From e422267322cd319e2695a535e47c5b1feeac45eb Mon Sep 17 00:00:00 2001 From: Hari Bathini Date: Wed, 8 Mar 2017 02:11:36 +0530 Subject: [PATCH] perf: Add PERF_RECORD_NAMESPACES to include namespaces related info With the advert of container technologies like docker, that depend on namespaces for isolation, there is a need for tracing support for namespaces. This patch introduces new PERF_RECORD_NAMESPACES event for recording namespaces related info. By recording info for every namespace, it is left to userspace to take a call on the definition of a container and trace containers by updating perf tool accordingly. Each namespace has a combination of device and inode numbers. Though every namespace has the same device number currently, that may change in future to avoid the need for a namespace of namespaces. Considering such possibility, record both device and inode numbers separately for each namespace. Signed-off-by: Hari Bathini Acked-by: Jiri Olsa Acked-by: Peter Zijlstra Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Ananth N Mavinakayanahalli Cc: Aravinda Prasad Cc: Brendan Gregg Cc: Daniel Borkmann Cc: Eric Biederman Cc: Sargun Dhillon Cc: Steven Rostedt Link: http://lkml.kernel.org/r/148891929686.25309.2827618988917007768.stgit@hbathini.in.ibm.com Signed-off-by: Arnaldo Carvalho de Melo --- include/linux/perf_event.h | 2 + include/uapi/linux/perf_event.h | 32 +++++++- kernel/events/core.c | 139 ++++++++++++++++++++++++++++++++ kernel/fork.c | 2 + kernel/nsproxy.c | 3 + 5 files changed, 177 insertions(+), 1 deletion(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 000fdb211c7d..f19a82362851 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1112,6 +1112,7 @@ extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks extern void perf_event_exec(void); extern void perf_event_comm(struct task_struct *tsk, bool exec); +extern void perf_event_namespaces(struct task_struct *tsk); extern void perf_event_fork(struct task_struct *tsk); /* Callchains */ @@ -1315,6 +1316,7 @@ static inline int perf_unregister_guest_info_callbacks static inline void perf_event_mmap(struct vm_area_struct *vma) { } static inline void perf_event_exec(void) { } static inline void perf_event_comm(struct task_struct *tsk, bool exec) { } +static inline void perf_event_namespaces(struct task_struct *tsk) { } static inline void perf_event_fork(struct task_struct *tsk) { } static inline void perf_event_init(void) { } static inline int perf_swevent_get_recursion_context(void) { return -1; } diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index c66a485a24ac..bec0aad0e15c 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -344,7 +344,8 @@ struct perf_event_attr { use_clockid : 1, /* use @clockid for time fields */ context_switch : 1, /* context switch data */ write_backward : 1, /* Write ring buffer from end to beginning */ - __reserved_1 : 36; + namespaces : 1, /* include namespaces data */ + __reserved_1 : 35; union { __u32 wakeup_events; /* wakeup every n events */ @@ -610,6 +611,23 @@ struct perf_event_header { __u16 size; }; +struct perf_ns_link_info { + __u64 dev; + __u64 ino; +}; + +enum { + NET_NS_INDEX = 0, + UTS_NS_INDEX = 1, + IPC_NS_INDEX = 2, + PID_NS_INDEX = 3, + USER_NS_INDEX = 4, + MNT_NS_INDEX = 5, + CGROUP_NS_INDEX = 6, + + NR_NAMESPACES, /* number of available namespaces */ +}; + enum perf_event_type { /* @@ -862,6 +880,18 @@ enum perf_event_type { */ PERF_RECORD_SWITCH_CPU_WIDE = 15, + /* + * struct { + * struct perf_event_header header; + * u32 pid; + * u32 tid; + * u64 nr_namespaces; + * { u64 dev, inode; } [nr_namespaces]; + * struct sample_id sample_id; + * }; + */ + PERF_RECORD_NAMESPACES = 16, + PERF_RECORD_MAX, /* non-ABI */ }; diff --git a/kernel/events/core.c b/kernel/events/core.c index 6f41548f2e32..16c877a121c8 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -48,6 +48,8 @@ #include #include #include +#include +#include #include "internal.h" @@ -379,6 +381,7 @@ static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events); static atomic_t nr_mmap_events __read_mostly; static atomic_t nr_comm_events __read_mostly; +static atomic_t nr_namespaces_events __read_mostly; static atomic_t nr_task_events __read_mostly; static atomic_t nr_freq_events __read_mostly; static atomic_t nr_switch_events __read_mostly; @@ -3991,6 +3994,8 @@ static void unaccount_event(struct perf_event *event) atomic_dec(&nr_mmap_events); if (event->attr.comm) atomic_dec(&nr_comm_events); + if (event->attr.namespaces) + atomic_dec(&nr_namespaces_events); if (event->attr.task) atomic_dec(&nr_task_events); if (event->attr.freq) @@ -6491,6 +6496,7 @@ static void perf_event_task(struct task_struct *task, void perf_event_fork(struct task_struct *task) { perf_event_task(task, NULL, 1); + perf_event_namespaces(task); } /* @@ -6592,6 +6598,132 @@ void perf_event_comm(struct task_struct *task, bool exec) perf_event_comm_event(&comm_event); } +/* + * namespaces tracking + */ + +struct perf_namespaces_event { + struct task_struct *task; + + struct { + struct perf_event_header header; + + u32 pid; + u32 tid; + u64 nr_namespaces; + struct perf_ns_link_info link_info[NR_NAMESPACES]; + } event_id; +}; + +static int perf_event_namespaces_match(struct perf_event *event) +{ + return event->attr.namespaces; +} + +static void perf_event_namespaces_output(struct perf_event *event, + void *data) +{ + struct perf_namespaces_event *namespaces_event = data; + struct perf_output_handle handle; + struct perf_sample_data sample; + int ret; + + if (!perf_event_namespaces_match(event)) + return; + + perf_event_header__init_id(&namespaces_event->event_id.header, + &sample, event); + ret = perf_output_begin(&handle, event, + namespaces_event->event_id.header.size); + if (ret) + return; + + namespaces_event->event_id.pid = perf_event_pid(event, + namespaces_event->task); + namespaces_event->event_id.tid = perf_event_tid(event, + namespaces_event->task); + + perf_output_put(&handle, namespaces_event->event_id); + + perf_event__output_id_sample(event, &handle, &sample); + + perf_output_end(&handle); +} + +static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info, + struct task_struct *task, + const struct proc_ns_operations *ns_ops) +{ + struct path ns_path; + struct inode *ns_inode; + void *error; + + error = ns_get_path(&ns_path, task, ns_ops); + if (!error) { + ns_inode = ns_path.dentry->d_inode; + ns_link_info->dev = new_encode_dev(ns_inode->i_sb->s_dev); + ns_link_info->ino = ns_inode->i_ino; + } +} + +void perf_event_namespaces(struct task_struct *task) +{ + struct perf_namespaces_event namespaces_event; + struct perf_ns_link_info *ns_link_info; + + if (!atomic_read(&nr_namespaces_events)) + return; + + namespaces_event = (struct perf_namespaces_event){ + .task = task, + .event_id = { + .header = { + .type = PERF_RECORD_NAMESPACES, + .misc = 0, + .size = sizeof(namespaces_event.event_id), + }, + /* .pid */ + /* .tid */ + .nr_namespaces = NR_NAMESPACES, + /* .link_info[NR_NAMESPACES] */ + }, + }; + + ns_link_info = namespaces_event.event_id.link_info; + + perf_fill_ns_link_info(&ns_link_info[MNT_NS_INDEX], + task, &mntns_operations); + +#ifdef CONFIG_USER_NS + perf_fill_ns_link_info(&ns_link_info[USER_NS_INDEX], + task, &userns_operations); +#endif +#ifdef CONFIG_NET_NS + perf_fill_ns_link_info(&ns_link_info[NET_NS_INDEX], + task, &netns_operations); +#endif +#ifdef CONFIG_UTS_NS + perf_fill_ns_link_info(&ns_link_info[UTS_NS_INDEX], + task, &utsns_operations); +#endif +#ifdef CONFIG_IPC_NS + perf_fill_ns_link_info(&ns_link_info[IPC_NS_INDEX], + task, &ipcns_operations); +#endif +#ifdef CONFIG_PID_NS + perf_fill_ns_link_info(&ns_link_info[PID_NS_INDEX], + task, &pidns_operations); +#endif +#ifdef CONFIG_CGROUPS + perf_fill_ns_link_info(&ns_link_info[CGROUP_NS_INDEX], + task, &cgroupns_operations); +#endif + + perf_iterate_sb(perf_event_namespaces_output, + &namespaces_event, + NULL); +} + /* * mmap tracking */ @@ -9146,6 +9278,8 @@ static void account_event(struct perf_event *event) atomic_inc(&nr_mmap_events); if (event->attr.comm) atomic_inc(&nr_comm_events); + if (event->attr.namespaces) + atomic_inc(&nr_namespaces_events); if (event->attr.task) atomic_inc(&nr_task_events); if (event->attr.freq) @@ -9691,6 +9825,11 @@ SYSCALL_DEFINE5(perf_event_open, return -EACCES; } + if (attr.namespaces) { + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + } + if (attr.freq) { if (attr.sample_freq > sysctl_perf_event_sample_rate) return -EINVAL; diff --git a/kernel/fork.c b/kernel/fork.c index 6c463c80e93d..afa2947286cd 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2352,6 +2352,8 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) } } + perf_event_namespaces(current); + bad_unshare_cleanup_cred: if (new_cred) put_cred(new_cred); diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 782102e59eed..f6c5d330059a 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -26,6 +26,7 @@ #include #include #include +#include static struct kmem_cache *nsproxy_cachep; @@ -262,6 +263,8 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype) goto out; } switch_task_namespaces(tsk, new_nsproxy); + + perf_event_namespaces(tsk); out: fput(file); return err; -- 2.39.5