From 6f9e682c15baaa8af2c2592fac8e99c29fefecd2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= Date: Tue, 19 Jul 2022 17:30:39 +0200 Subject: [PATCH] libsepol: add ebitmap_init_range MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add an initializer for ebitmaps that sets all bits in a given range to save node traversals for each bit to set, compared to calling ebitmap_init() followed by iterating ebitmap_set_bit(). Signed-off-by: Christian Göttsche Acked-by: James Carter --- libsepol/include/sepol/policydb/ebitmap.h | 1 + libsepol/src/ebitmap.c | 49 +++++++++++++++++++++++ libsepol/tests/test-ebitmap.c | 32 +++++++++++++++ 3 files changed, 82 insertions(+) diff --git a/libsepol/include/sepol/policydb/ebitmap.h b/libsepol/include/sepol/policydb/ebitmap.h index 81d0c7a6..85b7ccfb 100644 --- a/libsepol/include/sepol/policydb/ebitmap.h +++ b/libsepol/include/sepol/policydb/ebitmap.h @@ -94,6 +94,7 @@ extern int ebitmap_contains(const ebitmap_t * e1, const ebitmap_t * e2); extern int ebitmap_match_any(const ebitmap_t *e1, const ebitmap_t *e2); extern int ebitmap_get_bit(const ebitmap_t * e, unsigned int bit); extern int ebitmap_set_bit(ebitmap_t * e, unsigned int bit, int value); +extern int ebitmap_init_range(ebitmap_t * e, unsigned int minbit, unsigned int maxbit); extern unsigned int ebitmap_highest_set_bit(const ebitmap_t * e); extern void ebitmap_destroy(ebitmap_t * e); extern int ebitmap_read(ebitmap_t * e, void *fp); diff --git a/libsepol/src/ebitmap.c b/libsepol/src/ebitmap.c index bd98c0f8..0f9afd62 100644 --- a/libsepol/src/ebitmap.c +++ b/libsepol/src/ebitmap.c @@ -349,6 +349,55 @@ int ebitmap_set_bit(ebitmap_t * e, unsigned int bit, int value) return 0; } +int ebitmap_init_range(ebitmap_t * e, unsigned int minbit, unsigned int maxbit) +{ + ebitmap_node_t *new, *prev = NULL; + uint32_t minstartbit = minbit & ~(MAPSIZE - 1); + uint32_t maxstartbit = maxbit & ~(MAPSIZE - 1); + uint32_t minhighbit = minstartbit + MAPSIZE; + uint32_t maxhighbit = maxstartbit + MAPSIZE; + uint32_t startbit; + MAPTYPE mask; + + ebitmap_init(e); + + if (minbit > maxbit) + return -EINVAL; + + if (minhighbit == 0 || maxhighbit == 0) + return -EOVERFLOW; + + for (startbit = minstartbit; startbit <= maxstartbit; startbit += MAPSIZE) { + new = malloc(sizeof(ebitmap_node_t)); + if (!new) + return -ENOMEM; + + new->next = NULL; + new->startbit = startbit; + + if (startbit != minstartbit && startbit != maxstartbit) { + new->map = ~((MAPTYPE)0); + } else if (startbit != maxstartbit) { + new->map = ~((MAPTYPE)0) << (minbit - startbit); + } else if (startbit != minstartbit) { + new->map = ~((MAPTYPE)0) >> (MAPSIZE - (maxbit - startbit + 1)); + } else { + mask = ~((MAPTYPE)0) >> (MAPSIZE - (maxbit - minbit + 1)); + new->map = (mask << (minbit - startbit)); + } + + if (prev) + prev->next = new; + else + e->node = new; + prev = new; + } + + e->highbit = maxhighbit; + + return 0; +} + unsigned int ebitmap_highest_set_bit(const ebitmap_t * e) { const ebitmap_node_t *n; diff --git a/libsepol/tests/test-ebitmap.c b/libsepol/tests/test-ebitmap.c index fad5bd75..8774555e 100644 --- a/libsepol/tests/test-ebitmap.c +++ b/libsepol/tests/test-ebitmap.c @@ -253,6 +253,37 @@ static void test_ebitmap_set_and_get(void) ebitmap_destroy(&e); } +static void test_ebitmap_init_range(void) +{ + ebitmap_t e1, e2, e3, e4, e5, e6; + + CU_ASSERT_EQUAL(ebitmap_init_range(&e1, 0, 0), 0); + CU_ASSERT_EQUAL(ebitmap_highest_set_bit(&e1), 0); + CU_ASSERT_EQUAL(ebitmap_cardinality(&e1), 1); + + CU_ASSERT_EQUAL(ebitmap_init_range(&e2, 0, 5), 0); + CU_ASSERT_EQUAL(ebitmap_highest_set_bit(&e2), 5); + CU_ASSERT_EQUAL(ebitmap_cardinality(&e2), 6); + + CU_ASSERT_EQUAL(ebitmap_init_range(&e3, 20, 100), 0); + CU_ASSERT_EQUAL(ebitmap_highest_set_bit(&e3), 100); + CU_ASSERT_EQUAL(ebitmap_cardinality(&e3), 81); + + CU_ASSERT_EQUAL(ebitmap_init_range(&e4, 100, 400), 0); + CU_ASSERT_EQUAL(ebitmap_highest_set_bit(&e4), 400); + CU_ASSERT_EQUAL(ebitmap_cardinality(&e4), 301); + + CU_ASSERT_EQUAL(ebitmap_init_range(&e5, 10, 5), -EINVAL); + CU_ASSERT_EQUAL(ebitmap_init_range(&e6, 0, UINT32_MAX), -EOVERFLOW); + + ebitmap_destroy(&e6); + ebitmap_destroy(&e5); + ebitmap_destroy(&e4); + ebitmap_destroy(&e3); + ebitmap_destroy(&e2); + ebitmap_destroy(&e1); +} + static void test_ebitmap_or(void) { ebitmap_t e1, e2, e3, e4; @@ -1038,6 +1069,7 @@ int ebitmap_add_tests(CU_pSuite suite) ADD_TEST(ebitmap_init_destroy); ADD_TEST(ebitmap_cmp); ADD_TEST(ebitmap_set_and_get); + ADD_TEST(ebitmap_init_range); ADD_TEST(ebitmap_or); ADD_TEST(ebitmap_and); ADD_TEST(ebitmap_xor);