[PATCH 3/6] selinux: convert to kvmalloc

From: Kent Overstreet
Date: Fri Sep 07 2018 - 12:56:52 EST

The flex arrays were being used for constant sized arrays, so there's no
benefit to using flex_arrays over something simpler.

Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: linux-security-module@xxxxxxxxxxxxxxx
---
security/selinux/ss/avtab.c | 40 +++++-----
security/selinux/ss/avtab.h | 4 +-
security/selinux/ss/conditional.c | 6 +-
security/selinux/ss/policydb.c | 122 ++++++++----------------------
security/selinux/ss/policydb.h | 12 +--
security/selinux/ss/services.c | 22 ++----
6 files changed, 62 insertions(+), 144 deletions(-)

diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c
index a2c9148b06..5a7fd5f0b7 100644
--- a/security/selinux/ss/avtab.c
+++ b/security/selinux/ss/avtab.c
@@ -93,12 +93,10 @@ avtab_insert_node(struct avtab *h, int hvalue,
newnode->next = prev->next;
prev->next = newnode;
} else {
- newnode->next = flex_array_get_ptr(h->htable, hvalue);
- if (flex_array_put_ptr(h->htable, hvalue, newnode,
- GFP_KERNEL|__GFP_ZERO)) {
- kmem_cache_free(avtab_node_cachep, newnode);
- return NULL;
- }
+ struct avtab_node **n = &h->htable[hvalue];
+
+ newnode->next = *n;
+ *n = newnode;
}

h->nel++;
@@ -111,11 +109,11 @@ static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_dat
struct avtab_node *prev, *cur, *newnode;
u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);

- if (!h || !h->htable)
+ if (!h)
return -EINVAL;

hvalue = avtab_hash(key, h->mask);
- for (prev = NULL, cur = flex_array_get_ptr(h->htable, hvalue);
+ for (prev = NULL, cur = h->htable[hvalue];
cur;
prev = cur, cur = cur->next) {
if (key->source_type == cur->key.source_type &&
@@ -156,10 +154,10 @@ avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datu
struct avtab_node *prev, *cur;
u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);

- if (!h || !h->htable)
+ if (!h)
return NULL;
hvalue = avtab_hash(key, h->mask);
- for (prev = NULL, cur = flex_array_get_ptr(h->htable, hvalue);
+ for (prev = NULL, cur = h->htable[hvalue];
cur;
prev = cur, cur = cur->next) {
if (key->source_type == cur->key.source_type &&
@@ -186,11 +184,11 @@ struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
struct avtab_node *cur;
u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);

- if (!h || !h->htable)
+ if (!h)
return NULL;

hvalue = avtab_hash(key, h->mask);
- for (cur = flex_array_get_ptr(h->htable, hvalue); cur;
+ for (cur = h->htable[hvalue]; cur;
cur = cur->next) {
if (key->source_type == cur->key.source_type &&
key->target_type == cur->key.target_type &&
@@ -222,11 +220,11 @@ avtab_search_node(struct avtab *h, struct avtab_key *key)
struct avtab_node *cur;
u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);

- if (!h || !h->htable)
+ if (!h)
return NULL;

hvalue = avtab_hash(key, h->mask);
- for (cur = flex_array_get_ptr(h->htable, hvalue); cur;
+ for (cur = h->htable[hvalue]; cur;
cur = cur->next) {
if (key->source_type == cur->key.source_type &&
key->target_type == cur->key.target_type &&
@@ -281,11 +279,11 @@ void avtab_destroy(struct avtab *h)
int i;
struct avtab_node *cur, *temp;

- if (!h || !h->htable)
+ if (!h)
return;

for (i = 0; i < h->nslot; i++) {
- cur = flex_array_get_ptr(h->htable, i);
+ cur = h->htable[i];
while (cur) {
temp = cur;
cur = cur->next;
@@ -295,7 +293,7 @@ void avtab_destroy(struct avtab *h)
kmem_cache_free(avtab_node_cachep, temp);
}
}
- flex_array_free(h->htable);
+ kvfree(h->htable);
h->htable = NULL;
h->nslot = 0;
h->mask = 0;
@@ -303,6 +301,7 @@ void avtab_destroy(struct avtab *h)

int avtab_init(struct avtab *h)
{
+ kvfree(h->htable);
h->htable = NULL;
h->nel = 0;
return 0;
@@ -329,8 +328,7 @@ int avtab_alloc(struct avtab *h, u32 nrules)
nslot = MAX_AVTAB_HASH_BUCKETS;
mask = nslot - 1;

