Fix: kretprobe: null ptr deref on session destroy
[lttng-modules.git] / lttng-statedump-impl.c
CommitLineData
9f36eaed
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1/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
2 *
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3 * lttng-statedump.c
4 *
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5 * Linux Trace Toolkit Next Generation Kernel State Dump
6 *
7 * Copyright 2005 Jean-Hugues Deschenes <jean-hugues.deschenes@polymtl.ca>
8 * Copyright 2006-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 *
10 * Changes:
11 * Eric Clement: Add listing of network IP interface
12 * 2006, 2007 Mathieu Desnoyers Fix kernel threads
13 * Various updates
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14 */
15
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/netlink.h>
19#include <linux/inet.h>
20#include <linux/ip.h>
21#include <linux/kthread.h>
22#include <linux/proc_fs.h>
23#include <linux/file.h>
24#include <linux/interrupt.h>
25#include <linux/irqnr.h>
26#include <linux/cpu.h>
27#include <linux/netdevice.h>
28#include <linux/inetdevice.h>
29#include <linux/sched.h>
30#include <linux/mm.h>
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31#include <linux/swap.h>
32#include <linux/wait.h>
33#include <linux/mutex.h>
f0dbdefb 34#include <linux/device.h>
c337ddc2 35
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36#include <lttng-events.h>
37#include <lttng-tracer.h>
38#include <wrapper/irqdesc.h>
241ae9a8 39#include <wrapper/fdtable.h>
1965e6b4 40#include <wrapper/namespace.h>
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41#include <wrapper/irq.h>
42#include <wrapper/tracepoint.h>
43#include <wrapper/genhd.h>
44#include <wrapper/file.h>
518dba2d 45#include <wrapper/fdtable.h>
c337ddc2 46
29784493 47#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
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48#include <linux/irq.h>
49#endif
50
51/* Define the tracepoints, but do not build the probes */
52#define CREATE_TRACE_POINTS
241ae9a8 53#define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
c337ddc2 54#define TRACE_INCLUDE_FILE lttng-statedump
3bc29f0a 55#define LTTNG_INSTRUMENTATION
241ae9a8 56#include <instrumentation/events/lttng-module/lttng-statedump.h>
c337ddc2 57
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58LTTNG_DEFINE_TRACE(lttng_statedump_block_device,
59 TP_PROTO(struct lttng_session *session,
60 dev_t dev, const char *diskname),
61 TP_ARGS(session, dev, diskname));
62
63LTTNG_DEFINE_TRACE(lttng_statedump_end,
64 TP_PROTO(struct lttng_session *session),
65 TP_ARGS(session));
66
67LTTNG_DEFINE_TRACE(lttng_statedump_interrupt,
68 TP_PROTO(struct lttng_session *session,
69 unsigned int irq, const char *chip_name,
70 struct irqaction *action),
71 TP_ARGS(session, irq, chip_name, action));
72
73LTTNG_DEFINE_TRACE(lttng_statedump_file_descriptor,
74 TP_PROTO(struct lttng_session *session,
75 struct files_struct *files,
76 int fd, const char *filename,
77 unsigned int flags, fmode_t fmode),
78 TP_ARGS(session, files, fd, filename, flags, fmode));
79
80LTTNG_DEFINE_TRACE(lttng_statedump_start,
81 TP_PROTO(struct lttng_session *session),
82 TP_ARGS(session));
83
84LTTNG_DEFINE_TRACE(lttng_statedump_process_state,
85 TP_PROTO(struct lttng_session *session,
86 struct task_struct *p,
87 int type, int mode, int submode, int status,
88 struct files_struct *files),
89 TP_ARGS(session, p, type, mode, submode, status, files));
90
91LTTNG_DEFINE_TRACE(lttng_statedump_process_pid_ns,
92 TP_PROTO(struct lttng_session *session,
93 struct task_struct *p,
94 struct pid_namespace *pid_ns),
95 TP_ARGS(session, p, pid_ns));
96
2d042821 97#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,6,0))
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98LTTNG_DEFINE_TRACE(lttng_statedump_process_cgroup_ns,
99 TP_PROTO(struct lttng_session *session,
