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c337ddc2 | 1 | /* |
886d51a3 MD |
2 | * lttng-statedump.c |
3 | * | |
c337ddc2 MD |
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 | * | |
886d51a3 MD |
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 | * | |
c337ddc2 MD |
23 | * Changes: |
24 | * Eric Clement: Add listing of network IP interface | |
25 | * 2006, 2007 Mathieu Desnoyers Fix kernel threads | |
26 | * Various updates | |
c337ddc2 MD |
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" | |
3a523f5b | 51 | #include "wrapper/spinlock.h" |
c337ddc2 MD |
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 | ||
0658bdda MD |
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 | */ | |
c337ddc2 MD |
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 | } | |
0658bdda | 236 | #endif |
c337ddc2 MD |
237 | |
238 | #ifdef CONFIG_GENERIC_HARDIRQS | |
47faec4b JN |
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 | ||
c337ddc2 MD |
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); | |
3a523f5b | 259 | wrapper_desc_spin_lock(&desc->lock); |
c337ddc2 MD |
260 | for (action = desc->action; action; action = action->next) { |
261 | trace_lttng_statedump_interrupt(session, | |
262 | irq, irq_chip_name, action); | |
263 | } | |
3a523f5b | 264 | wrapper_desc_spin_unlock(&desc->lock); |
c337ddc2 MD |
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 | ||
73e8ba37 JD |
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); | |
af73f727 | 294 | pid_ns = pid_ns->parent; |
73e8ba37 JD |
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 | ||
c337ddc2 MD |
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; | |
73e8ba37 | 352 | lttng_statedump_process_ns(session, |
c337ddc2 MD |
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); | |
0658bdda | 379 | /* FIXME lttng_enumerate_vm_maps(session); */ |
c337ddc2 MD |
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"); |