[Linaro-mm-sig] Re: [RFC v3 8/8] selftests: Add binder cgroup gpu memory transfer test

On Wed, Mar 9, 2022 at 8:53 AM T.J. Mercier tjmercier@google.com wrote:

This test verifies that the cgroup GPU memory charge is transferred correctly when a dmabuf is passed between processes in two different cgroups and the sender specifies BINDER_BUFFER_FLAG_SENDER_NO_NEED in the binder transaction data containing the dmabuf file descriptor.

Signed-off-by: T.J. Mercier tjmercier@google.com

Reviewed-by: Todd Kjos tkjos@google.com for the binder driver interactions. Need Christian to take a look at the binderfs interactions.

---

.../selftests/drivers/android/binder/Makefile | 8 + .../drivers/android/binder/binder_util.c | 254 +++++++++ .../drivers/android/binder/binder_util.h | 32 ++ .../selftests/drivers/android/binder/config | 4 + .../binder/test_dmabuf_cgroup_transfer.c | 480 ++++++++++++++++++ 5 files changed, 778 insertions(+) create mode 100644 tools/testing/selftests/drivers/android/binder/Makefile create mode 100644 tools/testing/selftests/drivers/android/binder/binder_util.c create mode 100644 tools/testing/selftests/drivers/android/binder/binder_util.h create mode 100644 tools/testing/selftests/drivers/android/binder/config create mode 100644 tools/testing/selftests/drivers/android/binder/test_dmabuf_cgroup_transfer.c

diff --git a/tools/testing/selftests/drivers/android/binder/Makefile b/tools/testing/selftests/drivers/android/binder/Makefile new file mode 100644 index 000000000000..726439d10675 --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS += -Wall

+TEST_GEN_PROGS = test_dmabuf_cgroup_transfer

+include ../../../lib.mk

+$(OUTPUT)/test_dmabuf_cgroup_transfer: ../../../cgroup/cgroup_util.c binder_util.c diff --git a/tools/testing/selftests/drivers/android/binder/binder_util.c b/tools/testing/selftests/drivers/android/binder/binder_util.c new file mode 100644 index 000000000000..c9dcf5b9d42b --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/binder_util.c @@ -0,0 +1,254 @@ +// SPDX-License-Identifier: GPL-2.0

+#include "binder_util.h"

+#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/mount.h>

+#include <linux/limits.h> +#include <linux/android/binder.h> +#include <linux/android/binderfs.h>

+static const size_t BINDER_MMAP_SIZE = 64 * 1024;

+static void binderfs_unmount(const char *mountpoint) +{

•   if (umount2(mountpoint, MNT_DETACH))
  

•           fprintf(stderr, "Failed to unmount binderfs at %s: %s\n",
  

•                   mountpoint, strerror(errno));
  

•   else
  

•           fprintf(stderr, "Binderfs unmounted: %s\n", mountpoint);
  

•   if (rmdir(mountpoint))
  

•           fprintf(stderr, "Failed to remove binderfs mount %s: %s\n",
  

•                   mountpoint, strerror(errno));
  

•   else
  

•           fprintf(stderr, "Binderfs mountpoint destroyed: %s\n", mountpoint);
  

+}

+struct binderfs_ctx create_binderfs(const char *name) +{

•   int fd, ret, saved_errno;
  

•   struct binderfs_device device = { 0 };
  

•   struct binderfs_ctx ctx = { 0 };
  

•   /*
  

•    * P_tmpdir is set to "/tmp/" on Android platforms where Binder is most
  

•    * commonly used, but this path does not actually exist on Android. We
  

•    * will first try using "/data/local/tmp" and fallback to P_tmpdir if
  

•    * that fails for non-Android platforms.
  

•    */
  

•   static const char tmpdir[] = "/data/local/tmp";
  

•   static const size_t MAX_TMPDIR_SIZE =
  

•           sizeof(tmpdir) > sizeof(P_tmpdir) ?
  