- h->htable = flex_array_alloc(sizeof(struct avtab_node *), nslot,
- GFP_KERNEL | __GFP_ZERO);
+ h->htable = kvmalloc_array(nslot, sizeof(void *), GFP_KERNEL);
if (!h->htable)
return -ENOMEM;

@@ -353,7 +351,7 @@ void avtab_hash_eval(struct avtab *h, char *tag)
max_chain_len = 0;
chain2_len_sum = 0;
for (i = 0; i < h->nslot; i++) {
- cur = flex_array_get_ptr(h->htable, i);
+ cur = h->htable[i];
if (cur) {
slots_used++;
chain_len = 0;
@@ -645,7 +643,7 @@ int avtab_write(struct policydb *p, struct avtab *a, void *fp)
return rc;

for (i = 0; i < a->nslot; i++) {
- for (cur = flex_array_get_ptr(a->htable, i); cur;
+ for (cur = a->htable[i]; cur;
cur = cur->next) {
rc = avtab_write_item(p, cur, fp);
if (rc)
diff --git a/security/selinux/ss/avtab.h b/security/selinux/ss/avtab.h
index 0d652fad53..de16673b23 100644
--- a/security/selinux/ss/avtab.h
+++ b/security/selinux/ss/avtab.h
@@ -24,7 +24,6 @@
#define _SS_AVTAB_H_

#include "security.h"
-#include <linux/flex_array.h>

struct avtab_key {
u16 source_type; /* source type */
@@ -84,11 +83,10 @@ struct avtab_node {
};

struct avtab {
- struct flex_array *htable;
+ struct avtab_node **htable;
u32 nel; /* number of elements */
u32 nslot; /* number of hash slots */
u32 mask; /* mask to compute hash func */
-
};

int avtab_init(struct avtab *);
diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c
index c91543a617..c25a60b14f 100644
--- a/security/selinux/ss/conditional.c
+++ b/security/selinux/ss/conditional.c
@@ -195,7 +195,6 @@ int cond_index_bool(void *key, void *datum, void *datap)
{
struct policydb *p;
struct cond_bool_datum *booldatum;
- struct flex_array *fa;

booldatum = datum;
p = datap;
@@ -203,10 +202,7 @@ int cond_index_bool(void *key, void *datum, void *datap)
if (!booldatum->value || booldatum->value > p->p_bools.nprim)
return -EINVAL;

- fa = p->sym_val_to_name[SYM_BOOLS];
- if (flex_array_put_ptr(fa, booldatum->value - 1, key,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
+ p->sym_val_to_name[SYM_BOOLS][booldatum->value - 1] = key;
p->bool_val_to_struct[booldatum->value - 1] = booldatum;

return 0;
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 6e8c8056d7..fd46411e97 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -36,7 +36,6 @@
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/audit.h>
-#include <linux/flex_array.h>
#include "security.h"

#include "policydb.h"
@@ -341,17 +340,14 @@ static int common_index(void *key, void *datum, void *datap)
{
struct policydb *p;
struct common_datum *comdatum;
- struct flex_array *fa;

comdatum = datum;
p = datap;
if (!comdatum->value || comdatum->value > p->p_commons.nprim)
return -EINVAL;

- fa = p->sym_val_to_name[SYM_COMMONS];
- if (flex_array_put_ptr(fa, comdatum->value - 1, key,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
+ p->sym_val_to_name[SYM_COMMONS][comdatum->value - 1] = key;
+
return 0;
}

@@ -359,16 +355,13 @@ static int class_index(void *key, void *datum, void *datap)
{
struct policydb *p;
struct class_datum *cladatum;
- struct flex_array *fa;

cladatum = datum;
p = datap;
if (!cladatum->value || cladatum->value > p->p_classes.nprim)
return -EINVAL;
- fa = p->sym_val_to_name[SYM_CLASSES];
- if (flex_array_put_ptr(fa, cladatum->value - 1, key,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
+
+ p->sym_val_to_name[SYM_CLASSES][cladatum->value - 1] = key;
p->class_val_to_struct[cladatum->value - 1] = cladatum;
return 0;
}
@@ -377,7 +370,6 @@ static int role_index(void *key, void *datum, void *datap)
{
struct policydb *p;
struct role_datum *role;
- struct flex_array *fa;

role = datum;
p = datap;
@@ -386,10 +378,7 @@ static int role_index(void *key, void *datum, void *datap)
|| role->bounds > p->p_roles.nprim)
return -EINVAL;

