+++ /dev/null
-/*
- * lttng-statedump.c
- *
- * Linux Trace Toolkit Next Generation Kernel State Dump
- *
- * Copyright 2005 Jean-Hugues Deschenes <jean-hugues.deschenes@polymtl.ca>
- * Copyright 2006-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * Changes:
- * Eric Clement: Add listing of network IP interface
- * 2006, 2007 Mathieu Desnoyers Fix kernel threads
- * Various updates
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/netlink.h>
-#include <linux/inet.h>
-#include <linux/ip.h>
-#include <linux/kthread.h>
-#include <linux/proc_fs.h>
-#include <linux/file.h>
-#include <linux/interrupt.h>
-#include <linux/irqnr.h>
-#include <linux/cpu.h>
-#include <linux/netdevice.h>
-#include <linux/inetdevice.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/fdtable.h>
-#include <linux/swap.h>
-#include <linux/wait.h>
-#include <linux/mutex.h>
-#include <linux/device.h>
-
-#include "lttng-events.h"
-#include "lttng-tracer.h"
-#include "wrapper/irqdesc.h"
-#include "wrapper/spinlock.h"
-#include "wrapper/fdtable.h"
-#include "wrapper/nsproxy.h"
-#include "wrapper/irq.h"
-#include "wrapper/tracepoint.h"
-#include "wrapper/genhd.h"
-
-#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
-#include <linux/irq.h>
-#endif
-
-/* Define the tracepoints, but do not build the probes */
-#define CREATE_TRACE_POINTS
-#define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module
-#define TRACE_INCLUDE_FILE lttng-statedump
-#define LTTNG_INSTRUMENTATION
-#include "instrumentation/events/lttng-module/lttng-statedump.h"
-
-DEFINE_TRACE(lttng_statedump_block_device);
-DEFINE_TRACE(lttng_statedump_end);
-DEFINE_TRACE(lttng_statedump_interrupt);
-DEFINE_TRACE(lttng_statedump_file_descriptor);
-DEFINE_TRACE(lttng_statedump_start);
-DEFINE_TRACE(lttng_statedump_process_state);
-DEFINE_TRACE(lttng_statedump_network_interface);
-
-struct lttng_fd_ctx {
- char *page;
- struct lttng_session *session;
- struct task_struct *p;
- struct files_struct *files;
-};
-
-/*
- * Protected by the trace lock.
- */
-static struct delayed_work cpu_work[NR_CPUS];
-static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
-static atomic_t kernel_threads_to_run;
-
-enum lttng_thread_type {
- LTTNG_USER_THREAD = 0,
- LTTNG_KERNEL_THREAD = 1,
-};
-
-enum lttng_execution_mode {
- LTTNG_USER_MODE = 0,
- LTTNG_SYSCALL = 1,
- LTTNG_TRAP = 2,
- LTTNG_IRQ = 3,
- LTTNG_SOFTIRQ = 4,
- LTTNG_MODE_UNKNOWN = 5,
-};
-
-enum lttng_execution_submode {
- LTTNG_NONE = 0,
- LTTNG_UNKNOWN = 1,
-};
-
-enum lttng_process_status {
- LTTNG_UNNAMED = 0,
- LTTNG_WAIT_FORK = 1,
- LTTNG_WAIT_CPU = 2,
- LTTNG_EXIT = 3,
- LTTNG_ZOMBIE = 4,
- LTTNG_WAIT = 5,
- LTTNG_RUN = 6,
- LTTNG_DEAD = 7,
-};
-
-static
-int lttng_enumerate_block_devices(struct lttng_session *session)
-{
- struct class *ptr_block_class;
- struct device_type *ptr_disk_type;
- struct class_dev_iter iter;
- struct device *dev;
-
- ptr_block_class = wrapper_get_block_class();
- if (!ptr_block_class)
- return -ENOSYS;
- ptr_disk_type = wrapper_get_disk_type();
- if (!ptr_disk_type) {
- return -ENOSYS;
- }
- class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
- while ((dev = class_dev_iter_next(&iter))) {
- struct disk_part_iter piter;
- struct gendisk *disk = dev_to_disk(dev);
- struct hd_struct *part;
-
- /*
- * Don't show empty devices or things that have been
- * suppressed
- */
- if (get_capacity(disk) == 0 ||
- (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
- continue;
-
- disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
- while ((part = disk_part_iter_next(&piter))) {
- char name_buf[BDEVNAME_SIZE];
- char *p;
-
- p = wrapper_disk_name(disk, part->partno, name_buf);
- if (!p) {
- disk_part_iter_exit(&piter);
