Commit 709e50cf authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf_counter: Use PID namespaces properly 



Stop using task_struct::pid and start using PID namespaces.

PIDs will be reported in the PID namespace of the monitoring
task at the moment of counter creation.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent bf4e0ed3

include/linux/perf_counter.h

+3 −0
Original line number Diff line number Diff line
@@ -317,6 +317,7 @@ enum perf_event_type { 
#include <linux/spinlock.h>

#include <linux/hrtimer.h>

#include <linux/fs.h>

#include <linux/pid_namespace.h>

#include <asm/atomic.h>



struct task_struct;
@@ -500,6 +501,8 @@ struct perf_counter { 


	void (*destroy)(struct perf_counter *);

	struct rcu_head			rcu_head;



	struct pid_namespace		*ns;

#endif

};

kernel/perf_counter.c

+34 −8
Original line number Diff line number Diff line
@@ -1432,6 +1432,8 @@ static void free_counter_rcu(struct rcu_head *head) 
	struct perf_counter *counter;



	counter = container_of(head, struct perf_counter, rcu_head);

	if (counter->ns)

		put_pid_ns(counter->ns);

	kfree(counter);

}
@@ -2267,6 +2269,28 @@ static void perf_output_end(struct perf_output_handle *handle) 
	rcu_read_unlock();

}



static u32 perf_counter_pid(struct perf_counter *counter, struct task_struct *p)

{

	/*

	 * only top level counters have the pid namespace they were created in

	 */

	if (counter->parent)

		counter = counter->parent;



	return task_tgid_nr_ns(p, counter->ns);

}



static u32 perf_counter_tid(struct perf_counter *counter, struct task_struct *p)

{

	/*

	 * only top level counters have the pid namespace they were created in

	 */

	if (counter->parent)

		counter = counter->parent;



	return task_pid_nr_ns(p, counter->ns);

}



static void perf_counter_output(struct perf_counter *counter,

				int nmi, struct pt_regs *regs, u64 addr)

{
@@ -2303,8 +2327,8 @@ static void perf_counter_output(struct perf_counter *counter, 


	if (record_type & PERF_RECORD_TID) {

		/* namespace issues */

		tid_entry.pid = current->group_leader->pid;

		tid_entry.tid = current->pid;

		tid_entry.pid = perf_counter_pid(counter, current);

		tid_entry.tid = perf_counter_tid(counter, current);



		header.type |= PERF_RECORD_TID;

		header.size += sizeof(tid_entry);
@@ -2432,6 +2456,9 @@ static void perf_counter_comm_output(struct perf_counter *counter, 
	if (ret)

		return;



	comm_event->event.pid = perf_counter_pid(counter, comm_event->task);

	comm_event->event.tid = perf_counter_tid(counter, comm_event->task);



	perf_output_put(&handle, comm_event->event);

	perf_output_copy(&handle, comm_event->comm,

				   comm_event->comm_size);
@@ -2504,8 +2531,6 @@ void perf_counter_comm(struct task_struct *task) 
		.task	= task,

		.event  = {

			.header = { .type = PERF_EVENT_COMM, },

			.pid	= task->group_leader->pid,

			.tid	= task->pid,

		},

	};
@@ -2542,6 +2567,9 @@ static void perf_counter_mmap_output(struct perf_counter *counter, 
	if (ret)

		return;



	mmap_event->event.pid = perf_counter_pid(counter, current);

	mmap_event->event.tid = perf_counter_tid(counter, current);



	perf_output_put(&handle, mmap_event->event);

	perf_output_copy(&handle, mmap_event->file_name,

				   mmap_event->file_size);
@@ -2641,8 +2669,6 @@ void perf_counter_mmap(unsigned long addr, unsigned long len, 
		.file   = file,

		.event  = {

			.header = { .type = PERF_EVENT_MMAP, },

			.pid	= current->group_leader->pid,

			.tid	= current->pid,

			.start  = addr,

			.len    = len,

			.pgoff  = pgoff,
@@ -2664,8 +2690,6 @@ void perf_counter_munmap(unsigned long addr, unsigned long len, 
		.file   = file,

		.event  = {

			.header = { .type = PERF_EVENT_MUNMAP, },

			.pid	= current->group_leader->pid,

			.tid	= current->pid,

			.start  = addr,

			.len    = len,

			.pgoff  = pgoff,
@@ -3445,6 +3469,8 @@ SYSCALL_DEFINE5(perf_counter_open, 
	list_add_tail(&counter->owner_entry, &current->perf_counter_list);

	mutex_unlock(&current->perf_counter_mutex);



	counter->ns = get_pid_ns(current->nsproxy->pid_ns);



	fput_light(counter_file, fput_needed2);



out_fput:

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