ALSA: rawmidi: Use kvmalloc() for buffers

The size of in-kernel rawmidi buffers may be big up to 1MB, and it can
be specified freely by user-space; which implies that user-space may
trigger kmalloc() errors frequently.

This patch replaces the buffer allocation via kvmalloc() for dealing
with bigger buffers gracefully.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2018-07-17 23:12:33 +02:00
parent f5beb598b0
commit ef4db239cd

View file

@ -29,6 +29,7 @@
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <sound/rawmidi.h>
#include <sound/info.h>
#include <sound/control.h>
@ -128,7 +129,7 @@ static int snd_rawmidi_runtime_create(struct snd_rawmidi_substream *substream)
runtime->avail = 0;
else
runtime->avail = runtime->buffer_size;
runtime->buffer = kmalloc(runtime->buffer_size, GFP_KERNEL);
runtime->buffer = kvmalloc(runtime->buffer_size, GFP_KERNEL);
if (!runtime->buffer) {
kfree(runtime);
return -ENOMEM;
@ -142,7 +143,7 @@ static int snd_rawmidi_runtime_free(struct snd_rawmidi_substream *substream)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;
kfree(runtime->buffer);
kvfree(runtime->buffer);
kfree(runtime);
substream->runtime = NULL;
return 0;
@ -654,7 +655,7 @@ static int resize_runtime_buffer(struct snd_rawmidi_runtime *runtime,
if (params->avail_min < 1 || params->avail_min > params->buffer_size)
return -EINVAL;
if (params->buffer_size != runtime->buffer_size) {
newbuf = kmalloc(params->buffer_size, GFP_KERNEL);
newbuf = kvmalloc(params->buffer_size, GFP_KERNEL);
if (!newbuf)
return -ENOMEM;
spin_lock_irq(&runtime->lock);
@ -663,7 +664,7 @@ static int resize_runtime_buffer(struct snd_rawmidi_runtime *runtime,
runtime->buffer_size = params->buffer_size;
__reset_runtime_ptrs(runtime, is_input);
spin_unlock_irq(&runtime->lock);
kfree(oldbuf);
kvfree(oldbuf);
}
runtime->avail_min = params->avail_min;
return 0;