- class_dev_iter_exit(&iter);
- return -ENOSYS;
- }
- trace_lttng_statedump_block_device(session,
- part_devt(part), name_buf);
- }
- disk_part_iter_exit(&piter);
- }
- class_dev_iter_exit(&iter);
- return 0;
-}
-
-#ifdef CONFIG_INET
-
-static
-void lttng_enumerate_device(struct lttng_session *session,
- struct net_device *dev)
-{
- struct in_device *in_dev;
- struct in_ifaddr *ifa;
-
- if (dev->flags & IFF_UP) {
- in_dev = in_dev_get(dev);
- if (in_dev) {
- for (ifa = in_dev->ifa_list; ifa != NULL;
- ifa = ifa->ifa_next) {
- trace_lttng_statedump_network_interface(
- session, dev, ifa);
- }
- in_dev_put(in_dev);
- }
- } else {
- trace_lttng_statedump_network_interface(
- session, dev, NULL);
- }
-}
-
-static
-int lttng_enumerate_network_ip_interface(struct lttng_session *session)
-{
- struct net_device *dev;
-
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev)
- lttng_enumerate_device(session, dev);
- read_unlock(&dev_base_lock);
-
- return 0;
-}
-#else /* CONFIG_INET */
-static inline
-int lttng_enumerate_network_ip_interface(struct lttng_session *session)
-{
- return 0;
-}
-#endif /* CONFIG_INET */
-
-#ifdef FD_ISSET /* For old kernels lacking close_on_exec() */
-static inline bool lttng_close_on_exec(int fd, const struct fdtable *fdt)
-{
- return FD_ISSET(fd, fdt->close_on_exec);
-}
-#else
-static inline bool lttng_close_on_exec(int fd, const struct fdtable *fdt)
-{
- return close_on_exec(fd, fdt);
-}
-#endif
-
-static
-int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd)
-{
- const struct lttng_fd_ctx *ctx = p;
- const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
- unsigned int flags = file->f_flags;
- struct fdtable *fdt;
-
- /*
- * We don't expose kernel internal flags, only userspace-visible
- * flags.
- */
- flags &= ~FMODE_NONOTIFY;
- fdt = files_fdtable(ctx->files);
- /*
- * We need to check here again whether fd is within the fdt
- * max_fds range, because we might be seeing a different
- * files_fdtable() than iterate_fd(), assuming only RCU is
- * protecting the read. In reality, iterate_fd() holds
- * file_lock, which should ensure the fdt does not change while
- * the lock is taken, but we are not aware whether this is
- * guaranteed or not, so play safe.
- */
- if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
- flags |= O_CLOEXEC;
- if (IS_ERR(s)) {
- struct dentry *dentry = file->f_path.dentry;
-
- /* Make sure we give at least some info */
- spin_lock(&dentry->d_lock);
- trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd,
- dentry->d_name.name, flags, file->f_mode);
- spin_unlock(&dentry->d_lock);
- goto end;
- }
- trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s,
- flags, file->f_mode);
-end:
- return 0;
-}
-
-static
-void lttng_enumerate_task_fd(struct lttng_session *session,
- struct task_struct *p, char *tmp)
-{
- struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p };
- struct files_struct *files;
-
- task_lock(p);
- files = p->files;
- if (!files)
- goto end;
- ctx.files = files;
- lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
-end:
- task_unlock(p);
-}
-
-static
-int lttng_enumerate_file_descriptors(struct lttng_session *session)
-{
- struct task_struct *p;
- char *tmp;
-
- tmp = (char *) __get_free_page(GFP_KERNEL);
- if (!tmp)
- return -ENOMEM;
-
- /* Enumerate active file descriptors */
- rcu_read_lock();
- for_each_process(p)
- lttng_enumerate_task_fd(session, p, tmp);
- rcu_read_unlock();
- free_page((unsigned long) tmp);
- return 0;
-}
-
-#if 0
-/*
- * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
- * (scheduling in atomic). Normally, the tasklist lock protects this kind of
- * iteration, but it is not exported to modules.