•           sizeof(tmpdir) : sizeof(P_tmpdir);
  

•   static const char template[] = "/binderfs_XXXXXX";
  

•   char *mkdtemp_result;
  

•   char binderfs_mntpt[MAX_TMPDIR_SIZE + sizeof(template)];
  

•   char device_path[MAX_TMPDIR_SIZE + sizeof(template) + BINDERFS_MAX_NAME];
  

•   snprintf(binderfs_mntpt, sizeof(binderfs_mntpt), "%s%s", tmpdir, template);
  

•   mkdtemp_result = mkdtemp(binderfs_mntpt);
  

•   if (mkdtemp_result == NULL) {
  

•           fprintf(stderr, "Failed to create binderfs mountpoint at %s: %s.\n",
  

•                   binderfs_mntpt, strerror(errno));
  

•           fprintf(stderr, "Trying fallback mountpoint...\n");
  

•           snprintf(binderfs_mntpt, sizeof(binderfs_mntpt), "%s%s", P_tmpdir, template);
  

•           if (mkdtemp(binderfs_mntpt) == NULL) {
  

•                   fprintf(stderr, "Failed to create binderfs mountpoint at %s: %s\n",
  

•                   binderfs_mntpt, strerror(errno));
  

•                   return ctx;
  

•           }
  

•   }
  

•   fprintf(stderr, "Binderfs mountpoint created at %s\n", binderfs_mntpt);
  

•   if (mount(NULL, binderfs_mntpt, "binder", 0, 0)) {
  

•           perror("Could not mount binderfs");
  

•           rmdir(binderfs_mntpt);
  

•           return ctx;
  

•   }
  

•   fprintf(stderr, "Binderfs mounted at %s\n", binderfs_mntpt);
  

•   strncpy(device.name, name, sizeof(device.name));
  

•   snprintf(device_path, sizeof(device_path), "%s/binder-control", binderfs_mntpt);
  

•   fd = open(device_path, O_RDONLY | O_CLOEXEC);
  

•   if (!fd) {
  

•           perror("Failed to open binder-control device");
  

•           binderfs_unmount(binderfs_mntpt);
  

•           return ctx;
  

•   }
  

•   ret = ioctl(fd, BINDER_CTL_ADD, &device);
  

•   saved_errno = errno;
  

•   close(fd);
  

•   errno = saved_errno;
  

•   if (ret) {
  

•           perror("Failed to allocate new binder device");
  

•           binderfs_unmount(binderfs_mntpt);
  

•           return ctx;
  

•   }
  

•   fprintf(stderr, "Allocated new binder device with major %d, minor %d, and name %s at %s\n",
  

•           device.major, device.minor, device.name, binderfs_mntpt);
  

•   ctx.name = strdup(name);
  

•   ctx.mountpoint = strdup(binderfs_mntpt);
  

•   return ctx;
  

+}

+void destroy_binderfs(struct binderfs_ctx *ctx) +{

•   char path[PATH_MAX];
  

•   snprintf(path, sizeof(path), "%s/%s", ctx->mountpoint, ctx->name);
  

•   if (unlink(path))
  

•           fprintf(stderr, "Failed to unlink binder device %s: %s\n", path, strerror(errno));
  

•   else
  

•           fprintf(stderr, "Destroyed binder %s at %s\n", ctx->name, ctx->mountpoint);
  

•   binderfs_unmount(ctx->mountpoint);
  

•   free(ctx->name);
  

•   free(ctx->mountpoint);
  

+}

+struct binder_ctx open_binder(struct binderfs_ctx *bfs_ctx) +{

•   struct binder_ctx ctx = {.fd = -1, .memory = NULL};
  

•   char path[PATH_MAX];
  

•   snprintf(path, sizeof(path), "%s/%s", bfs_ctx->mountpoint, bfs_ctx->name);
  

•   ctx.fd = open(path, O_RDWR | O_NONBLOCK | O_CLOEXEC);
  

•   if (ctx.fd < 0) {
  

•           fprintf(stderr, "Error opening binder device %s: %s\n", path, strerror(errno));
  

•           return ctx;
  

•   }
  

•   ctx.memory = mmap(NULL, BINDER_MMAP_SIZE, PROT_READ, MAP_SHARED, ctx.fd, 0);
  

•   if (ctx.memory == NULL) {
  

•           perror("Error mapping binder memory");
  

•           close(ctx.fd);
  

•           ctx.fd = -1;
  

•   }
  

•   return ctx;
  

