Add setup and teardown for testing binder allocator code with KUnit. Include minimal test cases to verify that tests are initialized correctly.
Tested-by: Rae Moar rmoar@google.com Acked-by: Carlos Llamas cmllamas@google.com Reviewed-by: Kees Cook kees@kernel.org Signed-off-by: Tiffany Yang ynaffit@google.com --- v2: * Added Tested-by tag v3: * Split kunit lib change into separate change v4: * Added Google Copyright to new files * Collected tags --- drivers/android/Kconfig | 11 ++ drivers/android/Makefile | 1 + drivers/android/binder.c | 5 +- drivers/android/binder_alloc.c | 15 +- drivers/android/binder_alloc.h | 6 + drivers/android/binder_internal.h | 4 + drivers/android/tests/.kunitconfig | 7 + drivers/android/tests/Makefile | 6 + drivers/android/tests/binder_alloc_kunit.c | 169 +++++++++++++++++++++ 9 files changed, 218 insertions(+), 6 deletions(-) create mode 100644 drivers/android/tests/.kunitconfig create mode 100644 drivers/android/tests/Makefile create mode 100644 drivers/android/tests/binder_alloc_kunit.c
diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig index 07aa8ae0a058..b1bc7183366c 100644 --- a/drivers/android/Kconfig +++ b/drivers/android/Kconfig @@ -47,4 +47,15 @@ config ANDROID_BINDER_IPC_SELFTEST exhaustively with combinations of various buffer sizes and alignments.
+config ANDROID_BINDER_ALLOC_KUNIT_TEST + tristate "KUnit Tests for Android Binder Alloc" if !KUNIT_ALL_TESTS + depends on ANDROID_BINDER_IPC && KUNIT + default KUNIT_ALL_TESTS + help + This feature builds the binder alloc KUnit tests. + + Each test case runs using a pared-down binder_alloc struct and + test-specific freelist, which allows this KUnit module to be loaded + for testing without interfering with a running system. + endmenu diff --git a/drivers/android/Makefile b/drivers/android/Makefile index c9d3d0c99c25..74d02a335d4e 100644 --- a/drivers/android/Makefile +++ b/drivers/android/Makefile @@ -4,3 +4,4 @@ ccflags-y += -I$(src) # needed for trace events obj-$(CONFIG_ANDROID_BINDERFS) += binderfs.o obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o binder_alloc.o obj-$(CONFIG_ANDROID_BINDER_IPC_SELFTEST) += binder_alloc_selftest.o +obj-$(CONFIG_ANDROID_BINDER_ALLOC_KUNIT_TEST) += tests/ diff --git a/drivers/android/binder.c b/drivers/android/binder.c index c463ca4a8fff..9dfe90c284fc 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -68,6 +68,8 @@ #include <linux/sizes.h> #include <linux/ktime.h>
+#include <kunit/visibility.h> + #include <uapi/linux/android/binder.h>
#include <linux/cacheflush.h> @@ -5956,10 +5958,11 @@ static void binder_vma_close(struct vm_area_struct *vma) binder_alloc_vma_close(&proc->alloc); }
-static vm_fault_t binder_vm_fault(struct vm_fault *vmf) +VISIBLE_IF_KUNIT vm_fault_t binder_vm_fault(struct vm_fault *vmf) { return VM_FAULT_SIGBUS; } +EXPORT_SYMBOL_IF_KUNIT(binder_vm_fault);
static const struct vm_operations_struct binder_vm_ops = { .open = binder_vma_open, diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 2e89f9127883..c79e5c6721f0 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -23,6 +23,7 @@ #include <linux/uaccess.h> #include <linux/highmem.h> #include <linux/sizes.h> +#include <kunit/visibility.h> #include "binder_alloc.h" #include "binder_trace.h"
@@ -57,13 +58,14 @@ static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer) return list_entry(buffer->entry.prev, struct binder_buffer, entry); }
-static size_t binder_alloc_buffer_size(struct binder_alloc *alloc, - struct binder_buffer *buffer) +VISIBLE_IF_KUNIT size_t binder_alloc_buffer_size(struct binder_alloc *alloc, + struct binder_buffer *buffer) { if (list_is_last(&buffer->entry, &alloc->buffers)) return alloc->vm_start + alloc->buffer_size - buffer->user_data; return binder_buffer_next(buffer)->user_data - buffer->user_data; } +EXPORT_SYMBOL_IF_KUNIT(binder_alloc_buffer_size);
