279 void libcfs_register_panic_notifier(void)
 280 {
 281         atomic_notifier_chain_register(&panic_notifier_list, &libcfs_panic_notifier);
 282 }
 283
 284 void libcfs_unregister_panic_notifier(void)
 285 {
 286         atomic_notifier_chain_unregister(&panic_notifier_list, &libcfs_panic_notifier);
 287 }