+}

+void close_binder(struct binder_ctx *ctx) +{

•   if (munmap(ctx->memory, BINDER_MMAP_SIZE))
  

•           perror("Failed to unmap binder memory");
  

•   ctx->memory = NULL;
  

•   if (close(ctx->fd))
  

•           perror("Failed to close binder");
  

•   ctx->fd = -1;
  

+}

+int become_binder_context_manager(int binder_fd) +{

•   return ioctl(binder_fd, BINDER_SET_CONTEXT_MGR, 0);
  

+}

+int do_binder_write_read(int binder_fd, void *writebuf, binder_size_t writesize,

•                    void *readbuf, binder_size_t readsize)
  

+{

•   int err;
  

•   struct binder_write_read bwr = {
  

•           .write_buffer = (binder_uintptr_t)writebuf,
  

•           .write_size = writesize,
  

•           .read_buffer = (binder_uintptr_t)readbuf,
  

•           .read_size = readsize
  

•   };
  

•   do {
  

•           if (ioctl(binder_fd, BINDER_WRITE_READ, &bwr) >= 0)
  

•                   err = 0;
  

•           else
  

•                   err = -errno;
  

•   } while (err == -EINTR);
  

•   if (err < 0) {
  

•           perror("BINDER_WRITE_READ");
  

•           return -1;
  

•   }
  

•   if (bwr.write_consumed < writesize) {
  

•           fprintf(stderr, "Binder did not consume full write buffer %llu %llu\n",
  

•                   bwr.write_consumed, writesize);
  

•           return -1;
  

•   }
  

•   return bwr.read_consumed;
  

+}

+static const char *reply_string(int cmd) +{

•   switch (cmd) {
  

•   case BR_ERROR:
  

•           return("BR_ERROR");
  

•   case BR_OK:
  

•           return("BR_OK");
  

•   case BR_TRANSACTION_SEC_CTX:
  

•           return("BR_TRANSACTION_SEC_CTX");
  

•   case BR_TRANSACTION:
  

•           return("BR_TRANSACTION");
  

•   case BR_REPLY:
  

•           return("BR_REPLY");
  

•   case BR_ACQUIRE_RESULT:
  

•           return("BR_ACQUIRE_RESULT");
  

•   case BR_DEAD_REPLY:
  

•           return("BR_DEAD_REPLY");
  

•   case BR_TRANSACTION_COMPLETE:
  

•           return("BR_TRANSACTION_COMPLETE");
  

•   case BR_INCREFS:
  

•           return("BR_INCREFS");
  

•   case BR_ACQUIRE:
  

•           return("BR_ACQUIRE");
  

•   case BR_RELEASE:
  

•           return("BR_RELEASE");
  

•   case BR_DECREFS:
  

•           return("BR_DECREFS");
  

•   case BR_ATTEMPT_ACQUIRE:
  

•           return("BR_ATTEMPT_ACQUIRE");
  

•   case BR_NOOP:
  

•           return("BR_NOOP");
  

•   case BR_SPAWN_LOOPER:
  

•           return("BR_SPAWN_LOOPER");
  

•   case BR_FINISHED:
  

•           return("BR_FINISHED");
  

•   case BR_DEAD_BINDER:
  

•           return("BR_DEAD_BINDER");
  

•   case BR_CLEAR_DEATH_NOTIFICATION_DONE:
  

•           return("BR_CLEAR_DEATH_NOTIFICATION_DONE");
  

•   case BR_FAILED_REPLY:
  

•           return("BR_FAILED_REPLY");
  

•   case BR_FROZEN_REPLY:
  

•           return("BR_FROZEN_REPLY");
  

•   case BR_ONEWAY_SPAM_SUSPECT:
  

•           return("BR_ONEWAY_SPAM_SUSPECT");
  

•   default:
  

•           return("Unknown");
  

•   };
  

+}

+int expect_binder_reply(int32_t actual, int32_t expected) +{

•   if (actual != expected) {
  

•           fprintf(stderr, "Expected %s but received %s\n",
  

•                   reply_string(expected), reply_string(actual));
  

•           return -1;
  

•   }
  

•   return 0;
  

