Commit 160c26bc authored by Ma Wupeng's avatar Ma Wupeng
Browse files

mm: Use wrapper to fix KABI broken in struct mempolicy 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6I1Z2


CVE: NA

--------------------------------

Since struct mempolicy is commonly used by external users, use wrapper
to fix KABI broken in struct mempolicy.

Signed-off-by: default avatarMa Wupeng <mawupeng1@huawei.com>
parent 334e66da

include/linux/mempolicy.h

+5 −1
Original line number Diff line number Diff line
@@ -51,13 +51,17 @@ struct mempolicy { 
		nodemask_t	 nodes;		/* interleave/bind */

		/* undefined for default */

	} v;

	int home_node;		/* Home node to use for MPOL_BIND and MPOL_PREFERRED_MANY */

	union {

		nodemask_t cpuset_mems_allowed;	/* relative to these nodes */

		nodemask_t user_nodemask;	/* nodemask passed by user */

	} w;

};



struct mempolicy_wrapper {

	struct mempolicy policy;

	int home_node;		/* Home node to use for MPOL_BIND and MPOL_PREFERRED_MANY */

};



/*

 * Support for managing mempolicy data objects (clone, copy, destroy)

 * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.

mm/mempolicy.c

+41 −21
Original line number Diff line number Diff line
@@ -122,12 +122,14 @@ enum zone_type policy_zone = 0; 
/*

 * run-time system-wide default policy => local allocation

 */

static struct mempolicy default_policy = {

static struct mempolicy_wrapper default_policy = {

	.policy = {

		.refcnt = ATOMIC_INIT(1), /* never free it */

		.mode = MPOL_LOCAL,

	}

};



static struct mempolicy preferred_node_policy[MAX_NUMNODES];

static struct mempolicy_wrapper preferred_node_policy[MAX_NUMNODES];



/**

 * numa_map_to_online_node - Find closest online node
@@ -165,13 +167,13 @@ struct mempolicy *get_task_policy(struct task_struct *p) 


	node = numa_node_id();

	if (node != NUMA_NO_NODE) {

		pol = &preferred_node_policy[node];

		pol = &preferred_node_policy[node].policy;

		/* preferred_node_policy is not initialised early in boot */

		if (pol->mode)

			return pol;

	}



	return &default_policy;

	return &default_policy.policy;

}



static const struct mempolicy_operations {
@@ -311,6 +313,7 @@ static int mpol_set_nodemask(struct mempolicy *pol, 
static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,

				  nodemask_t *nodes)

{

	struct mempolicy_wrapper *wrapper;

	struct mempolicy *policy;



	pr_debug("setting mode %d flags %d nodes[0] %lx\n",
@@ -346,10 +349,11 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, 
	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);

	if (!policy)

		return ERR_PTR(-ENOMEM);

	wrapper = container_of(policy, struct mempolicy_wrapper, policy);

	atomic_set(&policy->refcnt, 1);

	policy->mode = mode;

	policy->flags = flags;

	policy->home_node = NUMA_NO_NODE;

	wrapper->home_node = NUMA_NO_NODE;



	return policy;

}
@@ -933,7 +937,7 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, 
static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)

{

	nodes_clear(*nodes);

	if (p == &default_policy)

	if (p == &default_policy.policy)

		return;



	switch (p->mode) {
@@ -1013,7 +1017,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, 
		return -EINVAL;



	if (!pol)

		pol = &default_policy;	/* indicates default behavior */

		pol = &default_policy.policy;	/* indicates default behavior */



	if (flags & MPOL_F_NODE) {

		if (flags & MPOL_F_ADDR) {
@@ -1038,7 +1042,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, 
			goto out;

		}

	} else {

		*policy = pol == &default_policy ? MPOL_DEFAULT :

		*policy = pol == &default_policy.policy ? MPOL_DEFAULT :

						pol->mode;

		/*

		 * Internal mempolicy flags must be masked off before exposing
@@ -1530,6 +1534,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le 
		unsigned long, home_node, unsigned long, flags)

{

	struct mm_struct *mm = current->mm;

	struct mempolicy_wrapper *wrapper;

	struct vm_area_struct *vma;

	struct mempolicy *new;

	unsigned long vmstart;
@@ -1588,7 +1593,8 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le 
			break;

