meminfo: Add memtrack dmabufinfo library

This is the userspace component for the improved shared memory buffer
tracking.

A new static library called libdmabufinfo will provide APIs to parse dmabuf
debugfs entries. The library can also map and read the file descriptors
per process to cross-reference the global data per process.

This change only adds a global API to read dmabuf stats from debugfs.

Bug: 63860998
Test: dmabufinfo_test
Change-Id: Ib0deedc73337a70875e03e07d3e9a692c4c33e63
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Erick Reyes <erickreyes@google.com>
Signed-off-by: Sandeep Patil <sspatil@google.com>

1 files changed, 252 insertions, 0 deletions

diff --git a/libmeminfo/libdmabufinfo/dmabufinfo_test.cpp b/libmeminfo/libdmabufinfo/dmabufinfo_test.cpp
new file mode 100644
index 000000000..aa5f16c22
--- /dev/null
+++ b/libmeminfo/libdmabufinfo/dmabufinfo_test.cpp
@@ -0,0 +1,252 @@
+/* Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+#include <linux/dma-buf.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <ion/ion.h>
+
+#include <dmabufinfo/dmabufinfo.h>
+
+using namespace ::android::dmabufinfo;
+using namespace ::android::base;
+
+#define MAX_HEAP_NAME 32
+#define ION_HEAP_ANY_MASK (0x7fffffff)
+
+struct ion_heap_data {
+    char name[MAX_HEAP_NAME];
+    __u32 type;
+    __u32 heap_id;
+    __u32 reserved0;
+    __u32 reserved1;
+    __u32 reserved2;
+};
+
+#ifndef DMA_BUF_SET_NAME
+#define DMA_BUF_SET_NAME _IOW(DMA_BUF_BASE, 5, const char*)
+#endif
+
+#define EXPECT_ONE_BUF_EQ(_bufptr, _name, _fdrefs, _maprefs, _expname, _count, _size) \
+    do {                                                                              \
+        EXPECT_EQ(_bufptr->name(), _name);                                            \
+        EXPECT_EQ(_bufptr->fdrefs().size(), _fdrefs);                                 \
+        EXPECT_EQ(_bufptr->maprefs().size(), _maprefs);                               \
+        EXPECT_EQ(_bufptr->exporter(), _expname);                                     \
+        EXPECT_EQ(_bufptr->count(), _count);                                          \
+        EXPECT_EQ(_bufptr->size(), _size);                                            \
+    } while (0)
+
+#define EXPECT_PID_IN_FDREFS(_bufptr, _pid, _expect)                         \
+    do {                                                                     \
+        const std::vector<pid_t>& _fdrefs = _bufptr->fdrefs();               \
+        auto _ref = std::find_if(_fdrefs.begin(), _fdrefs.end(),             \
+                                 [&](const pid_t& p) { return p == _pid; }); \
+        EXPECT_EQ((_ref == _fdrefs.end()), _expect);                         \
+    } while (0)
+
+#define EXPECT_PID_IN_MAPREFS(_bufptr, _pid, _expect)                        \
+    do {                                                                     \
+        const std::vector<pid_t>& _maprefs = _bufptr->maprefs();             \
+        auto _ref = std::find_if(_maprefs.begin(), _maprefs.end(),           \
+                                 [&](const pid_t& p) { return p == _pid; }); \
+        EXPECT_EQ((_ref == _maprefs.end()), _expect);                        \
+    } while (0)
+
+TEST(DmaBufInfoParser, TestReadDmaBufInfo) {
+    std::string bufinfo = R"bufinfo(00045056    00000002    00000007    00000002    ion 00022069    
+	Attached Devices:
+Total 0 devices attached
+01048576    00000002    00000007    00000001    ion 00019834    CAMERA
+	Attached Devices:
+	soc:qcom,cam_smmu:msm_cam_smmu_icp
+Total 1 devices attached)bufinfo";
+
+    TemporaryFile tf;
+    ASSERT_TRUE(tf.fd != -1);
+    ASSERT_TRUE(::android::base::WriteStringToFd(bufinfo, tf.fd));
+    std::string path = std::string(tf.path);
+
+    std::vector<DmaBuffer> dmabufs;
+    EXPECT_TRUE(ReadDmaBufInfo(&dmabufs, path));
+
+    EXPECT_EQ(dmabufs.size(), 2UL);
+
+    EXPECT_EQ(dmabufs[0].size(), 45056UL);
+    EXPECT_EQ(dmabufs[0].inode(), 22069UL);
+    EXPECT_EQ(dmabufs[0].count(), 2UL);
+    EXPECT_EQ(dmabufs[0].exporter(), "ion");
+    EXPECT_TRUE(dmabufs[0].name().empty());
+    EXPECT_EQ(dmabufs[0].total_refs(), 0ULL);
+    EXPECT_TRUE(dmabufs[0].fdrefs().empty());
+    EXPECT_TRUE(dmabufs[0].maprefs().empty());
+
+    EXPECT_EQ(dmabufs[1].size(), 1048576UL);
+    EXPECT_EQ(dmabufs[1].inode(), 19834UL);
+    EXPECT_EQ(dmabufs[1].count(), 1UL);
+    EXPECT_EQ(dmabufs[1].exporter(), "ion");
+    EXPECT_FALSE(dmabufs[1].name().empty());
+    EXPECT_EQ(dmabufs[1].name(), "CAMERA");
