On Fri, Jul 14, 2023 at 2:40 PM Christian Göttsche
<cgzones@xxxxxxxxxxxxxx> wrote:
>
> Support the destruction of the hashtable entries via an optional
> callback in hashtab_destroy(), to avoid iterating the hashtable twice in
> common use cases, one time for the entry destruction via hashtab_map()
> and a second time via hashtab_destroy() to free the hashtable itself.
>
> Also convert all the destroy callbacks to return void instead of the
> needless value of 0.
>
> Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
> ---
> checkpolicy/module_compiler.c | 6 +-
> libsepol/cil/src/cil_binary.c | 9 +--
> libsepol/cil/src/cil_strpool.c | 6 +-
> libsepol/cil/src/cil_symtab.c | 6 +-
> libsepol/include/sepol/policydb/conditional.h | 2 +-
> libsepol/include/sepol/policydb/hashtab.h | 8 ++-
> libsepol/include/sepol/policydb/policydb.h | 2 +-
> libsepol/src/conditional.c | 3 +-
> libsepol/src/hashtab.c | 7 ++-
> libsepol/src/policydb.c | 55 +++++++------------
> libsepol/src/symtab.c | 3 +-
> libsepol/src/write.c | 6 +-
> 12 files changed, 48 insertions(+), 65 deletions(-)
>
> diff --git a/checkpolicy/module_compiler.c b/checkpolicy/module_compiler.c
> index 5fe1729a..554b625f 100644
> --- a/checkpolicy/module_compiler.c
> +++ b/checkpolicy/module_compiler.c
> @@ -761,20 +761,18 @@ int add_perm_to_class(uint32_t perm_value, uint32_t class_value)
> return 0;
> }
>
> -static int perm_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void perm_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> if (key)
> free(key);
> free(datum);
> - return 0;
> }
>
> static void class_datum_destroy(class_datum_t * cladatum)
> {
> if (cladatum != NULL) {
> - hashtab_map(cladatum->permissions.table, perm_destroy, NULL);
> - hashtab_destroy(cladatum->permissions.table);
> + hashtab_destroy(cladatum->permissions.table, perm_destroy, NULL);
> free(cladatum);
> }
> }
> diff --git a/libsepol/cil/src/cil_binary.c b/libsepol/cil/src/cil_binary.c
> index ea0cef32..8aa305c9 100644
> --- a/libsepol/cil/src/cil_binary.c
> +++ b/libsepol/cil/src/cil_binary.c
> @@ -1984,13 +1984,11 @@ exit:
> return rc;
> }
>
> -static int __cil_avrulex_ioctl_destroy(hashtab_key_t k, hashtab_datum_t datum, __attribute__((unused)) void *args)
> +static void __cil_avrulex_ioctl_destroy(hashtab_key_t k, hashtab_datum_t datum, __attribute__((unused)) void *args)
> {
> free(k);
> ebitmap_destroy(datum);
> free(datum);
> -
> - return SEPOL_OK;
> }
>
> static int __cil_cond_to_policydb_helper(struct cil_tree_node *node, __attribute__((unused)) uint32_t *finished, void *extra_args)
> @@ -5230,9 +5228,8 @@ int cil_binary_create_allocated_pdb(const struct cil_db *db, sepol_policydb_t *p
> rc = SEPOL_OK;
>
> exit:
> - hashtab_destroy(role_trans_table);
> - hashtab_map(avrulex_ioctl_table, __cil_avrulex_ioctl_destroy, NULL);
> - hashtab_destroy(avrulex_ioctl_table);
> + hashtab_destroy(role_trans_table, NULL, NULL);
> + hashtab_destroy(avrulex_ioctl_table, __cil_avrulex_ioctl_destroy, NULL);
> free(type_value_to_cil);
> free(class_value_to_cil);
> if (perm_value_to_cil != NULL) {
> diff --git a/libsepol/cil/src/cil_strpool.c b/libsepol/cil/src/cil_strpool.c
> index e32ee4e9..18ecfe87 100644
> --- a/libsepol/cil/src/cil_strpool.c
> +++ b/libsepol/cil/src/cil_strpool.c
> @@ -87,12 +87,11 @@ char *cil_strpool_add(const char *str)
> return strpool_ref->str;
> }
>
> -static int cil_strpool_entry_destroy(hashtab_key_t k __attribute__ ((unused)), hashtab_datum_t d, void *args __attribute__ ((unused)))
