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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" |
361c023a | 52 | #include "wrapper/fdtable.h" |
3247f8bd | 53 | #include "wrapper/nsproxy.h" |
29784493 | 54 | #include "wrapper/irq.h" |
dd8d5afb | 55 | #include "wrapper/tracepoint.h" |
c337ddc2 | 56 | |
29784493 | 57 | #ifdef CONFIG_LTTNG_HAS_LIST_IRQ |
c337ddc2 MD |
58 | #include <linux/irq.h> |
59 | #endif | |
60 | ||
61 | /* Define the tracepoints, but do not build the probes */ | |
62 | #define CREATE_TRACE_POINTS | |
63 | #define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module | |
64 | #define TRACE_INCLUDE_FILE lttng-statedump | |
65 | #include "instrumentation/events/lttng-module/lttng-statedump.h" | |
66 | ||
361c023a MD |
67 | struct lttng_fd_ctx { |
68 | char *page; | |
69 | struct lttng_session *session; | |
70 | struct task_struct *p; | |
71 | }; | |
72 | ||
c337ddc2 MD |
73 | /* |
74 | * Protected by the trace lock. | |
75 | */ | |
76 | static struct delayed_work cpu_work[NR_CPUS]; | |
77 | static DECLARE_WAIT_QUEUE_HEAD(statedump_wq); | |
78 | static atomic_t kernel_threads_to_run; | |
79 | ||
80 | enum lttng_thread_type { | |
81 | LTTNG_USER_THREAD = 0, | |
82 | LTTNG_KERNEL_THREAD = 1, | |
83 | }; | |
84 | ||
85 | enum lttng_execution_mode { | |
86 | LTTNG_USER_MODE = 0, | |
87 | LTTNG_SYSCALL = 1, | |
88 | LTTNG_TRAP = 2, | |
89 | LTTNG_IRQ = 3, | |
90 | LTTNG_SOFTIRQ = 4, | |
91 | LTTNG_MODE_UNKNOWN = 5, | |
92 | }; | |
93 | ||
94 | enum lttng_execution_submode { | |
95 | LTTNG_NONE = 0, | |
96 | LTTNG_UNKNOWN = 1, | |
97 | }; | |
98 | ||
99 | enum lttng_process_status { | |
100 | LTTNG_UNNAMED = 0, | |
101 | LTTNG_WAIT_FORK = 1, | |
102 | LTTNG_WAIT_CPU = 2, | |
103 | LTTNG_EXIT = 3, | |
104 | LTTNG_ZOMBIE = 4, | |
105 | LTTNG_WAIT = 5, | |
106 | LTTNG_RUN = 6, | |
107 | LTTNG_DEAD = 7, | |
108 | }; | |
109 | ||
110 | #ifdef CONFIG_INET | |
111 | static | |
112 | void lttng_enumerate_device(struct lttng_session *session, | |
113 | struct net_device *dev) | |
114 | { | |
115 | struct in_device *in_dev; | |
116 | struct in_ifaddr *ifa; | |
117 | ||
118 | if (dev->flags & IFF_UP) { | |
119 | in_dev = in_dev_get(dev); | |
120 | if (in_dev) { | |
121 | for (ifa = in_dev->ifa_list; ifa != NULL; | |
122 | ifa = ifa->ifa_next) { | |
123 | trace_lttng_statedump_network_interface( | |
124 | session, dev, ifa); | |
125 | } | |
126 | in_dev_put(in_dev); | |
127 | } | |
128 | } else { | |
129 | trace_lttng_statedump_network_interface( | |
130 | session, dev, NULL); | |
131 | } | |
132 | } | |
133 | ||
134 | static | |
135 | int lttng_enumerate_network_ip_interface(struct lttng_session *session) | |
136 | { | |
137 | struct net_device *dev; | |
138 | ||
139 | read_lock(&dev_base_lock); | |
140 | for_each_netdev(&init_net, dev) | |
141 | lttng_enumerate_device(session, dev); | |
142 | read_unlock(&dev_base_lock); | |
143 | ||
144 | return 0; | |
145 | } | |
146 | #else /* CONFIG_INET */ | |
147 | static inline | |
148 | int lttng_enumerate_network_ip_interface(struct lttng_session *session) | |
149 | { | |
150 | return 0; | |
151 | } | |
152 | #endif /* CONFIG_INET */ | |
153 | ||
361c023a MD |
154 | static |
155 | int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd) | |
156 | { | |
157 | const struct lttng_fd_ctx *ctx = p; | |