+}

diff --git a/tools/testing/selftests/drivers/android/binder/binder_util.h b/tools/testing/selftests/drivers/android/binder/binder_util.h new file mode 100644 index 000000000000..807f5abe987e --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/binder_util.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 */

+#ifndef SELFTEST_BINDER_UTIL_H +#define SELFTEST_BINDER_UTIL_H

+#include <stdint.h>

+#include <linux/android/binder.h>

+struct binderfs_ctx {

•   char *name;
  

•   char *mountpoint;
  

+};

+struct binder_ctx {

•   int fd;
  

•   void *memory;
  

+};

+struct binderfs_ctx create_binderfs(const char *name); +void destroy_binderfs(struct binderfs_ctx *ctx);

+struct binder_ctx open_binder(struct binderfs_ctx *bfs_ctx); +void close_binder(struct binder_ctx *ctx);

+int become_binder_context_manager(int binder_fd);

+int do_binder_write_read(int binder_fd, void *writebuf, binder_size_t writesize,

•                    void *readbuf, binder_size_t readsize);
  

+int expect_binder_reply(int32_t actual, int32_t expected); +#endif diff --git a/tools/testing/selftests/drivers/android/binder/config b/tools/testing/selftests/drivers/android/binder/config new file mode 100644 index 000000000000..fcc5f8f693b3 --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/config @@ -0,0 +1,4 @@ +CONFIG_CGROUP_GPU=y +CONFIG_ANDROID=y +CONFIG_ANDROID_BINDERFS=y +CONFIG_ANDROID_BINDER_IPC=y diff --git a/tools/testing/selftests/drivers/android/binder/test_dmabuf_cgroup_transfer.c b/tools/testing/selftests/drivers/android/binder/test_dmabuf_cgroup_transfer.c new file mode 100644 index 000000000000..9b952ab401cc --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/test_dmabuf_cgroup_transfer.c @@ -0,0 +1,480 @@ +// SPDX-License-Identifier: GPL-2.0

+/*

• • This test verifies that the cgroup GPU memory charge is transferred correctly
• • when a dmabuf is passed between processes in two different cgroups and the
• • sender specifies BINDER_BUFFER_FLAG_SENDER_NO_NEED in the binder transaction
• • data containing the dmabuf file descriptor.
• • The gpu_cgroup_dmabuf_transfer test function becomes the binder context
• • manager, then forks a child who initiates a transaction with the context
• • manager by specifying a target of 0. The context manager reply contains a
• • dmabuf file descriptor which was allocated by the gpu_cgroup_dmabuf_transfer
• • test function, but should be charged to the child cgroup after the binder
• • transaction.
• */

+#include <errno.h> +#include <fcntl.h> +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/epoll.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <sys/wait.h>

+#include "binder_util.h" +#include "../../../cgroup/cgroup_util.h" +#include "../../../kselftest.h" +#include "../../../kselftest_harness.h"

+#include <linux/limits.h> +#include <linux/dma-heap.h> +#include <linux/android/binder.h>

+#define UNUSED(x) ((void)(x))

+static const unsigned int BINDER_CODE = 8675309; /* Any number will work here */

+struct cgroup_ctx {

•   char *root;
  

•   char *source;
  

•   char *dest;
  

+};

+void destroy_cgroups(struct __test_metadata *_metadata, struct cgroup_ctx *ctx) +{

•   if (ctx->source != NULL) {
  

•           TH_LOG("Destroying cgroup: %s", ctx->source);
  

•           rmdir(ctx->source);
  

•           free(ctx->source);
  

•   }
  

•   if (ctx->dest != NULL) {
  

•           TH_LOG("Destroying cgroup: %s", ctx->dest);
  

•           rmdir(ctx->dest);
  

•           free(ctx->dest);
  

•   }
  

•   free(ctx->root);
  

•   ctx->root = ctx->source = ctx->dest = NULL;
  

+}

+struct cgroup_ctx create_cgroups(struct __test_metadata *_metadata) +{

•   struct cgroup_ctx ctx = {0};
  

•   char root[PATH_MAX], *tmp;
  

•   static const char template[] = "/gpucg_XXXXXX";
  

•   if (cg_find_unified_root(root, sizeof(root))) {
  

•           TH_LOG("Could not find cgroups root");
  

•           return ctx;
  

