ALSA: compress_offload: improve file descriptors installation for dma-buf

Avoid to use single dma_buf_fd() call for both directions. This code
ensures that both file descriptors are allocated before fd_install().

Link: https://lore.kernel.org/linux-sound/6a923647-4495-4cff-a253-b73f48cfd0ea@stanley.mountain/
Fixes: 04177158cf98 ("ALSA: compress_offload: introduce accel operation mode")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20241217100726.732863-1-perex@perex.cz

diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index bdb6e307e453818ed3abdd36860c42f42a87ec17..edf5aadf38e5a36bfac39a14e3c2f9a9237f82a1 100644 (file)
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -1025,7 +1025,7 @@ static u64 snd_compr_seqno_next(struct snd_compr_stream *stream)
 static int snd_compr_task_new(struct snd_compr_stream *stream, struct snd_compr_task *utask)
 {
        struct snd_compr_task_runtime *task;
-       int retval;
+       int retval, fd_i, fd_o;
 
        if (stream->runtime->total_tasks >= stream->runtime->fragments)
                return -EBUSY;
@@ -1039,16 +1039,24 @@ static int snd_compr_task_new(struct snd_compr_stream *stream, struct snd_compr_
        retval = stream->ops->task_create(stream, task);
        if (retval < 0)
                goto cleanup;
-       utask->input_fd = dma_buf_fd(task->input, O_WRONLY|O_CLOEXEC);
-       if (utask->input_fd < 0) {
-               retval = utask->input_fd;
+       /* similar functionality as in dma_buf_fd(), but ensure that both
+          file descriptors are allocated before fd_install() */
+       if (!task->input || !task->input->file || !task->output || !task->output->file) {
+               retval = -EINVAL;
                goto cleanup;
        }
-       utask->output_fd = dma_buf_fd(task->output, O_RDONLY|O_CLOEXEC);
-       if (utask->output_fd < 0) {
-               retval = utask->output_fd;
+       fd_i = get_unused_fd_flags(O_WRONLY|O_CLOEXEC);
+       if (fd_i < 0)
+               goto cleanup;
+       fd_o = get_unused_fd_flags(O_RDONLY|O_CLOEXEC);
+       if (fd_o < 0) {
+               put_unused_fd(fd_i);
                goto cleanup;
        }
+       fd_install(fd_i, task->input->file);
+       fd_install(fd_o, task->output->file);
+       utask->input_fd = fd_i;
+       utask->output_fd = fd_o;
        /* keep dmabuf reference until freed with task free ioctl */
        dma_buf_get(utask->input_fd);
        dma_buf_get(utask->output_fd);