Merge tag 'y2038-alsa-v8-signed' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground into for-next

ALSA: Fix year 2038 issue for sound subsystem

This is a series I worked on with Baolin in 2017 and 2018, but we
never quite managed to finish up the last pieces. During the
ALSA developer meetup at ELC-E 2018 in Edinburgh, a decision was
made to go with this approach for keeping best compatibility
with existing source code, and then I failed to follow up by
resending the patches.

Now I have patches for all remaining time_t uses in the kernel,
so it's absolutely time to revisit them. I have done more
review of the patches myself and found a couple of minor issues
that I have fixed up, otherwise the series is still the same as
before.

Conceptually, the idea of these patches is:

- 64-bit applications should see no changes at all, neither
  compile-time nor run-time.

- 32-bit code compiled with a 64-bit time_t currently
  does not work with ALSA, and requires kernel changes and/or
  sound/asound.h changes

- Most 32-bit code using these interfaces will work correctly
  on a modified kernel, with or without the uapi header changes.

- 32-bit code using SNDRV_TIMER_IOCTL_TREAD requires the
  updated header file for 64-bit time_t support

- 32-bit i386 user space with 64-bit time_t is broken for
  SNDRV_PCM_IOCTL_STATUS, SNDRV_RAWMIDI_IOCTL_STATUS and
  SNDRV_PCM_IOCTL_SYNC_PTR because of i386 alignment. This is also
  addressed by the updated uapi header.

- PCM mmap is currently supported on native x86 kernels
  (both 32-bit and 64-bit) but not for compat mode. This series breaks
  the 32-bit native mmap support for 32-bit time_t, but instead allows
  it for 64-bit time_t on both native and compat kernels. This seems to
  be the best trade-off, as mmap support is optional already, and most
  32-bit code runs in compat mode anyway.

- I've tried to avoid breaking compilation of 32-bit code
  as much as possible. Anything that does break however is likely code
  that is already broken on 64-bit time_t and needs source changes to
  fix them.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git y2038-alsa-v8
[2] https://lore.kernel.org/lkml/CAK8P3a2Os66+iwQYf97qh05W2JP8rmWao8zmKoHiXqVHvyYAJA@mail.gmail.com/T/#m6519cb07cfda08adf1dedea6596bb98892b4d5dc

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Changes since v7: (Arnd):
 - Fix a typo found by Ben Hutchings

Changes since v6: (Arnd):
 - Add a patch to update the API versions
 - Hide a timespec reference in #ifndef __KERNEL__ to remove the
   last reference to time_t
 - Use a more readable way to do padding and describe it in the
   changelog
 - Rebase to linux-5.5-rc1, changing include/sound/soc-component.h
   and sound/drivers/aloop.c as needed.

Changes since v5 (Arnd):
 - Rebased to linux-5.4-rc4
 - Updated to completely remove timespec and time_t references from alsa
 - found and fixed a few bugs

Changes since v4 (Baolin):
 - Add patch 5 to change trigger_tstamp member of struct snd_pcm_runtime.
 - Add patch 8 to change internal timespec.
 - Add more explanation in commit message.
 - Use ktime_get_real_ts64() in patch 6.
 - Split common code out into a separate function in patch 6.
 - Fix tu->tread bug in patch 6 and remove #if __BITS_PER_LONG == 64 macro.

Changes since v3:
 - Move struct snd_pcm_status32 to pcm.h file.
 - Modify comments and commit message.
 - Add new patch2 ~ patch6.

Changes since v2:
 - Renamed all structures to make clear.
 - Remove CONFIG_X86_X32 macro and introduced new compat_snd_pcm_status64_x86_32.

Changes since v1:
 - Add one macro for struct snd_pcm_status_32 which only active in 32bits kernel.
 - Convert pcm_compat.c to use struct snd_pcm_status_64.
 - Convert pcm_native.c to use struct snd_pcm_status_64.

