ALSA: timer: fix gparams ioctl compatibility for different architectures

'struct snd_timer_gparams' includes some members with 'unsigned long',
therefore its size differs depending on data models of architecture. As
a result, x86/x32 applications fail to execute ioctl(2) with
SNDRV_TIMER_GPARAMS command on x86_64 machine.

This commit fixes this bug by adding a pair of structure and ioctl
command for the compatibility.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto 2016-03-23 08:03:59 +09:00 committed by Takashi Iwai
parent c64c1437af
commit 91d2178e26
2 changed files with 42 additions and 8 deletions

View File

@ -1502,17 +1502,13 @@ static int snd_timer_user_ginfo(struct file *file,
return err;
}
static int snd_timer_user_gparams(struct file *file,
struct snd_timer_gparams __user *_gparams)
static int timer_set_gparams(struct snd_timer_gparams *gparams)
{
struct snd_timer_gparams gparams;
struct snd_timer *t;
int err;
if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
return -EFAULT;
mutex_lock(&register_mutex);
t = snd_timer_find(&gparams.tid);
t = snd_timer_find(&gparams->tid);
if (!t) {
err = -ENODEV;
goto _error;
@ -1525,12 +1521,22 @@ static int snd_timer_user_gparams(struct file *file,
err = -ENOSYS;
goto _error;
}
err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
_error:
mutex_unlock(&register_mutex);
return err;
}
static int snd_timer_user_gparams(struct file *file,
struct snd_timer_gparams __user *_gparams)
{
struct snd_timer_gparams gparams;
if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
return -EFAULT;
return timer_set_gparams(&gparams);
}
static int snd_timer_user_gstatus(struct file *file,
struct snd_timer_gstatus __user *_gstatus)
{

View File

@ -22,6 +22,19 @@
#include <linux/compat.h>
/*
* ILP32/LP64 has different size for 'long' type. Additionally, the size
* of storage alignment differs depending on architectures. Here, '__packed'
* qualifier is used so that the size of this structure is multiple of 4 and
* it fits to any architectures with 32 bit storage alignment.
*/
struct snd_timer_gparams32 {
struct snd_timer_id tid;
u32 period_num;
u32 period_den;
unsigned char reserved[32];
} __packed;
struct snd_timer_info32 {
u32 flags;
s32 card;
@ -32,6 +45,19 @@ struct snd_timer_info32 {
unsigned char reserved[64];
};
static int snd_timer_user_gparams_compat(struct file *file,
struct snd_timer_gparams32 __user *user)
{
struct snd_timer_gparams gparams;
if (copy_from_user(&gparams.tid, &user->tid, sizeof(gparams.tid)) ||
get_user(gparams.period_num, &user->period_num) ||
get_user(gparams.period_den, &user->period_den))
return -EFAULT;
return timer_set_gparams(&gparams);
}
static int snd_timer_user_info_compat(struct file *file,
struct snd_timer_info32 __user *_info)
{
@ -99,6 +125,7 @@ static int snd_timer_user_status_compat(struct file *file,
*/
enum {
SNDRV_TIMER_IOCTL_GPARAMS32 = _IOW('T', 0x04, struct snd_timer_gparams32),
SNDRV_TIMER_IOCTL_INFO32 = _IOR('T', 0x11, struct snd_timer_info32),
SNDRV_TIMER_IOCTL_STATUS32 = _IOW('T', 0x14, struct snd_timer_status32),
#ifdef CONFIG_X86_X32
@ -114,7 +141,6 @@ static long snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd, uns
case SNDRV_TIMER_IOCTL_PVERSION:
case SNDRV_TIMER_IOCTL_TREAD:
case SNDRV_TIMER_IOCTL_GINFO:
case SNDRV_TIMER_IOCTL_GPARAMS:
case SNDRV_TIMER_IOCTL_GSTATUS:
case SNDRV_TIMER_IOCTL_SELECT:
case SNDRV_TIMER_IOCTL_PARAMS:
@ -128,6 +154,8 @@ static long snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd, uns
case SNDRV_TIMER_IOCTL_PAUSE_OLD:
case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
return snd_timer_user_ioctl(file, cmd, (unsigned long)argp);
case SNDRV_TIMER_IOCTL_GPARAMS32:
return snd_timer_user_gparams_compat(file, argp);
case SNDRV_TIMER_IOCTL_INFO32:
return snd_timer_user_info_compat(file, argp);
case SNDRV_TIMER_IOCTL_STATUS32: