ALSA: Avoid using timespec for struct snd_timer_status

struct snd_timer_status uses 'timespec' type variables to record
timestamp, which will be changed to an incompatible layout with
updated user space using 64-bit time_t.

To handle both the old and the new layout on 32-bit architectures,
this patch introduces 'struct snd_timer_status32' and 'struct snd_timer_status64'
to handle 32bit time_t and 64bit time_t in native mode and compat mode,
which replaces timespec with s64 type.

When glibc changes time_t to 64-bit, any recompiled program will issue
ioctl commands that the kernel does not understand without this patch.

In the public uapi header, snd_timer_status is now guarded by
an #ifndef __KERNEL__ to avoid referencing 'struct timespec'.
The timespec definition will be removed from the kernel to prevent
new y2038 bugs and to avoid the conflict with an incompatible libc
type of the same name.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 6 insertions, 51 deletions

diff --git a/sound/core/timer_compat.c b/sound/core/timer_compat.c
index bb6be484dfd3..20eef5bc304b 100644
--- a/sound/core/timer_compat.c
+++ b/sound/core/timer_compat.c
@@ -69,54 +69,11 @@ static int snd_timer_user_info_compat(struct file *file,
 	return 0;
 }
 
-struct snd_timer_status32 {
-	struct compat_timespec tstamp;
-	u32 resolution;
-	u32 lost;
-	u32 overrun;
-	u32 queue;
-	unsigned char reserved[64];
-};
-
-static int snd_timer_user_status_compat(struct file *file,
-					struct snd_timer_status32 __user *_status)
-{
-	struct snd_timer_user *tu;
-	struct snd_timer_status32 status;
-	
-	tu = file->private_data;
-	if (!tu->timeri)
-		return -EBADFD;
-	memset(&status, 0, sizeof(status));
-	status.tstamp.tv_sec = tu->tstamp.tv_sec;
-	status.tstamp.tv_nsec = tu->tstamp.tv_nsec;
-	status.resolution = snd_timer_resolution(tu->timeri);
-	status.lost = tu->timeri->lost;
-	status.overrun = tu->overrun;
-	spin_lock_irq(&tu->qlock);
-	status.queue = tu->qused;
-	spin_unlock_irq(&tu->qlock);
-	if (copy_to_user(_status, &status, sizeof(status)))
-		return -EFAULT;
-	return 0;
-}
-
-#ifdef CONFIG_X86_X32
-/* X32 ABI has the same struct as x86-64 */
-#define snd_timer_user_status_x32(file, s) \
-	snd_timer_user_status(file, s)
-#endif /* CONFIG_X86_X32 */
-
-/*
- */
-
 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
-	SNDRV_TIMER_IOCTL_STATUS_X32 = _IOW('T', 0x14, struct snd_timer_status),
-#endif /* CONFIG_X86_X32 */
+	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,
@@ -145,12 +102,10 @@ static long __snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd,
 		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:
-		return snd_timer_user_status_compat(file, argp);
-#ifdef CONFIG_X86_X32
-	case SNDRV_TIMER_IOCTL_STATUS_X32:
-		return snd_timer_user_status_x32(file, argp);
-#endif /* CONFIG_X86_X32 */
+	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;
 }