From 2b3dd2c77db9ead593ae811bac49dbd6c80fe419 Mon Sep 17 00:00:00 2001 From: James Carter Date: Wed, 12 Apr 2023 10:18:39 -0400 Subject: [PATCH] libsepol/cil: Do not call ebitmap_init twice for an ebitmap While it does no harm to call ebitmap_init() twice for an ebitmap, since it is just memsetting the ebitmap to 0, it is poor practice. In the function cil_type_matches() in cil_find.c, either ebitmap_and() or ebitmap_set_bit() will be called. The function ebitmap_and() will call ebitmap_init() on the destination ebitmap, but ebitmap_set_bit() does not. Instead of calling ebitmap_init() before the call to cil_type_matches(), let cil_type_matches() make the call if it is going to call ebitmap_set_bit(). It can also call ebitmap_destroy() on an error. Since we are removing the call to ebitmap_init() in cil_self_match_any(), cleanup some other things in the function (like using the FLAVOR() macro and using ebitmap_is_empty()). Signed-off-by: James Carter Acked-by: Petr Lautrbach --- libsepol/cil/src/cil_find.c | 60 +++++++++++++++++++------------------ 1 file changed, 31 insertions(+), 29 deletions(-) diff --git a/libsepol/cil/src/cil_find.c b/libsepol/cil/src/cil_find.c index 8b755277..0246d133 100644 --- a/libsepol/cil/src/cil_find.c +++ b/libsepol/cil/src/cil_find.c @@ -85,29 +85,34 @@ static int cil_type_matches(ebitmap_t *matches, struct cil_symtab_datum *d1, str enum cil_flavor f1 = FLAVOR(d1); enum cil_flavor f2 = FLAVOR(d2); - if (f1 != CIL_TYPEATTRIBUTE && f2 != CIL_TYPEATTRIBUTE) { - struct cil_type *t1 = (struct cil_type *)d1; - struct cil_type *t2 = (struct cil_type *)d2; - if (t1->value == t2->value) { - ebitmap_set_bit(matches, t1->value, 1); - } - } else if (f1 == CIL_TYPEATTRIBUTE && f2 != CIL_TYPEATTRIBUTE) { - struct cil_typeattribute *a = (struct cil_typeattribute *)d1; - struct cil_type *t = (struct cil_type *)d2; - if (ebitmap_get_bit(a->types, t->value)) { - ebitmap_set_bit(matches, t->value, 1); - } - } else if (f1 != CIL_TYPEATTRIBUTE && f2 == CIL_TYPEATTRIBUTE) { - struct cil_type *t = (struct cil_type *)d1; - struct cil_typeattribute *a = (struct cil_typeattribute *)d2; - if (ebitmap_get_bit(a->types, t->value)) { - ebitmap_set_bit(matches, t->value, 1); - } - } else { - /* Both are attributes */ + if (f1 == CIL_TYPEATTRIBUTE && f2 == CIL_TYPEATTRIBUTE) { struct cil_typeattribute *a1 = (struct cil_typeattribute *)d1; struct cil_typeattribute *a2 = (struct cil_typeattribute *)d2; rc = ebitmap_and(matches, a1->types, a2->types); + } else { + ebitmap_init(matches); + if (f1 != CIL_TYPEATTRIBUTE && f2 != CIL_TYPEATTRIBUTE) { + struct cil_type *t1 = (struct cil_type *)d1; + struct cil_type *t2 = (struct cil_type *)d2; + if (t1->value == t2->value) { + rc = ebitmap_set_bit(matches, t1->value, 1); + } + } else if (f1 == CIL_TYPEATTRIBUTE && f2 != CIL_TYPEATTRIBUTE) { + struct cil_typeattribute *a = (struct cil_typeattribute *)d1; + struct cil_type *t = (struct cil_type *)d2; + if (ebitmap_get_bit(a->types, t->value)) { + rc = ebitmap_set_bit(matches, t->value, 1); + } + } else { // f1 != CIL_TYPEATTRIBUTE && f2 == CIL_TYPEATTRIBUTE + struct cil_type *t = (struct cil_type *)d1; + struct cil_typeattribute *a = (struct cil_typeattribute *)d2; + if (ebitmap_get_bit(a->types, t->value)) { + rc = ebitmap_set_bit(matches, t->value, 1); + } + } + if (rc != SEPOL_OK) { + ebitmap_destroy(matches); + } } return rc; @@ -115,31 +120,28 @@ static int cil_type_matches(ebitmap_t *matches, struct cil_symtab_datum *d1, str /* s1 is the src type that is matched with a self * s2, and t2 are the source and type of the other rule + * Assumes there is a match between s1 and s2 */ static int cil_self_match_any(struct cil_symtab_datum *s1, struct cil_symtab_datum *s2, struct cil_symtab_datum *t2) { int rc; - struct cil_tree_node *n1 = NODE(s1); - if (n1->flavor != CIL_TYPEATTRIBUTE) { + + if (FLAVOR(s1) != CIL_TYPEATTRIBUTE) { rc = cil_type_match_any(s1, t2); } else { struct cil_typeattribute *a = (struct cil_typeattribute *)s1; ebitmap_t map; - ebitmap_init(&map); rc = cil_type_matches(&map, s2, t2); if (rc < 0) { - ebitmap_destroy(&map); - goto exit; + return rc; } - if (map.node == NULL) { - rc = CIL_FALSE; - goto exit; + if (ebitmap_is_empty(&map)) { + return CIL_FALSE; } rc = ebitmap_match_any(&map, a->types); ebitmap_destroy(&map); } -exit: return rc; }