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 <[email protected]>
---
 include/uapi/sound/asound.h |   13 +++-
 sound/core/timer.c          |  144 ++++++++++++++++++++++++++++++++-----------
 sound/core/timer_compat.c   |    2 +-
 3 files changed, 121 insertions(+), 38 deletions(-)

diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
index fad66ad..f368e80 100644
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -773,7 +773,7 @@ struct snd_timer_status {
 
 #define SNDRV_TIMER_IOCTL_PVERSION     _IOR('T', 0x00, int)
 #define SNDRV_TIMER_IOCTL_NEXT_DEVICE  _IOWR('T', 0x01, struct snd_timer_id)
-#define SNDRV_TIMER_IOCTL_TREAD                _IOW('T', 0x02, int)
+#define SNDRV_TIMER_IOCTL_TREAD_OLD    _IOW('T', 0x02, int)
 #define SNDRV_TIMER_IOCTL_GINFO                _IOWR('T', 0x03, struct 
snd_timer_ginfo)
 #define SNDRV_TIMER_IOCTL_GPARAMS      _IOW('T', 0x04, struct 
snd_timer_gparams)
 #define SNDRV_TIMER_IOCTL_GSTATUS      _IOWR('T', 0x05, struct 
snd_timer_gstatus)
@@ -786,6 +786,15 @@ struct snd_timer_status {
 #define SNDRV_TIMER_IOCTL_STOP         _IO('T', 0xa1)
 #define SNDRV_TIMER_IOCTL_CONTINUE     _IO('T', 0xa2)
 #define SNDRV_TIMER_IOCTL_PAUSE                _IO('T', 0xa3)
+#define SNDRV_TIMER_IOCTL_TREAD64      _IOW('T', 0xa4, int)
+
+#if __BITS_PER_LONG == 64
+#define SNDRV_TIMER_IOCTL_TREAD SNDRV_TIMER_IOCTL_TREAD_OLD
+#else
+#define SNDRV_TIMER_IOCTL_TREAD ((sizeof(__kernel_long_t) >= sizeof(time_t)) ? 
\
+                                SNDRV_TIMER_IOCTL_TREAD_OLD : \
+                                SNDRV_TIMER_IOCTL_TREAD64)
+#endif
 
 struct snd_timer_read {
        unsigned int resolution;
@@ -813,8 +822,10 @@ enum {
 
 struct snd_timer_tread {
        int event;
+       __u8 pad1[sizeof(time_t) - sizeof(int)];
        struct timespec tstamp;
        unsigned int val;
+       __u8 pad2[sizeof(time_t) - sizeof(unsigned int)];
 };
 
 /****************************************************************************
diff --git a/sound/core/timer.c b/sound/core/timer.c
index c9d7ddb..729a643 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -58,6 +58,21 @@
 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
 MODULE_ALIAS("devname:snd/timer");
 
+enum timer_tread_format {
+       TREAD_FORMAT_NONE = 0,
+       TREAD_FORMAT_TIME64,
+       TREAD_FORMAT_TIME32,
+};
+
+struct snd_timer_tread64 {
+       int event;
+       u8 pad1[sizeof(time_t) - sizeof(int)];
+       s64 tstamp_sec;
+       s64 tstamp_nsec;
+       unsigned int val;
+       u32 pad2;
+};
+
 struct snd_timer_user {
        struct snd_timer_instance *timeri;
        int tread;              /* enhanced read with timestamps and events */
@@ -69,7 +84,7 @@ struct snd_timer_user {
        int queue_size;
        bool disconnected;
        struct snd_timer_read *queue;
-       struct snd_timer_tread *tqueue;
+       struct snd_timer_tread64 *tqueue;
        spinlock_t qlock;
        unsigned long last_resolution;
        unsigned int filter;
@@ -1306,7 +1321,7 @@ static void snd_timer_user_interrupt(struct 
snd_timer_instance *timeri,
 }
 
 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
-                                           struct snd_timer_tread *tread)
+                                           struct snd_timer_tread64 *tread)
 {
        if (tu->qused >= tu->queue_size) {
                tu->overrun++;
@@ -1323,7 +1338,7 @@ static void snd_timer_user_ccallback(struct 
snd_timer_instance *timeri,
                                     unsigned long resolution)
 {
        struct snd_timer_user *tu = timeri->callback_data;
-       struct snd_timer_tread r1;
+       struct snd_timer_tread64 r1;
        unsigned long flags;
 