•   }
  

•   if (cg_read_strstr(root, "cgroup.controllers", "gpu")) {
  

•           TH_LOG("Could not find GPU controller");
  

•           return ctx;
  

•   }
  

•   if (cg_write(root, "cgroup.subtree_control", "+gpu")) {
  

•           TH_LOG("Could not enable GPU controller");
  

•           return ctx;
  

•   }
  

•   ctx.root = strdup(root);
  

•   snprintf(root, sizeof(root), "%s/%s", ctx.root, template);
  

•   tmp = mkdtemp(root);
  

•   if (tmp == NULL) {
  

•           TH_LOG("%s - Could not create source cgroup", strerror(errno));
  

•           destroy_cgroups(_metadata, &ctx);
  

•           return ctx;
  

•   }
  

•   ctx.source = strdup(tmp);
  

•   snprintf(root, sizeof(root), "%s/%s", ctx.root, template);
  

•   tmp = mkdtemp(root);
  

•   if (tmp == NULL) {
  

•           TH_LOG("%s - Could not create destination cgroup", strerror(errno));
  

•           destroy_cgroups(_metadata, &ctx);
  

•           return ctx;
  

•   }
  

•   ctx.dest = strdup(tmp);
  

•   TH_LOG("Created cgroups: %s %s", ctx.source, ctx.dest);
  

•   return ctx;
  

+}

+int dmabuf_heap_alloc(int fd, size_t len, int *dmabuf_fd) +{

•   struct dma_heap_allocation_data data = {
  

•           .len = len,
  

•           .fd = 0,
  

•           .fd_flags = O_RDONLY | O_CLOEXEC,
  

•           .heap_flags = 0,
  

•   };
  

•   int ret;
  

•   if (!dmabuf_fd)
  

•           return -EINVAL;
  

•   ret = ioctl(fd, DMA_HEAP_IOCTL_ALLOC, &data);
  

•   if (ret < 0)
  

•           return ret;
  

•   *dmabuf_fd = (int)data.fd;
  

•   return ret;
  

+}

+/* The system heap is known to export dmabufs with support for cgroup tracking */ +int alloc_dmabuf_from_system_heap(struct __test_metadata *_metadata, size_t bytes) +{

•   int heap_fd = -1, dmabuf_fd = -1;
  

•   static const char * const heap_path = "/dev/dma_heap/system";
  

•   heap_fd = open(heap_path, O_RDONLY);
  

•   if (heap_fd < 0) {
  

•           TH_LOG("%s - open %s failed!\n", strerror(errno), heap_path);
  

•           return -1;
  

•   }
  

•   if (dmabuf_heap_alloc(heap_fd, bytes, &dmabuf_fd))
  

•           TH_LOG("dmabuf allocation failed! - %s", strerror(errno));
  

•   close(heap_fd);
  

•   return dmabuf_fd;
  

+}

+int binder_request_dmabuf(int binder_fd) +{

•   int ret;
  

•   /*
  

•    * We just send an empty binder_buffer_object to initiate a transaction
  

•    * with the context manager, who should respond with a single dmabuf
  

•    * inside a binder_fd_array_object.
  

•    */
  

•   struct binder_buffer_object bbo = {
  

•           .hdr.type = BINDER_TYPE_PTR,
  

•           .flags = 0,
  

•           .buffer = 0,
  

•           .length = 0,
  

•           .parent = 0, /* No parent */
  

•           .parent_offset = 0 /* No parent */
  

•   };
  

•   binder_size_t offsets[] = {0};
  

•   struct {
  

•           int32_t cmd;
  

•           struct binder_transaction_data btd;
  

•   } __attribute__((packed)) bc = {
  

•           .cmd = BC_TRANSACTION,
  

•           .btd = {
  

•                   .target = { 0 },
  

•                   .cookie = 0,
  

•                   .code = BINDER_CODE,
  

•                   .flags = TF_ACCEPT_FDS, /* We expect a FDA in the reply */
  

•                   .data_size = sizeof(bbo),
  

•                   .offsets_size = sizeof(offsets),
  

•                   .data.ptr = {
  

•                           (binder_uintptr_t)&bbo,
  

•                           (binder_uintptr_t)offsets
  

•                   }
  

•           },
  

•   };
  