100 struct task_struct *p,
101 struct cgroup_namespace *cgroup_ns),
102 TP_ARGS(session, p, cgroup_ns));
1965e6b4 103#endif
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104
105LTTNG_DEFINE_TRACE(lttng_statedump_process_ipc_ns,
106 TP_PROTO(struct lttng_session *session,
107 struct task_struct *p,
108 struct ipc_namespace *ipc_ns),
109 TP_ARGS(session, p, ipc_ns));
110
1965e6b4 111#ifndef LTTNG_MNT_NS_MISSING_HEADER
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112LTTNG_DEFINE_TRACE(lttng_statedump_process_mnt_ns,
113 TP_PROTO(struct lttng_session *session,
114 struct task_struct *p,
115 struct mnt_namespace *mnt_ns),
116 TP_ARGS(session, p, mnt_ns));
1965e6b4 117#endif
bb346792 118
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119LTTNG_DEFINE_TRACE(lttng_statedump_process_net_ns,
120 TP_PROTO(struct lttng_session *session,
121 struct task_struct *p,
122 struct net *net_ns),
123 TP_ARGS(session, p, net_ns));
124
125LTTNG_DEFINE_TRACE(lttng_statedump_process_user_ns,
126 TP_PROTO(struct lttng_session *session,
127 struct task_struct *p,
128 struct user_namespace *user_ns),
129 TP_ARGS(session, p, user_ns));
130
131LTTNG_DEFINE_TRACE(lttng_statedump_process_uts_ns,
132 TP_PROTO(struct lttng_session *session,
133 struct task_struct *p,
134 struct uts_namespace *uts_ns),
135 TP_ARGS(session, p, uts_ns));
136
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137LTTNG_DEFINE_TRACE(lttng_statedump_network_interface,
138 TP_PROTO(struct lttng_session *session,
139 struct net_device *dev, struct in_ifaddr *ifa),
140 TP_ARGS(session, dev, ifa));
141
d0b55e4c 142#ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
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143LTTNG_DEFINE_TRACE(lttng_statedump_cpu_topology,
144 TP_PROTO(struct lttng_session *session, struct cpuinfo_x86 *c),
145 TP_ARGS(session, c));
502e4132 146#endif
20591cf7 147
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148struct lttng_fd_ctx {
149 char *page;
150 struct lttng_session *session;
d561ecfb 151 struct files_struct *files;
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152};
153
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154/*
155 * Protected by the trace lock.
156 */
157static struct delayed_work cpu_work[NR_CPUS];
158static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
159static atomic_t kernel_threads_to_run;
160
161enum lttng_thread_type {
162 LTTNG_USER_THREAD = 0,
163 LTTNG_KERNEL_THREAD = 1,
164};
165
166enum lttng_execution_mode {
167 LTTNG_USER_MODE = 0,
168 LTTNG_SYSCALL = 1,
169 LTTNG_TRAP = 2,
170 LTTNG_IRQ = 3,
171 LTTNG_SOFTIRQ = 4,
172 LTTNG_MODE_UNKNOWN = 5,
173};
174
175enum lttng_execution_submode {
176 LTTNG_NONE = 0,
177 LTTNG_UNKNOWN = 1,
178};
179
180enum lttng_process_status {
181 LTTNG_UNNAMED = 0,
182 LTTNG_WAIT_FORK = 1,
183 LTTNG_WAIT_CPU = 2,
184 LTTNG_EXIT = 3,
185 LTTNG_ZOMBIE = 4,
186 LTTNG_WAIT = 5,
187 LTTNG_RUN = 6,
188 LTTNG_DEAD = 7,
189};
190
c2d5363f 191
2d042821 192#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,11,0))
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193
194#define LTTNG_PART_STRUCT_TYPE struct block_device
195
196static
197int lttng_get_part_name(struct gendisk *disk, struct block_device *part, char *name_buf)
198{
199 const char *p;
200
201 p = bdevname(part, name_buf);
202 if (!p)
203 return -ENOSYS;
204
205 return 0;
206}
207
208static
209dev_t lttng_get_part_devt(struct block_device *part)
210{
211 return part->bd_dev;
212}
213
214#else
215
216#define LTTNG_PART_STRUCT_TYPE struct hd_struct
217
218static
219int lttng_get_part_name(struct gendisk *disk, struct hd_struct *part, char *name_buf)
220{
221 const char *p;
222 struct block_device bdev;
223
224 /*
225 * Create a partial 'struct blockdevice' to use
226 * 'bdevname()' which is a simple wrapper over
227 * 'disk_name()' but has the honor to be EXPORT_SYMBOL.
