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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" | |
51 | ||
52 | #ifdef CONFIG_GENERIC_HARDIRQS | |
53 | #include <linux/irq.h> | |
54 | #endif | |
55 | ||
56 | /* Define the tracepoints, but do not build the probes */ | |
57 | #define CREATE_TRACE_POINTS | |
58 | #define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module | |
59 | #define TRACE_INCLUDE_FILE lttng-statedump | |
60 | #include "instrumentation/events/lttng-module/lttng-statedump.h" | |
61 | ||
62 | /* | |
63 | * Protected by the trace lock. | |
64 | */ | |
65 | static struct delayed_work cpu_work[NR_CPUS]; | |
66 | static DECLARE_WAIT_QUEUE_HEAD(statedump_wq); | |
67 | static atomic_t kernel_threads_to_run; | |
68 | ||
69 | enum lttng_thread_type { | |
70 | LTTNG_USER_THREAD = 0, | |
71 | LTTNG_KERNEL_THREAD = 1, | |
72 | }; | |
73 | ||
74 | enum lttng_execution_mode { | |
75 | LTTNG_USER_MODE = 0, | |
76 | LTTNG_SYSCALL = 1, | |
77 | LTTNG_TRAP = 2, | |
78 | LTTNG_IRQ = 3, | |
79 | LTTNG_SOFTIRQ = 4, | |
80 | LTTNG_MODE_UNKNOWN = 5, | |
81 | }; | |
82 | ||
83 | enum lttng_execution_submode { | |
84 | LTTNG_NONE = 0, | |
85 | LTTNG_UNKNOWN = 1, | |
86 | }; | |
87 | ||
88 | enum lttng_process_status { | |
89 | LTTNG_UNNAMED = 0, | |
90 | LTTNG_WAIT_FORK = 1, | |
91 | LTTNG_WAIT_CPU = 2, | |
92 | LTTNG_EXIT = 3, | |
93 | LTTNG_ZOMBIE = 4, | |
94 | LTTNG_WAIT = 5, | |
95 | LTTNG_RUN = 6, | |
96 | LTTNG_DEAD = 7, | |
97 | }; | |
98 | ||
99 | #ifdef CONFIG_INET | |
100 | static | |
101 | void lttng_enumerate_device(struct lttng_session *session, | |
102 | struct net_device *dev) | |
103 | { | |
104 | struct in_device *in_dev; | |
105 | struct in_ifaddr *ifa; | |
106 | ||
107 | if (dev->flags & IFF_UP) { | |
108 | in_dev = in_dev_get(dev); | |
109 | if (in_dev) { | |
110 | for (ifa = in_dev->ifa_list; ifa != NULL; | |
111 | ifa = ifa->ifa_next) { | |
112 | trace_lttng_statedump_network_interface( | |
113 | session, dev, ifa); | |
114 | } | |
115 | in_dev_put(in_dev); | |
116 | } | |
117 | } else { | |
118 | trace_lttng_statedump_network_interface( | |
119 | session, dev, NULL); | |
120 | } | |
121 | } | |
122 | ||
123 | static | |
124 | int lttng_enumerate_network_ip_interface(struct lttng_session *session) | |
125 | { | |
126 | struct net_device *dev; | |
127 | ||
128 | read_lock(&dev_base_lock); | |
129 | for_each_netdev(&init_net, dev) | |
130 | lttng_enumerate_device(session, dev); | |
131 | read_unlock(&dev_base_lock); | |
132 | ||
133 | return 0; | |
134 | } | |
135 | #else /* CONFIG_INET */ | |
136 | static inline | |
137 | int lttng_enumerate_network_ip_interface(struct lttng_session *session) | |
138 | { | |
139 | return 0; | |
140 | } | |
141 | #endif /* CONFIG_INET */ | |
142 | ||
143 | ||
144 | static | |
145 | void lttng_enumerate_task_fd(struct lttng_session *session, | |
146 | struct task_struct *p, char *tmp) | |
147 | { | |
148 | struct fdtable *fdt; | |
149 | struct file *filp; | |
150 | unsigned int i; | |
151 | const unsigned char *path; | |
152 | ||
153 | task_lock(p); | |
154 | if (!p->files) | |
155 | goto unlock_task; | |
156 | spin_lock(&p->files->file_lock); | |
157 | fdt = files_fdtable(p->files); | |
158 | for (i = 0; i < fdt->max_fds; i++) { | |
159 | filp = fcheck_files(p->files, i); | |
160 | if (!filp) | |
161 | continue; | |
162 | path = d_path(&filp->f_path, tmp, PAGE_SIZE); | |
163 | /* Make sure we give at least some info */ | |
164 | trace_lttng_statedump_file_descriptor(session, p, i, | |
165 | IS_ERR(path) ? | |
166 | filp->f_dentry->d_name.name : | |
167 | path); | |
168 | } | |
169 | spin_unlock(&p->files->file_lock); | |
170 | unlock_task: | |
171 | task_unlock(p); | |
172 | } | |
173 | ||
174 | static | |
175 | int lttng_enumerate_file_descriptors(struct lttng_session *session) | |
176 | { | |
177 | struct task_struct *p; | |
178 | char *tmp = (char *) __get_free_page(GFP_KERNEL); | |
179 | ||
180 | /* Enumerate active file descriptors */ | |
181 | rcu_read_lock(); | |
