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 #include <linux/string.h>
  44 #include <linux/unistd.h>
  45 #include <linux/stacktrace.h>
  46 #include <linux/utsname.h>
  47
  48 # define DEBUG_SUBSYSTEM S_LNET
  49
  50 #include <libcfs/libcfs.h>
  51
  52 #include "tracefile.h"
  53
  54 char lnet_debug_log_upcall[1024] = "/usr/lib/lustre/lnet_debug_log_upcall";
  55
  56 /**
  57  * Upcall function once a Lustre log has been dumped.
  58  *
  59  * \param file  path of the dumped log
  60  */
  61 void libcfs_run_debug_log_upcall(char *file)
  62 {
  63         char *argv[3];
  64         int   rc;
  65         char *envp[] = {
  66                 "HOME=/",
  67                 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
  68                 NULL};
  69         ENTRY;
  70
  71         argv[0] = lnet_debug_log_upcall;
  72
  73         LASSERTF(file != NULL, "called on a null filename\n");
  74         argv[1] = file; //only need to pass the path of the file
  75
  76         argv[2] = NULL;
  77
  78         rc = call_usermodehelper(argv[0], argv, envp, 1);
  79         if (rc < 0 && rc != -ENOENT) {
  80                 CERROR("Error %d invoking LNET debug log upcall %s %s; "
  81                        "check /proc/sys/lnet/debug_log_upcall\n",
  82                        rc, argv[0], argv[1]);
  83         } else {
  84                 CDEBUG(D_HA, "Invoked LNET debug log upcall %s %s\n",
  85                        argv[0], argv[1]);
  86         }
  87
  88         EXIT;
  89 }
  90
  91 /* coverity[+kill] */
  92 void lbug_with_loc(struct libcfs_debug_msg_data *msgdata)
  93 {
  94         libcfs_catastrophe = 1;
  95         libcfs_debug_msg(msgdata, "LBUG\n");
  96
  97         if (in_interrupt()) {
  98                 panic("LBUG in interrupt.\n");
  99                 /* not reached */
 100         }
 101
 102         libcfs_debug_dumpstack(NULL);
 103         if (libcfs_panic_on_lbug)
 104                 panic("LBUG");
 105         else
 106                 libcfs_debug_dumplog();
 107         set_current_state(TASK_UNINTERRUPTIBLE);
 108         while (1)
 109                 schedule();
 110 }
 111 EXPORT_SYMBOL(lbug_with_loc);
 112
 113 #ifdef CONFIG_STACKTRACE
 114
 115 #ifndef HAVE_SAVE_STACK_TRACE_TSK
 116 #define save_stack_trace_tsk(tsk, trace)                                       \
 117 do {                                                                           \
 118         if (tsk == current)                                                    \
 119                 save_stack_trace(trace);                                       \
 120         else                                                                   \
 121                 pr_info("No stack, save_stack_trace_tsk() not exported\n");    \
 122 } while (0)
 123 #endif
 124
 125 #define MAX_ST_ENTRIES  100
 126 static DEFINE_SPINLOCK(st_lock);
 127
 128 /*
 129  * Linux v5.1-rc5 214d8ca6ee ("stacktrace: Provide common infrastructure")
 130  * CONFIG_ARCH_STACKWALK indicates that save_stack_trace_tsk symbol is not
 131  * exported. Use symbol_get() to find if save_stack_trace_tsk is available.
 132  */
 133 #ifdef CONFIG_ARCH_STACKWALK
 134 typedef unsigned int (stack_trace_save_tsk_t)(struct task_struct *task,
 135                 unsigned long *store, unsigned int size,
 136                 unsigned int skipnr);
 137 static stack_trace_save_tsk_t *task_dump_stack;
 138 #endif
 139
 140 static void libcfs_call_trace(struct task_struct *tsk)
 141 {
 142 #ifdef CONFIG_ARCH_STACKWALK
 143         static unsigned long entries[MAX_ST_ENTRIES];
 144         unsigned int i, nr_entries;
 145
 146         if (!task_dump_stack)
 147                 task_dump_stack = (stack_trace_save_tsk_t *)
 148                         symbol_get("stack_trace_save_tsk");
 149
 150         spin_lock(&st_lock);
 151         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 152                init_utsname()->release, init_utsname()->version);
 153         pr_info("Call Trace TBD:\n");
 154         if (task_dump_stack) {
 155                 nr_entries = task_dump_stack(tsk, entries, MAX_ST_ENTRIES, 0);
 156                 for (i = 0; i < nr_entries; i++)
 157                         pr_info("[<0>] %pB\n", (void *)entries[i]);
 158         }
 159         spin_unlock(&st_lock);
 160 #else
 161         struct stack_trace trace;
 162         static unsigned long entries[MAX_ST_ENTRIES];
 163
 164         trace.nr_entries = 0;
