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Commit 596d7cfa authored by KOSAKI Motohiro's avatar KOSAKI Motohiro Committed by Linus Torvalds
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mempolicy: reduce stack size of migrate_pages() 



migrate_pages() is using >500 bytes stack. Reduce it.

   mm/mempolicy.c: In function 'sys_migrate_pages':
   mm/mempolicy.c:1344: warning: the frame size of 528 bytes is larger than 512 bytes

[akpm@linux-foundation.org: don't play with a might-be-NULL pointer]
Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: default avatarChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 25106000

mm/mempolicy.c

+25 −13
Original line number Diff line number Diff line
@@ -1275,33 +1275,42 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, 
		const unsigned long __user *, new_nodes)

{

	const struct cred *cred = current_cred(), *tcred;

	struct mm_struct *mm;

	struct mm_struct *mm = NULL;

	struct task_struct *task;

	nodemask_t old;

	nodemask_t new;

	nodemask_t task_nodes;

	int err;

	nodemask_t *old;

	nodemask_t *new;

	NODEMASK_SCRATCH(scratch);



	if (!scratch)

		return -ENOMEM;



	err = get_nodes(&old, old_nodes, maxnode);

	old = &scratch->mask1;

	new = &scratch->mask2;



	err = get_nodes(old, old_nodes, maxnode);

	if (err)

		return err;

		goto out;



	err = get_nodes(&new, new_nodes, maxnode);

	err = get_nodes(new, new_nodes, maxnode);

	if (err)

		return err;

		goto out;



	/* Find the mm_struct */

	read_lock(&tasklist_lock);

	task = pid ? find_task_by_vpid(pid) : current;

	if (!task) {

		read_unlock(&tasklist_lock);

		return -ESRCH;

		err = -ESRCH;

		goto out;

	}

	mm = get_task_mm(task);

	read_unlock(&tasklist_lock);



	err = -EINVAL;

	if (!mm)

		return -EINVAL;

		goto out;



	/*

	 * Check if this process has the right to modify the specified
@@ -1322,12 +1331,12 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, 


	task_nodes = cpuset_mems_allowed(task);

	/* Is the user allowed to access the target nodes? */

	if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) {

	if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {

		err = -EPERM;

		goto out;

	}



	if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) {

	if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) {

		err = -EINVAL;

		goto out;

	}
@@ -1336,10 +1345,13 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, 
	if (err)

		goto out;



	err = do_migrate_pages(mm, &old, &new,

	err = do_migrate_pages(mm, old, new,

		capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);

out:

	if (mm)

		mmput(mm);

	NODEMASK_SCRATCH_FREE(scratch);



	return err;

}