•   struct {
  

•           int32_t reply_noop;
  

•   } __attribute__((packed)) br;
  

•   ret = do_binder_write_read(binder_fd, &bc, sizeof(bc), &br, sizeof(br));
  

•   if (ret >= sizeof(br) && expect_binder_reply(br.reply_noop, BR_NOOP)) {
  

•           return -1;
  

•   } else if (ret < sizeof(br)) {
  

•           fprintf(stderr, "Not enough bytes in binder reply %d\n", ret);
  

•           return -1;
  

•   }
  

•   return 0;
  

+}

+int send_dmabuf_reply(int binder_fd, struct binder_transaction_data *tr, int dmabuf_fd) +{

•   int ret;
  

•   /*
  

•    * The trailing 0 is to achieve the necessary alignment for the binder
  

•    * buffer_size.
  

•    */
  

•   int fdarray[] = { dmabuf_fd, 0 };
  

•   struct binder_buffer_object bbo = {
  

•           .hdr.type = BINDER_TYPE_PTR,
  

•           .flags = BINDER_BUFFER_FLAG_SENDER_NO_NEED,
  

•           .buffer = (binder_uintptr_t)fdarray,
  

•           .length = sizeof(fdarray),
  

•           .parent = 0, /* No parent */
  

•           .parent_offset = 0 /* No parent */
  

•   };
  

•   struct binder_fd_array_object bfdao = {
  

•           .hdr.type = BINDER_TYPE_FDA,
  

•           .num_fds = 1,
  

•           .parent = 0, /* The binder_buffer_object */
  

•           .parent_offset = 0 /* FDs follow immediately */
  

•   };
  

•   uint64_t sz = sizeof(fdarray);
  

•   uint8_t data[sizeof(sz) + sizeof(bbo) + sizeof(bfdao)];
  

•   binder_size_t offsets[] = {sizeof(sz), sizeof(sz)+sizeof(bbo)};
  

•   memcpy(data,                            &sz, sizeof(sz));
  

•   memcpy(data + sizeof(sz),               &bbo, sizeof(bbo));
  

•   memcpy(data + sizeof(sz) + sizeof(bbo), &bfdao, sizeof(bfdao));
  

•   struct {
  

•           int32_t cmd;
  

•           struct binder_transaction_data_sg btd;
  

•   } __attribute__((packed)) bc = {
  

•           .cmd = BC_REPLY_SG,
  

•           .btd.transaction_data = {
  

•                   .target = { tr->target.handle },
  

•                   .cookie = tr->cookie,
  

•                   .code = BINDER_CODE,
  

•                   .flags = 0,
  

•                   .data_size = sizeof(data),
  

•                   .offsets_size = sizeof(offsets),
  

•                   .data.ptr = {
  

•                           (binder_uintptr_t)data,
  

•                           (binder_uintptr_t)offsets
  

•                   }
  

•           },
  

•           .btd.buffers_size = sizeof(fdarray)
  

•   };
  

•   struct {
  

•           int32_t reply_noop;
  

•   } __attribute__((packed)) br;
  

•   ret = do_binder_write_read(binder_fd, &bc, sizeof(bc), &br, sizeof(br));
  

•   if (ret >= sizeof(br) && expect_binder_reply(br.reply_noop, BR_NOOP)) {
  

•           return -1;
  

•   } else if (ret < sizeof(br)) {
  

•           fprintf(stderr, "Not enough bytes in binder reply %d\n", ret);
  

•           return -1;
  

•   }
  

•   return 0;
  

+}

+struct binder_transaction_data *binder_wait_for_transaction(int binder_fd,

•                                                       uint32_t *readbuf,
  

•                                                       size_t readsize)
  

+{

•   static const int MAX_EVENTS = 1, EPOLL_WAIT_TIME_MS = 3 * 1000;
  

•   struct binder_reply {
  

•           int32_t reply0;
  

•           int32_t reply1;
  

•           struct binder_transaction_data btd;
  

•   } *br;
  

•   struct binder_transaction_data *ret = NULL;
  

•   struct epoll_event events[MAX_EVENTS];
  

•   int epoll_fd, num_events, readcount;
  

