| 1 | /* |
| 2 | * lttng-statedump.c |
| 3 | * |
| 4 | * Linux Trace Toolkit Next Generation Kernel State Dump |
| 5 | * |
| 6 | * Copyright 2005 Jean-Hugues Deschenes <jean-hugues.deschenes@polymtl.ca> |
| 7 | * Copyright 2006-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 8 | * |
| 9 | * This library is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU Lesser General Public |
| 11 | * License as published by the Free Software Foundation; only |
| 12 | * version 2.1 of the License. |
| 13 | * |
| 14 | * This library is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 17 | * Lesser General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Lesser General Public |
| 20 | * License along with this library; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 22 | * |
| 23 | * Changes: |
| 24 | * Eric Clement: Add listing of network IP interface |
| 25 | * 2006, 2007 Mathieu Desnoyers Fix kernel threads |
| 26 | * Various updates |
| 27 | */ |
| 28 | |
| 29 | #include <linux/init.h> |
| 30 | #include <linux/module.h> |
| 31 | #include <linux/netlink.h> |
| 32 | #include <linux/inet.h> |
| 33 | #include <linux/ip.h> |
| 34 | #include <linux/kthread.h> |
| 35 | #include <linux/proc_fs.h> |
| 36 | #include <linux/file.h> |
| 37 | #include <linux/interrupt.h> |
| 38 | #include <linux/irqnr.h> |
| 39 | #include <linux/cpu.h> |
| 40 | #include <linux/netdevice.h> |
| 41 | #include <linux/inetdevice.h> |
| 42 | #include <linux/sched.h> |
| 43 | #include <linux/mm.h> |
| 44 | #include <linux/fdtable.h> |
| 45 | #include <linux/swap.h> |
| 46 | #include <linux/wait.h> |
| 47 | #include <linux/mutex.h> |
| 48 | |
| 49 | #include "lttng-events.h" |
| 50 | #include "wrapper/irqdesc.h" |
| 51 | #include "wrapper/spinlock.h" |
| 52 | |
| 53 | #ifdef CONFIG_GENERIC_HARDIRQS |
| 54 | #include <linux/irq.h> |
| 55 | #endif |
| 56 | |
| 57 | /* Define the tracepoints, but do not build the probes */ |
| 58 | #define CREATE_TRACE_POINTS |
| 59 | #define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module |
| 60 | #define TRACE_INCLUDE_FILE lttng-statedump |
| 61 | #include "instrumentation/events/lttng-module/lttng-statedump.h" |
| 62 | |
| 63 | /* |
| 64 | * Protected by the trace lock. |
| 65 | */ |
| 66 | static struct delayed_work cpu_work[NR_CPUS]; |
| 67 | static DECLARE_WAIT_QUEUE_HEAD(statedump_wq); |
| 68 | static atomic_t kernel_threads_to_run; |
| 69 | |
| 70 | enum lttng_thread_type { |
| 71 | LTTNG_USER_THREAD = 0, |
| 72 | LTTNG_KERNEL_THREAD = 1, |
| 73 | }; |
| 74 | |
| 75 | enum lttng_execution_mode { |
| 76 | LTTNG_USER_MODE = 0, |
| 77 | LTTNG_SYSCALL = 1, |
| 78 | LTTNG_TRAP = 2, |
| 79 | LTTNG_IRQ = 3, |
| 80 | LTTNG_SOFTIRQ = 4, |
| 81 | LTTNG_MODE_UNKNOWN = 5, |
| 82 | }; |
| 83 | |
| 84 | enum lttng_execution_submode { |
| 85 | LTTNG_NONE = 0, |
| 86 | LTTNG_UNKNOWN = 1, |
| 87 | }; |
| 88 | |
| 89 | enum lttng_process_status { |
| 90 | LTTNG_UNNAMED = 0, |
| 91 | LTTNG_WAIT_FORK = 1, |
| 92 | LTTNG_WAIT_CPU = 2, |
| 93 | LTTNG_EXIT = 3, |
| 94 | LTTNG_ZOMBIE = 4, |
| 95 | LTTNG_WAIT = 5, |
| 96 | LTTNG_RUN = 6, |
| 97 | LTTNG_DEAD = 7, |
| 98 | }; |
| 99 | |
| 100 | #ifdef CONFIG_INET |
| 101 | static |
| 102 | void lttng_enumerate_device(struct lttng_session *session, |
| 103 | struct net_device *dev) |
| 104 | { |
| 105 | struct in_device *in_dev; |
| 106 | struct in_ifaddr *ifa; |
| 107 | |
| 108 | if (dev->flags & IFF_UP) { |
| 109 | in_dev = in_dev_get(dev); |
| 110 | if (in_dev) { |
| 111 | for (ifa = in_dev->ifa_list; ifa != NULL; |
| 112 | ifa = ifa->ifa_next) { |
| 113 | trace_lttng_statedump_network_interface( |
| 114 | session, dev, ifa); |
| 115 | } |
| 116 | in_dev_put(in_dev); |
| 117 | } |
| 118 | } else { |
| 119 | trace_lttng_statedump_network_interface( |
| 120 | session, dev, NULL); |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | static |
| 125 | int lttng_enumerate_network_ip_interface(struct lttng_session *session) |
| 126 | { |
| 127 | struct net_device *dev; |
| 128 | |
| 129 | read_lock(&dev_base_lock); |
| 130 | for_each_netdev(&init_net, dev) |
| 131 | lttng_enumerate_device(session, dev); |
| 132 | read_unlock(&dev_base_lock); |
| 133 | |
| 134 | return 0; |
| 135 | } |
| 136 | #else /* CONFIG_INET */ |
| 137 | static inline |
| 138 | int lttng_enumerate_network_ip_interface(struct lttng_session *session) |
| 139 | { |
| 140 | return 0; |
| 141 | } |
| 142 | #endif /* CONFIG_INET */ |
| 143 | |
| 144 | |
| 145 | static |
| 146 | void lttng_enumerate_task_fd(struct lttng_session *session, |
| 147 | struct task_struct *p, char *tmp) |
| 148 | { |
| 149 | struct fdtable *fdt; |
| 150 | struct file *filp; |
| 151 | unsigned int i; |
| 152 | const unsigned char *path; |
| 153 | |
| 154 | task_lock(p); |
| 155 | if (!p->files) |
| 156 | goto unlock_task; |
| 157 | spin_lock(&p->files->file_lock); |
| 158 | fdt = files_fdtable(p->files); |
| 159 | for (i = 0; i < fdt->max_fds; i++) { |
| 160 | filp = fcheck_files(p->files, i); |
| 161 | if (!filp) |
| 162 | continue; |
| 163 | path = d_path(&filp->f_path, tmp, PAGE_SIZE); |
| 164 | /* Make sure we give at least some info */ |
| 165 | trace_lttng_statedump_file_descriptor(session, p, i, |
| 166 | IS_ERR(path) ? |
| 167 | filp->f_dentry->d_name.name : |
| 168 | path); |
| 169 | } |
| 170 | spin_unlock(&p->files->file_lock); |
| 171 | unlock_task: |
| 172 | task_unlock(p); |
| 173 | } |
| 174 | |
| 175 | static |
| 176 | int lttng_enumerate_file_descriptors(struct lttng_session *session) |
| 177 | { |
| 178 | struct task_struct *p; |
| 179 | char *tmp = (char *) __get_free_page(GFP_KERNEL); |
| 180 | |
| 181 | /* Enumerate active file descriptors */ |
| 182 | rcu_read_lock(); |
| 183 | for_each_process(p) |
| 184 | lttng_enumerate_task_fd(session, p, tmp); |
| 185 | rcu_read_unlock(); |
| 186 | free_page((unsigned long) tmp); |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | #if 0 |
| 191 | /* |
| 192 | * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section |
| 193 | * (scheduling in atomic). Normally, the tasklist lock protects this kind of |
| 194 | * iteration, but it is not exported to modules. |
| 195 | */ |
| 196 | static |
| 197 | void lttng_enumerate_task_vm_maps(struct lttng_session *session, |
| 198 | struct task_struct *p) |
| 199 | { |
| 200 | struct mm_struct *mm; |
| 201 | struct vm_area_struct *map; |
| 202 | unsigned long ino; |
| 203 | |
| 204 | /* get_task_mm does a task_lock... */ |
| 205 | mm = get_task_mm(p); |
| 206 | if (!mm) |
| 207 | return; |
| 208 | |
| 209 | map = mm->mmap; |
| 210 | if (map) { |
| 211 | down_read(&mm->mmap_sem); |
| 212 | while (map) { |
| 213 | if (map->vm_file) |
| 214 | ino = map->vm_file->f_dentry->d_inode->i_ino; |
| 215 | else |
| 216 | ino = 0; |
| 217 | trace_lttng_statedump_vm_map(session, p, map, ino); |
| 218 | map = map->vm_next; |