static void binder_insert_free_buffer(struct binder_alloc *alloc, struct binder_buffer *new_buffer) @@ -959,7 +961,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc, failure_string, ret); return ret; } - +EXPORT_SYMBOL_IF_KUNIT(binder_alloc_mmap_handler);
void binder_alloc_deferred_release(struct binder_alloc *alloc) { @@ -1028,6 +1030,7 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc) "%s: %d buffers %d, pages %d\n", __func__, alloc->pid, buffers, page_count); } +EXPORT_SYMBOL_IF_KUNIT(binder_alloc_deferred_release);
/** * binder_alloc_print_allocated() - print buffer info @@ -1122,6 +1125,7 @@ void binder_alloc_vma_close(struct binder_alloc *alloc) { binder_alloc_set_mapped(alloc, false); } +EXPORT_SYMBOL_IF_KUNIT(binder_alloc_vma_close);
/** * binder_alloc_free_page() - shrinker callback to free pages @@ -1229,8 +1233,8 @@ binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
static struct shrinker *binder_shrinker;
-static void __binder_alloc_init(struct binder_alloc *alloc, - struct list_lru *freelist) +VISIBLE_IF_KUNIT void __binder_alloc_init(struct binder_alloc *alloc, + struct list_lru *freelist) { alloc->pid = current->group_leader->pid; alloc->mm = current->mm; @@ -1239,6 +1243,7 @@ static void __binder_alloc_init(struct binder_alloc *alloc, INIT_LIST_HEAD(&alloc->buffers); alloc->freelist = freelist; } +EXPORT_SYMBOL_IF_KUNIT(__binder_alloc_init);
/** * binder_alloc_init() - called by binder_open() for per-proc initialization diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h index aa05a9df1360..dc8dce2469a7 100644 --- a/drivers/android/binder_alloc.h +++ b/drivers/android/binder_alloc.h @@ -188,5 +188,11 @@ int binder_alloc_copy_from_buffer(struct binder_alloc *alloc, binder_size_t buffer_offset, size_t bytes);
+#if IS_ENABLED(CONFIG_KUNIT) +void __binder_alloc_init(struct binder_alloc *alloc, struct list_lru *freelist); +size_t binder_alloc_buffer_size(struct binder_alloc *alloc, + struct binder_buffer *buffer); +#endif + #endif /* _LINUX_BINDER_ALLOC_H */
diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h index 1ba5caf1d88d..b5d3014fb4dc 100644 --- a/drivers/android/binder_internal.h +++ b/drivers/android/binder_internal.h @@ -592,4 +592,8 @@ void binder_add_device(struct binder_device *device); */ void binder_remove_device(struct binder_device *device);
+#if IS_ENABLED(CONFIG_KUNIT) +vm_fault_t binder_vm_fault(struct vm_fault *vmf); +#endif + #endif /* _LINUX_BINDER_INTERNAL_H */ diff --git a/drivers/android/tests/.kunitconfig b/drivers/android/tests/.kunitconfig new file mode 100644 index 000000000000..39b76bab9d9a --- /dev/null +++ b/drivers/android/tests/.kunitconfig @@ -0,0 +1,7 @@ +# +# Copyright 2025 Google LLC. +# + +CONFIG_KUNIT=y +CONFIG_ANDROID_BINDER_IPC=y +CONFIG_ANDROID_BINDER_ALLOC_KUNIT_TEST=y diff --git a/drivers/android/tests/Makefile b/drivers/android/tests/Makefile new file mode 100644 index 000000000000..27268418eb03 --- /dev/null +++ b/drivers/android/tests/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Copyright 2025 Google LLC. +# + +obj-$(CONFIG_ANDROID_BINDER_ALLOC_KUNIT_TEST) += binder_alloc_kunit.o diff --git a/drivers/android/tests/binder_alloc_kunit.c b/drivers/android/tests/binder_alloc_kunit.c new file mode 100644 index 000000000000..5e49078c9b23 --- /dev/null +++ b/drivers/android/tests/binder_alloc_kunit.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test cases for binder allocator code. + * + * Copyright 2025 Google LLC. + * Author: Tiffany Yang ynaffit@google.com + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <kunit/test.h> +#include <linux/anon_inodes.h> +#include <linux/err.