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-rw-r--r--sound/core/rawmidi.c31
1 files changed, 27 insertions, 4 deletions
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 20dd08e1f675..2a688b711a9a 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -120,6 +120,17 @@ static void snd_rawmidi_input_event_work(struct work_struct *work)
runtime->event(runtime->substream);
}
+/* buffer refcount management: call with runtime->lock held */
+static inline void snd_rawmidi_buffer_ref(struct snd_rawmidi_runtime *runtime)
+{
+ runtime->buffer_ref++;
+}
+
+static inline void snd_rawmidi_buffer_unref(struct snd_rawmidi_runtime *runtime)
+{
+ runtime->buffer_ref--;
+}
+
static int snd_rawmidi_runtime_create(struct snd_rawmidi_substream *substream)
{
struct snd_rawmidi_runtime *runtime;
@@ -669,6 +680,11 @@ static int resize_runtime_buffer(struct snd_rawmidi_runtime *runtime,
if (!newbuf)
return -ENOMEM;
spin_lock_irq(&runtime->lock);
+ if (runtime->buffer_ref) {
+ spin_unlock_irq(&runtime->lock);
+ kvfree(newbuf);
+ return -EBUSY;
+ }
oldbuf = runtime->buffer;
runtime->buffer = newbuf;
runtime->buffer_size = params->buffer_size;
@@ -1019,8 +1035,10 @@ static long snd_rawmidi_kernel_read1(struct snd_rawmidi_substream *substream,
long result = 0, count1;
struct snd_rawmidi_runtime *runtime = substream->runtime;
unsigned long appl_ptr;
+ int err = 0;
spin_lock_irqsave(&runtime->lock, flags);
+ snd_rawmidi_buffer_ref(runtime);
while (count > 0 && runtime->avail) {
count1 = runtime->buffer_size - runtime->appl_ptr;
if (count1 > count)
@@ -1039,16 +1057,19 @@ static long snd_rawmidi_kernel_read1(struct snd_rawmidi_substream *substream,
if (userbuf) {
spin_unlock_irqrestore(&runtime->lock, flags);
if (copy_to_user(userbuf + result,
- runtime->buffer + appl_ptr, count1)) {
- return result > 0 ? result : -EFAULT;
- }
+ runtime->buffer + appl_ptr, count1))
+ err = -EFAULT;
spin_lock_irqsave(&runtime->lock, flags);
+ if (err)
+ goto out;
}
result += count1;
count -= count1;
}
+ out:
+ snd_rawmidi_buffer_unref(runtime);
spin_unlock_irqrestore(&runtime->lock, flags);
- return result;
+ return result > 0 ? result : err;
}
long snd_rawmidi_kernel_read(struct snd_rawmidi_substream *substream,
@@ -1342,6 +1363,7 @@ static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
return -EAGAIN;
}
}
+ snd_rawmidi_buffer_ref(runtime);
while (count > 0 && runtime->avail > 0) {
count1 = runtime->buffer_size - runtime->appl_ptr;
if (count1 > count)
@@ -1373,6 +1395,7 @@ static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
}
__end:
count1 = runtime->avail < runtime->buffer_size;
+ snd_rawmidi_buffer_unref(runtime);
spin_unlock_irqrestore(&runtime->lock, flags);
if (count1)
snd_rawmidi_output_trigger(substream, 1);