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  1. 17 Dec, 2019 2 commits
    • Takashi Iwai's avatar
      Merge tag 'y2038-alsa-v8-signed' of... · df1d6ea0
      Takashi Iwai authored 
      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/#m6519cb07cfda08adf1dedea6596bb98892b4d5dcSigned-off-by: default avatarArnd 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.
      df1d6ea0
    • Takashi Iwai's avatar
      ALSA: cmipci: Allow disabling MPU port via module option · d8cac620
      Takashi Iwai authored 
      Patrick May reported that his sound card with CMI8378 chip causes a
crash / reboot when accessing the MIDI port that isn't actually
present on the board.  Moreover, despite of the documentation,
passing mpu_port=0 doesn't disable the MIDI port on this board.

It implies that the chip is a newer revision and the MPU401 port is
integrated and mapped on the PCI register.  For this chip model, the
driver enables the MPU port unconditionally, so far.

Although fixing the unexpected reboot would be the best solution, it's
not so trivial to identify the cause.  So, as a plan B, this patch
extends the existing mpu_port option usage to allow disabling the port
by specifying the value 0, just like we applied for fm_port option in
commit 2f24d159 ("[ALSA] cmipci - Allow to disable integrated FM
port").  As default, the MPU port is still enabled, but user can pass
mpu_port=0 to disable it.
Reported-and-tested-by: default avatarPatrick May <dusthillresident@gmail.com>
Link: https://lore.kernel.org/r/20191217081448.1144-1-tiwai@suse.deSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      d8cac620
  3. 14 Dec, 2019 2 commits
  5. 13 Dec, 2019 6 commits
    • Takashi Iwai's avatar
      ALSA: hda: Unify get_response handling · 5f2cb361
      Takashi Iwai authored 
      Now most of the get_response handling became quite similar between
HDA-core and legacy drivers, and the only differences are:

- the handling of extra-long polling delay for some codecs
- the debug message for the stalled communication

and both are worth to share in the common code.

This patch unifies the code into snd_hdac_bus_get_response(), and use
this from the legacy get_response callback.  It results in a good
amount of code reduction in the end.
Reviewed-by: default avatarKai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20191212191101.19517-3-tiwai@suse.deSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      5f2cb361
    • Takashi Iwai's avatar
      ALSA: hda: Use waitqueue for RIRB in HDA-core helper, too · 89698ed5
      Takashi Iwai authored 
      This patch implements the same logic that was done for the legacy
HD-audio controller driver by the commit 88452da9 ("ALSA: hda: Use
standard waitqueue for RIRB wakeup") to the HDA-core helper code,
too.  This makes snd_hdac_bus_get_response() waiting for the response
with bus->rirb_wq instead of polling when bus->polling is false.
It'll save both CPU time and response latency.
Reviewed-by: default avatarKai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20191212191101.19517-2-tiwai@suse.deSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      89698ed5
    • Arnd Bergmann's avatar
      ALSA: bump uapi version numbers · 1cfaef96
      Arnd Bergmann authored 
      Change SNDRV_PCM_VERSION, SNDRV_RAWMIDI_VERSION and SNDRV_TIMER_VERSION
to indicate the addition of the time64 version of the mmap interface and
these ioctl commands:

SNDRV_PCM_IOCTL_SYNC
SNDRV_RAWMIDI_IOCTL_STATUS
SNDRV_PCM_IOCTL_STATUS
SNDRV_PCM_IOCTL_STATUS_EXT
SNDRV_TIMER_IOCTL_TREAD
SNDRV_TIMER_IOCTL_STATUS

32-bit applications built with 64-bit time_t require both the headers
and the running kernel to support at least the new API version. When
built with earlier kernel headers, some of these may not work
correctly, so applications are encouraged to fail compilation like

 #if SNDRV_PCM_VERSION < SNDRV_PROTOCOL_VERSION(2, 0, 15)
 extern int __fail_build_for_time_64[sizeof(long) - sizeof(time_t)];
 #endif

or provide their own updated copy of the header file.
At runtime, the interface is unchanged for 32-bit time_t, but new
kernels are required to work with user compiled with 64-bit time_t.

A runtime check can be used to detect old kernel versions and
warn about those.
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      1cfaef96
    • Arnd Bergmann's avatar
      ALSA: add new 32-bit layout for snd_pcm_mmap_status/control · 80fe7430
      Arnd Bergmann authored 
      The snd_pcm_mmap_status and snd_pcm_mmap_control interfaces are one of the
trickiest areas to get right when moving to 64-bit time_t in user space.