- */
-static
-void lttng_enumerate_task_vm_maps(struct lttng_session *session,
- struct task_struct *p)
-{
- struct mm_struct *mm;
- struct vm_area_struct *map;
- unsigned long ino;
-
- /* get_task_mm does a task_lock... */
- mm = get_task_mm(p);
- if (!mm)
- return;
-
- map = mm->mmap;
- if (map) {
- down_read(&mm->mmap_sem);
- while (map) {
- if (map->vm_file)
- ino = map->vm_file->f_dentry->d_inode->i_ino;
- else
- ino = 0;
- trace_lttng_statedump_vm_map(session, p, map, ino);
- map = map->vm_next;
- }
- up_read(&mm->mmap_sem);
- }
- mmput(mm);
-}
-
-static
-int lttng_enumerate_vm_maps(struct lttng_session *session)
-{
- struct task_struct *p;
-
- rcu_read_lock();
- for_each_process(p)
- lttng_enumerate_task_vm_maps(session, p);
- rcu_read_unlock();
- return 0;
-}
-#endif
-
-#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
-
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39))
-#define irq_desc_get_chip(desc) get_irq_desc_chip(desc)
-#endif
-
-static
-int lttng_list_interrupts(struct lttng_session *session)
-{
- unsigned int irq;
- unsigned long flags = 0;
- struct irq_desc *desc;
-
-#define irq_to_desc wrapper_irq_to_desc
- /* needs irq_desc */
- for_each_irq_desc(irq, desc) {
- struct irqaction *action;
- const char *irq_chip_name =
- irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
-
- local_irq_save(flags);
- wrapper_desc_spin_lock(&desc->lock);
- for (action = desc->action; action; action = action->next) {
- trace_lttng_statedump_interrupt(session,
- irq, irq_chip_name, action);
- }
- wrapper_desc_spin_unlock(&desc->lock);
- local_irq_restore(flags);
- }
- return 0;
-#undef irq_to_desc
-}
-#else
-static inline
-int lttng_list_interrupts(struct lttng_session *session)
-{
- return 0;
-}
-#endif
-
-/*
- * Called with task lock held.
- */
-static
-void lttng_statedump_process_ns(struct lttng_session *session,
- struct task_struct *p,
- enum lttng_thread_type type,
- enum lttng_execution_mode mode,
- enum lttng_execution_submode submode,
- enum lttng_process_status status)
-{
- struct nsproxy *proxy;
- struct pid_namespace *pid_ns;
-
- /*
- * Back and forth on locking strategy within Linux upstream for nsproxy.
- * See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
- * "namespaces: Use task_lock and not rcu to protect nsproxy"
- * for details.
- */
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0))
- proxy = p->nsproxy;
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0)) */
- rcu_read_lock();
- proxy = task_nsproxy(p);
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0)) */
- if (proxy) {
- pid_ns = lttng_get_proxy_pid_ns(proxy);
- do {
- trace_lttng_statedump_process_state(session,
- p, type, mode, submode, status, pid_ns);
- pid_ns = pid_ns->parent;
- } while (pid_ns);
- } else {
- trace_lttng_statedump_process_state(session,
- p, type, mode, submode, status, NULL);
- }
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0))
- /* (nothing) */
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0)) */
- rcu_read_unlock();
-#endif /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0)) */
-}
-
-static
-int lttng_enumerate_process_states(struct lttng_session *session)
-{
- struct task_struct *g, *p;
-
- rcu_read_lock();
- for_each_process(g) {
- p = g;
- do {
- enum lttng_execution_mode mode =
- LTTNG_MODE_UNKNOWN;
- enum lttng_execution_submode submode =
- LTTNG_UNKNOWN;
- enum lttng_process_status status;
- enum lttng_thread_type type;
-
- task_lock(p);
- if (p->exit_state == EXIT_ZOMBIE)
- status = LTTNG_ZOMBIE;
- else if (p->exit_state == EXIT_DEAD)
- status = LTTNG_DEAD;
- else if (p->state == TASK_RUNNING) {
- /* Is this a forked child that has not run yet? */
- if (list_empty(&p->rt.run_list))
- status = LTTNG_WAIT_FORK;
- else
- /*
- * All tasks are considered as wait_cpu;
- * the viewer will sort out if the task
- * was really running at this time.