158 | const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE); | |
159 | ||
160 | if (IS_ERR(s)) { | |
161 | struct dentry *dentry = file->f_path.dentry; | |
162 | ||
163 | /* Make sure we give at least some info */ | |
164 | spin_lock(&dentry->d_lock); | |
165 | trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, | |
166 | dentry->d_name.name); | |
167 | spin_unlock(&dentry->d_lock); | |
168 | goto end; | |
169 | } | |
170 | trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s); | |
171 | end: | |
172 | return 0; | |
173 | } | |
c337ddc2 MD |
174 | |
175 | static | |
176 | void lttng_enumerate_task_fd(struct lttng_session *session, | |
177 | struct task_struct *p, char *tmp) | |
178 | { | |
361c023a | 179 | struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p }; |
c337ddc2 MD |
180 | |
181 | task_lock(p); | |
361c023a | 182 | lttng_iterate_fd(p->files, 0, lttng_dump_one_fd, &ctx); |
c337ddc2 MD |
183 | task_unlock(p); |
184 | } | |
185 | ||
186 | static | |
187 | int lttng_enumerate_file_descriptors(struct lttng_session *session) | |
188 | { | |
189 | struct task_struct *p; | |
190 | char *tmp = (char *) __get_free_page(GFP_KERNEL); | |
191 | ||
192 | /* Enumerate active file descriptors */ | |
193 | rcu_read_lock(); | |
194 | for_each_process(p) | |
195 | lttng_enumerate_task_fd(session, p, tmp); | |
196 | rcu_read_unlock(); | |
197 | free_page((unsigned long) tmp); | |
198 | return 0; | |
199 | } | |
200 | ||
0658bdda MD |
201 | #if 0 |
202 | /* | |
203 | * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section | |
204 | * (scheduling in atomic). Normally, the tasklist lock protects this kind of | |
205 | * iteration, but it is not exported to modules. | |
206 | */ | |
c337ddc2 MD |
207 | static |
208 | void lttng_enumerate_task_vm_maps(struct lttng_session *session, | |
209 | struct task_struct *p) | |
210 | { | |
211 | struct mm_struct *mm; | |
212 | struct vm_area_struct *map; | |
213 | unsigned long ino; | |
214 | ||
215 | /* get_task_mm does a task_lock... */ | |
216 | mm = get_task_mm(p); | |
217 | if (!mm) | |
218 | return; | |
219 | ||
220 | map = mm->mmap; | |
221 | if (map) { | |
222 | down_read(&mm->mmap_sem); | |
223 | while (map) { | |
224 | if (map->vm_file) | |
225 | ino = map->vm_file->f_dentry->d_inode->i_ino; | |
226 | else | |
227 | ino = 0; | |
228 | trace_lttng_statedump_vm_map(session, p, map, ino); | |
229 | map = map->vm_next; | |
230 | } | |
231 | up_read(&mm->mmap_sem); | |
232 | } | |
233 | mmput(mm); | |
234 | } | |
235 | ||
236 | static | |
237 | int lttng_enumerate_vm_maps(struct lttng_session *session) | |
238 | { | |
239 | struct task_struct *p; | |
240 | ||
241 | rcu_read_lock(); | |
242 | for_each_process(p) | |
243 | lttng_enumerate_task_vm_maps(session, p); | |
244 | rcu_read_unlock(); | |
245 | return 0; | |
246 | } | |
0658bdda | 247 | #endif |
c337ddc2 | 248 | |
29784493 | 249 | #ifdef CONFIG_LTTNG_HAS_LIST_IRQ |
47faec4b JN |
250 | |
251 | #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)) | |
252 | #define irq_desc_get_chip(desc) get_irq_desc_chip(desc) | |
253 | #endif | |
254 | ||
c337ddc2 MD |
255 | static |
256 | void lttng_list_interrupts(struct lttng_session *session) | |
257 | { | |
258 | unsigned int irq; | |
259 | unsigned long flags = 0; | |
260 | struct irq_desc *desc; | |
261 | ||
262 | #define irq_to_desc wrapper_irq_to_desc | |
