[PATCH 5/5] kselftests: dmabuf-heaps: Add extra checking that allocated buffers are zeroed

[John Stultz]

Add a check to validate that buffers allocated from the heaps
are properly zeroed before being given to userland.

It is done by allocating a number of buffers, and filling them
with a nonzero pattern, then closing and reallocating more
buffers and checking that they are all properly zeroed.

This is helpful to validate any cached buffers are zeroed
before being given back out.

Cc: Shuah Khan <shuah at kernel.org>
Cc: Brian Starkey <brian.starkey at arm.com>
Cc: Sumit Semwal <sumit.semwal at linaro.org>
Cc: Laura Abbott <labbott at kernel.org>
Cc: Hridya Valsaraju <hridya at google.com>
Cc: Suren Baghdasaryan <surenb at google.com>
Cc: Sandeep Patil <sspatil at google.com>
Cc: Daniel Mentz <danielmentz at google.com>
Cc: linux-media at vger.kernel.org
Cc: dri-devel at lists.freedesktop.org
Cc: linux-kselftest at vger.kernel.org
Signed-off-by: John Stultz <john.stultz at linaro.org>
---
 .../selftests/dmabuf-heaps/dmabuf-heap.c      | 86 +++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
index d179d81e2355..29af27acd40e 100644
--- a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
+++ b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
@@ -218,6 +218,84 @@ static int test_alloc_and_import(char *heap_name)
 	return ret;
 }
 
+static int test_alloc_zeroed(char *heap_name, size_t size)
+{
+	int heap_fd = -1, dmabuf_fd[32];
+	int i, j, ret;
+	void *p = NULL;
+	char *c;
+
+	printf("  Testing alloced %ldk buffers are zeroed:  ", size / 1024);
+	heap_fd = dmabuf_heap_open(heap_name);
+	if (heap_fd < 0)
+		return -1;
+
+	/* Allocate and fill a bunch of buffers */
+	for (i = 0; i < 32; i++) {
+		ret = dmabuf_heap_alloc(heap_fd, size, 0, &dmabuf_fd[i]);
+		if (ret < 0) {
+			printf("FAIL (Allocation (%i) failed)\n", i);
+			goto out;
+		}
+		/* mmap and fill with simple pattern */
+		p = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, dmabuf_fd[i], 0);
+		if (p == MAP_FAILED) {
+			printf("FAIL (mmap() failed!)\n");
+			ret = -1;
+			goto out;
+		}
+		dmabuf_sync(dmabuf_fd[i], DMA_BUF_SYNC_START);
+		memset(p, 0xff, size);
+		dmabuf_sync(dmabuf_fd[i], DMA_BUF_SYNC_END);
+		munmap(p, size);
+	}
+	/* close them all */
+	for (i = 0; i < 32; i++)
+		close(dmabuf_fd[i]);
+
+	/* Allocate and validate all buffers are zeroed */
+	for (i = 0; i < 32; i++) {
+		ret = dmabuf_heap_alloc(heap_fd, size, 0, &dmabuf_fd[i]);
+		if (ret < 0) {
+			printf("FAIL (Allocation (%i) failed)\n", i);
+			goto out;
+		}
+
+		/* mmap and validate everything is zero */
+		p = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, dmabuf_fd[i], 0);
+		if (p == MAP_FAILED) {
+			printf("FAIL (mmap() failed!)\n");
+			ret = -1;
+			goto out;
+		}
+		dmabuf_sync(dmabuf_fd[i], DMA_BUF_SYNC_START);
+		c = (char *)p;
+		for (j = 0; j < size; j++) {
+			if (c[j] != 0) {
+				printf("FAIL (Allocated buffer not zeroed @ %i)\n", j);
+				break;
+			}
+		}
+		dmabuf_sync(dmabuf_fd[i], DMA_BUF_SYNC_END);
+		munmap(p, size);
+	}
+	/* close them all */
+	for (i = 0; i < 32; i++)
+		close(dmabuf_fd[i]);
+
+	close(heap_fd);
+	printf("OK\n");
+	return 0;
+
+out:
+	while (i > 0) {
+		close(dmabuf_fd[i]);
+		i--;
+	}
+	close(heap_fd);
+	return ret;
+}
+
 /* Test the ioctl version compatibility w/ a smaller structure then expected */
 static int dmabuf_heap_alloc_older(int fd, size_t len, unsigned int flags,
 				   int *dmabuf_fd)
@@ -386,6 +464,14 @@ int main(void)
 		if (ret)
 			break;
 
+		ret = test_alloc_zeroed(dir->d_name, 4 * 1024);
+		if (ret)
+			break;
+
+		ret = test_alloc_zeroed(dir->d_name, ONE_MEG);
+		if (ret)
+			break;
+
 		ret = test_alloc_compat(dir->d_name);
 		if (ret)
 			break;
-- 
2.25.1