- fa = p->sym_val_to_name[SYM_ROLES];
- if (flex_array_put_ptr(fa, role->value - 1, key,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
+ p->sym_val_to_name[SYM_ROLES][role->value - 1] = key;
p->role_val_to_struct[role->value - 1] = role;
return 0;
}
@@ -398,7 +387,6 @@ static int type_index(void *key, void *datum, void *datap)
{
struct policydb *p;
struct type_datum *typdatum;
- struct flex_array *fa;

typdatum = datum;
p = datap;
@@ -408,15 +396,8 @@ static int type_index(void *key, void *datum, void *datap)
|| typdatum->value > p->p_types.nprim
|| typdatum->bounds > p->p_types.nprim)
return -EINVAL;
- fa = p->sym_val_to_name[SYM_TYPES];
- if (flex_array_put_ptr(fa, typdatum->value - 1, key,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
-
- fa = p->type_val_to_struct_array;
- if (flex_array_put_ptr(fa, typdatum->value - 1, typdatum,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
+ p->sym_val_to_name[SYM_TYPES][typdatum->value - 1] = key;
+ p->type_val_to_struct_array[typdatum->value - 1] = typdatum;
}

return 0;
@@ -426,7 +407,6 @@ static int user_index(void *key, void *datum, void *datap)
{
struct policydb *p;
struct user_datum *usrdatum;
- struct flex_array *fa;

usrdatum = datum;
p = datap;
@@ -435,10 +415,7 @@ static int user_index(void *key, void *datum, void *datap)
|| usrdatum->bounds > p->p_users.nprim)
return -EINVAL;

- fa = p->sym_val_to_name[SYM_USERS];
- if (flex_array_put_ptr(fa, usrdatum->value - 1, key,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
+ p->sym_val_to_name[SYM_USERS][usrdatum->value - 1] = key;
p->user_val_to_struct[usrdatum->value - 1] = usrdatum;
return 0;
}
@@ -447,7 +424,6 @@ static int sens_index(void *key, void *datum, void *datap)
{
struct policydb *p;
struct level_datum *levdatum;
- struct flex_array *fa;

levdatum = datum;
p = datap;
@@ -456,10 +432,8 @@ static int sens_index(void *key, void *datum, void *datap)
if (!levdatum->level->sens ||
levdatum->level->sens > p->p_levels.nprim)
return -EINVAL;
- fa = p->sym_val_to_name[SYM_LEVELS];
- if (flex_array_put_ptr(fa, levdatum->level->sens - 1, key,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
+
+ p->sym_val_to_name[SYM_LEVELS][levdatum->level->sens - 1] = key;
}

return 0;
@@ -469,7 +443,6 @@ static int cat_index(void *key, void *datum, void *datap)
{
struct policydb *p;
struct cat_datum *catdatum;
- struct flex_array *fa;

catdatum = datum;
p = datap;
@@ -477,10 +450,8 @@ static int cat_index(void *key, void *datum, void *datap)
if (!catdatum->isalias) {
if (!catdatum->value || catdatum->value > p->p_cats.nprim)
return -EINVAL;
- fa = p->sym_val_to_name[SYM_CATS];
- if (flex_array_put_ptr(fa, catdatum->value - 1, key,
- GFP_KERNEL | __GFP_ZERO))
- BUG();
+
+ p->sym_val_to_name[SYM_CATS][catdatum->value - 1] = key;
}

return 0;
@@ -566,35 +537,23 @@ static int policydb_index(struct policydb *p)
if (!p->user_val_to_struct)
return -ENOMEM;

- /* Yes, I want the sizeof the pointer, not the structure */
- p->type_val_to_struct_array = flex_array_alloc(sizeof(struct type_datum *),
- p->p_types.nprim,
- GFP_KERNEL | __GFP_ZERO);
+ p->type_val_to_struct_array = kvcalloc(p->p_types.nprim,
+ sizeof(*p->type_val_to_struct_array),
+ GFP_KERNEL);
if (!p->type_val_to_struct_array)
return -ENOMEM;