> +static void cil_strpool_entry_destroy(hashtab_key_t k __attribute__ ((unused)), hashtab_datum_t d, void *args __attribute__ ((unused)))
> {
> struct cil_strpool_entry *strpool_ref = (struct cil_strpool_entry*)d;
> free(strpool_ref->str);
> free(strpool_ref);
> - return SEPOL_OK;
> }
>
> void cil_strpool_init(void)
> @@ -115,8 +114,7 @@ void cil_strpool_destroy(void)
> pthread_mutex_lock(&cil_strpool_mutex);
> cil_strpool_readers--;
> if (cil_strpool_readers == 0) {
> - hashtab_map(cil_strpool_tab, cil_strpool_entry_destroy, NULL);
> - hashtab_destroy(cil_strpool_tab);
> + hashtab_destroy(cil_strpool_tab, cil_strpool_entry_destroy, NULL);
> cil_strpool_tab = NULL;
> }
> pthread_mutex_unlock(&cil_strpool_mutex);
> diff --git a/libsepol/cil/src/cil_symtab.c b/libsepol/cil/src/cil_symtab.c
> index 7e43a690..73cdd734 100644
> --- a/libsepol/cil/src/cil_symtab.c
> +++ b/libsepol/cil/src/cil_symtab.c
> @@ -133,18 +133,16 @@ int cil_symtab_map(symtab_t *symtab,
> return hashtab_map(symtab->table, apply, args);
> }
>
> -static int __cil_symtab_destroy_helper(__attribute__((unused)) hashtab_key_t k, hashtab_datum_t d, __attribute__((unused)) void *args)
> +static void __cil_symtab_destroy_helper(__attribute__((unused)) hashtab_key_t k, hashtab_datum_t d, __attribute__((unused)) void *args)
> {
> struct cil_symtab_datum *datum = d;
> datum->symtab = NULL;
> - return SEPOL_OK;
> }
>
> void cil_symtab_destroy(symtab_t *symtab)
> {
> if (symtab->table != NULL){
> - cil_symtab_map(symtab, __cil_symtab_destroy_helper, NULL);
> - hashtab_destroy(symtab->table);
> + hashtab_destroy(symtab->table, __cil_symtab_destroy_helper, NULL);
> symtab->table = NULL;
> }
> }
> diff --git a/libsepol/include/sepol/policydb/conditional.h b/libsepol/include/sepol/policydb/conditional.h
> index 5318ea19..9b19946b 100644
> --- a/libsepol/include/sepol/policydb/conditional.h
> +++ b/libsepol/include/sepol/policydb/conditional.h
> @@ -127,7 +127,7 @@ extern void cond_policydb_destroy(policydb_t * p);
> extern void cond_list_destroy(cond_list_t * list);
>
> extern int cond_init_bool_indexes(policydb_t * p);
> -extern int cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p);
> +extern void cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p);
>
> extern int cond_index_bool(hashtab_key_t key, hashtab_datum_t datum,
> void *datap);
> diff --git a/libsepol/include/sepol/policydb/hashtab.h b/libsepol/include/sepol/policydb/hashtab.h
> index 354ebb43..7aa88f3b 100644
> --- a/libsepol/include/sepol/policydb/hashtab.h
> +++ b/libsepol/include/sepol/policydb/hashtab.h
> @@ -89,8 +89,14 @@ extern hashtab_datum_t hashtab_search(hashtab_t h, const_hashtab_key_t k);
>
> /*
> Destroys the specified hash table.
> + Applies the specified destroy function to (key,datum,args) for
> + all entries.
> +
> */
> -extern void hashtab_destroy(hashtab_t h);
> +extern void hashtab_destroy(hashtab_t h,
> + void (*destroy) (hashtab_key_t k,
> + hashtab_datum_t d,
> + void *args), void *args);
>
The args argument is never used. For hashtab_map() it is in other
cases, but not in the case of destroying the items in the hashtab.
Also, 1/3 of the calls to hashtab_destroy() do not even need to pass
in a destroy function.
I think that it would make more sense to create a new function
(without the args argument) that could be used to destroy both the
elements and the hashtab. If the destroy function is not needed, then
the old hashtab_destroy() function could be used. If something more
complex comes up in the future, there would still be the option of
using the hashtab_map() and the hashtab_destroy() functions to deal
with it.
