Commit 5f7b703f authored by Pavel Emelyanov's avatar Pavel Emelyanov Committed by Linus Torvalds
Browse files

bsd_acct: using task_struct->tgid is not right in pid-namespaces 



In case we're accounting from a sub-namespace, the tgids reported will not
refer to the right namespace.

Save the pid_namespace we're accounting in on the acct_glbs and use it in
do_acct_process.

Two less :) places using the task_struct.tgid member.

Signed-off-by: default avatarPavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a846a195

kernel/acct.c

+15 −6
Original line number Original line Diff line number Diff line
@@ -58,6 +58,7 @@ 
#include <asm/uaccess.h>

#include <asm/uaccess.h>

#include <asm/div64.h>

#include <asm/div64.h>

#include <linux/blkdev.h> /* sector_div */

#include <linux/blkdev.h> /* sector_div */

#include <linux/pid_namespace.h>





/*

/*

 * These constants control the amount of freespace that suspend and

 * These constants control the amount of freespace that suspend and
@@ -74,7 +75,7 @@ int acct_parm[3] = {4, 2, 30}; 
/*

/*

 * External references and all of the globals.

 * External references and all of the globals.

 */

 */

static void do_acct_process(struct file *);

static void do_acct_process(struct pid_namespace *ns, struct file *);





/*

/*

 * This structure is used so that all the data protected by lock

 * This structure is used so that all the data protected by lock
@@ -86,6 +87,7 @@ struct acct_glbs { 
	volatile int		active;

	volatile int		active;

	volatile int		needcheck;

	volatile int		needcheck;

	struct file		*file;

	struct file		*file;

	struct pid_namespace	*ns;

	struct timer_list	timer;

	struct timer_list	timer;

};

};
@@ -175,9 +177,11 @@ out: 
static void acct_file_reopen(struct file *file)

static void acct_file_reopen(struct file *file)

{

{

	struct file *old_acct = NULL;

	struct file *old_acct = NULL;

	struct pid_namespace *old_ns = NULL;





	if (acct_globals.file) {

	if (acct_globals.file) {

		old_acct = acct_globals.file;

		old_acct = acct_globals.file;

		old_ns = acct_globals.ns;

		del_timer(&acct_globals.timer);

		del_timer(&acct_globals.timer);

		acct_globals.active = 0;

		acct_globals.active = 0;

		acct_globals.needcheck = 0;

		acct_globals.needcheck = 0;
@@ -185,6 +189,7 @@ static void acct_file_reopen(struct file *file) 
	}

	}

	if (file) {

	if (file) {

		acct_globals.file = file;

		acct_globals.file = file;

		acct_globals.ns = get_pid_ns(task_active_pid_ns(current));

		acct_globals.needcheck = 0;

		acct_globals.needcheck = 0;

		acct_globals.active = 1;

		acct_globals.active = 1;

		/* It's been deleted if it was used before so this is safe */

		/* It's been deleted if it was used before so this is safe */
@@ -196,8 +201,9 @@ static void acct_file_reopen(struct file *file) 
	if (old_acct) {

	if (old_acct) {

		mnt_unpin(old_acct->f_path.mnt);

		mnt_unpin(old_acct->f_path.mnt);

		spin_unlock(&acct_globals.lock);

		spin_unlock(&acct_globals.lock);

		do_acct_process(old_acct);

		do_acct_process(old_ns, old_acct);

		filp_close(old_acct, NULL);

		filp_close(old_acct, NULL);

		put_pid_ns(old_ns);

		spin_lock(&acct_globals.lock);

		spin_lock(&acct_globals.lock);

	}

	}

}

}
@@ -419,7 +425,7 @@ static u32 encode_float(u64 value) 
/*

/*

 *  do_acct_process does all actual work. Caller holds the reference to file.

 *  do_acct_process does all actual work. Caller holds the reference to file.

 */

 */

static void do_acct_process(struct file *file)

static void do_acct_process(struct pid_namespace *ns, struct file *file)

{

{

	struct pacct_struct *pacct = &current->signal->pacct;

	struct pacct_struct *pacct = &current->signal->pacct;

	acct_t ac;

	acct_t ac;
@@ -481,9 +487,9 @@ static void do_acct_process(struct file *file) 
	ac.ac_gid16 = current->gid;

	ac.ac_gid16 = current->gid;

#endif

#endif

#if ACCT_VERSION==3

#if ACCT_VERSION==3

	ac.ac_pid = current->tgid;

	ac.ac_pid = task_tgid_nr_ns(current, ns);

	rcu_read_lock();

	rcu_read_lock();

	ac.ac_ppid = rcu_dereference(current->real_parent)->tgid;

	ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns);

	rcu_read_unlock();

	rcu_read_unlock();

#endif

#endif
@@ -580,6 +586,7 @@ void acct_collect(long exitcode, int group_dead) 
void acct_process(void)

void acct_process(void)

{

{

	struct file *file = NULL;

	struct file *file = NULL;

	struct pid_namespace *ns;





	/*

	/*

	 * accelerate the common fastpath:

	 * accelerate the common fastpath:
@@ -594,8 +601,10 @@ void acct_process(void) 
		return;

		return;

	}

	}

	get_file(file);

	get_file(file);

	ns = get_pid_ns(acct_globals.ns);

	spin_unlock(&acct_globals.lock);

	spin_unlock(&acct_globals.lock);





	do_acct_process(file);

	do_acct_process(ns, file);

	fput(file);

	fput(file);

	put_pid_ns(ns);

}
 
}

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