228 */
229 bdev.bd_disk = disk;
230 bdev.bd_part = part;
231
232 p = bdevname(&bdev, name_buf);
233 if (!p)
234 return -ENOSYS;
235
236 return 0;
237}
238
239static
240dev_t lttng_get_part_devt(struct hd_struct *part)
241{
242 return part_devt(part);
243}
244#endif
245
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246static
247int lttng_enumerate_block_devices(struct lttng_session *session)
248{
249 struct class *ptr_block_class;
250 struct device_type *ptr_disk_type;
251 struct class_dev_iter iter;
252 struct device *dev;
253
254 ptr_block_class = wrapper_get_block_class();
255 if (!ptr_block_class)
256 return -ENOSYS;
257 ptr_disk_type = wrapper_get_disk_type();
258 if (!ptr_disk_type) {
259 return -ENOSYS;
260 }
261 class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
262 while ((dev = class_dev_iter_next(&iter))) {
263 struct disk_part_iter piter;
264 struct gendisk *disk = dev_to_disk(dev);
c2d5363f 265 LTTNG_PART_STRUCT_TYPE *part;
f0dbdefb 266
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267 /*
268 * Don't show empty devices or things that have been
269 * suppressed
270 */
271 if (get_capacity(disk) == 0 ||
272 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
273 continue;
274
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275 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
276 while ((part = disk_part_iter_next(&piter))) {
277 char name_buf[BDEVNAME_SIZE];
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278
279 if (lttng_get_part_name(disk, part, name_buf) == -ENOSYS) {
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280 disk_part_iter_exit(&piter);
281 class_dev_iter_exit(&iter);
282 return -ENOSYS;
283 }
284 trace_lttng_statedump_block_device(session,
c2d5363f 285 lttng_get_part_devt(part), name_buf);
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286 }
287 disk_part_iter_exit(&piter);
288 }
289 class_dev_iter_exit(&iter);
290 return 0;
291}
292
c337ddc2 293#ifdef CONFIG_INET
f0dbdefb 294
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295static
296void lttng_enumerate_device(struct lttng_session *session,
297 struct net_device *dev)
298{
299 struct in_device *in_dev;
300 struct in_ifaddr *ifa;
301
302 if (dev->flags & IFF_UP) {
303 in_dev = in_dev_get(dev);
304 if (in_dev) {
305 for (ifa = in_dev->ifa_list; ifa != NULL;
306 ifa = ifa->ifa_next) {
307 trace_lttng_statedump_network_interface(
308 session, dev, ifa);
309 }
310 in_dev_put(in_dev);
311 }
312 } else {
313 trace_lttng_statedump_network_interface(
314 session, dev, NULL);
315 }
316}
317
318static
319int lttng_enumerate_network_ip_interface(struct lttng_session *session)
320{
321 struct net_device *dev;
322
323 read_lock(&dev_base_lock);
324 for_each_netdev(&init_net, dev)
325 lttng_enumerate_device(session, dev);
326 read_unlock(&dev_base_lock);
327
328 return 0;
329}
330#else /* CONFIG_INET */
331static inline
332int lttng_enumerate_network_ip_interface(struct lttng_session *session)
333{
334 return 0;
335}
336#endif /* CONFIG_INET */
337
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338static
339int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd)
340{
341 const struct lttng_fd_ctx *ctx = p;
342 const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
29021503 343 unsigned int flags = file->f_flags;
d561ecfb 344 struct fdtable *fdt;
361c023a 345
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346 /*
347 * We don't expose kernel internal flags, only userspace-visible
348 * flags.
349 */
350 flags &= ~FMODE_NONOTIFY;
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351 fdt = files_fdtable(ctx->files);
352 /*
353 * We need to check here again whether fd is within the fdt
354 * max_fds range, because we might be seeing a different
355 * files_fdtable() than iterate_fd(), assuming only RCU is
356 * protecting the read. In reality, iterate_fd() holds
357 * file_lock, which should ensure the fdt does not change while
358 * the lock is taken, but we are not aware whether this is
359 * guaranteed or not, so play safe.
