X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-statedump-impl.c;h=657031ec9e535990683d37c24bbb64ae6e75ced0;hb=a6b7e443b580cf9d79d556239f0c131ce34dd95a;hp=066b9612c0ee5f3884f023c1211eef17c58ad305;hpb=d2a927acb6018b445a2b254b7aa11e63acb77858;p=lttng-modules.git diff --git a/lttng-statedump-impl.c b/lttng-statedump-impl.c index 066b9612..657031ec 100644 --- a/lttng-statedump-impl.c +++ b/lttng-statedump-impl.c @@ -1,4 +1,4 @@ -/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1) +/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) * * lttng-statedump.c * @@ -28,26 +28,16 @@ #include #include #include -#include #include #include #include #include +#include +#include +#include #include #include -#include -#include -#include -#include -#include -#include -#include -#include - -#ifdef CONFIG_LTTNG_HAS_LIST_IRQ -#include -#endif /* Define the tracepoints, but do not build the probes */ #define CREATE_TRACE_POINTS @@ -81,7 +71,6 @@ DEFINE_TRACE(lttng_statedump_cpu_topology); struct lttng_fd_ctx { char *page; struct lttng_session *session; - struct task_struct *p; struct files_struct *files; }; @@ -125,19 +114,11 @@ enum lttng_process_status { 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); + class_dev_iter_init(&iter, gendisk_block_class(), NULL, + gendisk_device_type()); while ((dev = class_dev_iter_next(&iter))) { struct disk_part_iter piter; struct gendisk *disk = dev_to_disk(dev); @@ -156,7 +137,7 @@ int lttng_enumerate_block_devices(struct lttng_session *session) char name_buf[BDEVNAME_SIZE]; char *p; - p = wrapper_disk_name(disk, part->partno, name_buf); + p = gendisk_name(disk, part->partno, name_buf); if (!p) { disk_part_iter_exit(&piter); class_dev_iter_exit(&iter); @@ -239,58 +220,34 @@ int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd) * 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)) + if (fd < fdt->max_fds && 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); + trace_lttng_statedump_file_descriptor(ctx->session, + ctx->files, 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); + trace_lttng_statedump_file_descriptor(ctx->session, + ctx->files, fd, s, flags, file->f_mode); end: return 0; } +/* Called with task lock held. */ 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) +void lttng_enumerate_files(struct lttng_session *session, + struct files_struct *files, + char *tmp) { - struct task_struct *p; - char *tmp; + struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = files, }; - 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; + iterate_fd(files, 0, lttng_dump_one_fd, &ctx); } #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY @@ -339,7 +296,7 @@ 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->lttng_f_dentry->d_inode->i_ino; + ino = map->vm_file->f_path.dentry->d_inode->i_ino; else ino = 0; trace_lttng_statedump_vm_map(session, p, map, ino); @@ -363,8 +320,6 @@ int lttng_enumerate_vm_maps(struct lttng_session *session) } #endif -#ifdef CONFIG_LTTNG_HAS_LIST_IRQ - static int lttng_list_interrupts(struct lttng_session *session) { @@ -372,7 +327,6 @@ int lttng_list_interrupts(struct lttng_session *session) 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; @@ -389,15 +343,7 @@ int lttng_list_interrupts(struct lttng_session *session) local_irq_restore(flags); } return 0; -#undef irq_to_desc -} -#else -static inline -int lttng_list_interrupts(struct lttng_session *session) -{ - return 0; } -#endif /* * Statedump the task's namespaces using the proc filesystem inode number as @@ -426,14 +372,23 @@ void lttng_statedump_process_ns(struct lttng_session *session, pid_ns = task_active_pid_ns(p); do { trace_lttng_statedump_process_pid_ns(session, p, pid_ns); - pid_ns = pid_ns->parent; + pid_ns = pid_ns ? pid_ns->parent : NULL; } while (pid_ns); user_ns = task_cred_xxx(p, user_ns); do { trace_lttng_statedump_process_user_ns(session, p, user_ns); - user_ns = user_ns->lttng_user_ns_parent; + /* + * trace_lttng_statedump_process_user_ns() internally + * checks whether user_ns is NULL. While this does not + * appear to be a possible return value for + * task_cred_xxx(), err on the safe side and check + * for NULL here as well to be consistent with the + * paranoid behavior of + * trace_lttng_statedump_process_user_ns(). + */ + user_ns = user_ns ? user_ns->parent : NULL; } while (user_ns); /* @@ -476,9 +431,16 @@ static int lttng_enumerate_process_states(struct lttng_session *session) { struct task_struct *g, *p; + char *tmp; + + tmp = (char *) __get_free_page(GFP_KERNEL); + if (!tmp) + return -ENOMEM; rcu_read_lock(); for_each_process(g) { + struct files_struct *prev_files = NULL; + p = g; do { enum lttng_execution_mode mode = @@ -487,6 +449,7 @@ int lttng_enumerate_process_states(struct lttng_session *session) LTTNG_UNKNOWN; enum lttng_process_status status; enum lttng_thread_type type; + struct files_struct *files; task_lock(p); if (p->exit_state == EXIT_ZOMBIE) @@ -521,16 +484,31 @@ int lttng_enumerate_process_states(struct lttng_session *session) type = LTTNG_USER_THREAD; else type = LTTNG_KERNEL_THREAD; + files = p->files; trace_lttng_statedump_process_state(session, - p, type, mode, submode, status); + p, type, mode, submode, status, files); lttng_statedump_process_ns(session, p, type, mode, submode, status); + /* + * As an optimisation for the common case, do not + * repeat information for the same files_struct in + * two consecutive threads. This is the common case + * for threads sharing the same fd table. RCU guarantees + * that the same files_struct pointer is not re-used + * throughout processes/threads iteration. + */ + if (files && files != prev_files) { + lttng_enumerate_files(session, files, tmp); + prev_files = files; + } task_unlock(p); } while_each_thread(g, p); } rcu_read_unlock(); + free_page((unsigned long) tmp); + return 0; } @@ -549,9 +527,6 @@ int do_lttng_statedump(struct lttng_session *session) 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; /* @@ -616,13 +591,6 @@ 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; }