From be11d570ecd6d49e1ec06c83609d51431268efdb Mon Sep 17 00:00:00 2001 From: Greg Hackmann Date: Wed, 5 Apr 2017 10:03:10 -0700 Subject: [PATCH 1/2] AshmemTest: test lseek() and read() on ashmem fds ashmem has in-kernel handlers for lseek() and read(), but they aren't currently being tested. Add tests for various seeks on a buffer containing holes. If we land inside data, then check that we read() the expected data at that offset. Test: /data/nativetest64/libcutils_test/libcutils_test64 \ --gtest_filter=AshmemTest.* (on hikey) Test: /data/nativetest/libcutils_test/libcutils_test32 \ --gtest_filter=AshmemTest.* (on hikey) Bug: 37254818 Change-Id: I96135a8cea2ce99932e3bc97b5254c95ef6b264a Signed-off-by: Greg Hackmann --- libcutils/tests/AshmemTest.cpp | 66 +++++++++++++++++++++++++++++++--- 1 file changed, 62 insertions(+), 4 deletions(-) diff --git a/libcutils/tests/AshmemTest.cpp b/libcutils/tests/AshmemTest.cpp index 51c679f5d..5493b2cd1 100644 --- a/libcutils/tests/AshmemTest.cpp +++ b/libcutils/tests/AshmemTest.cpp @@ -14,10 +14,11 @@ * limitations under the License. */ -#include +#include #include #include -#include +#include +#include using android::base::unique_fd; @@ -29,8 +30,8 @@ void TestCreateRegion(size_t size, unique_fd &fd, int prot) { ASSERT_EQ(0, ashmem_set_prot_region(fd, prot)); } -void TestMmap(const unique_fd &fd, size_t size, int prot, void **region) { - *region = mmap(nullptr, size, prot, MAP_SHARED, fd, 0); +void TestMmap(const unique_fd& fd, size_t size, int prot, void** region, off_t off = 0) { + *region = mmap(nullptr, size, prot, MAP_SHARED, fd, off); ASSERT_NE(MAP_FAILED, *region); } @@ -101,6 +102,63 @@ TEST(AshmemTest, ForkTest) { EXPECT_EQ(0, munmap(region2, size)); } +TEST(AshmemTest, FileOperationsTest) { + unique_fd fd; + void* region; + + // Allocate a 4-page buffer, but leave page-sized holes on either side + constexpr size_t size = PAGE_SIZE * 4; + constexpr size_t dataSize = PAGE_SIZE * 2; + constexpr size_t holeSize = PAGE_SIZE; + ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE)); + ASSERT_NO_FATAL_FAILURE(TestMmap(fd, dataSize, PROT_READ | PROT_WRITE, ®ion, holeSize)); + + uint8_t data[dataSize]; + FillData(data, dataSize); + memcpy(region, data, dataSize); + + constexpr off_t dataStart = holeSize; + constexpr off_t dataEnd = dataStart + dataSize; + + // The sequence of seeks below looks something like this: + // + // [ ][data][data][ ] + // --^ lseek(99, SEEK_SET) + // ------^ lseek(dataStart, SEEK_CUR) + // ------^ lseek(0, SEEK_DATA) + // ------------^ lseek(dataStart, SEEK_HOLE) + // ^-- lseek(-99, SEEK_END) + // ^------ lseek(-dataStart, SEEK_CUR) + const struct { + // lseek() parameters + off_t offset; + int whence; + // Expected lseek() return value + off_t ret; + } seeks[] = { + {99, SEEK_SET, 99}, {dataStart, SEEK_CUR, dataStart + 99}, + {0, SEEK_DATA, dataStart}, {dataStart, SEEK_HOLE, dataEnd}, + {-99, SEEK_END, size - 99}, {-dataStart, SEEK_CUR, dataEnd - 99}, + }; + for (const auto& cfg : seeks) { + errno = 0; + auto off = lseek(fd, cfg.offset, cfg.whence); + ASSERT_EQ(cfg.ret, off) << "lseek(" << cfg.offset << ", " << cfg.whence << ") failed" + << (errno ? ": " : "") << (errno ? strerror(errno) : ""); + + if (off >= dataStart && off < dataEnd) { + off_t dataOff = off - dataStart; + ssize_t readSize = dataSize - dataOff; + uint8_t buf[readSize]; + + ASSERT_EQ(readSize, TEMP_FAILURE_RETRY(read(fd, buf, readSize))); + EXPECT_EQ(0, memcmp(buf, data + dataOff, readSize)); + } + } + + EXPECT_EQ(0, munmap(region, dataSize)); +} + TEST(AshmemTest, ProtTest) { unique_fd fd; constexpr size_t size = PAGE_SIZE; From 4a9531d3263c5ea32501d3a1417373d465d04aac Mon Sep 17 00:00:00 2001 From: Greg Hackmann Date: Tue, 11 Apr 2017 15:08:36 -0700 Subject: [PATCH 2/2] AshmemTest: expand ProtTest cases ashmem buffers start with PROT_EXEC | PROT_READ | PROT_WRITE and can have bits individually removed (but not added) through the ASHMEM_SET_PROT_MASK ioctl. Test that removing prot bits more than once works, and that the kernel blocks adding prot bits. Also test that the complementary ASHMEM_GET_PROT_MASK ioctl returns the expected prot mask. Test: /data/nativetest64/libcutils_test/libcutils_test64 \ --gtest_filter=AshmemTest.* (on hikey) Test: /data/nativetest/libcutils_test/libcutils_test32 \ --gtest_filter=AshmemTest.* (on hikey) Change-Id: If7b13672547ec4cf6dfd1886197f40f12b2f1c85 Signed-off-by: Greg Hackmann --- libcutils/tests/AshmemTest.cpp | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/libcutils/tests/AshmemTest.cpp b/libcutils/tests/AshmemTest.cpp index 5493b2cd1..a87e23e30 100644 --- a/libcutils/tests/AshmemTest.cpp +++ b/libcutils/tests/AshmemTest.cpp @@ -39,6 +39,10 @@ void TestProtDenied(const unique_fd &fd, size_t size, int prot) { EXPECT_EQ(MAP_FAILED, mmap(nullptr, size, prot, MAP_SHARED, fd, 0)); } +void TestProtIs(const unique_fd& fd, int prot) { + EXPECT_EQ(prot, ioctl(fd, ASHMEM_GET_PROT_MASK)); +} + void FillData(uint8_t* data, size_t dataLen) { for (size_t i = 0; i < dataLen; i++) { data[i] = i & 0xFF; @@ -166,13 +170,25 @@ TEST(AshmemTest, ProtTest) { ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ)); TestProtDenied(fd, size, PROT_WRITE); + TestProtIs(fd, PROT_READ); ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ, ®ion)); EXPECT_EQ(0, munmap(region, size)); ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_WRITE)); TestProtDenied(fd, size, PROT_READ); + TestProtIs(fd, PROT_WRITE); ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_WRITE, ®ion)); EXPECT_EQ(0, munmap(region, size)); + + ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE)); + TestProtIs(fd, PROT_READ | PROT_WRITE); + ASSERT_EQ(0, ashmem_set_prot_region(fd, PROT_READ)); + errno = 0; + ASSERT_EQ(-1, ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE)) + << "kernel shouldn't allow adding protection bits"; + EXPECT_EQ(EINVAL, errno); + TestProtIs(fd, PROT_READ); + TestProtDenied(fd, size, PROT_WRITE); } TEST(AshmemTest, ForkProtTest) {