		}



		new->home_node = home_node;

		wrapper = container_of(new, struct mempolicy_wrapper, policy);

		wrapper->home_node = home_node;

		err = mbind_range(mm, vmstart, vmend, new);

		mpol_put(new);

		if (err)
@@ -2022,6 +2028,9 @@ nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) 
 */

static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd)

{

	struct mempolicy_wrapper *warpper;



	warpper = container_of(policy, struct mempolicy_wrapper, policy);

	if (policy->mode == MPOL_PREFERRED) {

		nd = policy->v.preferred_node;

	} else {
@@ -2042,8 +2051,8 @@ static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd) 


	if ((policy->mode == MPOL_BIND ||

	     policy->mode == MPOL_PREFERRED_MANY) &&

	    policy->home_node != NUMA_NO_NODE)

		return policy->home_node;

	    warpper->home_node != NUMA_NO_NODE)

		return warpper->home_node;



	return nd;

}
@@ -2439,7 +2448,7 @@ EXPORT_SYMBOL(alloc_pages_vma); 
 */

struct page *alloc_pages(gfp_t gfp, unsigned order)

{

	struct mempolicy *pol = &default_policy;

	struct mempolicy *pol = &default_policy.policy;

	struct page *page;



	if (!in_interrupt() && !(gfp & __GFP_THISNODE))
@@ -2488,17 +2497,22 @@ int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst) 
struct mempolicy *__mpol_dup(struct mempolicy *old)

{

	struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);

	struct mempolicy_wrapper *old_wrapper, *new_wrapper;



	if (!new)

		return ERR_PTR(-ENOMEM);



	old_wrapper = container_of(old, struct mempolicy_wrapper, policy);

	new_wrapper = container_of(new, struct mempolicy_wrapper, policy);



	/* task's mempolicy is protected by alloc_lock */

	if (old == current->mempolicy) {

		task_lock(current);

		*new = *old;

		*new_wrapper = *old_wrapper;

		task_unlock(current);

	} else

		*new = *old;

	} else {

		*new_wrapper = *old_wrapper;

	}



	if (current_cpuset_is_being_rebound()) {

		nodemask_t mems = cpuset_mems_allowed(current);
@@ -2511,13 +2525,18 @@ struct mempolicy *__mpol_dup(struct mempolicy *old) 
/* Slow path of a mempolicy comparison */

bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)

{

	struct mempolicy_wrapper *wrapper_a, *wrapper_b;



	wrapper_a = container_of(a, struct mempolicy_wrapper, policy);

	wrapper_b = container_of(b, struct mempolicy_wrapper, policy);



	if (!a || !b)

		return false;

	if (a->mode != b->mode)

		return false;

	if (a->flags != b->flags)

		return false;

	if (a->home_node != b->home_node)

	if (wrapper_a->home_node != wrapper_b->home_node)

		return false;

	if (mpol_store_user_nodemask(a))

		if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
@@ -2981,7 +3000,7 @@ void __init numa_policy_init(void) 
	int nid, prefer = 0;



	policy_cache = kmem_cache_create("numa_policy",

					 sizeof(struct mempolicy),

					 sizeof(struct mempolicy_wrapper),

					 0, SLAB_PANIC, NULL);



	sn_cache = kmem_cache_create("shared_policy_node",
@@ -2989,7 +3008,7 @@ void __init numa_policy_init(void) 
				     0, SLAB_PANIC, NULL);



	for_each_node(nid) {

		preferred_node_policy[nid] = (struct mempolicy) {

		preferred_node_policy[nid].policy = (struct mempolicy) {

			.refcnt = ATOMIC_INIT(1),

			.mode = MPOL_PREFERRED,

			.flags = MPOL_F_MOF | MPOL_F_MORON,
@@ -3202,7 +3221,8 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) 
	unsigned short mode = MPOL_DEFAULT;

	unsigned short flags = 0;



	if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) {

	if (pol && pol != &default_policy.policy &&

	    !(pol->flags & MPOL_F_MORON)) {

		mode = pol->mode;

		flags = pol->flags;

	}