        if (event >= SNDRV_TIMER_EVENT_START &&
@@ -1333,7 +1348,8 @@ static void snd_timer_user_ccallback(struct 
snd_timer_instance *timeri,
                return;
        memset(&r1, 0, sizeof(r1));
        r1.event = event;
-       r1.tstamp = timespec64_to_timespec(*tstamp);
+       r1.tstamp_sec = tstamp->tv_sec;
+       r1.tstamp_nsec = tstamp->tv_nsec;
        r1.val = resolution;
        spin_lock_irqsave(&tu->qlock, flags);
        snd_timer_user_append_to_tqueue(tu, &r1);
@@ -1355,7 +1371,7 @@ static void snd_timer_user_tinterrupt(struct 
snd_timer_instance *timeri,
                                      unsigned long ticks)
 {
        struct snd_timer_user *tu = timeri->callback_data;
-       struct snd_timer_tread *r, r1;
+       struct snd_timer_tread64 *r, r1;
        struct timespec64 tstamp;
        int prev, append = 0;
 
@@ -1376,7 +1392,8 @@ static void snd_timer_user_tinterrupt(struct 
snd_timer_instance *timeri,
        if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
            tu->last_resolution != resolution) {
                r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
-               r1.tstamp = timespec64_to_timespec(tstamp);
+               r1.tstamp_sec = tstamp.tv_sec;
+               r1.tstamp_nsec = tstamp.tv_nsec;
                r1.val = resolution;
                snd_timer_user_append_to_tqueue(tu, &r1);
                tu->last_resolution = resolution;
@@ -1390,14 +1407,16 @@ static void snd_timer_user_tinterrupt(struct 
snd_timer_instance *timeri,
                prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
                r = &tu->tqueue[prev];
                if (r->event == SNDRV_TIMER_EVENT_TICK) {
-                       r->tstamp = timespec64_to_timespec(tstamp);
+                       r->tstamp_sec = tstamp.tv_sec;
+                       r->tstamp_nsec = tstamp.tv_nsec;
                        r->val += ticks;
                        append++;
                        goto __wake;
                }
        }
        r1.event = SNDRV_TIMER_EVENT_TICK;
-       r1.tstamp = timespec64_to_timespec(tstamp);
+       r1.tstamp_sec = tstamp.tv_sec;
+       r1.tstamp_nsec = tstamp.tv_nsec;
        r1.val = ticks;
        snd_timer_user_append_to_tqueue(tu, &r1);
        append++;
@@ -1412,7 +1431,7 @@ static void snd_timer_user_tinterrupt(struct 
snd_timer_instance *timeri,
 static int realloc_user_queue(struct snd_timer_user *tu, int size)
 {
        struct snd_timer_read *queue = NULL;
-       struct snd_timer_tread *tqueue = NULL;
+       struct snd_timer_tread64 *tqueue = NULL;
 
        if (tu->tread) {
                tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
@@ -1841,11 +1860,11 @@ static int snd_timer_user_params(struct file *file,
        tu->qhead = tu->qtail = tu->qused = 0;
        if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
                if (tu->tread) {
-                       struct snd_timer_tread tread;
+                       struct snd_timer_tread64 tread;
                        memset(&tread, 0, sizeof(tread));
                        tread.event = SNDRV_TIMER_EVENT_EARLY;
-                       tread.tstamp.tv_sec = 0;
-                       tread.tstamp.tv_nsec = 0;
+                       tread.tstamp_sec = 0;
+                       tread.tstamp_nsec = 0;
                        tread.val = 0;
                        snd_timer_user_append_to_tqueue(tu, &tread);
                } else {
@@ -1963,6 +1982,36 @@ static int snd_timer_user_pause(struct file *file)
        return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
 }
 
+static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
+                               unsigned int cmd, bool compat)
+{
+       int __user *p = argp;
+       int xarg, old_tread;
+
+       if (tu->timeri) /* too late */
+               return -EBUSY;
+       if (get_user(xarg, p))
+               return -EFAULT;
+
+       old_tread = tu->tread;
+
+       if (!xarg)
+               tu->tread = TREAD_FORMAT_NONE;
+       else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
+                (IS_ENABLED(CONFIG_64BITS) && !compat))
+               tu->tread = TREAD_FORMAT_TIME64;
+       else
+               tu->tread = TREAD_FORMAT_TIME32;
+
+       if (tu->tread != old_tread &&
+           realloc_user_queue(tu, tu->queue_size) < 0) {
+               tu->tread = old_tread;
+               return -ENOMEM;
+       }
+
+       return 0;
+}
+
 enum {
        SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
        SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
@@ -1971,7 +2020,7 @@ enum {
 };
 
