sockptr is a universal pointer that can represent both kernel- and
user-space pointers. Despite of its name, sockptr is already widely
used in quite a few subsystems as a generic solution, and it fits
pretty well for ALSA PCM copy ops, too; we had to split to copy_user
and copy_kernel, and those can be unified to a single ops with
sockptr_t.
So here it is: this patch adds a new PCM copy ops that passes
sockptr_t pointer for copying both kernel and user-space more
consistently. This patch touches only the ALSA PCM core part, and the
actual users will be replaced in the following patches.
As of now, the old copy_user and copy_kernel ops are still kept.
Once after all users are converted, we'll drop the old copy_user and
copy_kernel ops, too.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
include/sound/pcm.h | 3 ++
sound/core/pcm_lib.c | 97 ++++++++++++++++++++++-------------------
sound/core/pcm_native.c | 2 +-
3 files changed, 57 insertions(+), 45 deletions(-)
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 19f564606ac4..04b935200d0e 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -16,6 +16,7 @@
#include <linux/bitops.h>
#include <linux/pm_qos.h>
#include <linux/refcount.h>
+#include <linux/sockptr.h>
#define snd_pcm_substream_chip(substream) ((substream)->private_data)
#define snd_pcm_chip(pcm) ((pcm)->private_data)
@@ -68,6 +69,8 @@ struct snd_pcm_ops {
struct snd_pcm_audio_tstamp_report *audio_tstamp_report);
int (*fill_silence)(struct snd_pcm_substream *substream, int channel,
unsigned long pos, unsigned long bytes);
+ int (*copy)(struct snd_pcm_substream *substream, int channel,
+ unsigned long pos, sockptr_t buf, unsigned long bytes);
int (*copy_user)(struct snd_pcm_substream *substream, int channel,
unsigned long pos, void __user *buf,
unsigned long bytes);
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 9c121a921b04..1dd630cd22a7 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1973,10 +1973,11 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
- void *buf, unsigned long bytes);
+ sockptr_t buf, unsigned long bytes);
typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
- snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);
+ snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f,
+ bool);
/* calculate the target DMA-buffer position to be written/read */
static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
@@ -1986,32 +1987,23 @@ static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
channel * (runtime->dma_bytes / runtime->channels);
}
-/* default copy_user ops for write; used for both interleaved and non- modes */
+/* default copy ops for write; used for both interleaved and non- modes */
static int default_write_copy(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
- void *buf, unsigned long bytes)
+ sockptr_t buf, unsigned long bytes)
{
- if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
- (void __user *)buf, bytes))
+ if (copy_from_sockptr(get_dma_ptr(substream->runtime, channel, hwoff),
+ buf, bytes))
return -EFAULT;
return 0;
}
-/* default copy_kernel ops for write */
-static int default_write_copy_kernel(struct snd_pcm_substream *substream,
- int channel, unsigned long hwoff,
- void *buf, unsigned long bytes)
-{
- memcpy(get_dma_ptr(substream->runtime, channel, hwoff), buf, bytes);
- return 0;
-}
-
/* fill silence instead of copy data; called as a transfer helper
* from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
* a NULL buffer is passed
*/
static int fill_silence(struct snd_pcm_substream *substream, int channel,
- unsigned long hwoff, void *buf, unsigned long bytes)
+ unsigned long hwoff, sockptr_t buf, unsigned long bytes)
{
struct snd_pcm_runtime *runtime = substream->runtime;
@@ -2027,27 +2019,42 @@ static int fill_silence(struct snd_pcm_substream *substream, int channel,
return 0;
}
-/* default copy_user ops for read; used for both interleaved and non- modes */
+/* default copy ops for read; used for both interleaved and non- modes */
static int default_read_copy(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
- void *buf, unsigned long bytes)
+ sockptr_t buf, unsigned long bytes)
{
- if (copy_to_user((void __user *)buf,
- get_dma_ptr(substream->runtime, channel, hwoff),
- bytes))
+ if (copy_to_sockptr(buf,
+ get_dma_ptr(substream->runtime, channel, hwoff),
+ bytes))
return -EFAULT;
return 0;
}
-/* default copy_kernel ops for read */
-static int default_read_copy_kernel(struct snd_pcm_substream *substream,
- int channel, unsigned long hwoff,
- void *buf, unsigned long bytes)
+/* a wrapper for calling old copy_kernel or copy_user ops */
+static int call_old_copy(struct snd_pcm_substream *substream,
+ int channel, unsigned long hwoff,
+ sockptr_t buf, unsigned long bytes)
{
- memcpy(buf, get_dma_ptr(substream->runtime, channel, hwoff), bytes);
- return 0;
+ if (sockptr_is_kernel(buf))
+ return substream->ops->copy_kernel(substream, channel, hwoff,
+ buf.kernel, bytes);
+ else
+ return substream->ops->copy_user(substream, channel, hwoff,
+ buf.user, bytes);
}
+/* create a sockptr_t */
+static inline sockptr_t make_sockptr(void *p, bool in_kernel)
+{
+ if (in_kernel)
+ return KERNEL_SOCKPTR(p);
+ else
+ return USER_SOCKPTR((void __user *)p);
+}
+
+#define NULL_SOCKPTR USER_SOCKPTR(NULL)
+
/* call transfer function with the converted pointers and sizes;
* for interleaved mode, it's one shot for all samples
*/
@@ -2055,7 +2062,8 @@ static int interleaved_copy(struct snd_pcm_substream *substream,
snd_pcm_uframes_t hwoff, void *data,
snd_pcm_uframes_t off,
snd_pcm_uframes_t frames,
- pcm_transfer_f transfer)
+ pcm_transfer_f transfer,
+ bool in_kernel)
{
struct snd_pcm_runtime *runtime = substream->runtime;
@@ -2063,7 +2071,8 @@ static int interleaved_copy(struct snd_pcm_substream *substream,
hwoff = frames_to_bytes(runtime, hwoff);
off = frames_to_bytes(runtime, off);
frames = frames_to_bytes(runtime, frames);
- return transfer(substream, 0, hwoff, data + off, frames);
+ return transfer(substream, 0, hwoff,
+ make_sockptr(data + off, in_kernel), frames);
}
/* call transfer function with the converted pointers and sizes for each
@@ -2073,7 +2082,8 @@ static int noninterleaved_copy(struct snd_pcm_substream *substream,
snd_pcm_uframes_t hwoff, void *data,
snd_pcm_uframes_t off,
snd_pcm_uframes_t frames,
- pcm_transfer_f transfer)
+ pcm_transfer_f transfer,
+ bool in_kernel)
{
struct snd_pcm_runtime *runtime = substream->runtime;
int channels = runtime->channels;
@@ -2089,9 +2099,11 @@ static int noninterleaved_copy(struct snd_pcm_substream *substream,
hwoff = samples_to_bytes(runtime, hwoff);
for (c = 0; c < channels; ++c, ++bufs) {
if (!data || !*bufs)
- err = fill_silence(substream, c, hwoff, NULL, frames);
+ err = fill_silence(substream, c, hwoff,
+ NULL_SOCKPTR, frames);
else
- err = transfer(substream, c, hwoff, *bufs + off,
+ err = transfer(substream, c, hwoff,
+ make_sockptr(*bufs + off, in_kernel),
frames);
if (err < 0)
return err;
@@ -2108,10 +2120,10 @@ static int fill_silence_frames(struct snd_pcm_substream *substream,
if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
return interleaved_copy(substream, off, NULL, 0, frames,
- fill_silence);
+ fill_silence, true);
else
return noninterleaved_copy(substream, off, NULL, 0, frames,
- fill_silence);
+ fill_silence, true);
}
/* sanity-check for read/write methods */
@@ -2121,7 +2133,7 @@ static int pcm_sanity_check(struct snd_pcm_substream *substream)
if (PCM_RUNTIME_CHECK(substream))
return -ENXIO;
runtime = substream->runtime;
- if (snd_BUG_ON(!substream->ops->copy_user && !runtime->dma_area))
+ if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
return -EINVAL;
if (runtime->state == SNDRV_PCM_STATE_OPEN)
return -EBADFD;
@@ -2226,15 +2238,12 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
transfer = fill_silence;
else
return -EINVAL;
- } else if (in_kernel) {
- if (substream->ops->copy_kernel)
- transfer = substream->ops->copy_kernel;
- else
- transfer = is_playback ?
- default_write_copy_kernel : default_read_copy_kernel;
} else {
- if (substream->ops->copy_user)
- transfer = (pcm_transfer_f)substream->ops->copy_user;
+ if (substream->ops->copy)
+ transfer = substream->ops->copy;
+ else if ((in_kernel && substream->ops->copy_kernel) ||
+ (!in_kernel && substream->ops->copy_user))
+ transfer = call_old_copy;
else
transfer = is_playback ?
default_write_copy : default_read_copy;
@@ -2307,7 +2316,7 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
if (!is_playback)
snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU);
err = writer(substream, appl_ofs, data, offset, frames,
- transfer);
+ transfer, in_kernel);
if (is_playback)
snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
snd_pcm_stream_lock_irq(substream);
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 95fc56e403b1..34efd4d198d6 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -809,7 +809,7 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
runtime->boundary *= 2;
/* clear the buffer for avoiding possible kernel info leaks */
- if (runtime->dma_area && !substream->ops->copy_user) {
+ if (runtime->dma_area && !substream->ops->copy && !substream->ops->copy_user) {
size_t size = runtime->dma_bytes;
if (runtime->info & SNDRV_PCM_INFO_MMAP)
--
2.35.3