360 */
aa29f2d3 361 if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
29021503 362 flags |= O_CLOEXEC;
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363 if (IS_ERR(s)) {
364 struct dentry *dentry = file->f_path.dentry;
365
366 /* Make sure we give at least some info */
367 spin_lock(&dentry->d_lock);
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368 trace_lttng_statedump_file_descriptor(ctx->session,
369 ctx->files, fd, dentry->d_name.name, flags,
370 file->f_mode);
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371 spin_unlock(&dentry->d_lock);
372 goto end;
373 }
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374 trace_lttng_statedump_file_descriptor(ctx->session,
375 ctx->files, fd, s, flags, file->f_mode);
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376end:
377 return 0;
378}
c337ddc2 379
df493bfd 380/* Called with task lock held. */
c337ddc2 381static
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382void lttng_enumerate_files(struct lttng_session *session,
383 struct files_struct *files,
384 char *tmp)
c337ddc2 385{
df493bfd 386 struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = files, };
c337ddc2 387
d561ecfb 388 lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
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389}
390
d0b55e4c 391#ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
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392static
393int lttng_enumerate_cpu_topology(struct lttng_session *session)
394{
395 int cpu;
396 const cpumask_t *cpumask = cpu_possible_mask;
397
398 for (cpu = cpumask_first(cpumask); cpu < nr_cpu_ids;
399 cpu = cpumask_next(cpu, cpumask)) {
400 trace_lttng_statedump_cpu_topology(session, &cpu_data(cpu));
401 }
402
403 return 0;
404}
405#else
406static
407int lttng_enumerate_cpu_topology(struct lttng_session *session)
408{
409 return 0;
410}
411#endif
412
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413#if 0
414/*
415 * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
416 * (scheduling in atomic). Normally, the tasklist lock protects this kind of
417 * iteration, but it is not exported to modules.
418 */
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419static
420void lttng_enumerate_task_vm_maps(struct lttng_session *session,
421 struct task_struct *p)
422{
423 struct mm_struct *mm;
424 struct vm_area_struct *map;
425 unsigned long ino;
426
427 /* get_task_mm does a task_lock... */
428 mm = get_task_mm(p);
429 if (!mm)
430 return;
431
432 map = mm->mmap;
433 if (map) {
434 down_read(&mm->mmap_sem);
435 while (map) {
436 if (map->vm_file)
b06ed645 437 ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
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438 else
439 ino = 0;
440 trace_lttng_statedump_vm_map(session, p, map, ino);
441 map = map->vm_next;
442 }
443 up_read(&mm->mmap_sem);
444 }
445 mmput(mm);
446}
447
448static
449int lttng_enumerate_vm_maps(struct lttng_session *session)
450{
451 struct task_struct *p;
452
453 rcu_read_lock();
454 for_each_process(p)
455 lttng_enumerate_task_vm_maps(session, p);
456 rcu_read_unlock();
457 return 0;
458}
0658bdda 459#endif
c337ddc2 460
29784493 461#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
47faec4b 462
c337ddc2 463static
cfcee1c7 464int lttng_list_interrupts(struct lttng_session *session)
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465{
466 unsigned int irq;
467 unsigned long flags = 0;
468 struct irq_desc *desc;
469
470#define irq_to_desc wrapper_irq_to_desc
471 /* needs irq_desc */
472 for_each_irq_desc(irq, desc) {
473 struct irqaction *action;
474 const char *irq_chip_name =
475 irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
476
477 local_irq_save(flags);
fc94c945 478 raw_spin_lock(&desc->lock);
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479 for (action = desc->action; action; action = action->next) {
480 trace_lttng_statedump_interrupt(session,
481 irq, irq_chip_name, action);
482 }
fc94c945 483 raw_spin_unlock(&desc->lock);
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484 local_irq_restore(flags);
485 }
cfcee1c7 486 return 0;
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487#undef irq_to_desc
488}
489#else
490static inline
cfcee1c7 491int lttng_list_interrupts(struct lttng_session *session)
c337ddc2 492{
cfcee1c7 493 return 0;
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494}
495#endif
496
4ba1f53c 497/*
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498 * Statedump the task's namespaces using the proc filesystem inode number as
499 * the unique identifier. The user and pid ns are nested and will be dumped
500 * recursively.