| 219 | } |
| 220 | up_read(&mm->mmap_sem); |
| 221 | } |
| 222 | mmput(mm); |
| 223 | } |
| 224 | |
| 225 | static |
| 226 | int lttng_enumerate_vm_maps(struct lttng_session *session) |
| 227 | { |
| 228 | struct task_struct *p; |
| 229 | |
| 230 | rcu_read_lock(); |
| 231 | for_each_process(p) |
| 232 | lttng_enumerate_task_vm_maps(session, p); |
| 233 | rcu_read_unlock(); |
| 234 | return 0; |
| 235 | } |
| 236 | #endif |
| 237 | |
| 238 | #ifdef CONFIG_GENERIC_HARDIRQS |
| 239 | |
| 240 | #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)) |
| 241 | #define irq_desc_get_chip(desc) get_irq_desc_chip(desc) |
| 242 | #endif |
| 243 | |
| 244 | static |
| 245 | void lttng_list_interrupts(struct lttng_session *session) |
| 246 | { |
| 247 | unsigned int irq; |
| 248 | unsigned long flags = 0; |
| 249 | struct irq_desc *desc; |
| 250 | |
| 251 | #define irq_to_desc wrapper_irq_to_desc |
| 252 | /* needs irq_desc */ |
| 253 | for_each_irq_desc(irq, desc) { |
| 254 | struct irqaction *action; |
| 255 | const char *irq_chip_name = |
| 256 | irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip"; |
| 257 | |
| 258 | local_irq_save(flags); |
| 259 | wrapper_desc_spin_lock(&desc->lock); |
| 260 | for (action = desc->action; action; action = action->next) { |
| 261 | trace_lttng_statedump_interrupt(session, |
| 262 | irq, irq_chip_name, action); |
| 263 | } |
| 264 | wrapper_desc_spin_unlock(&desc->lock); |
| 265 | local_irq_restore(flags); |
| 266 | } |
| 267 | #undef irq_to_desc |
| 268 | } |
| 269 | #else |
| 270 | static inline |
| 271 | void list_interrupts(struct lttng_session *session) |
| 272 | { |
| 273 | } |
| 274 | #endif |
| 275 | |
| 276 | static |
| 277 | void lttng_statedump_process_ns(struct lttng_session *session, |
| 278 | struct task_struct *p, |
| 279 | enum lttng_thread_type type, |
| 280 | enum lttng_execution_mode mode, |
| 281 | enum lttng_execution_submode submode, |
| 282 | enum lttng_process_status status) |
| 283 | { |
| 284 | struct nsproxy *proxy; |
| 285 | struct pid_namespace *pid_ns; |
| 286 | |
| 287 | rcu_read_lock(); |
| 288 | proxy = task_nsproxy(p); |
| 289 | if (proxy) { |
| 290 | pid_ns = proxy->pid_ns; |
| 291 | do { |
| 292 | trace_lttng_statedump_process_state(session, |
| 293 | p, type, mode, submode, status, pid_ns); |
| 294 | pid_ns = pid_ns->parent; |
| 295 | } while (pid_ns); |
| 296 | } else { |
| 297 | trace_lttng_statedump_process_state(session, |
| 298 | p, type, mode, submode, status, NULL); |
| 299 | } |
| 300 | rcu_read_unlock(); |
| 301 | } |
| 302 | |
| 303 | static |
| 304 | int lttng_enumerate_process_states(struct lttng_session *session) |
| 305 | { |
| 306 | struct task_struct *g, *p; |
| 307 | |
| 308 | rcu_read_lock(); |
| 309 | for_each_process(g) { |
| 310 | p = g; |
| 311 | do { |
| 312 | enum lttng_execution_mode mode = |
| 313 | LTTNG_MODE_UNKNOWN; |
| 314 | enum lttng_execution_submode submode = |
| 315 | LTTNG_UNKNOWN; |
| 316 | enum lttng_process_status status; |
| 317 | enum lttng_thread_type type; |
| 318 | |
| 319 | task_lock(p); |
| 320 | if (p->exit_state == EXIT_ZOMBIE) |
| 321 | status = LTTNG_ZOMBIE; |
| 322 | else if (p->exit_state == EXIT_DEAD) |
| 323 | status = LTTNG_DEAD; |
| 324 | else if (p->state == TASK_RUNNING) { |
| 325 | /* Is this a forked child that has not run yet? */ |
| 326 | if (list_empty(&p->rt.run_list)) |
| 327 | status = LTTNG_WAIT_FORK; |