•   uint32_t bc[] = { BC_ENTER_LOOPER };
  

•   do_binder_write_read(binder_fd, &bc, sizeof(bc), NULL, 0);
  

•   epoll_fd = epoll_create1(EPOLL_CLOEXEC);
  

•   if (epoll_fd == -1) {
  

•           perror("epoll_create");
  

•           return NULL;
  

•   }
  

•   events[0].events = EPOLLIN;
  

•   if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, binder_fd, &events[0])) {
  

•           perror("epoll_ctl add");
  

•           goto err_close;
  

•   }
  

•   num_events = epoll_wait(epoll_fd, events, MAX_EVENTS, EPOLL_WAIT_TIME_MS);
  

•   if (num_events < 0) {
  

•           perror("epoll_wait");
  

•           goto err_ctl;
  

•   } else if (num_events == 0) {
  

•           fprintf(stderr, "No events\n");
  

•           goto err_ctl;
  

•   }
  

•   readcount = do_binder_write_read(binder_fd, NULL, 0, readbuf, readsize);
  

•   fprintf(stderr, "Read %d bytes from binder\n", readcount);
  

•   if (readcount < (int)sizeof(struct binder_reply)) {
  

•           fprintf(stderr, "read_consumed not large enough\n");
  

•           goto err_ctl;
  

•   }
  

•   br = (struct binder_reply *)readbuf;
  

•   if (expect_binder_reply(br->reply0, BR_NOOP))
  

•           goto err_ctl;
  

•   if (br->reply1 == BR_TRANSACTION) {
  

•           if (br->btd.code == BINDER_CODE)
  

•                   ret = &br->btd;
  

•           else
  

•                   fprintf(stderr, "Received transaction with unexpected code: %u\n",
  

•                           br->btd.code);
  

•   } else {
  

•           expect_binder_reply(br->reply1, BR_TRANSACTION_COMPLETE);
  

•   }
  

+err_ctl:

•   if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, binder_fd, NULL))
  

•           perror("epoll_ctl del");
  

+err_close:

•   close(epoll_fd);
  

•   return ret;
  

+}

+static int child_request_dmabuf_transfer(const char *cgroup, void *arg) +{

•   UNUSED(cgroup);
  

•   int ret = -1;
  

•   uint32_t readbuf[32];
  

•   struct binderfs_ctx bfs_ctx = *(struct binderfs_ctx *)arg;
  

•   struct binder_ctx b_ctx;
  

•   fprintf(stderr, "Child PID: %d\n", getpid());
  

•   b_ctx = open_binder(&bfs_ctx);
  

•   if (b_ctx.fd < 0) {
  

•           fprintf(stderr, "Child unable to open binder\n");
  

•           return -1;
  

•   }
  

•   if (binder_request_dmabuf(b_ctx.fd))
  

•           goto err;
  

•   /* The child must stay alive until the binder reply is received */
  

•   if (binder_wait_for_transaction(b_ctx.fd, readbuf, sizeof(readbuf)) == NULL)
  

•           ret = 0;
  

•   /*
  

•    * We don't close the received dmabuf here so that the parent can
  

•    * inspect the cgroup gpu memory charges to verify the charge transfer
  

•    * completed successfully.
  

•    */
  

+err:

•   close_binder(&b_ctx);
  

•   fprintf(stderr, "Child done\n");
  

•   return ret;
  

+}

+TEST(gpu_cgroup_dmabuf_transfer) +{

•   static const char * const GPUMEM_FILENAME = "gpu.memory.current";
  

•   static const size_t ONE_MiB = 1024 * 1024;
  

•   int ret, dmabuf_fd;
  

•   uint32_t readbuf[32];
  

•   long memsize;
  

•   pid_t child_pid;
  

•   struct binderfs_ctx bfs_ctx;
  

•   struct binder_ctx b_ctx;
  

•   struct cgroup_ctx cg_ctx;
  

•   struct binder_transaction_data *tr;
  

•   struct flat_binder_object *fbo;
  

•   struct binder_buffer_object *bbo;
  

•   bfs_ctx = create_binderfs("testbinder");
  

•   if (bfs_ctx.name == NULL)
  

•           ksft_exit_skip("The Android binderfs filesystem is not available\n");
  