263 | /* needs irq_desc */ | |
264 | for_each_irq_desc(irq, desc) { | |
265 | struct irqaction *action; | |
266 | const char *irq_chip_name = | |
267 | irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip"; | |
268 | ||
269 | local_irq_save(flags); | |
3a523f5b | 270 | wrapper_desc_spin_lock(&desc->lock); |
c337ddc2 MD |
271 | for (action = desc->action; action; action = action->next) { |
272 | trace_lttng_statedump_interrupt(session, | |
273 | irq, irq_chip_name, action); | |
274 | } | |
3a523f5b | 275 | wrapper_desc_spin_unlock(&desc->lock); |
c337ddc2 MD |
276 | local_irq_restore(flags); |
277 | } | |
278 | #undef irq_to_desc | |
279 | } | |
280 | #else | |
281 | static inline | |
2e7a0709 | 282 | void lttng_list_interrupts(struct lttng_session *session) |
c337ddc2 MD |
283 | { |
284 | } | |
285 | #endif | |
286 | ||
73e8ba37 JD |
287 | static |
288 | void lttng_statedump_process_ns(struct lttng_session *session, | |
289 | struct task_struct *p, | |
290 | enum lttng_thread_type type, | |
291 | enum lttng_execution_mode mode, | |
292 | enum lttng_execution_submode submode, | |
293 | enum lttng_process_status status) | |
294 | { | |
295 | struct nsproxy *proxy; | |
296 | struct pid_namespace *pid_ns; | |
297 | ||
298 | rcu_read_lock(); | |
299 | proxy = task_nsproxy(p); | |
300 | if (proxy) { | |
3247f8bd | 301 | pid_ns = lttng_get_proxy_pid_ns(proxy); |
73e8ba37 JD |
302 | do { |
303 | trace_lttng_statedump_process_state(session, | |
304 | p, type, mode, submode, status, pid_ns); | |
af73f727 | 305 | pid_ns = pid_ns->parent; |
73e8ba37 JD |
306 | } while (pid_ns); |
307 | } else { | |
308 | trace_lttng_statedump_process_state(session, | |
309 | p, type, mode, submode, status, NULL); | |
310 | } | |
311 | rcu_read_unlock(); | |
312 | } | |
313 | ||
c337ddc2 MD |
314 | static |
315 | int lttng_enumerate_process_states(struct lttng_session *session) | |
316 | { | |
317 | struct task_struct *g, *p; | |
318 | ||
319 | rcu_read_lock(); | |
320 | for_each_process(g) { | |
321 | p = g; | |
322 | do { | |
323 | enum lttng_execution_mode mode = | |
324 | LTTNG_MODE_UNKNOWN; | |
325 | enum lttng_execution_submode submode = | |
326 | LTTNG_UNKNOWN; | |
327 | enum lttng_process_status status; | |
328 | enum lttng_thread_type type; | |
329 | ||
330 | task_lock(p); | |
331 | if (p->exit_state == EXIT_ZOMBIE) | |
332 | status = LTTNG_ZOMBIE; | |
333 | else if (p->exit_state == EXIT_DEAD) | |
334 | status = LTTNG_DEAD; | |
335 | else if (p->state == TASK_RUNNING) { | |
336 | /* Is this a forked child that has not run yet? */ | |
337 | if (list_empty(&p->rt.run_list)) | |
338 | status = LTTNG_WAIT_FORK; | |
339 | else | |
340 | /* | |
341 | * All tasks are considered as wait_cpu; | |
342 | * the viewer will sort out if the task | |
343 | * was really running at this time. | |
344 | */ | |
345 | status = LTTNG_WAIT_CPU; | |
346 | } else if (p->state & | |
347 | (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) { | |
348 | /* Task is waiting for something to complete */ | |
349 | status = LTTNG_WAIT; | |
350 | } else | |
351 | status = LTTNG_UNNAMED; | |
352 | submode = LTTNG_NONE; | |
353 | ||
354 | /* | |
355 | * Verification of t->mm is to filter out kernel | |
356 | * threads; Viewer will further filter out if a | |
357 | * user-space thread was in syscall mode or not. | |
358 | */ | |
359 | if (p->mm) | |
