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 /*
 132  * Linux v5.1-rc5 214d8ca6ee ("stacktrace: Provide common infrastructure")
 133  * CONFIG_ARCH_STACKWALK indicates that save_stack_trace_tsk symbol is not
 134  * exported. Use symbol_get() to find if save_stack_trace_tsk is available.
 135  */
 136 #ifdef CONFIG_ARCH_STACKWALK
 137 typedef unsigned int (stack_trace_save_tsk_t)(struct task_struct *task,
 138                 unsigned long *store, unsigned int size,
 139                 unsigned int skipnr);
 140 static stack_trace_save_tsk_t *task_dump_stack;
 141 #endif
 142
 143 static void libcfs_call_trace(struct task_struct *tsk)
 144 {
 145 #ifdef CONFIG_ARCH_STACKWALK
 146         static unsigned long entries[MAX_ST_ENTRIES];
 147         unsigned int i, nr_entries;
 148
 149         if (!task_dump_stack)
 150                 task_dump_stack = (stack_trace_save_tsk_t *)
 151                         symbol_get("stack_trace_save_tsk");
 152
 153         spin_lock(&st_lock);
 154         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 155                init_utsname()->release, init_utsname()->version);
 156         pr_info("Call Trace TBD:\n");
 157         if (task_dump_stack) {
 158                 nr_entries = task_dump_stack(tsk, entries, MAX_ST_ENTRIES, 0);
 159                 for (i = 0; i < nr_entries; i++)
 160                         pr_info("[<0>] %pB\n", (void *)entries[i]);
 161         }
 162         spin_unlock(&st_lock);
 163 #else
 164         struct stack_trace trace;
 165         static unsigned long entries[MAX_ST_ENTRIES];
 166
 167         trace.nr_entries = 0;
 168         trace.max_entries = MAX_ST_ENTRIES;
 169         trace.entries = entries;
 170         trace.skip = 0;
 171
 172         spin_lock(&st_lock);
 173         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 174                init_utsname()->release, init_utsname()->version);
 175         pr_info("Call Trace:\n");
 176         save_stack_trace_tsk(tsk, &trace);
 177         print_stack_trace(&trace, 0);
 178         spin_unlock(&st_lock);
 179 #endif
 180 }
 181
 182 #else /* !CONFIG_STACKTRACE */
 183
 184 #ifdef CONFIG_X86
 185 #include <linux/nmi.h>
 186 #include <asm/stacktrace.h>
 187
 188 #ifdef HAVE_STACKTRACE_OPS
 189 #ifdef HAVE_STACKTRACE_WARNING
 190 static void
 191 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
 192 {
 193         printk("%s", (char *)data);
 194         print_symbol(msg, symbol);
 195         printk("\n");
 196 }
 197
 198 static void print_trace_warning(void *data, char *msg)
 199 {
 200         printk("%s%s\n", (char *)data, msg);
 201 }
 202 #endif
 203
 204 static int print_trace_stack(void *data, char *name)
 205 {
 206         printk(" <%s> ", name);
 207         return 0;
 208 }
 209
 210 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 211 static int
 212 #else
 213 static void
 214 #endif
 215 print_trace_address(void *data, unsigned long addr, int reliable)
 216 {
 217         char fmt[32];
 218
 219         touch_nmi_watchdog();
 220         sprintf(fmt, " [<%016lx>] %s%%s\n", addr, reliable ? "": "? ");
 221         __print_symbol(fmt, addr);
 222 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 223         return 0;
 224 #endif
 225 }
 226
 227 static const struct stacktrace_ops print_trace_ops = {
 228 #ifdef HAVE_STACKTRACE_WARNING
 229         .warning = print_trace_warning,
 230         .warning_symbol = print_trace_warning_symbol,
 231 #endif
 232         .stack = print_trace_stack,
 233         .address = print_trace_address,
 234 #ifdef STACKTRACE_OPS_HAVE_WALK_STACK
 235         .walk_stack = print_context_stack,
 236 #endif
 237 };
 238 #endif /* HAVE_STACKTRACE_OPS */
 239
 240 static void libcfs_call_trace(struct task_struct *tsk)
 241 {
 242 #ifdef HAVE_STACKTRACE_OPS
 243         printk("Pid: %d, comm: %.20s\n", tsk->pid, tsk->comm);
 244         printk("\nCall Trace:\n");
 245         dump_trace(tsk, NULL, NULL,
 246 #ifdef HAVE_DUMP_TRACE_ADDRESS
 247                    0,
 248 #endif /* HAVE_DUMP_TRACE_ADDRESS */
 249                    &print_trace_ops, NULL);
 250         printk("\n");
 251 #else /* !HAVE_STACKTRACE_OPS */
 252         if (tsk == current)
 253                 dump_stack();
 254         else
 255                 CWARN("can't show stack: kernel doesn't export show_task\n");
 256 #endif /* HAVE_STACKTRACE_OPS */
 257 }
 258
 259 #else /* !CONFIG_X86 */
 260
 261 static void libcfs_call_trace(struct task_struct *tsk)
 262 {
 263         if (tsk == current)
 264                 dump_stack();
 265         else
 266                 CWARN("can't show stack: kernel doesn't export show_task\n");
 267 }
 268
 269 #endif /* CONFIG_X86 */
 270
 271 #endif /* CONFIG_STACKTRACE */
 272
 273 void libcfs_debug_dumpstack(struct task_struct *tsk)
 274 {
 275         libcfs_call_trace(tsk ?: current);
 276 }
 277 EXPORT_SYMBOL(libcfs_debug_dumpstack);
 278
 279 static int panic_notifier(struct notifier_block *self, unsigned long unused1,
 280                          void *unused2)
 281 {
 282         if (libcfs_panic_in_progress)
 283                 return 0;
 284
 285         libcfs_panic_in_progress = 1;
 286         mb();
 287
 288 #ifdef LNET_DUMP_ON_PANIC
 289         /* This is currently disabled because it spews far too much to the
 290          * console on the rare cases it is ever triggered. */
 291
 292         if (in_interrupt()) {
 293                 cfs_trace_debug_print();
 294         } else {
 295 #ifdef HAVE_KERNEL_LOCKED
 296                 while (kernel_locked())
 297                         unlock_kernel();
 298 #endif
 299                 libcfs_debug_dumplog_internal((void *)(long)current_pid());
 300         }
 301 #endif
 302         return 0;
 303 }
 304
 305 static struct notifier_block libcfs_panic_notifier = {
 306         .notifier_call  = panic_notifier,
 307         .next           = NULL,
 308         .priority       = 10000
 309 };
 310
 311 void libcfs_register_panic_notifier(void)
 312 {
 313         atomic_notifier_chain_register(&panic_notifier_list, &libcfs_panic_notifier);
 314 }
 315
 316 void libcfs_unregister_panic_notifier(void)
 317 {
 318         atomic_notifier_chain_unregister(&panic_notifier_list, &libcfs_panic_notifier);
 319 }