fix: adjust ranges for RHEL 8.4
[lttng-modules.git] / lttng-statedump-impl.c
old mode 100755 (executable)
new mode 100644 (file)
index ce47f04..fc9e9db
@@ -1,4 +1,5 @@
-/*
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
  * lttng-statedump.c
  *
  * Linux Trace Toolkit Next Generation Kernel State Dump
@@ -6,20 +7,6 @@
  * 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
 #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 "lttng-events.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 <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/irq.h>
+#include <wrapper/tracepoint.h>
+#include <wrapper/genhd.h>
+#include <wrapper/file.h>
+#include <wrapper/fdtable.h>
 
 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
 #include <linux/irq.h>
 
 /* Define the tracepoints, but do not build the probes */
 #define CREATE_TRACE_POINTS
-#define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module
+#define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
 #define TRACE_INCLUDE_FILE lttng-statedump
-#include "instrumentation/events/lttng-module/lttng-statedump.h"
+#define LTTNG_INSTRUMENTATION
+#include <instrumentation/events/lttng-module/lttng-statedump.h>
+
+LTTNG_DEFINE_TRACE(lttng_statedump_block_device,
+       TP_PROTO(struct lttng_session *session,
+               dev_t dev, const char *diskname),
+       TP_ARGS(session, dev, diskname));
+
+LTTNG_DEFINE_TRACE(lttng_statedump_end,
+       TP_PROTO(struct lttng_session *session),
+       TP_ARGS(session));
+
+LTTNG_DEFINE_TRACE(lttng_statedump_interrupt,
+       TP_PROTO(struct lttng_session *session,
+               unsigned int irq, const char *chip_name,
+               struct irqaction *action),
+       TP_ARGS(session, irq, chip_name, action));
+
+LTTNG_DEFINE_TRACE(lttng_statedump_file_descriptor,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p, int fd, const char *filename,
+               unsigned int flags, fmode_t fmode),
+       TP_ARGS(session, p, fd, filename, flags, fmode));
+
+LTTNG_DEFINE_TRACE(lttng_statedump_start,
+       TP_PROTO(struct lttng_session *session),
+       TP_ARGS(session));
+
+LTTNG_DEFINE_TRACE(lttng_statedump_process_state,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p,
+               int type, int mode, int submode, int status,
+               struct pid_namespace *pid_ns),
+       TP_ARGS(session, p, type, mode, submode, status, pid_ns));
+
+LTTNG_DEFINE_TRACE(lttng_statedump_network_interface,
+       TP_PROTO(struct lttng_session *session,
+               struct net_device *dev, struct in_ifaddr *ifa),
+       TP_ARGS(session, dev, ifa));
 
 struct lttng_fd_ctx {
        char *page;
        struct lttng_session *session;
        struct task_struct *p;
+       struct files_struct *files;
 };
 
 /*
@@ -107,7 +136,156 @@ enum lttng_process_status {
        LTTNG_DEAD = 7,
 };
 
+
+#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,11,0))
+
+#define LTTNG_PART_STRUCT_TYPE struct block_device
+
+static
+int lttng_get_part_name(struct gendisk *disk, struct block_device *part, char *name_buf)
+{
+       const char *p;
+
+       p = bdevname(part, name_buf);
+       if (!p)
+               return -ENOSYS;
+
+       return 0;
+}
+
+static
+dev_t lttng_get_part_devt(struct block_device *part)
+{
+       return part->bd_dev;
+}
+
+#else
+
+#define LTTNG_PART_STRUCT_TYPE struct hd_struct
+
+static
+int lttng_get_part_name(struct gendisk *disk, struct hd_struct *part, char *name_buf)
+{
+       const char *p;
+       struct block_device bdev;
+
+       /*
+        * Create a partial 'struct blockdevice' to use
+        * 'bdevname()' which is a simple wrapper over
+        * 'disk_name()' but has the honor to be EXPORT_SYMBOL.
+        */
+       bdev.bd_disk = disk;
+       bdev.bd_part = part;
+
+       p = bdevname(&bdev, name_buf);
+       if (!p)
+               return -ENOSYS;
+
+       return 0;
+}
+
+static
+dev_t lttng_get_part_devt(struct hd_struct *part)
+{
+       return part_devt(part);
+}
+#endif
+
+#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,12,0))
+static
+int lttng_statedump_each_block_device(struct lttng_session *session, struct gendisk *disk)
+{
+       struct block_device *part;
+       unsigned long idx;
+       int ret = 0;
+
+       /* Include partition 0 */
+       idx = 0;
+
+       rcu_read_lock();
+       xa_for_each(&disk->part_tbl, idx, part) {
+               char name_buf[BDEVNAME_SIZE];
+
+               /* Exclude non-partitions bdev and empty partitions. */
+               if (bdev_is_partition(part) && !bdev_nr_sectors(part))
+                       continue;
+
+               if (lttng_get_part_name(disk, part, name_buf) == -ENOSYS) {
+                       ret = -ENOSYS;
+                       goto end;
+               }
+               trace_lttng_statedump_block_device(session, lttng_get_part_devt(part),
+                               name_buf);
+       }
+end:
+       rcu_read_unlock();
+       return ret;
+}
+#else
+static
+int lttng_statedump_each_block_device(struct lttng_session *session, struct gendisk *disk)
+{
+       struct disk_part_iter piter;
+       LTTNG_PART_STRUCT_TYPE *part;
+
+       disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
+
+       while ((part = disk_part_iter_next(&piter))) {
+               char name_buf[BDEVNAME_SIZE];
+
+               if (lttng_get_part_name(disk, part, name_buf) == -ENOSYS) {
+                       disk_part_iter_exit(&piter);
+                       return -ENOSYS;
+               }
+               trace_lttng_statedump_block_device(session, lttng_get_part_devt(part),
+                               name_buf);
+       }
+       disk_part_iter_exit(&piter);
+
+       return 0;
+}
+#endif
+
+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;
+       int ret = 0;
+
+       ptr_block_class = wrapper_get_block_class();
+       if (!ptr_block_class) {
+               ret = -ENOSYS;
+               goto end;
+       }
+       ptr_disk_type = wrapper_get_disk_type();
+       if (!ptr_disk_type) {
+               ret = -ENOSYS;
+               goto end;
+       }
+       class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
+       while ((dev = class_dev_iter_next(&iter))) {
+               struct gendisk *disk = dev_to_disk(dev);
+
+               /*
+                * Don't show empty devices or things that have been
+                * suppressed
+                */
+               if (get_capacity(disk) == 0 ||
+                   (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
+                       continue;
+
+               ret = lttng_statedump_each_block_device(session, disk);
+       }
+       class_dev_iter_exit(&iter);
+end:
+       return ret;
+}
+
 #ifdef CONFIG_INET
+
 static
 void lttng_enumerate_device(struct lttng_session *session,
                struct net_device *dev)
@@ -156,18 +334,38 @@ 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);
+                       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);
+       trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s,
+               flags, file->f_mode);
 end:
        return 0;
 }
@@ -177,9 +375,15 @@ 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);
-       lttng_iterate_fd(p->files, 0, lttng_dump_one_fd, &ctx);
+       files = p->files;
+       if (!files)
+               goto end;
+       ctx.files = files;
+       lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
+end:
        task_unlock(p);
 }
 