182 | for_each_process(p) | |
183 | lttng_enumerate_task_fd(session, p, tmp); | |
184 | rcu_read_unlock(); | |
185 | free_page((unsigned long) tmp); | |
186 | return 0; | |
187 | } | |
188 | ||
0658bdda MD |
189 | #if 0 |
190 | /* | |
191 | * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section | |
192 | * (scheduling in atomic). Normally, the tasklist lock protects this kind of | |
193 | * iteration, but it is not exported to modules. | |
194 | */ | |
c337ddc2 MD |
195 | static |
196 | void lttng_enumerate_task_vm_maps(struct lttng_session *session, | |
197 | struct task_struct *p) | |
198 | { | |
199 | struct mm_struct *mm; | |
200 | struct vm_area_struct *map; | |
201 | unsigned long ino; | |
202 | ||
203 | /* get_task_mm does a task_lock... */ | |
204 | mm = get_task_mm(p); | |
205 | if (!mm) | |
206 | return; | |
207 | ||
208 | map = mm->mmap; | |
209 | if (map) { | |
210 | down_read(&mm->mmap_sem); | |
211 | while (map) { | |
212 | if (map->vm_file) | |
213 | ino = map->vm_file->f_dentry->d_inode->i_ino; | |
214 | else | |
215 | ino = 0; | |
216 | trace_lttng_statedump_vm_map(session, p, map, ino); | |
217 | map = map->vm_next; | |
218 | } | |
219 | up_read(&mm->mmap_sem); | |
220 | } | |
221 | mmput(mm); | |
222 | } | |
223 | ||
224 | static | |
225 | int lttng_enumerate_vm_maps(struct lttng_session *session) | |
226 | { | |
227 | struct task_struct *p; | |
228 | ||
229 | rcu_read_lock(); | |
230 | for_each_process(p) | |
231 | lttng_enumerate_task_vm_maps(session, p); | |
232 | rcu_read_unlock(); | |
233 | return 0; | |
234 | } | |
0658bdda | 235 | #endif |
c337ddc2 MD |
236 | |
237 | #ifdef CONFIG_GENERIC_HARDIRQS | |
47faec4b JN |
238 | |
239 | #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)) | |
240 | #define irq_desc_get_chip(desc) get_irq_desc_chip(desc) | |
241 | #endif | |
242 | ||
c337ddc2 MD |
243 | static |
244 | void lttng_list_interrupts(struct lttng_session *session) | |
245 | { | |
246 | unsigned int irq; | |
247 | unsigned long flags = 0; | |
248 | struct irq_desc *desc; | |
249 | ||
250 | #define irq_to_desc wrapper_irq_to_desc | |
251 | /* needs irq_desc */ | |
252 | for_each_irq_desc(irq, desc) { | |
253 | struct irqaction *action; | |
254 | const char *irq_chip_name = | |
255 | irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip"; | |
256 | ||
257 | local_irq_save(flags); | |
258 | raw_spin_lock(&desc->lock); | |
259 | for (action = desc->action; action; action = action->next) { | |
260 | trace_lttng_statedump_interrupt(session, | |
261 | irq, irq_chip_name, action); | |
262 | } | |
263 | raw_spin_unlock(&desc->lock); | |
264 | local_irq_restore(flags); | |
265 | } | |
266 | #undef irq_to_desc | |
267 | } | |
268 | #else | |
269 | static inline | |
270 | void list_interrupts(struct lttng_session *session) | |
271 | { | |
272 | } | |
273 | #endif | |
274 | ||
73e8ba37 JD |
275 | static |
276 | void lttng_statedump_process_ns(struct lttng_session *session, | |
277 | struct task_struct *p, | |
278 | enum lttng_thread_type type, | |
279 | enum lttng_execution_mode mode, | |
280 | enum lttng_execution_submode submode, | |
281 | enum lttng_process_status status) | |
282 | { | |
283 | struct nsproxy *proxy; | |
284 | struct pid_namespace *pid_ns; | |
285 | ||
286 | rcu_read_lock(); | |
287 | proxy = task_nsproxy(p); | |
288 | if (proxy) { | |
289 | pid_ns = proxy->pid_ns; | |
290 | do { | |
291 | trace_lttng_statedump_process_state(session, | |
292 | p, type, mode, submode, status, pid_ns); | |
293 | } while (pid_ns); | |
294 | } else { | |
295 | trace_lttng_statedump_process_state(session, | |
296 | p, type, mode, submode, status, NULL); | |
297 | } | |
298 | rcu_read_unlock(); | |
299 | } | |
300 | ||
c337ddc2 MD |
301 | static |
302 | int lttng_enumerate_process_states(struct lttng_session *session) | |
303 | { | |
304 | struct task_struct *g, *p; | |
305 | ||
306 | rcu_read_lock(); | |
307 | for_each_process(g) { | |
308 | p = g; | |
309 | do { | |
310 | enum lttng_execution_mode mode = | |