 165         trace.max_entries = MAX_ST_ENTRIES;
 166         trace.entries = entries;
 167         trace.skip = 0;
 168
 169         spin_lock(&st_lock);
 170         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 171                init_utsname()->release, init_utsname()->version);
 172         pr_info("Call Trace:\n");
 173         save_stack_trace_tsk(tsk, &trace);
 174         print_stack_trace(&trace, 0);
 175         spin_unlock(&st_lock);
 176 #endif
 177 }
 178
 179 #else /* !CONFIG_STACKTRACE */
 180
 181 #ifdef CONFIG_X86
 182 #include <linux/nmi.h>
 183 #include <asm/stacktrace.h>
 184
 185 #ifdef HAVE_STACKTRACE_OPS
 186 #ifdef HAVE_STACKTRACE_WARNING
 187 static void
 188 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
 189 {
 190         printk("%s", (char *)data);
 191         print_symbol(msg, symbol);
 192         printk("\n");
 193 }
 194
 195 static void print_trace_warning(void *data, char *msg)
 196 {
 197         printk("%s%s\n", (char *)data, msg);
 198 }
 199 #endif
 200
 201 static int print_trace_stack(void *data, char *name)
 202 {
 203         printk(" <%s> ", name);
 204         return 0;
 205 }
 206
 207 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 208 static int
 209 #else
 210 static void
 211 #endif
 212 print_trace_address(void *data, unsigned long addr, int reliable)
 213 {
 214         char fmt[32];
 215
 216         touch_nmi_watchdog();
 217         sprintf(fmt, " [<%016lx>] %s%%s\n", addr, reliable ? "": "? ");
 218         __print_symbol(fmt, addr);
 219 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 220         return 0;
 221 #endif
 222 }
 223
 224 static const struct stacktrace_ops print_trace_ops = {
 225 #ifdef HAVE_STACKTRACE_WARNING
 226         .warning = print_trace_warning,
 227         .warning_symbol = print_trace_warning_symbol,
 228 #endif
 229         .stack = print_trace_stack,
 230         .address = print_trace_address,
 231 #ifdef STACKTRACE_OPS_HAVE_WALK_STACK
 232         .walk_stack = print_context_stack,
 233 #endif
 234 };
 235 #endif /* HAVE_STACKTRACE_OPS */
 236
 237 static void libcfs_call_trace(struct task_struct *tsk)
 238 {
 239 #ifdef HAVE_STACKTRACE_OPS
 240         printk("Pid: %d, comm: %.20s\n", tsk->pid, tsk->comm);
 241         printk("\nCall Trace:\n");
 242         dump_trace(tsk, NULL, NULL,
 243 #ifdef HAVE_DUMP_TRACE_ADDRESS
 244                    0,
 245 #endif /* HAVE_DUMP_TRACE_ADDRESS */
 246                    &print_trace_ops, NULL);
 247         printk("\n");
 248 #else /* !HAVE_STACKTRACE_OPS */
 249         if (tsk == current)
 250                 dump_stack();
 251         else
 252                 CWARN("can't show stack: kernel doesn't export show_task\n");
 253 #endif /* HAVE_STACKTRACE_OPS */
 254 }
 255
 256 #else /* !CONFIG_X86 */
 257
 258 static void libcfs_call_trace(struct task_struct *tsk)
 259 {
 260         if (tsk == current)
 261                 dump_stack();
 262         else
 263                 CWARN("can't show stack: kernel doesn't export show_task\n");
 264 }
 265
 266 #endif /* CONFIG_X86 */
 267
 268 #endif /* CONFIG_STACKTRACE */
 269
 270 void libcfs_debug_dumpstack(struct task_struct *tsk)
 271 {
 272         libcfs_call_trace(tsk ?: current);
 273 }
 274 EXPORT_SYMBOL(libcfs_debug_dumpstack);
 275
 276 static int panic_notifier(struct notifier_block *self, unsigned long unused1,
 277                          void *unused2)
 278 {
 279         if (libcfs_panic_in_progress)
 280                 return 0;
 281
 282         libcfs_panic_in_progress = 1;
 283         mb();
 284
 285 #ifdef LNET_DUMP_ON_PANIC
 286         /* This is currently disabled because it spews far too much to the
 287          * console on the rare cases it is ever triggered. */
 288
 289         if (in_interrupt()) {
 290                 cfs_trace_debug_print();
 291         } else {
 292                 libcfs_debug_dumplog_internal((void *)(long)current_pid());
 293         }
 294 #endif
 295         return 0;
 296 }
 297
 298 static struct notifier_block libcfs_panic_notifier = {
 299         .notifier_call  = panic_notifier,
 300         .next           = NULL,
 301         .priority       = 10000
 302 };
 303
 304 void libcfs_register_panic_notifier(void)
 305 {
 306         atomic_notifier_chain_register(&panic_notifier_list, &libcfs_panic_notifier);
 307 }
 308
 309 void libcfs_unregister_panic_notifier(void)
 310 {
 311         atomic_notifier_chain_unregister(&panic_notifier_list, &libcfs_panic_notifier);
 312 }