501 *
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502 * Called with task lock held.
503 */
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504static
505void lttng_statedump_process_ns(struct lttng_session *session,
506 struct task_struct *p,
507 enum lttng_thread_type type,
508 enum lttng_execution_mode mode,
509 enum lttng_execution_submode submode,
510 enum lttng_process_status status)
511{
1965e6b4 512 struct nsproxy *proxy;
73e8ba37 513 struct pid_namespace *pid_ns;
1965e6b4 514 struct user_namespace *user_ns;
73e8ba37 515
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516 /*
517 * The pid and user namespaces are special, they are nested and
518 * accessed with specific functions instead of the nsproxy struct
519 * like the other namespaces.
520 */
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521 pid_ns = task_active_pid_ns(p);
522 do {
1965e6b4 523 trace_lttng_statedump_process_pid_ns(session, p, pid_ns);
51831abd 524 pid_ns = pid_ns ? pid_ns->parent : NULL;
887bcdac 525 } while (pid_ns);
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526
527
528 user_ns = task_cred_xxx(p, user_ns);
529 do {
530 trace_lttng_statedump_process_user_ns(session, p, user_ns);
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531 /*
532 * trace_lttng_statedump_process_user_ns() internally
533 * checks whether user_ns is NULL. While this does not
534 * appear to be a possible return value for
535 * task_cred_xxx(), err on the safe side and check
536 * for NULL here as well to be consistent with the
537 * paranoid behavior of
538 * trace_lttng_statedump_process_user_ns().
539 */
540 user_ns = user_ns ? user_ns->lttng_user_ns_parent : NULL;
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541 } while (user_ns);
542
543 /*
544 * Back and forth on locking strategy within Linux upstream for nsproxy.
545 * See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
546 * "namespaces: Use task_lock and not rcu to protect nsproxy"
547 * for details.
548 */
2d042821 549#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,17,0) || \
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550 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
551 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
552 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
553 proxy = p->nsproxy;
554#else
555 rcu_read_lock();
556 proxy = task_nsproxy(p);
557#endif
558 if (proxy) {
2d042821 559#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,6,0))
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560 trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns);
561#endif
562 trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns);
563#ifndef LTTNG_MNT_NS_MISSING_HEADER
564 trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns);
565#endif
566 trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns);
567 trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns);
568 }
2d042821 569#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,17,0) || \
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570 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
571 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
572 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
573 /* (nothing) */
574#else
575 rcu_read_unlock();
576#endif
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577}
578
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579static
580int lttng_enumerate_process_states(struct lttng_session *session)
581{
582 struct task_struct *g, *p;
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583 char *tmp;
584
585 tmp = (char *) __get_free_page(GFP_KERNEL);
586 if (!tmp)
587 return -ENOMEM;
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588
589 rcu_read_lock();
590 for_each_process(g) {
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591 struct files_struct *prev_files = NULL;
592
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593 p = g;
594 do {
595 enum lttng_execution_mode mode =
596 LTTNG_MODE_UNKNOWN;
597 enum lttng_execution_submode submode =
598 LTTNG_UNKNOWN;
599 enum lttng_process_status status;
600 enum lttng_thread_type type;
df493bfd 601 struct files_struct *files;
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602
603 task_lock(p);
604 if (p->exit_state == EXIT_ZOMBIE)
605 status = LTTNG_ZOMBIE;
606 else if (p->exit_state == EXIT_DEAD)
607 status = LTTNG_DEAD;
608 else if (p->state == TASK_RUNNING) {
609 /* Is this a forked child that has not run yet? */
610 if (list_empty(&p->rt.run_list))
611 status = LTTNG_WAIT_FORK;
612 else
613 /*
614 * All tasks are considered as wait_cpu;
615 * the viewer will sort out if the task
616 * was really running at this time.
617 */
618 status = LTTNG_WAIT_CPU;
619 } else if (p->state &
620 (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) {
621 /* Task is waiting for something to complete */
622 status = LTTNG_WAIT;
623 } else
624 status = LTTNG_UNNAMED;
625 submode = LTTNG_NONE;
626
627 /*
628 * Verification of t->mm is to filter out kernel
629 * threads; Viewer will further filter out if a
630 * user-space thread was in syscall mode or not.