360 | type = LTTNG_USER_THREAD; | |
361 | else | |
362 | type = LTTNG_KERNEL_THREAD; | |
73e8ba37 | 363 | lttng_statedump_process_ns(session, |
c337ddc2 MD |
364 | p, type, mode, submode, status); |
365 | task_unlock(p); | |
366 | } while_each_thread(g, p); | |
367 | } | |
368 | rcu_read_unlock(); | |
369 | ||
370 | return 0; | |
371 | } | |
372 | ||
373 | static | |
374 | void lttng_statedump_work_func(struct work_struct *work) | |
375 | { | |
376 | if (atomic_dec_and_test(&kernel_threads_to_run)) | |
377 | /* If we are the last thread, wake up do_lttng_statedump */ | |
378 | wake_up(&statedump_wq); | |
379 | } | |
380 | ||
381 | static | |
382 | int do_lttng_statedump(struct lttng_session *session) | |
383 | { | |
384 | int cpu; | |
385 | ||
c337ddc2 MD |
386 | trace_lttng_statedump_start(session); |
387 | lttng_enumerate_process_states(session); | |
388 | lttng_enumerate_file_descriptors(session); | |
0658bdda | 389 | /* FIXME lttng_enumerate_vm_maps(session); */ |
c337ddc2 MD |
390 | lttng_list_interrupts(session); |
391 | lttng_enumerate_network_ip_interface(session); | |
392 | ||
393 | /* TODO lttng_dump_idt_table(session); */ | |
394 | /* TODO lttng_dump_softirq_vec(session); */ | |
395 | /* TODO lttng_list_modules(session); */ | |
396 | /* TODO lttng_dump_swap_files(session); */ | |
397 | ||
398 | /* | |
399 | * Fire off a work queue on each CPU. Their sole purpose in life | |
400 | * is to guarantee that each CPU has been in a state where is was in | |
401 | * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ). | |
402 | */ | |
403 | get_online_cpus(); | |
404 | atomic_set(&kernel_threads_to_run, num_online_cpus()); | |
405 | for_each_online_cpu(cpu) { | |
406 | INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func); | |
407 | schedule_delayed_work_on(cpu, &cpu_work[cpu], 0); | |
408 | } | |
409 | /* Wait for all threads to run */ | |
7a7128e0 | 410 | __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0)); |
c337ddc2 MD |
411 | put_online_cpus(); |
412 | /* Our work is done */ | |
c337ddc2 MD |
413 | trace_lttng_statedump_end(session); |
414 | return 0; | |
415 | } | |
416 | ||
417 | /* | |
418 | * Called with session mutex held. | |
419 | */ | |
420 | int lttng_statedump_start(struct lttng_session *session) | |
421 | { | |
c337ddc2 MD |
422 | return do_lttng_statedump(session); |
423 | } | |
424 | EXPORT_SYMBOL_GPL(lttng_statedump_start); | |
425 | ||
dd8d5afb MD |
426 | static |
427 | int __init lttng_statedump_init(void) | |
428 | { | |
d16aa9c9 MD |
429 | /* |
430 | * Allow module to load even if the fixup cannot be done. This | |
431 | * will allow seemless transition when the underlying issue fix | |
432 | * is merged into the Linux kernel, and when tracepoint.c | |
433 | * "tracepoint_module_notify" is turned into a static function. | |
434 | */ | |
435 | (void) wrapper_lttng_fixup_sig(THIS_MODULE); | |
436 | return 0; | |
dd8d5afb MD |
437 | } |
438 | ||
439 | module_init(lttng_statedump_init); | |
440 | ||
461277e7 MD |
441 | static |
442 | void __exit lttng_statedump_exit(void) | |
443 | { | |
444 | } | |
445 | ||
446 | module_exit(lttng_statedump_exit); | |
447 | ||
c337ddc2 MD |
448 | MODULE_LICENSE("GPL and additional rights"); |
449 | MODULE_AUTHOR("Jean-Hugues Deschenes"); | |
450 | MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Statedump"); |