- rc = flex_array_prealloc(p->type_val_to_struct_array, 0,
- p->p_types.nprim, GFP_KERNEL | __GFP_ZERO);
- if (rc)
- goto out;
-
rc = cond_init_bool_indexes(p);
if (rc)
goto out;

for (i = 0; i < SYM_NUM; i++) {
- p->sym_val_to_name[i] = flex_array_alloc(sizeof(char *),
- p->symtab[i].nprim,
- GFP_KERNEL | __GFP_ZERO);
+ p->sym_val_to_name[i] = kvcalloc(p->symtab[i].nprim,
+ sizeof(char *),
+ GFP_KERNEL);
if (!p->sym_val_to_name[i])
return -ENOMEM;

- rc = flex_array_prealloc(p->sym_val_to_name[i],
- 0, p->symtab[i].nprim,
- GFP_KERNEL | __GFP_ZERO);
- if (rc)
- goto out;
-
rc = hashtab_map(p->symtab[i].table, index_f[i], p);
if (rc)
goto out;
@@ -807,16 +766,13 @@ void policydb_destroy(struct policydb *p)
hashtab_destroy(p->symtab[i].table);
}

- for (i = 0; i < SYM_NUM; i++) {
- if (p->sym_val_to_name[i])
- flex_array_free(p->sym_val_to_name[i]);
- }
+ for (i = 0; i < SYM_NUM; i++)
+ kvfree(p->sym_val_to_name[i]);

kfree(p->class_val_to_struct);
kfree(p->role_val_to_struct);
kfree(p->user_val_to_struct);
- if (p->type_val_to_struct_array)
- flex_array_free(p->type_val_to_struct_array);
+ kvfree(p->type_val_to_struct_array);

avtab_destroy(&p->te_avtab);

@@ -869,17 +825,9 @@ void policydb_destroy(struct policydb *p)
hashtab_map(p->range_tr, range_tr_destroy, NULL);
hashtab_destroy(p->range_tr);

- if (p->type_attr_map_array) {
- for (i = 0; i < p->p_types.nprim; i++) {
- struct ebitmap *e;
-
- e = flex_array_get(p->type_attr_map_array, i);
- if (!e)
- continue;
- ebitmap_destroy(e);
- }
- flex_array_free(p->type_attr_map_array);
- }
+ for (i = 0; i < p->p_types.nprim; i++)
+ ebitmap_destroy(&p->type_attr_map_array[i]);
+ kvfree(p->type_attr_map_array);

ebitmap_destroy(&p->filename_trans_ttypes);
ebitmap_destroy(&p->policycaps);
@@ -1760,8 +1708,7 @@ static int type_bounds_sanity_check(void *key, void *datum, void *datap)
return -EINVAL;
}

- upper = flex_array_get_ptr(p->type_val_to_struct_array,
- upper->bounds - 1);
+ upper = p->type_val_to_struct_array[upper->bounds - 1];
BUG_ON(!upper);

if (upper->attribute) {
@@ -2518,23 +2465,15 @@ int policydb_read(struct policydb *p, void *fp)
if (rc)
goto bad;

- rc = -ENOMEM;
- p->type_attr_map_array = flex_array_alloc(sizeof(struct ebitmap),
- p->p_types.nprim,
- GFP_KERNEL | __GFP_ZERO);
+ p->type_attr_map_array = kvcalloc(p->p_types.nprim,
+ sizeof(*p->type_attr_map_array),
+ GFP_KERNEL);
if (!p->type_attr_map_array)
goto bad;

- /* preallocate so we don't have to worry about the put ever failing */
- rc = flex_array_prealloc(p->type_attr_map_array, 0, p->p_types.nprim,
- GFP_KERNEL | __GFP_ZERO);
- if (rc)
- goto bad;
-
for (i = 0; i < p->p_types.nprim; i++) {
- struct ebitmap *e = flex_array_get(p->type_attr_map_array, i);
+ struct ebitmap *e = &p->type_attr_map_array[i];

- BUG_ON(!e);
ebitmap_init(e);
if (p->policyvers >= POLICYDB_VERSION_AVTAB) {
rc = ebitmap_read(e, fp);
@@ -3523,9 +3462,8 @@ int policydb_write(struct policydb *p, void *fp)
return rc;

for (i = 0; i < p->p_types.nprim; i++) {
- struct ebitmap *e = flex_array_get(p->type_attr_map_array, i);
+ struct ebitmap *e = &p->type_attr_map_array[i];