- */
- status = LTTNG_WAIT_CPU;
- } else if (p->state &
- (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) {
- /* Task is waiting for something to complete */
- status = LTTNG_WAIT;
- } else
- status = LTTNG_UNNAMED;
- submode = LTTNG_NONE;
-
- /*
- * Verification of t->mm is to filter out kernel
- * threads; Viewer will further filter out if a
- * user-space thread was in syscall mode or not.
- */
- if (p->mm)
- type = LTTNG_USER_THREAD;
- else
- type = LTTNG_KERNEL_THREAD;
- lttng_statedump_process_ns(session,
- p, type, mode, submode, status);
- task_unlock(p);
- } while_each_thread(g, p);
- }
- rcu_read_unlock();
-
- return 0;
-}
-
-static
-void lttng_statedump_work_func(struct work_struct *work)
-{
- if (atomic_dec_and_test(&kernel_threads_to_run))
- /* If we are the last thread, wake up do_lttng_statedump */
- wake_up(&statedump_wq);
-}
-
-static
-int do_lttng_statedump(struct lttng_session *session)
-{
- int cpu, ret;
-
- trace_lttng_statedump_start(session);
- ret = lttng_enumerate_process_states(session);
- if (ret)
- return ret;
- ret = lttng_enumerate_file_descriptors(session);
- if (ret)
- return ret;
- /*
- * FIXME
- * ret = lttng_enumerate_vm_maps(session);
- * if (ret)
- * return ret;
- */
- ret = lttng_list_interrupts(session);
- if (ret)
- return ret;
- ret = lttng_enumerate_network_ip_interface(session);
- if (ret)
- return ret;
- ret = lttng_enumerate_block_devices(session);
- switch (ret) {
- case -ENOSYS:
- printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
- break;
- default:
- return ret;
- }
-
- /* TODO lttng_dump_idt_table(session); */
- /* TODO lttng_dump_softirq_vec(session); */
- /* TODO lttng_list_modules(session); */
- /* TODO lttng_dump_swap_files(session); */
-
- /*
- * Fire off a work queue on each CPU. Their sole purpose in life
- * is to guarantee that each CPU has been in a state where is was in
- * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
- */
- get_online_cpus();
- atomic_set(&kernel_threads_to_run, num_online_cpus());
- for_each_online_cpu(cpu) {
- INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
- schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
- }
- /* Wait for all threads to run */
- __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
- put_online_cpus();
- /* Our work is done */
- trace_lttng_statedump_end(session);
- return 0;
-}
-
-/*
- * Called with session mutex held.
- */
-int lttng_statedump_start(struct lttng_session *session)
-{
- return do_lttng_statedump(session);
-}
-EXPORT_SYMBOL_GPL(lttng_statedump_start);
-
-static
-int __init lttng_statedump_init(void)
-{
- /*
- * Allow module to load even if the fixup cannot be done. This
- * will allow seemless transition when the underlying issue fix
- * is merged into the Linux kernel, and when tracepoint.c
- * "tracepoint_module_notify" is turned into a static function.
- */
- (void) wrapper_lttng_fixup_sig(THIS_MODULE);
- return 0;
-}
-
-module_init(lttng_statedump_init);
-
-static
-void __exit lttng_statedump_exit(void)
-{
-}
-
-module_exit(lttng_statedump_exit);
-
-MODULE_LICENSE("GPL and additional rights");
-MODULE_AUTHOR("Jean-Hugues Deschenes");
-MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Statedump");
-MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
- __stringify(LTTNG_MODULES_MINOR_VERSION) "."
- __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
- LTTNG_MODULES_EXTRAVERSION);
projects / lttng-modules.git / blobdiff