| 328 | else |
| 329 | /* |
| 330 | * All tasks are considered as wait_cpu; |
| 331 | * the viewer will sort out if the task |
| 332 | * was really running at this time. |
| 333 | */ |
| 334 | status = LTTNG_WAIT_CPU; |
| 335 | } else if (p->state & |
| 336 | (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) { |
| 337 | /* Task is waiting for something to complete */ |
| 338 | status = LTTNG_WAIT; |
| 339 | } else |
| 340 | status = LTTNG_UNNAMED; |
| 341 | submode = LTTNG_NONE; |
| 342 | |
| 343 | /* |
| 344 | * Verification of t->mm is to filter out kernel |
| 345 | * threads; Viewer will further filter out if a |
| 346 | * user-space thread was in syscall mode or not. |
| 347 | */ |
| 348 | if (p->mm) |
| 349 | type = LTTNG_USER_THREAD; |
| 350 | else |
| 351 | type = LTTNG_KERNEL_THREAD; |
| 352 | lttng_statedump_process_ns(session, |
| 353 | p, type, mode, submode, status); |
| 354 | task_unlock(p); |
| 355 | } while_each_thread(g, p); |
| 356 | } |
| 357 | rcu_read_unlock(); |
| 358 | |
| 359 | return 0; |
| 360 | } |
| 361 | |
| 362 | static |
| 363 | void lttng_statedump_work_func(struct work_struct *work) |
| 364 | { |
| 365 | if (atomic_dec_and_test(&kernel_threads_to_run)) |
| 366 | /* If we are the last thread, wake up do_lttng_statedump */ |
| 367 | wake_up(&statedump_wq); |
| 368 | } |
| 369 | |
| 370 | static |
| 371 | int do_lttng_statedump(struct lttng_session *session) |
| 372 | { |
| 373 | int cpu; |
| 374 | |
| 375 | printk(KERN_DEBUG "LTT state dump thread start\n"); |
| 376 | trace_lttng_statedump_start(session); |
| 377 | lttng_enumerate_process_states(session); |
| 378 | lttng_enumerate_file_descriptors(session); |
| 379 | /* FIXME lttng_enumerate_vm_maps(session); */ |
| 380 | lttng_list_interrupts(session); |
| 381 | lttng_enumerate_network_ip_interface(session); |
| 382 | |
| 383 | /* TODO lttng_dump_idt_table(session); */ |
| 384 | /* TODO lttng_dump_softirq_vec(session); */ |
| 385 | /* TODO lttng_list_modules(session); */ |
| 386 | /* TODO lttng_dump_swap_files(session); */ |
| 387 | |
| 388 | /* |
| 389 | * Fire off a work queue on each CPU. Their sole purpose in life |
| 390 | * is to guarantee that each CPU has been in a state where is was in |
| 391 | * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ). |
| 392 | */ |
| 393 | get_online_cpus(); |
| 394 | atomic_set(&kernel_threads_to_run, num_online_cpus()); |
| 395 | for_each_online_cpu(cpu) { |
| 396 | INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func); |
| 397 | schedule_delayed_work_on(cpu, &cpu_work[cpu], 0); |
| 398 | } |
| 399 | /* Wait for all threads to run */ |
| 400 | wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) != 0)); |
| 401 | put_online_cpus(); |
| 402 | /* Our work is done */ |
| 403 | printk(KERN_DEBUG "LTT state dump end\n"); |
| 404 | trace_lttng_statedump_end(session); |
| 405 | return 0; |
| 406 | } |
| 407 | |
| 408 | /* |
| 409 | * Called with session mutex held. |
| 410 | */ |
| 411 | int lttng_statedump_start(struct lttng_session *session) |
| 412 | { |
| 413 | printk(KERN_DEBUG "LTTng: state dump begin\n"); |
| 414 | return do_lttng_statedump(session); |
| 415 | } |
| 416 | EXPORT_SYMBOL_GPL(lttng_statedump_start); |
| 417 | |
| 418 | MODULE_LICENSE("GPL and additional rights"); |
| 419 | MODULE_AUTHOR("Jean-Hugues Deschenes"); |
| 420 | MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Statedump"); |