test/poll-race-mshot: fix missing init of buffer ring

It's critical to initialize the ring before use, obviously... As is also
documented.

Outside of that, intialize the buffer written. This doesn't really
matter, but it's a nice thing to do.

Use the appropriate helpers to add buffers to the ring, rather than
maintain a private mask.

Finally, free the ring and buffers when done. This usually doesn't matter
in test cases, but we are calling these thousands of times. Better to
free the memory than bloat the usage.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

test/poll-race-mshot.c

@@ -9,13 +9,13 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <string.h>
 #include <sys/socket.h>
 
 #include "liburing.h"
 #include "helpers.h"
 
 #define NREQS		64
-#define BR_MASK		(NREQS - 1)
 #define BUF_SIZE	64
 
 static int no_buf_ring;
@@ -31,6 +31,7 @@ static void *thread(void *data)
 	char buf[BUF_SIZE];
 	int ret, i, fd;
 
+	memset(buf, 0x5a, BUF_SIZE);
 	pthread_barrier_wait(&d->barrier);
 	fd = d->fd;
 	for (i = 0; i < NREQS; i++) {
@@ -64,11 +65,12 @@ static int test(struct io_uring *ring, struct data *d)
 
 	d->fd = fd[1];
 
-	if (posix_memalign((void *) &buf, 16384, BUF_SIZE * NREQS))
+	if (posix_memalign((void **) &buf, 16384, BUF_SIZE * NREQS))
 		return T_EXIT_FAIL;
-	if (posix_memalign((void *) &br, 16384, 4096))
+	if (posix_memalign((void **) &br, 16384, sizeof(struct io_uring_buf) * NREQS))
 		return T_EXIT_FAIL;
 
+	io_uring_buf_ring_init(br);
 	reg.ring_addr = (unsigned long) br;
 	reg.ring_entries = NREQS;
 	reg.bgid = 1;
@@ -85,7 +87,8 @@ static int test(struct io_uring *ring, struct data *d)
 
 	ptr = buf;
 	for (i = 0; i < NREQS; i++) {
-		io_uring_buf_ring_add(br, ptr, BUF_SIZE, i + 1, BR_MASK, i);
+		io_uring_buf_ring_add(br, ptr, BUF_SIZE, i + 1,
+				io_uring_buf_ring_mask(NREQS), i);
 		ptr += BUF_SIZE;
 	}
 	io_uring_buf_ring_advance(br, NREQS);
@@ -139,6 +142,8 @@ static int test(struct io_uring *ring, struct data *d)
 	} while (i < NREQS);
 
 	pthread_join(t, &ret2);
+	free(buf);
+	free(br);
 	close(fd[0]);
 	close(fd[1]);
 	return T_EXIT_PASS;
@@ -164,9 +169,10 @@ static int test_mshot(struct io_uring *ring, struct data *d)
 
 	if (posix_memalign((void *) &buf, 16384, BUF_SIZE * NREQS))
 		return T_EXIT_FAIL;
-	if (posix_memalign((void *) &br, 16384, 4096))
+	if (posix_memalign((void *) &br, 16384, sizeof(struct io_uring_buf) * NREQS))
 		return T_EXIT_FAIL;
 
+	io_uring_buf_ring_init(br);
 	reg.ring_addr = (unsigned long) br;
 	reg.ring_entries = NREQS;
 	reg.bgid = 1;
@@ -179,7 +185,8 @@ static int test_mshot(struct io_uring *ring, struct data *d)
 
 	ptr = buf;
 	for (i = 0; i < NREQS; i++) {
-		io_uring_buf_ring_add(br, ptr, BUF_SIZE, i + 1, BR_MASK, i);
+		io_uring_buf_ring_add(br, ptr, BUF_SIZE, i + 1,
+				io_uring_buf_ring_mask(NREQS), i);
 		ptr += BUF_SIZE;
 	}
 	io_uring_buf_ring_advance(br, NREQS);
@@ -238,6 +245,8 @@ static int test_mshot(struct io_uring *ring, struct data *d)
 	}
 
 	pthread_join(t, &ret2);
+	free(buf);
+	free(br);
 	close(fd[0]);
 	close(fd[1]);
 	return T_EXIT_PASS;