+    EXPECT_EQ(dmabufs[1].total_refs(), 0ULL);
+    EXPECT_TRUE(dmabufs[1].fdrefs().empty());
+    EXPECT_TRUE(dmabufs[1].maprefs().empty());
+}
+
+class DmaBufTester : public ::testing::Test {
+  public:
+    DmaBufTester() : ion_fd(ion_open()), ion_heap_mask(get_ion_heap_mask()) {}
+
+    ~DmaBufTester() {
+        if (is_valid()) {
+            ion_close(ion_fd);
+        }
+    }
+
+    bool is_valid() { return (ion_fd >= 0 && ion_heap_mask > 0); }
+
+    unique_fd allocate(uint64_t size, const std::string& name) {
+        int fd;
+        int err = ion_alloc_fd(ion_fd, size, 0, ion_heap_mask, 0, &fd);
+        if (err < 0) {
+            return unique_fd{err};
+        }
+
+        if (!name.empty()) {
+            err = ioctl(fd, DMA_BUF_SET_NAME, name.c_str());
+            if (err < 0) return unique_fd{-errno};
+        }
+
+        return unique_fd{fd};
+    }
+
+  private:
+    int get_ion_heap_mask() {
+        if (ion_fd < 0) {
+            return 0;
+        }
+
+        if (ion_is_legacy(ion_fd)) {
+            // Since ION is still in staging, we've seen that the heap mask ids are also
+            // changed across kernels for some reason. So, here we basically ask for a buffer
+            // from _any_ heap.
+            return ION_HEAP_ANY_MASK;
+        }
+
+        int cnt;
+        int err = ion_query_heap_cnt(ion_fd, &cnt);
+        if (err < 0) {
+            return err;
+        }
+
+        std::vector<ion_heap_data> heaps;
+        heaps.resize(cnt);
+        err = ion_query_get_heaps(ion_fd, cnt, &heaps[0]);
+        if (err < 0) {
+            return err;
+        }
+
+        unsigned int ret = 0;
+        for (auto& it : heaps) {
+            if (!strcmp(it.name, "ion_system_heap")) {
+                ret |= (1 << it.heap_id);
+            }
+        }
+
+        return ret;
+    }
+
+    unique_fd ion_fd;
+    const int ion_heap_mask;
+};
+
+TEST_F(DmaBufTester, TestFdRef) {
+    // Test if a dma buffer is found while the corresponding file descriptor
+    // is open
+    ASSERT_TRUE(is_valid());
+    pid_t pid = getpid();
+    std::vector<DmaBuffer> dmabufs;
+    {
+        // Allocate one buffer and make sure the library can see it
+        unique_fd buf = allocate(4096, "dmabuftester-4k");
+        ASSERT_GT(buf, 0) << "Allocated buffer is invalid";
+        ASSERT_TRUE(ReadDmaBufInfo(pid, &dmabufs));
+
+        EXPECT_EQ(dmabufs.size(), 1UL);
+        EXPECT_ONE_BUF_EQ(dmabufs.begin(), "dmabuftester-4k", 1UL, 0UL, "ion", 1UL, 4096ULL);
+
+        // Make sure the buffer has the right pid too.
+        EXPECT_PID_IN_FDREFS(dmabufs.begin(), pid, false);
+    }
+
+    // Now make sure the buffer has disappeared
+    ASSERT_TRUE(ReadDmaBufInfo(pid, &dmabufs));
+    EXPECT_TRUE(dmabufs.empty());
+}
+
+TEST_F(DmaBufTester, TestMapRef) {
+    // Test to make sure we can find a buffer if the fd is closed but the buffer
+    // is mapped
+    ASSERT_TRUE(is_valid());
+    pid_t pid = getpid();
+    std::vector<DmaBuffer> dmabufs;
+    {
+        // Allocate one buffer and make sure the library can see it
+        unique_fd buf = allocate(4096, "dmabuftester-4k");
+        ASSERT_GT(buf, 0) << "Allocated buffer is invalid";
+        auto ptr = mmap(0, 4096, PROT_READ, MAP_SHARED, buf, 0);
+        ASSERT_NE(ptr, MAP_FAILED);
+        ASSERT_TRUE(ReadDmaBufInfo(pid, &dmabufs));
+
+        EXPECT_EQ(dmabufs.size(), 1UL);
+        EXPECT_ONE_BUF_EQ(dmabufs.begin(), "dmabuftester-4k", 1UL, 1UL, "ion", 2UL, 4096ULL);
+
+        // Make sure the buffer has the right pid too.
+        EXPECT_PID_IN_FDREFS(dmabufs.begin(), pid, false);
+        EXPECT_PID_IN_MAPREFS(dmabufs.begin(), pid, false);
+
+        // close the file descriptor and re-read the stats
+        buf.reset(-1);
+        ASSERT_TRUE(ReadDmaBufInfo(pid, &dmabufs));
+
+        EXPECT_EQ(dmabufs.size(), 1UL);
+        EXPECT_ONE_BUF_EQ(dmabufs.begin(), "<unknown>", 0UL, 1UL, "<unknown>", 0UL, 4096ULL);
+
+        EXPECT_PID_IN_FDREFS(dmabufs.begin(), pid, true);
+        EXPECT_PID_IN_MAPREFS(dmabufs.begin(), pid, false);
+
+        // unmap the bufer and lose all references
+        munmap(ptr, 4096);
+    }
+
+    // Now make sure the buffer has disappeared
+    ASSERT_TRUE(ReadDmaBufInfo(pid, &dmabufs));
+    EXPECT_TRUE(dmabufs.empty());
+}
+
+int main(int argc, char** argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+    ::android::base::InitLogging(argv, android::base::StderrLogger);
+    return RUN_ALL_TESTS();
+}