ALSA: compress_offload: avoid 64-bit get_user()

On some architectures, get_user() cannot read a 64-bit user variable:

arm-linux-gnueabi-ld: sound/core/compress_offload.o: in function `snd_compr_ioctl':
compress_offload.c:(.text.snd_compr_ioctl+0x538): undefined reference to `__get_user_bad'

Use an equivalent copy_from_user() instead.

Fixes: 04177158cf98 ("ALSA: compress_offload: introduce accel operation mode")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20241216093410.377112-2-arnd@kernel.org

diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index ec2485c00e49711fa68aeea2c454f4e272583188..1d6769a66810e6b2082a8cbf899e5d3504fe0103 100644 (file)
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -1180,9 +1180,9 @@ static int snd_compr_task_seq(struct snd_compr_stream *stream, unsigned long arg
 
        if (stream->runtime->state != SNDRV_PCM_STATE_SETUP)
                return -EPERM;
-       retval = get_user(seqno, (__u64 __user *)arg);
-       if (retval < 0)
-               return retval;
+       retval = copy_from_user(&seqno, (__u64 __user *)arg, sizeof(seqno));
+       if (retval)
+               return -EFAULT;
        retval = 0;
        if (seqno == 0) {
                list_for_each_entry_reverse(task, &stream->runtime->tasks, list)