631 */
632 if (p->mm)
633 type = LTTNG_USER_THREAD;
634 else
635 type = LTTNG_KERNEL_THREAD;
df493bfd 636 files = p->files;
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637
638 trace_lttng_statedump_process_state(session,
df493bfd 639 p, type, mode, submode, status, files);
73e8ba37 640 lttng_statedump_process_ns(session,
c337ddc2 641 p, type, mode, submode, status);
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642 /*
643 * As an optimisation for the common case, do not
644 * repeat information for the same files_struct in
645 * two consecutive threads. This is the common case
646 * for threads sharing the same fd table. RCU guarantees
647 * that the same files_struct pointer is not re-used
648 * throughout processes/threads iteration.
649 */
650 if (files && files != prev_files) {
651 lttng_enumerate_files(session, files, tmp);
652 prev_files = files;
653 }
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654 task_unlock(p);
655 } while_each_thread(g, p);
656 }
657 rcu_read_unlock();
658
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659 free_page((unsigned long) tmp);
660
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661 return 0;
662}
663
664static
665void lttng_statedump_work_func(struct work_struct *work)
666{
667 if (atomic_dec_and_test(&kernel_threads_to_run))
668 /* If we are the last thread, wake up do_lttng_statedump */
669 wake_up(&statedump_wq);
670}
671
672static
673int do_lttng_statedump(struct lttng_session *session)
674{
cfcee1c7 675 int cpu, ret;
c337ddc2 676
c337ddc2 677 trace_lttng_statedump_start(session);
cfcee1c7 678 ret = lttng_enumerate_process_states(session);
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679 if (ret)
680 return ret;
681 /*
682 * FIXME
683 * ret = lttng_enumerate_vm_maps(session);
684 * if (ret)
685 * return ret;
686 */
687 ret = lttng_list_interrupts(session);
688 if (ret)
689 return ret;
690 ret = lttng_enumerate_network_ip_interface(session);
691 if (ret)
692 return ret;
693 ret = lttng_enumerate_block_devices(session);
694 switch (ret) {
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695 case 0:
696 break;
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697 case -ENOSYS:
698 printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
699 break;
700 default:
701 return ret;
702 }
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703 ret = lttng_enumerate_cpu_topology(session);
704 if (ret)
705 return ret;
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706
707 /* TODO lttng_dump_idt_table(session); */
708 /* TODO lttng_dump_softirq_vec(session); */
709 /* TODO lttng_list_modules(session); */
710 /* TODO lttng_dump_swap_files(session); */
711
712 /*
713 * Fire off a work queue on each CPU. Their sole purpose in life
714 * is to guarantee that each CPU has been in a state where is was in
715 * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
716 */
717 get_online_cpus();
718 atomic_set(&kernel_threads_to_run, num_online_cpus());
719 for_each_online_cpu(cpu) {
720 INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
721 schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
722 }
723 /* Wait for all threads to run */
7a7128e0 724 __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
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725 put_online_cpus();
726 /* Our work is done */
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727 trace_lttng_statedump_end(session);
728 return 0;
729}
730
731/*
732 * Called with session mutex held.
733 */
734int lttng_statedump_start(struct lttng_session *session)
735{
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736 return do_lttng_statedump(session);
737}
738EXPORT_SYMBOL_GPL(lttng_statedump_start);
739
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740static
741int __init lttng_statedump_init(void)
742{
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743 /*
744 * Allow module to load even if the fixup cannot be done. This
745 * will allow seemless transition when the underlying issue fix
746 * is merged into the Linux kernel, and when tracepoint.c
747 * "tracepoint_module_notify" is turned into a static function.
748 */
749 (void) wrapper_lttng_fixup_sig(THIS_MODULE);
750 return 0;
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751}
752
753module_init(lttng_statedump_init);
754
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755static
756void __exit lttng_statedump_exit(void)
757{
758}
759
760module_exit(lttng_statedump_exit);
761
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762MODULE_LICENSE("GPL and additional rights");
763MODULE_AUTHOR("Jean-Hugues Deschenes");
1c124020 764MODULE_DESCRIPTION("LTTng statedump provider");
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765MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
766 __stringify(LTTNG_MODULES_MINOR_VERSION) "."
767 __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
768 LTTNG_MODULES_EXTRAVERSION);
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