Thanks,
Jim
> /*
> Applies the specified apply function to (key,datum,args)
> diff --git a/libsepol/include/sepol/policydb/policydb.h b/libsepol/include/sepol/policydb/policydb.h
> index 48b7b8bb..8cf82da6 100644
> --- a/libsepol/include/sepol/policydb/policydb.h
> +++ b/libsepol/include/sepol/policydb/policydb.h
> @@ -634,7 +634,7 @@ extern int policydb_context_isvalid(const policydb_t * p,
> const context_struct_t * c);
>
> extern void symtabs_destroy(symtab_t * symtab);
> -extern int scope_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p);
> +extern void scope_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p);
>
> extern void class_perm_node_init(class_perm_node_t * x);
> extern void type_set_init(type_set_t * x);
> diff --git a/libsepol/src/conditional.c b/libsepol/src/conditional.c
> index 7900e928..b51639d4 100644
> --- a/libsepol/src/conditional.c
> +++ b/libsepol/src/conditional.c
> @@ -528,13 +528,12 @@ int cond_init_bool_indexes(policydb_t * p)
> return 0;
> }
>
> -int cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p
> +void cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> if (key)
> free(key);
> free(datum);
> - return 0;
> }
>
> int cond_index_bool(hashtab_key_t key, hashtab_datum_t datum, void *datap)
> diff --git a/libsepol/src/hashtab.c b/libsepol/src/hashtab.c
> index 922a8a4a..7f3dd00b 100644
> --- a/libsepol/src/hashtab.c
> +++ b/libsepol/src/hashtab.c
> @@ -193,7 +193,10 @@ hashtab_datum_t hashtab_search(hashtab_t h, const_hashtab_key_t key)
> return cur->datum;
> }
>
> -void hashtab_destroy(hashtab_t h)
> +void hashtab_destroy(hashtab_t h,
> + void (*destroy) (hashtab_key_t k,
> + hashtab_datum_t d,
> + void *args), void *args)
> {
> unsigned int i;
> hashtab_ptr_t cur, temp;
> @@ -206,6 +209,8 @@ void hashtab_destroy(hashtab_t h)
> while (cur != NULL) {
> temp = cur;
> cur = cur->next;
> + if (destroy)
> + destroy(temp->key, temp->datum, args);
> free(temp);
> }
> h->htable[i] = NULL;
> diff --git a/libsepol/src/policydb.c b/libsepol/src/policydb.c
> index 552eb77a..f443ea88 100644
> --- a/libsepol/src/policydb.c
> +++ b/libsepol/src/policydb.c
> @@ -895,10 +895,10 @@ int policydb_init(policydb_t * p)
>
> return 0;
> err:
> - hashtab_destroy(p->range_tr);
> + hashtab_destroy(p->range_tr, NULL, NULL);
> for (i = 0; i < SYM_NUM; i++) {
> - hashtab_destroy(p->symtab[i].table);
> - hashtab_destroy(p->scope[i].table);
> + hashtab_destroy(p->symtab[i].table, NULL, NULL);
> + hashtab_destroy(p->scope[i].table, NULL, NULL);
> }
> avrule_block_list_destroy(p->global);
> return rc;
> @@ -1264,16 +1264,15 @@ int policydb_index_others(sepol_handle_t * handle,
> * symbol data in the policy database.
> */
>
> -static int perm_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void perm_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> if (key)
> free(key);
> free(datum);
> - return 0;
> }
>
> -static int common_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void common_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> common_datum_t *comdatum;
> @@ -1281,13 +1280,11 @@ static int common_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> if (key)
> free(key);
> comdatum = (common_datum_t *) datum;
> - (void)hashtab_map(comdatum->permissions.table, perm_destroy, 0);
> - hashtab_destroy(comdatum->permissions.table);
> + hashtab_destroy(comdatum->permissions.table, perm_destroy, NULL);
> free(datum);
> - return 0;
> }
>
> -static int class_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void class_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> class_datum_t *cladatum;
> @@ -1297,10 +1294,9 @@ static int class_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> free(key);
> cladatum = (class_datum_t *) datum;
> if (cladatum == NULL) {
> - return 0;
> + return;
> }
> - (void)hashtab_map(cladatum->permissions.table, perm_destroy, 0);
> - hashtab_destroy(cladatum->permissions.table);
> + hashtab_destroy(cladatum->permissions.table, perm_destroy, NULL);
> constraint = cladatum->constraints;
> while (constraint) {
> constraint_expr_destroy(constraint->expr);
> @@ -1320,37 +1316,33 @@ static int class_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> if (cladatum->comkey)
> free(cladatum->comkey);
> free(datum);
> - return 0;
> }
>
> -static int role_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void role_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> free(key);
> role_datum_destroy((role_datum_t *) datum);
> free(datum);
> - return 0;
> }
>