The snd_pcm_mmap_status structure layout is incompatible with user space
that uses a 64-bit time_t, so we need a new layout for it. Since the
SNDRV_PCM_IOCTL_SYNC_PTR ioctl combines it with snd_pcm_mmap_control
into snd_pcm_sync_ptr, we need to change those two as well.

Both structures are also exported via an mmap() operation on certain
architectures, and this suffers from incompatibility between 32-bit
and 64-bit user space. As we have to change both structures anyway,
this is a good opportunity to fix the mmap() problem as well, so let's
standardize on the existing 64-bit layout of the structure where possible.

The downside is that we lose mmap() support for existing 32-bit x86 and
powerpc applications, adding that would introduce very noticeable runtime
overhead and complexity. My assumption here is that not too many people
will miss the removed feature, given that:

- Almost all x86 and powerpc users these days are on 64-bit kernels,
the majority of today's 32-bit users are on architectures that never
supported mmap (ARM, MIPS, ...).
- It never worked in compat mode (it was intentionally disabled there)
- The application already needs to work with a fallback to
SNDRV_PCM_IOCTL_SYNC_PTR, which will keep working with both the old
and new structure layout.

Both the ioctl() and mmap() based interfaces are changed at the same
time, as they are based on the same structures. Unlike other interfaces,
we change the uapi header to export both the traditional structure and
a version that is portable between 32-bit and 64-bit user space code
and that corresponds to the existing 64-bit layout. We further check the
__USE_TIME_BITS64 macro that will be defined by future C library versions
whenever we use the new time_t definition, so any existing user space
source code will not see any changes until it gets rebuilt against a new
C library. However, the new structures are all visible in addition to the
old ones, allowing applications to explicitly request the new structures.

In order to detect the difference between the old snd_pcm_mmap_status and
the new __snd_pcm_mmap_status64 structure from the ioctl command number,
we rely on one quirk in the structure definition: snd_pcm_mmap_status
must be aligned to alignof(time_t), which leads the compiler to insert
four bytes of padding in struct snd_pcm_sync_ptr after 'flags' and a
corresponding change in the size of snd_pcm_sync_ptr itself. On x86-32
(and only there), the compiler doesn't use 64-bit alignment in structure,
so I'm adding an explicit pad in the structure that has no effect on the
existing 64-bit architectures but ensures that the layout matches for x86.

The snd_pcm_uframes_t type compatibility requires another hack: we can't
easily make that 64 bit wide, so I leave the type as 'unsigned long',
but add padding before and after it, to ensure that the data is properly
aligned to the respective 64-bit field in the in-kernel structure.

For the SNDRV_PCM_MMAP_OFFSET_STATUS/CONTROL constants that are used
as the virtual file offset in the mmap() function, we also have to
introduce new constants that depend on hte __USE_TIME_BITS64 macro:
The existing macros are renamed to SNDRV_PCM_MMAP_OFFSET_STATUS_OLD
and SNDRV_PCM_MMAP_OFFSET_CONTROL_OLD, they continue to work fine on
64-bit architectures, but stop working on native 32-bit user space.
The replacement _NEW constants are now used by default for user space
built with __USE_TIME_BITS64, those now work on all new kernels for x86,
ppc and alpha (32 and 64 bit, native and compat). It might be a good idea
for a future alsa-lib to support both the _OLD and _NEW macros and use
the corresponding structures directly. Unmodified alsa-lib source code
will retain the current behavior, so it will no longer be able to use
mmap() for the status/control structures on 32-bit systems, until either
the C library gets updated to 64-bit time_t or alsa-lib gets updated to
support both mmap() layouts.

Co-developed-with: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: default avatarBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      80fe7430
    • Arnd Bergmann's avatar
      ALSA: move snd_pcm_ioctl_sync_ptr_compat into pcm_native.c · 09d94175
      Arnd Bergmann authored 
      This is a preparation patch, moving the compat handler for
snd_pcm_ioctl_sync_ptr_compat from pcm_compat.c to pcm_native.c.
No other changes are indented.
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      09d94175
    • Baolin Wang's avatar
      ALSA: Avoid using timespec for struct snd_timer_tread · 07094ae6
      Baolin Wang authored 
      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: default avatarBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      07094ae6
  7. 12 Dec, 2019 1 commit
  9. 11 Dec, 2019 29 commits
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