@@ -187,7 +391,11 @@ static
 int lttng_enumerate_file_descriptors(struct lttng_session *session)
 {
        struct task_struct *p;
-       char *tmp = (char *) __get_free_page(GFP_KERNEL);
+       char *tmp;
+
+       tmp = (char *) __get_free_page(GFP_KERNEL);
+       if (!tmp)
+               return -ENOMEM;
 
        /* Enumerate active file descriptors */
        rcu_read_lock();
@@ -222,7 +430,7 @@ void lttng_enumerate_task_vm_maps(struct lttng_session *session,
                down_read(&mm->mmap_sem);
                while (map) {
                        if (map->vm_file)
-                               ino = map->vm_file->f_dentry->d_inode->i_ino;
+                               ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
                        else
                                ino = 0;
                        trace_lttng_statedump_vm_map(session, p, map, ino);
@@ -248,12 +456,12 @@ int lttng_enumerate_vm_maps(struct lttng_session *session)
 
 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
 
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39))
+#if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(2,6,39))
 #define irq_desc_get_chip(desc) get_irq_desc_chip(desc)
 #endif
 
 static
-void lttng_list_interrupts(struct lttng_session *session)
+int lttng_list_interrupts(struct lttng_session *session)
 {
        unsigned int irq;
        unsigned long flags = 0;
@@ -275,15 +483,20 @@ void lttng_list_interrupts(struct lttng_session *session)
                wrapper_desc_spin_unlock(&desc->lock);
                local_irq_restore(flags);
        }
+       return 0;
 #undef irq_to_desc
 }
 #else
 static inline
-void lttng_list_interrupts(struct lttng_session *session)
+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,
@@ -292,23 +505,14 @@ void lttng_statedump_process_ns(struct lttng_session *session,
                enum lttng_execution_submode submode,
                enum lttng_process_status status)
 {
-       struct nsproxy *proxy;
        struct pid_namespace *pid_ns;
 
-       rcu_read_lock();
-       proxy = task_nsproxy(p);
-       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 {
+       pid_ns = task_active_pid_ns(p);
+       do {
                trace_lttng_statedump_process_state(session,
-                       p, type, mode, submode, status, NULL);
-       }
-       rcu_read_unlock();
+                       p, type, mode, submode, status, pid_ns);
+               pid_ns = pid_ns ? pid_ns->parent : NULL;
+       } while (pid_ns);
 }
 
 static
@@ -381,14 +585,37 @@ void lttng_statedump_work_func(struct work_struct *work)
 static
 int do_lttng_statedump(struct lttng_session *session)
 {
-       int cpu;
+       int cpu, ret;
 
        trace_lttng_statedump_start(session);
-       lttng_enumerate_process_states(session);
-       lttng_enumerate_file_descriptors(session);
-       /* FIXME lttng_enumerate_vm_maps(session); */
-       lttng_list_interrupts(session);
-       lttng_enumerate_network_ip_interface(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 0:
+               break;
+       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); */
@@ -426,11 +653,29 @@ EXPORT_SYMBOL_GPL(lttng_statedump_start);
 static
 int __init lttng_statedump_init(void)
 {
-       return wrapper_lttng_fixup_sig(THIS_MODULE);
+       /*
+        * 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_DESCRIPTION("LTTng statedump provider");
+MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
+       __stringify(LTTNG_MODULES_MINOR_VERSION) "."
+       __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
+       LTTNG_MODULES_EXTRAVERSION);
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