fix broken double close in BpfMapTest.cpp
am: e6cbd40468
Change-Id: Icf3e5dd8056e5c58d62c0bd91fd00837fbaa9dce
diff --git a/libbpf_android/BpfMapTest.cpp b/libbpf_android/BpfMapTest.cpp
index 895dda6..94d273e 100644
--- a/libbpf_android/BpfMapTest.cpp
+++ b/libbpf_android/BpfMapTest.cpp
@@ -52,7 +52,13 @@
class BpfMapTest : public testing::Test {
protected:
BpfMapTest() {}
- int mMapFd;
+
+ // SetUp() will always populate this with a map, but only some tests will use it.
+ // They may use it once via 'mMapFd.release()', or multiple times via 'dup(mMapFd)'
+ // to initialize a BpfMap object.
+ // If it's not used or only dup'ed then TearDown() will close() it, otherwise
+ // whoever got ownership via mMapFd.release() will close() it - possibly much earlier.
+ unique_fd mMapFd;
void SetUp() {
SKIP_IF_BPF_NOT_SUPPORTED;
@@ -61,9 +67,9 @@
if (!access(PINNED_MAP_PATH, R_OK)) {
EXPECT_EQ(0, remove(PINNED_MAP_PATH));
}
- mMapFd = createMap(BPF_MAP_TYPE_HASH, sizeof(uint32_t), sizeof(uint32_t), TEST_MAP_SIZE,
- BPF_F_NO_PREALLOC);
- EXPECT_LE(0, mMapFd);
+ mMapFd.reset(createMap(BPF_MAP_TYPE_HASH, sizeof(uint32_t), sizeof(uint32_t), TEST_MAP_SIZE,
+ BPF_F_NO_PREALLOC));
+ ASSERT_LE(0, mMapFd);
}
void TearDown() {
@@ -72,7 +78,8 @@
if (!access(PINNED_MAP_PATH, R_OK)) {
EXPECT_EQ(0, remove(PINNED_MAP_PATH));
}
- close(mMapFd);
+
+ mMapFd.reset(-1); // close(mMapFd) if still open
}
void checkMapInvalid(BpfMap<uint32_t, uint32_t>& map) {
@@ -117,7 +124,7 @@
BpfMap<uint32_t, uint32_t> testMap1;
checkMapInvalid(testMap1);
- BpfMap<uint32_t, uint32_t> testMap2(mMapFd);
+ BpfMap<uint32_t, uint32_t> testMap2(mMapFd.release());
checkMapValid(testMap2);
BpfMap<uint32_t, uint32_t> testMap3(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
@@ -127,7 +134,7 @@
TEST_F(BpfMapTest, basicHelpers) {
SKIP_IF_BPF_NOT_SUPPORTED;
- BpfMap<uint32_t, uint32_t> testMap(mMapFd);
+ BpfMap<uint32_t, uint32_t> testMap(mMapFd.release());
uint32_t key = TEST_KEY1;
uint32_t value_write = TEST_VALUE1;
writeToMapAndCheck(testMap, key, value_write);
@@ -144,21 +151,21 @@
SKIP_IF_BPF_NOT_SUPPORTED;
BpfMap<uint32_t, uint32_t> testMap;
- testMap.reset(mMapFd);
+ testMap.reset(mMapFd.release());
uint32_t key = TEST_KEY1;
uint32_t value_write = TEST_VALUE1;
writeToMapAndCheck(testMap, key, value_write);
+
testMap.reset();
checkMapInvalid(testMap);
- unique_fd invalidFd(mMapFd);
- ASSERT_GT(0, findMapEntry(invalidFd, &key, &value_write));
+ ASSERT_GT(0, findMapEntry(testMap.getMap(), &key, &value_write));
ASSERT_EQ(EBADF, errno);
}
TEST_F(BpfMapTest, moveConstructor) {
SKIP_IF_BPF_NOT_SUPPORTED;
- BpfMap<uint32_t, uint32_t> testMap1(mMapFd);
+ BpfMap<uint32_t, uint32_t> testMap1(mMapFd.release());
BpfMap<uint32_t, uint32_t> testMap2;
testMap2 = std::move(testMap1);
uint32_t key = TEST_KEY1;
@@ -188,7 +195,7 @@
TEST_F(BpfMapTest, iterate) {
SKIP_IF_BPF_NOT_SUPPORTED;
- BpfMap<uint32_t, uint32_t> testMap(mMapFd);
+ BpfMap<uint32_t, uint32_t> testMap(mMapFd.release());
populateMap(TEST_MAP_SIZE, testMap);
int totalCount = 0;
int totalSum = 0;
@@ -208,7 +215,7 @@
TEST_F(BpfMapTest, iterateWithValue) {
SKIP_IF_BPF_NOT_SUPPORTED;
- BpfMap<uint32_t, uint32_t> testMap(mMapFd);
+ BpfMap<uint32_t, uint32_t> testMap(mMapFd.release());
populateMap(TEST_MAP_SIZE, testMap);
int totalCount = 0;
int totalSum = 0;
@@ -230,7 +237,7 @@
TEST_F(BpfMapTest, mapIsEmpty) {
SKIP_IF_BPF_NOT_SUPPORTED;
- BpfMap<uint32_t, uint32_t> testMap(mMapFd);
+ BpfMap<uint32_t, uint32_t> testMap(mMapFd.release());
expectMapEmpty(testMap);
uint32_t key = TEST_KEY1;
uint32_t value_write = TEST_VALUE1;
@@ -262,7 +269,7 @@
TEST_F(BpfMapTest, mapClear) {
SKIP_IF_BPF_NOT_SUPPORTED;
- BpfMap<uint32_t, uint32_t> testMap(mMapFd);
+ BpfMap<uint32_t, uint32_t> testMap(mMapFd.release());
populateMap(TEST_MAP_SIZE, testMap);
auto isEmpty = testMap.isEmpty();
ASSERT_TRUE(isOk(isEmpty));
diff --git a/libbpf_android/include/bpf/BpfMap.h b/libbpf_android/include/bpf/BpfMap.h
index d47698e..a894b57 100644
--- a/libbpf_android/include/bpf/BpfMap.h
+++ b/libbpf_android/include/bpf/BpfMap.h
@@ -46,8 +46,19 @@
template <class Key, class Value>
class BpfMap {
public:
- BpfMap<Key, Value>() : mMapFd(-1){};
+ BpfMap<Key, Value>() {};
explicit BpfMap<Key, Value>(int fd) : mMapFd(fd){};
+
+ // We could technically implement this constructor either with
+ // : mMapFd(dup(fd)) {} // fd valid in caller, we have our own local copy
+ // or
+ // : mMapFd(fd.release()) {} // fd no longer valid in caller, we 'stole' it
+ //
+ // However, I think we're much better off with a compile time failure, since
+ // it's better for whoever passes in a unique_fd to think twice about whether
+ // they're trying to pass in ownership or not.
+ explicit BpfMap<Key, Value>(base::unique_fd fd) = delete;
+
BpfMap<Key, Value>(bpf_map_type map_type, uint32_t max_entries, uint32_t map_flags) {
int map_fd = createMap(map_type, sizeof(Key), sizeof(Value), max_entries, map_flags);
if (map_fd < 0) {