•   cg_ctx = create_cgroups(_metadata);
  

•   if (cg_ctx.root == NULL) {
  

•           destroy_binderfs(&bfs_ctx);
  

•           ksft_exit_skip("cgroup v2 isn't mounted\n");
  

•   }
  

•   ASSERT_EQ(cg_enter_current(cg_ctx.source), 0) {
  

•           TH_LOG("Could not move parent to cgroup: %s", cg_ctx.source);
  

•           goto err_cg;
  

•   }
  

•   dmabuf_fd = alloc_dmabuf_from_system_heap(_metadata, ONE_MiB);
  

•   ASSERT_GE(dmabuf_fd, 0) {
  

•           goto err_cg;
  

•   }
  

•   TH_LOG("Allocated dmabuf");
  

•   memsize = cg_read_key_long(cg_ctx.source, GPUMEM_FILENAME, "system");
  

•   ASSERT_EQ(memsize, ONE_MiB) {
  

•           TH_LOG("GPU memory used after allocation: %ld but it should be %lu",
  

•                  memsize, (unsigned long)ONE_MiB);
  

•           goto err_dmabuf;
  

•   }
  

•   b_ctx = open_binder(&bfs_ctx);
  

•   ASSERT_GE(b_ctx.fd, 0) {
  

•           TH_LOG("Parent unable to open binder");
  

•           goto err_dmabuf;
  

•   }
  

•   TH_LOG("Opened binder at %s/%s", bfs_ctx.mountpoint, bfs_ctx.name);
  

•   ASSERT_EQ(become_binder_context_manager(b_ctx.fd), 0) {
  

•           TH_LOG("Cannot become context manager: %s", strerror(errno));
  

•           goto err_binder;
  

•   }
  

•   child_pid = cg_run_nowait(cg_ctx.dest, child_request_dmabuf_transfer, &bfs_ctx);
  

•   ASSERT_GT(child_pid, 0) {
  

•           TH_LOG("Error forking: %s", strerror(errno));
  

•           goto err_binder;
  

•   }
  

•   tr = binder_wait_for_transaction(b_ctx.fd, readbuf, sizeof(readbuf));
  

•   ASSERT_NE(tr, NULL) {
  

•           TH_LOG("Error receiving transaction request from child");
  

•           goto err_child;
  

•   }
  

•   fbo = (struct flat_binder_object *)tr->data.ptr.buffer;
  

•   ASSERT_EQ(fbo->hdr.type, BINDER_TYPE_PTR) {
  

•           TH_LOG("Did not receive a buffer object from child");
  

•           goto err_child;
  

•   }
  

•   bbo = (struct binder_buffer_object *)fbo;
  

•   ASSERT_EQ(bbo->length, 0) {
  

•           TH_LOG("Did not receive an empty buffer object from child");
  

•           goto err_child;
  

•   }
  

•   TH_LOG("Received transaction from child");
  

•   send_dmabuf_reply(b_ctx.fd, tr, dmabuf_fd);
  

•   ASSERT_EQ(cg_read_key_long(cg_ctx.dest, GPUMEM_FILENAME, "system"), ONE_MiB) {
  

•           TH_LOG("Destination cgroup does not have system charge!");
  

•           goto err_child;
  

•   }
  

•   ASSERT_EQ(cg_read_key_long(cg_ctx.source, GPUMEM_FILENAME, "system"), 0) {
  

•           TH_LOG("Source cgroup still has system charge!");
  

•           goto err_child;
  

•   }
  

•   TH_LOG("Charge transfer succeeded!");
  

+err_child:

•   waitpid(child_pid, &ret, 0);
  

•   if (WIFEXITED(ret))
  

•           TH_LOG("Child %d terminated with %d", child_pid, WEXITSTATUS(ret));
  

•   else
  

•           TH_LOG("Child terminated abnormally");
  

+err_binder:

•   close_binder(&b_ctx);
  

+err_dmabuf:

•   close(dmabuf_fd);
  

+err_cg:

•   destroy_cgroups(_metadata, &cg_ctx);
  

•   destroy_binderfs(&bfs_ctx);
  

+}

+TEST_HARNESS_MAIN

2.35.1.616.g0bdcbb4464-goog