X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-statedump-impl.c;h=9dc0eb199f90c4c61048223ba58dff651a815e47;hb=b7cdc18250880cc44edeef4a4b42c8ac7a135a6d;hp=8ce50c09fc110d7e64e8d721ce60dc6a50536765;hpb=fc94c945a818ebfff1b05c08d11cef564208749c;p=lttng-modules.git diff --git a/lttng-statedump-impl.c b/lttng-statedump-impl.c index 8ce50c09..9dc0eb19 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 * @@ -28,7 +28,6 @@ #include #include #include -#include #include #include #include @@ -38,11 +37,12 @@ #include #include #include +#include #include #include #include #include -#include +#include #ifdef CONFIG_LTTNG_HAS_LIST_IRQ #include @@ -61,6 +61,17 @@ 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_process_pid_ns); +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0)) +DEFINE_TRACE(lttng_statedump_process_cgroup_ns); +#endif +DEFINE_TRACE(lttng_statedump_process_ipc_ns); +#ifndef LTTNG_MNT_NS_MISSING_HEADER +DEFINE_TRACE(lttng_statedump_process_mnt_ns); +#endif +DEFINE_TRACE(lttng_statedump_process_net_ns); +DEFINE_TRACE(lttng_statedump_process_user_ns); +DEFINE_TRACE(lttng_statedump_process_uts_ns); DEFINE_TRACE(lttng_statedump_network_interface); #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY DEFINE_TRACE(lttng_statedump_cpu_topology); @@ -69,7 +80,6 @@ DEFINE_TRACE(lttng_statedump_cpu_topology); struct lttng_fd_ctx { char *page; struct lttng_session *session; - struct task_struct *p; struct files_struct *files; }; @@ -234,51 +244,27 @@ int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd) /* 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) +void lttng_enumerate_files(struct lttng_session *session, + struct files_struct *files, + char *tmp) { - struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p }; - struct files_struct *files; + struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = 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; } #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY @@ -353,10 +339,6 @@ int lttng_enumerate_vm_maps(struct lttng_session *session) #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) { @@ -392,6 +374,10 @@ int lttng_list_interrupts(struct lttng_session *session) #endif /* + * Statedump the task's namespaces using the proc filesystem inode number as + * the unique identifier. The user and pid ns are nested and will be dumped + * recursively. + * * Called with task lock held. */ static @@ -402,23 +388,87 @@ 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; + struct user_namespace *user_ns; + /* + * The pid and user namespaces are special, they are nested and + * accessed with specific functions instead of the nsproxy struct + * like the other namespaces. + */ pid_ns = task_active_pid_ns(p); do { - trace_lttng_statedump_process_state(session, - p, type, mode, submode, status, pid_ns); - pid_ns = pid_ns->parent; + trace_lttng_statedump_process_pid_ns(session, p, pid_ns); + 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); + /* + * 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->lttng_user_ns_parent : NULL; + } while (user_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) || \ + LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \ + LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \ + LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0)) + proxy = p->nsproxy; +#else + rcu_read_lock(); + proxy = task_nsproxy(p); +#endif + if (proxy) { +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0)) + trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns); +#endif + trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns); +#ifndef LTTNG_MNT_NS_MISSING_HEADER + trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns); +#endif + trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns); + trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns); + } +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \ + LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \ + LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \ + LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0)) + /* (nothing) */ +#else + rcu_read_unlock(); +#endif } 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 = @@ -427,6 +477,7 @@ 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) @@ -461,13 +512,31 @@ 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, 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; } @@ -486,9 +555,6 @@ 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; /*