linux/sound/core/timer_compat.c
Baolin Wang 07094ae6f9 ALSA: Avoid using timespec for struct snd_timer_tread
The struct snd_timer_tread will use 'timespec' type variables to record
timestamp, which is not year 2038 safe on 32bits system.

Since the struct snd_timer_tread is passed through read() rather than
ioctl(), and the read syscall has no command number that lets us pick
between the 32-bit or 64-bit version of this structure.

Thus we introduced one new command SNDRV_TIMER_IOCTL_TREAD64 and new
struct snd_timer_tread64 replacing timespec with s64 type to handle
64bit time_t. That means we will set tu->tread = TREAD_FORMAT_64BIT
when user space has a 64bit time_t, then we will copy to user with
struct snd_timer_tread64. Otherwise we will use 32bit time_t variables
when copying to user.

Moreover this patch replaces timespec type with timespec64 type and
related y2038 safe APIs.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-12-13 11:25:57 +01:00

125 lines
3.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 32bit -> 64bit ioctl wrapper for timer API
* Copyright (c) by Takashi Iwai <tiwai@suse.de>
*/
/* This file included from timer.c */
#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;
unsigned char id[64];
unsigned char name[80];
u32 reserved0;
u32 resolution;
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)
{
struct snd_timer_user *tu;
struct snd_timer_info32 info;
struct snd_timer *t;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
t = tu->timeri->timer;
if (!t)
return -EBADFD;
memset(&info, 0, sizeof(info));
info.card = t->card ? t->card->number : -1;
if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
info.flags |= SNDRV_TIMER_FLG_SLAVE;
strlcpy(info.id, t->id, sizeof(info.id));
strlcpy(info.name, t->name, sizeof(info.name));
info.resolution = t->hw.resolution;
if (copy_to_user(_info, &info, sizeof(*_info)))
return -EFAULT;
return 0;
}
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_STATUS_COMPAT32 = _IOW('T', 0x14, struct snd_timer_status32),
SNDRV_TIMER_IOCTL_STATUS_COMPAT64 = _IOW('T', 0x14, struct snd_timer_status64),
};
static long __snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = compat_ptr(arg);
switch (cmd) {
case SNDRV_TIMER_IOCTL_PVERSION:
case SNDRV_TIMER_IOCTL_TREAD_OLD:
case SNDRV_TIMER_IOCTL_TREAD64:
case SNDRV_TIMER_IOCTL_GINFO:
case SNDRV_TIMER_IOCTL_GSTATUS:
case SNDRV_TIMER_IOCTL_SELECT:
case SNDRV_TIMER_IOCTL_PARAMS:
case SNDRV_TIMER_IOCTL_START:
case SNDRV_TIMER_IOCTL_START_OLD:
case SNDRV_TIMER_IOCTL_STOP:
case SNDRV_TIMER_IOCTL_STOP_OLD:
case SNDRV_TIMER_IOCTL_CONTINUE:
case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
case SNDRV_TIMER_IOCTL_PAUSE:
case SNDRV_TIMER_IOCTL_PAUSE_OLD:
case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
return __snd_timer_user_ioctl(file, cmd, (unsigned long)argp, true);
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_STATUS_COMPAT32:
return snd_timer_user_status32(file, argp);
case SNDRV_TIMER_IOCTL_STATUS_COMPAT64:
return snd_timer_user_status64(file, argp);
}
return -ENOIOCTLCMD;
}
static long snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct snd_timer_user *tu = file->private_data;
long ret;
mutex_lock(&tu->ioctl_lock);
ret = __snd_timer_user_ioctl_compat(file, cmd, arg);
mutex_unlock(&tu->ioctl_lock);
return ret;
}