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Message-Id: <20230519093114.28813-18-tiwai@suse.de>
Date: Fri, 19 May 2023 11:30:55 +0200
From: Takashi Iwai <tiwai@...e.de>
To: alsa-devel@...a-project.org
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH 17/36] ALSA: seq: Add snd_seq_expand_var_event_at() helper
Create a new variant of snd_seq_expand_var_event() for expanding the
data starting from the given byte offset. It'll be used by the new
UMP sequencer code later.
Signed-off-by: Takashi Iwai <tiwai@...e.de>
---
include/sound/seq_kernel.h | 2 +
sound/core/seq/seq_memory.c | 86 +++++++++++++++++++++++++++++--------
2 files changed, 69 insertions(+), 19 deletions(-)
diff --git a/include/sound/seq_kernel.h b/include/sound/seq_kernel.h
index 658911926f3a..527e7f8ad661 100644
--- a/include/sound/seq_kernel.h
+++ b/include/sound/seq_kernel.h
@@ -70,6 +70,8 @@ int snd_seq_kernel_client_ctl(int client, unsigned int cmd, void *arg);
typedef int (*snd_seq_dump_func_t)(void *ptr, void *buf, int count);
int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
int in_kernel, int size_aligned);
+int snd_seq_expand_var_event_at(const struct snd_seq_event *event, int count,
+ char *buf, int offset);
int snd_seq_dump_var_event(const struct snd_seq_event *event,
snd_seq_dump_func_t func, void *private_data);
diff --git a/sound/core/seq/seq_memory.c b/sound/core/seq/seq_memory.c
index c8d26bce69ff..a8d2db439f86 100644
--- a/sound/core/seq/seq_memory.c
+++ b/sound/core/seq/seq_memory.c
@@ -63,8 +63,9 @@ static int get_var_len(const struct snd_seq_event *event)
return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
}
-int snd_seq_dump_var_event(const struct snd_seq_event *event,
- snd_seq_dump_func_t func, void *private_data)
+static int dump_var_event(const struct snd_seq_event *event,
+ snd_seq_dump_func_t func, void *private_data,
+ int offset, int maxlen)
{
int len, err;
struct snd_seq_event_cell *cell;
@@ -72,10 +73,16 @@ int snd_seq_dump_var_event(const struct snd_seq_event *event,
len = get_var_len(event);
if (len <= 0)
return len;
+ if (len <= offset)
+ return 0;
+ if (maxlen && len > offset + maxlen)
+ len = offset + maxlen;
if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
char buf[32];
char __user *curptr = (char __force __user *)event->data.ext.ptr;
+ curptr += offset;
+ len -= offset;
while (len > 0) {
int size = sizeof(buf);
if (len < size)
@@ -91,20 +98,35 @@ int snd_seq_dump_var_event(const struct snd_seq_event *event,
return 0;
}
if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED))
- return func(private_data, event->data.ext.ptr, len);
+ return func(private_data, event->data.ext.ptr + offset,
+ len - offset);
cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
for (; len > 0 && cell; cell = cell->next) {
int size = sizeof(struct snd_seq_event);
+ char *curptr = (char *)&cell->event;
+
+ if (offset >= size) {
+ offset -= size;
+ len -= size;
+ continue;
+ }
if (len < size)
size = len;
- err = func(private_data, &cell->event, size);
+ err = func(private_data, curptr + offset, size - offset);
if (err < 0)
return err;
+ offset = 0;
len -= size;
}
return 0;
}
+
+int snd_seq_dump_var_event(const struct snd_seq_event *event,
+ snd_seq_dump_func_t func, void *private_data)
+{
+ return dump_var_event(event, func, private_data, 0, 0);
+}
EXPORT_SYMBOL(snd_seq_dump_var_event);
@@ -132,11 +154,27 @@ static int seq_copy_in_user(void *ptr, void *src, int size)
return 0;
}
+static int expand_var_event(const struct snd_seq_event *event,
+ int offset, int size, char *buf, bool in_kernel)
+{
+ if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
+ if (! in_kernel)
+ return -EINVAL;
+ if (copy_from_user(buf,
+ (char __force __user *)event->data.ext.ptr + offset,
+ size))
+ return -EFAULT;
+ return 0;
+ }
+ return dump_var_event(event,
+ in_kernel ? seq_copy_in_kernel : seq_copy_in_user,
+ &buf, offset, size);
+}
+
int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
int in_kernel, int size_aligned)
{
- int len, newlen;
- int err;
+ int len, newlen, err;
len = get_var_len(event);
if (len < 0)
@@ -146,25 +184,35 @@ int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char
newlen = roundup(len, size_aligned);
if (count < newlen)
return -EAGAIN;
-
- if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
- if (! in_kernel)
- return -EINVAL;
- if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len))
- return -EFAULT;
- } else {
- err = snd_seq_dump_var_event(event,
- in_kernel ? seq_copy_in_kernel : seq_copy_in_user,
- &buf);
- if (err < 0)
- return err;
- }
+ err = expand_var_event(event, 0, len, buf, in_kernel);
+ if (err < 0)
+ return err;
if (len != newlen)
memset(buf + len, 0, newlen - len);
return newlen;
}
EXPORT_SYMBOL(snd_seq_expand_var_event);
+int snd_seq_expand_var_event_at(const struct snd_seq_event *event, int count,
+ char *buf, int offset)
+{
+ int len, err;
+
+ len = get_var_len(event);
+ if (len < 0)
+ return len;
+ if (len <= offset)
+ return 0;
+ len -= offset;
+ if (len > count)
+ len = count;
+ err = expand_var_event(event, offset, count, buf, true);
+ if (err < 0)
+ return err;
+ return len;
+}
+EXPORT_SYMBOL_GPL(snd_seq_expand_var_event_at);
+
/*
* release this cell, free extended data if available
*/
--
2.35.3
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