3 files changed, 67 insertions, 15 deletions

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 8a89fa6fdd5e..5a31525e2df6 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -44,6 +44,7 @@ struct snd_pcm_hardware {
 	size_t fifo_size;		/* fifo size in bytes */
 };
 
+struct snd_pcm_status64;
 struct snd_pcm_substream;
 
 struct snd_pcm_audio_tstamp_config; /* definitions further down */
@@ -62,7 +63,7 @@ struct snd_pcm_ops {
 	int (*sync_stop)(struct snd_pcm_substream *substream);
 	snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *substream);
 	int (*get_time_info)(struct snd_pcm_substream *substream,
-			struct timespec *system_ts, struct timespec *audio_ts,
+			struct timespec64 *system_ts, struct timespec64 *audio_ts,
 			struct snd_pcm_audio_tstamp_config *audio_tstamp_config,
 			struct snd_pcm_audio_tstamp_report *audio_tstamp_report);
 	int (*fill_silence)(struct snd_pcm_substream *substream, int channel,
@@ -343,7 +344,7 @@ static inline void snd_pcm_pack_audio_tstamp_report(__u32 *data, __u32 *accuracy
 struct snd_pcm_runtime {
 	/* -- Status -- */
 	struct snd_pcm_substream *trigger_master;
-	struct timespec trigger_tstamp;	/* trigger timestamp */
+	struct timespec64 trigger_tstamp;	/* trigger timestamp */
 	bool trigger_tstamp_latched;     /* trigger timestamp latched in low-level driver/hardware */
 	int overrange;
 	snd_pcm_uframes_t avail_max;
@@ -421,7 +422,7 @@ struct snd_pcm_runtime {
 	/* -- audio timestamp config -- */
 	struct snd_pcm_audio_tstamp_config audio_tstamp_config;
 	struct snd_pcm_audio_tstamp_report audio_tstamp_report;
-	struct timespec driver_tstamp;
+	struct timespec64 driver_tstamp;
 
 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 	/* -- OSS things -- */
@@ -558,8 +559,8 @@ int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree);
 int snd_pcm_info(struct snd_pcm_substream *substream, struct snd_pcm_info *info);
 int snd_pcm_info_user(struct snd_pcm_substream *substream,
 		      struct snd_pcm_info __user *info);
-int snd_pcm_status(struct snd_pcm_substream *substream,
-		   struct snd_pcm_status *status);
+int snd_pcm_status64(struct snd_pcm_substream *substream,
+		     struct snd_pcm_status64 *status);
 int snd_pcm_start(struct snd_pcm_substream *substream);
 int snd_pcm_stop(struct snd_pcm_substream *substream, snd_pcm_state_t status);
 int snd_pcm_drain_done(struct snd_pcm_substream *substream);
@@ -1155,22 +1156,22 @@ static inline void snd_pcm_set_runtime_buffer(struct snd_pcm_substream *substrea
 }
 
 /**
- * snd_pcm_gettime - Fill the timespec depending on the timestamp mode
+ * snd_pcm_gettime - Fill the timespec64 depending on the timestamp mode
  * @runtime: PCM runtime instance
- * @tv: timespec to fill
+ * @tv: timespec64 to fill
  */
 static inline void snd_pcm_gettime(struct snd_pcm_runtime *runtime,
-				   struct timespec *tv)
+				   struct timespec64 *tv)
 {
 	switch (runtime->tstamp_type) {
 	case SNDRV_PCM_TSTAMP_TYPE_MONOTONIC:
-		ktime_get_ts(tv);
+		ktime_get_ts64(tv);
 		break;
 	case SNDRV_PCM_TSTAMP_TYPE_MONOTONIC_RAW:
-		getrawmonotonic(tv);
+		ktime_get_raw_ts64(tv);
 		break;
 	default:
-		getnstimeofday(tv);
+		ktime_get_real_ts64(tv);
 		break;
 	}
 }
@@ -1422,4 +1423,55 @@ static inline u64 pcm_format_to_bits(snd_pcm_format_t pcm_format)
 #define pcm_dbg(pcm, fmt, args...) \
 	dev_dbg((pcm)->card->dev, fmt, ##args)
 