 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
-                                unsigned long arg)
+                                unsigned long arg, bool compat)
 {
        struct snd_timer_user *tu;
        void __user *argp = (void __user *)arg;
@@ -1983,23 +2032,9 @@ static long __snd_timer_user_ioctl(struct file *file, 
unsigned int cmd,
                return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
        case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
                return snd_timer_user_next_device(argp);
-       case SNDRV_TIMER_IOCTL_TREAD:
-       {
-               int xarg, old_tread;
-
-               if (tu->timeri) /* too late */
-                       return -EBUSY;
-               if (get_user(xarg, p))
-                       return -EFAULT;
-               old_tread = tu->tread;
-               tu->tread = xarg ? 1 : 0;
-               if (tu->tread != old_tread &&
-                   realloc_user_queue(tu, tu->queue_size) < 0) {
-                       tu->tread = old_tread;
-                       return -ENOMEM;
-               }
-               return 0;
-       }
+       case SNDRV_TIMER_IOCTL_TREAD_OLD:
+       case SNDRV_TIMER_IOCTL_TREAD64:
+               return snd_timer_user_tread(argp, tu, cmd, compat);
        case SNDRV_TIMER_IOCTL_GINFO:
                return snd_timer_user_ginfo(file, argp);
        case SNDRV_TIMER_IOCTL_GPARAMS:
@@ -2039,7 +2074,7 @@ static long snd_timer_user_ioctl(struct file *file, 
unsigned int cmd,
        long ret;
 
        mutex_lock(&tu->ioctl_lock);
-       ret = __snd_timer_user_ioctl(file, cmd, arg);
+       ret = __snd_timer_user_ioctl(file, cmd, arg, false);
        mutex_unlock(&tu->ioctl_lock);
        return ret;
 }
@@ -2055,13 +2090,28 @@ static int snd_timer_user_fasync(int fd, struct file * 
file, int on)
 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
                                   size_t count, loff_t *offset)
 {
+       struct snd_timer_tread64 *tread;
+       struct snd_timer_tread tread32;
        struct snd_timer_user *tu;
        long result = 0, unit;
        int qhead;
        int err = 0;
 
        tu = file->private_data;
-       unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct 
snd_timer_read);
+       switch (tu->tread) {
+       case TREAD_FORMAT_TIME64:
+               unit = sizeof(struct snd_timer_tread64);
+               break;
+       case TREAD_FORMAT_TIME32:
+               unit = sizeof(struct snd_timer_tread);
+               break;
+       case TREAD_FORMAT_NONE:
+               unit = sizeof(struct snd_timer_read);
+               break;
+       default:
+               return -ENOTSUPP;
+       }
+
        mutex_lock(&tu->ioctl_lock);
        spin_lock_irq(&tu->qlock);
        while ((long)count - result >= unit) {
@@ -2100,14 +2150,36 @@ static ssize_t snd_timer_user_read(struct file *file, 
char __user *buffer,
                tu->qused--;
                spin_unlock_irq(&tu->qlock);
 
-               if (tu->tread) {
-                       if (copy_to_user(buffer, &tu->tqueue[qhead],
-                                        sizeof(struct snd_timer_tread)))
+               tread = &tu->tqueue[qhead];
+
+               switch (tu->tread) {
+               case TREAD_FORMAT_TIME64:
+                       if (copy_to_user(buffer, tread,
+                                        sizeof(struct snd_timer_tread64)))
                                err = -EFAULT;
-               } else {
+                       break;
+               case TREAD_FORMAT_TIME32:
+                       memset(&tread32, 0, sizeof(tread32));
+                       tread32 = (struct snd_timer_tread) {
+                               .event = tread->event,
+                               .tstamp = {
+                                       .tv_sec = tread->tstamp_sec,
+                                       .tv_nsec = tread->tstamp_nsec,
+                               },
+                               .val = tread->val,
+                       };
+
+                       if (copy_to_user(buffer, &tread32, sizeof(tread32)))
+                               err = -EFAULT;
+                       break;
+               case TREAD_FORMAT_NONE:
                        if (copy_to_user(buffer, &tu->queue[qhead],
                                         sizeof(struct snd_timer_read)))
                                err = -EFAULT;
+                       break;
+               default:
+                       err = -ENOTSUPP;
+                       break;
                }
 
                spin_lock_irq(&tu->qlock);
diff --git a/sound/core/timer_compat.c b/sound/core/timer_compat.c
index 0495ede..bef7f87 100644
--- a/sound/core/timer_compat.c
+++ b/sound/core/timer_compat.c
@@ -111,7 +111,7 @@ static long __snd_timer_user_ioctl_compat(struct file 
*file, unsigned int cmd,
        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);
+               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:
-- 
1.7.9.5

Reply via email to