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/sizes.h> + +#include "../binder_alloc.h" +#include "../binder_internal.h" + +MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING"); + +#define BINDER_MMAP_SIZE SZ_128K + +struct binder_alloc_test { + struct binder_alloc alloc; + struct list_lru binder_test_freelist; + struct file *filp; + unsigned long mmap_uaddr; +}; + +static void binder_alloc_test_init_freelist(struct kunit *test) +{ + struct binder_alloc_test *priv = test->priv; + + KUNIT_EXPECT_PTR_EQ(test, priv->alloc.freelist, + &priv->binder_test_freelist); +} + +static void binder_alloc_test_mmap(struct kunit *test) +{ + struct binder_alloc_test *priv = test->priv; + struct binder_alloc *alloc = &priv->alloc; + struct binder_buffer *buf; + struct rb_node *n; + + KUNIT_EXPECT_EQ(test, alloc->mapped, true); + KUNIT_EXPECT_EQ(test, alloc->buffer_size, BINDER_MMAP_SIZE); + + n = rb_first(&alloc->allocated_buffers); + KUNIT_EXPECT_PTR_EQ(test, n, NULL); + + n = rb_first(&alloc->free_buffers); + buf = rb_entry(n, struct binder_buffer, rb_node); + KUNIT_EXPECT_EQ(test, binder_alloc_buffer_size(alloc, buf), + BINDER_MMAP_SIZE); + KUNIT_EXPECT_TRUE(test, list_is_last(&buf->entry, &alloc->buffers)); +} + +/* ===== End test cases ===== */ + +static void binder_alloc_test_vma_close(struct vm_area_struct *vma) +{ + struct binder_alloc *alloc = vma->vm_private_data; + + binder_alloc_vma_close(alloc); +} + +static const struct vm_operations_struct binder_alloc_test_vm_ops = { + .close = binder_alloc_test_vma_close, + .fault = binder_vm_fault, +}; + +static int binder_alloc_test_mmap_handler(struct file *filp, + struct vm_area_struct *vma) +{ + struct binder_alloc *alloc = filp->private_data; + + vm_flags_mod(vma, VM_DONTCOPY | VM_MIXEDMAP, VM_MAYWRITE); + + vma->vm_ops = &binder_alloc_test_vm_ops; + vma->vm_private_data = alloc; + + return binder_alloc_mmap_handler(alloc, vma); +} + +static const struct file_operations binder_alloc_test_fops = { + .mmap = binder_alloc_test_mmap_handler, +}; + +static int binder_alloc_test_init(struct kunit *test) +{ + struct binder_alloc_test *priv; + int ret; + + priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + test->priv = priv; + + ret = list_lru_init(&priv->binder_test_freelist); + if (ret) { + kunit_err(test, "Failed to initialize test freelist\n"); + return ret; + } + + /* __binder_alloc_init requires mm to be attached */ + ret = kunit_attach_mm(); + if (ret) { + kunit_err(test, "Failed to attach mm\n"); + return ret; + } + __binder_alloc_init(&priv->alloc, &priv->binder_test_freelist); + + priv->filp = anon_inode_getfile("binder_alloc_kunit", + &binder_alloc_test_fops, &priv->alloc, + O_RDWR | O_CLOEXEC); + if (IS_ERR_OR_NULL(priv->filp)) { + kunit_err(test, "Failed to open binder alloc test driver file\n"); + return priv->filp ? PTR_ERR(priv->filp) : -ENOMEM; + } + + priv->mmap_uaddr = kunit_vm_mmap(test, priv->filp, 0, BINDER_MMAP_SIZE, + PROT_READ, MAP_PRIVATE | MAP_NORESERVE, + 0); + if (!priv->mmap_uaddr) { + kunit_err(test, "Could not map the test's transaction memory\n"); + return -ENOMEM; + } + + return 0; +} + +static void binder_alloc_test_exit(struct kunit *test) +{ + struct binder_alloc_test *priv = test->priv; + + /* Close the backing file to make sure binder_alloc_vma_close runs */ + if (!IS_ERR_OR_NULL(priv->filp)) + fput(priv->filp); + + if (priv->alloc.mm) + binder_alloc_deferred_release(&priv->alloc); + + /* Make sure freelist is empty */ + KUNIT_EXPECT_EQ(test, list_lru_count(&priv->binder_test_freelist), 0); + list_lru_destroy(&priv->binder_test_freelist); +} + +static struct kunit_case binder_alloc_test_cases[] = { + KUNIT_CASE(binder_alloc_test_init_freelist), + KUNIT_CASE(binder_alloc_test_mmap), + {} +}; + +static struct kunit_suite binder_alloc_test_suite = { + .name = "binder_alloc", + .test_cases = binder_alloc_test_cases, + .init = binder_alloc_test_init, + .exit = binder_alloc_test_exit, +}; + +kunit_test_suite(binder_alloc_test_suite); + +MODULE_AUTHOR("Tiffany Yang ynaffit@google.com"); +MODULE_DESCRIPTION("Binder Alloc KUnit tests"); +MODULE_LICENSE("GPL");