Linux Sound subsystem development
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From: Arnd Bergmann <arnd@kernel.org>
To: "Vinod Koul" <vkoul@kernel.org>,
	"Jaroslav Kysela" <perex@perex.cz>,
	"Takashi Iwai" <tiwai@suse.com>,
	"Amadeusz Sławiński" <amadeuszx.slawinski@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Yu Jiaoliang <yujiaoliang@vivo.com>,
	Peter Ujfalusi <peter.ujfalusi@linux.intel.com>,
	linux-sound@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] ALSA: compress_offload: avoid 64-bit get_user()
Date: Mon, 16 Dec 2024 10:33:41 +0100	[thread overview]
Message-ID: <20241216093410.377112-2-arnd@kernel.org> (raw)
In-Reply-To: <20241216093410.377112-1-arnd@kernel.org>

From: Arnd Bergmann <arnd@arndb.de>

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>
---
 sound/core/compress_offload.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index ec2485c00e49..1d6769a66810 100644
--- 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)
-- 
2.39.5


  reply	other threads:[~2024-12-16  9:34 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-16  9:33 [PATCH 1/2] ALSA: compress_offload: import DMA_BUF namespace Arnd Bergmann
2024-12-16  9:33 ` Arnd Bergmann [this message]
2024-12-16 10:16   ` [PATCH 2/2] ALSA: compress_offload: avoid 64-bit get_user() Shengjiu Wang
2024-12-16 16:28   ` Vinod Koul
2024-12-16 10:15 ` [PATCH 1/2] ALSA: compress_offload: import DMA_BUF namespace Shengjiu Wang
2024-12-16 16:28 ` Vinod Koul
2024-12-20  8:50 ` Takashi Iwai

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