311 | LTTNG_MODE_UNKNOWN; | |
312 | enum lttng_execution_submode submode = | |
313 | LTTNG_UNKNOWN; | |
314 | enum lttng_process_status status; | |
315 | enum lttng_thread_type type; | |
316 | ||
317 | task_lock(p); | |
318 | if (p->exit_state == EXIT_ZOMBIE) | |
319 | status = LTTNG_ZOMBIE; | |
320 | else if (p->exit_state == EXIT_DEAD) | |
321 | status = LTTNG_DEAD; | |
322 | else if (p->state == TASK_RUNNING) { | |
323 | /* Is this a forked child that has not run yet? */ | |
324 | if (list_empty(&p->rt.run_list)) | |
325 | status = LTTNG_WAIT_FORK; | |
326 | else | |
327 | /* | |
328 | * All tasks are considered as wait_cpu; | |
329 | * the viewer will sort out if the task | |
330 | * was really running at this time. | |
331 | */ | |
332 | status = LTTNG_WAIT_CPU; | |
333 | } else if (p->state & | |
334 | (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) { | |
335 | /* Task is waiting for something to complete */ | |
336 | status = LTTNG_WAIT; | |
337 | } else | |
338 | status = LTTNG_UNNAMED; | |
339 | submode = LTTNG_NONE; | |
340 | ||
341 | /* | |
342 | * Verification of t->mm is to filter out kernel | |
343 | * threads; Viewer will further filter out if a | |
344 | * user-space thread was in syscall mode or not. | |
345 | */ | |
346 | if (p->mm) | |
347 | type = LTTNG_USER_THREAD; | |
348 | else | |
349 | type = LTTNG_KERNEL_THREAD; | |
73e8ba37 | 350 | lttng_statedump_process_ns(session, |
c337ddc2 MD |
351 | p, type, mode, submode, status); |
352 | task_unlock(p); | |
353 | } while_each_thread(g, p); | |
354 | } | |
355 | rcu_read_unlock(); | |
356 | ||
357 | return 0; | |
358 | } | |
359 | ||
360 | static | |
361 | void lttng_statedump_work_func(struct work_struct *work) | |
362 | { | |
363 | if (atomic_dec_and_test(&kernel_threads_to_run)) | |
364 | /* If we are the last thread, wake up do_lttng_statedump */ | |
365 | wake_up(&statedump_wq); | |
366 | } | |
367 | ||
368 | static | |
369 | int do_lttng_statedump(struct lttng_session *session) | |
370 | { | |
371 | int cpu; | |
372 | ||
373 | printk(KERN_DEBUG "LTT state dump thread start\n"); | |
374 | trace_lttng_statedump_start(session); | |
375 | lttng_enumerate_process_states(session); | |
376 | lttng_enumerate_file_descriptors(session); | |
0658bdda | 377 | /* FIXME lttng_enumerate_vm_maps(session); */ |
c337ddc2 MD |
378 | lttng_list_interrupts(session); |
379 | lttng_enumerate_network_ip_interface(session); | |
380 | ||
381 | /* TODO lttng_dump_idt_table(session); */ | |
382 | /* TODO lttng_dump_softirq_vec(session); */ | |
383 | /* TODO lttng_list_modules(session); */ | |
384 | /* TODO lttng_dump_swap_files(session); */ | |
385 | ||
386 | /* | |
387 | * Fire off a work queue on each CPU. Their sole purpose in life | |
388 | * is to guarantee that each CPU has been in a state where is was in | |
389 | * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ). | |
390 | */ | |
391 | get_online_cpus(); | |
392 | atomic_set(&kernel_threads_to_run, num_online_cpus()); | |
393 | for_each_online_cpu(cpu) { | |
394 | INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func); | |
395 | schedule_delayed_work_on(cpu, &cpu_work[cpu], 0); | |
396 | } | |
397 | /* Wait for all threads to run */ | |
398 | __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) != 0)); | |
399 | put_online_cpus(); | |
400 | /* Our work is done */ | |
401 | printk(KERN_DEBUG "LTT state dump end\n"); | |
402 | trace_lttng_statedump_end(session); | |
403 | return 0; | |
404 | } | |
405 | ||
406 | /* | |
407 | * Called with session mutex held. | |
408 | */ | |
409 | int lttng_statedump_start(struct lttng_session *session) | |
410 | { | |
411 | printk(KERN_DEBUG "LTTng: state dump begin\n"); | |
412 | return do_lttng_statedump(session); | |
413 | } | |
414 | EXPORT_SYMBOL_GPL(lttng_statedump_start); | |
415 | ||
416 | MODULE_LICENSE("GPL and additional rights"); | |
417 | MODULE_AUTHOR("Jean-Hugues Deschenes"); | |
418 | MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Statedump"); |