+struct snd_pcm_status64 {
+	snd_pcm_state_t state;		/* stream state */
+	u8 rsvd[4];
+	s64 trigger_tstamp_sec;		/* time when stream was started/stopped/paused */
+	s64 trigger_tstamp_nsec;
+	s64 tstamp_sec;			/* reference timestamp */
+	s64 tstamp_nsec;
+	snd_pcm_uframes_t appl_ptr;	/* appl ptr */
+	snd_pcm_uframes_t hw_ptr;	/* hw ptr */
+	snd_pcm_sframes_t delay;	/* current delay in frames */
+	snd_pcm_uframes_t avail;	/* number of frames available */
+	snd_pcm_uframes_t avail_max;	/* max frames available on hw since last status */
+	snd_pcm_uframes_t overrange;	/* count of ADC (capture) overrange detections from last status */
+	snd_pcm_state_t suspended_state; /* suspended stream state */
+	__u32 audio_tstamp_data;	 /* needed for 64-bit alignment, used for configs/report to/from userspace */
+	s64 audio_tstamp_sec;		/* sample counter, wall clock, PHC or on-demand sync'ed */
+	s64 audio_tstamp_nsec;
+	s64 driver_tstamp_sec;		/* useful in case reference system tstamp is reported with delay */
+	s64 driver_tstamp_nsec;
+	__u32 audio_tstamp_accuracy;	/* in ns units, only valid if indicated in audio_tstamp_data */
+	unsigned char reserved[52-4*sizeof(s64)]; /* must be filled with zero */
+};
+
+#define SNDRV_PCM_IOCTL_STATUS64	_IOR('A', 0x20, struct snd_pcm_status64)
+#define SNDRV_PCM_IOCTL_STATUS_EXT64	_IOWR('A', 0x24, struct snd_pcm_status64)
+
+struct snd_pcm_status32 {
+	s32 state;		/* stream state */
+	s32 trigger_tstamp_sec;	/* time when stream was started/stopped/paused */
+	s32 trigger_tstamp_nsec;
+	s32 tstamp_sec;		/* reference timestamp */
+	s32 tstamp_nsec;
+	u32 appl_ptr;		/* appl ptr */
+	u32 hw_ptr;		/* hw ptr */
+	s32 delay;		/* current delay in frames */
+	u32 avail;		/* number of frames available */
+	u32 avail_max;		/* max frames available on hw since last status */
+	u32 overrange;		/* count of ADC (capture) overrange detections from last status */
+	s32 suspended_state;	/* suspended stream state */
+	u32 audio_tstamp_data;	/* needed for 64-bit alignment, used for configs/report to/from userspace */
+	s32 audio_tstamp_sec;	/* sample counter, wall clock, PHC or on-demand sync'ed */
+	s32 audio_tstamp_nsec;
+	s32 driver_tstamp_sec;	/* useful in case reference system tstamp is reported with delay */
+	s32 driver_tstamp_nsec;
+	u32 audio_tstamp_accuracy;	/* in ns units, only valid if indicated in audio_tstamp_data */
+	unsigned char reserved[52-4*sizeof(s32)]; /* must be filled with zero */
+};
+
+#define SNDRV_PCM_IOCTL_STATUS32	_IOR('A', 0x20, struct snd_pcm_status32)
+#define SNDRV_PCM_IOCTL_STATUS_EXT32	_IOWR('A', 0x24, struct snd_pcm_status32)
+
 #endif /* __SOUND_PCM_H */
diff --git a/include/sound/soc-component.h b/include/sound/soc-component.h
index 506f72a6b2c2..154d02fbbfed 100644
--- a/include/sound/soc-component.h
+++ b/include/sound/soc-component.h
@@ -93,8 +93,8 @@ struct snd_soc_component_driver {
 	snd_pcm_uframes_t (*pointer)(struct snd_soc_component *component,
 				     struct snd_pcm_substream *substream);
 	int (*get_time_info)(struct snd_soc_component *component,
-		struct snd_pcm_substream *substream, struct timespec *system_ts,
-		struct timespec *audio_ts,
+		struct snd_pcm_substream *substream, struct timespec64 *system_ts,
+		struct timespec64 *audio_ts,
 		struct snd_pcm_audio_tstamp_config *audio_tstamp_config,
 		struct snd_pcm_audio_tstamp_report *audio_tstamp_report);
 	int (*copy_user)(struct snd_soc_component *component,
diff --git a/include/sound/timer.h b/include/sound/timer.h
index a53e37bcd746..23e885d31525 100644
--- a/include/sound/timer.h
+++ b/include/sound/timer.h
@@ -89,7 +89,7 @@ struct snd_timer_instance {
 			  unsigned long ticks, unsigned long resolution);
 	void (*ccallback) (struct snd_timer_instance * timeri,
 			   int event,
-			   struct timespec * tstamp,
+			   struct timespec64 * tstamp,
 			   unsigned long resolution);
 	void (*disconnect)(struct snd_timer_instance *timeri);
 	void *callback_data;
@@ -113,7 +113,7 @@ struct snd_timer_instance {
  */
 
 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid, struct snd_timer **rtimer);
-void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp);
+void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp);
 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer);
 int snd_timer_global_free(struct snd_timer *timer);
 int snd_timer_global_register(struct snd_timer *timer);