> -static int type_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void type_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> free(key);
> type_datum_destroy((type_datum_t *) datum);
> free(datum);
> - return 0;
> }
>
> -static int user_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void user_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> free(key);
> user_datum_destroy((user_datum_t *) datum);
> free(datum);
> - return 0;
> }
>
> -static int sens_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void sens_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> level_datum_t *levdatum;
> @@ -1362,25 +1354,23 @@ static int sens_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> free(levdatum->level);
> level_datum_destroy(levdatum);
> free(levdatum);
> - return 0;
> }
>
> -static int cat_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +static void cat_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> if (key)
> free(key);
> cat_datum_destroy((cat_datum_t *) datum);
> free(datum);
> - return 0;
> }
>
> -static int (*destroy_f[SYM_NUM]) (hashtab_key_t key, hashtab_datum_t datum,
> +static void (*destroy_f[SYM_NUM]) (hashtab_key_t key, hashtab_datum_t datum,
> void *datap) = {
> common_destroy, class_destroy, role_destroy, type_destroy, user_destroy,
> cond_destroy_bool, sens_destroy, cat_destroy,};
>
> -static int range_tr_destroy(hashtab_key_t key, hashtab_datum_t datum,
> +static void range_tr_destroy(hashtab_key_t key, hashtab_datum_t datum,
> void *p __attribute__ ((unused)))
> {
> struct mls_range *rt = (struct mls_range *)datum;
> @@ -1388,7 +1378,6 @@ static int range_tr_destroy(hashtab_key_t key, hashtab_datum_t datum,
> ebitmap_destroy(&rt->level[0].cat);
> ebitmap_destroy(&rt->level[1].cat);
> free(datum);
> - return 0;
> }
>
> static void ocontext_selinux_free(ocontext_t **ocontexts)
> @@ -1468,8 +1457,7 @@ void policydb_destroy(policydb_t * p)
> free(p->decl_val_to_struct);
>
> for (i = 0; i < SYM_NUM; i++) {
> - (void)hashtab_map(p->scope[i].table, scope_destroy, 0);
> - hashtab_destroy(p->scope[i].table);
> + hashtab_destroy(p->scope[i].table, scope_destroy, NULL);
> }
> avrule_block_list_destroy(p->global);
> free(p->name);
> @@ -1515,8 +1503,7 @@ void policydb_destroy(policydb_t * p)
> if (lra)
> free(lra);
>
> - hashtab_map(p->range_tr, range_tr_destroy, NULL);
> - hashtab_destroy(p->range_tr);
> + hashtab_destroy(p->range_tr, range_tr_destroy, NULL);
>
> if (p->type_attr_map) {
> for (i = 0; i < p->p_types.nprim; i++) {
> @@ -1539,12 +1526,11 @@ void symtabs_destroy(symtab_t * symtab)
> {
> int i;
> for (i = 0; i < SYM_NUM; i++) {
> - (void)hashtab_map(symtab[i].table, destroy_f[i], 0);
> - hashtab_destroy(symtab[i].table);
> + hashtab_destroy(symtab[i].table, destroy_f[i], NULL);
> }
> }
>
> -int scope_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> +void scope_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> __attribute__ ((unused)))
> {
> scope_datum_t *cur = (scope_datum_t *) datum;
> @@ -1553,7 +1539,6 @@ int scope_destroy(hashtab_key_t key, hashtab_datum_t datum, void *p
> free(cur->decl_ids);
> }
> free(cur);
> - return 0;
> }
>
> /*
> diff --git a/libsepol/src/symtab.c b/libsepol/src/symtab.c
> index a6061851..3430bfc0 100644
> --- a/libsepol/src/symtab.c
> +++ b/libsepol/src/symtab.c
> @@ -51,7 +51,6 @@ void symtab_destroy(symtab_t * s)
> if (!s)
> return;
> if (s->table)
> - hashtab_destroy(s->table);
> - return;
> + hashtab_destroy(s->table, NULL, NULL);
> }
> /* FLASK */
> diff --git a/libsepol/src/write.c b/libsepol/src/write.c
> index f0ed9e33..2eb08bb7 100644
> --- a/libsepol/src/write.c
> +++ b/libsepol/src/write.c
> @@ -539,7 +539,7 @@ static int filenametr_cmp(hashtab_t h __attribute__ ((unused)),
> return strcmp(ft1->name, ft2->name);
> }
>
> -static int filenametr_destroy(hashtab_key_t key, hashtab_datum_t datum,
> +static void filenametr_destroy(hashtab_key_t key, hashtab_datum_t datum,
> void *p __attribute__ ((unused)))
> {
> filenametr_key_t *ft = (filenametr_key_t *)key;
> @@ -553,7 +553,6 @@ static int filenametr_destroy(hashtab_key_t key, hashtab_datum_t datum,
> free(fd);
> fd = next;
> } while (fd);
> - return 0;
> }
>
> typedef struct {
> @@ -778,8 +777,7 @@ static int avtab_filename_trans_write(policydb_t *pol, avtab_t *a,
>
> out:
> /* destroy temp filename transitions table */
> - hashtab_map(fnts_tab, filenametr_destroy, NULL);
> - hashtab_destroy(fnts_tab);
> + hashtab_destroy(fnts_tab, filenametr_destroy, NULL);
>
> return rc ? -1 : 0;
> }
> --
> 2.40.1
>