- BUG_ON(!e);
rc = ebitmap_write(e, fp);
if (rc)
return rc;
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index 215f8f30ac..27039149ff 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -24,8 +24,6 @@
#ifndef _SS_POLICYDB_H_
#define _SS_POLICYDB_H_

-#include <linux/flex_array.h>
-
#include "symtab.h"
#include "avtab.h"
#include "sidtab.h"
@@ -251,13 +249,13 @@ struct policydb {
#define p_cats symtab[SYM_CATS]

/* symbol names indexed by (value - 1) */
- struct flex_array *sym_val_to_name[SYM_NUM];
+ char **sym_val_to_name[SYM_NUM];

/* class, role, and user attributes indexed by (value - 1) */
struct class_datum **class_val_to_struct;
struct role_datum **role_val_to_struct;
struct user_datum **user_val_to_struct;
- struct flex_array *type_val_to_struct_array;
+ struct type_datum **type_val_to_struct_array;

/* type enforcement access vectors and transitions */
struct avtab te_avtab;
@@ -294,7 +292,7 @@ struct policydb {
struct hashtab *range_tr;

/* type -> attribute reverse mapping */
- struct flex_array *type_attr_map_array;
+ struct ebitmap *type_attr_map_array;

struct ebitmap policycaps;

@@ -369,9 +367,7 @@ static inline int put_entry(const void *buf, size_t bytes, int num, struct polic

static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
{
- struct flex_array *fa = p->sym_val_to_name[sym_num];
-
- return flex_array_get_ptr(fa, element_nr);
+ return p->sym_val_to_name[sym_num][element_nr];
}

extern u16 string_to_security_class(struct policydb *p, const char *name);
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index dd2ceec06f..16b0af5086 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -50,7 +50,6 @@
#include <linux/audit.h>
#include <linux/mutex.h>
#include <linux/selinux.h>
-#include <linux/flex_array.h>
#include <linux/vmalloc.h>
#include <net/netlabel.h>

@@ -548,15 +547,13 @@ static void type_attribute_bounds_av(struct policydb *policydb,
struct type_datum *target;
u32 masked = 0;

- source = flex_array_get_ptr(policydb->type_val_to_struct_array,
- scontext->type - 1);
+ source = policydb->type_val_to_struct_array[scontext->type - 1];
BUG_ON(!source);

if (!source->bounds)
return;

- target = flex_array_get_ptr(policydb->type_val_to_struct_array,
- tcontext->type - 1);
+ target = policydb->type_val_to_struct_array[tcontext->type - 1];
BUG_ON(!target);

memset(&lo_avd, 0, sizeof(lo_avd));
@@ -656,11 +653,9 @@ static void context_struct_compute_av(struct policydb *policydb,
*/
avkey.target_class = tclass;
avkey.specified = AVTAB_AV | AVTAB_XPERMS;
- sattr = flex_array_get(policydb->type_attr_map_array,
- scontext->type - 1);
+ sattr = &policydb->type_attr_map_array[scontext->type - 1];
BUG_ON(!sattr);
- tattr = flex_array_get(policydb->type_attr_map_array,
- tcontext->type - 1);
+ tattr = &policydb->type_attr_map_array[tcontext->type - 1];
BUG_ON(!tattr);
ebitmap_for_each_positive_bit(sattr, snode, i) {
ebitmap_for_each_positive_bit(tattr, tnode, j) {
@@ -903,8 +898,7 @@ int security_bounded_transition(struct selinux_state *state,

index = new_context->type;
while (true) {
- type = flex_array_get_ptr(policydb->type_val_to_struct_array,
- index - 1);
+ type = policydb->type_val_to_struct_array[index - 1];
BUG_ON(!type);

/* not bounded anymore */
@@ -1067,11 +1061,9 @@ void security_compute_xperms_decision(struct selinux_state *state,

avkey.target_class = tclass;
avkey.specified = AVTAB_XPERMS;
- sattr = flex_array_get(policydb->type_attr_map_array,
- scontext->type - 1);
+ sattr = &policydb->type_attr_map_array[scontext->type - 1];
BUG_ON(!sattr);
- tattr = flex_array_get(policydb->type_attr_map_array,
- tcontext->type - 1);
+ tattr = &policydb->type_attr_map_array[tcontext->type - 1];
BUG_ON(!tattr);
ebitmap_for_each_positive_bit(sattr, snode, i) {
ebitmap_for_each_positive_bit(tattr, tnode, j) {
--
2.19.0.rc2