Skip to content

L
linux
Switch branch/tag
  1. 23 May, 2024 2 commits
  3. 22 May, 2024 2 commits
    • Takashi Iwai's avatar
      ALSA: core: Enable proc module when CONFIG_MODULES=y · c1a8d5f3
      Takashi Iwai authored 
      We used '#ifdef MODULE' for judging whether the system supports the
sound module or not, and /proc/asound/modules is created only when
'#ifdef MODULE' is true.  The check is not really appropriate, though,
because the flag means only for the sound core and the drivers are
still allowed to be built as modules even if 'MODULE' is not set in
sound/core/init.c.

For fixing the inconsistency, replace those ifdefs with 'ifdef
CONFIG_MODULES'.  One place for a NULL module check is rewritten with
IS_MODULE(CONFIG_SND) to be more intuitive.  It can't be changed to
CONFIG_MODULES; otherwise it would hit a WARN_ON() incorrectly.

This is a slight behavior change; the modules proc entry appears now
no matter whether the sound core is built-in or not as long as modules
are enabled on the kernel in general.  This can't be avoided due to
the nature of kernel builds.

Link: https://lore.kernel.org/r/20240520170349.2417900-1-xu.yang_2@nxp.comSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Tested-by: default avatarXu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240522070442.17786-2-tiwai@suse.de
      c1a8d5f3
    • Takashi Iwai's avatar
      ALSA: core: Fix NULL module pointer assignment at card init · 39381fe7
      Takashi Iwai authored 
      The commit 81033c6b ("ALSA: core: Warn on empty module")
introduced a WARN_ON() for a NULL module pointer passed at snd_card
object creation, and it also wraps the code around it with '#ifdef
MODULE'.  This works in most cases, but the devils are always in
details.  "MODULE" is defined when the target code (i.e. the sound
core) is built as a module; but this doesn't mean that the caller is
also built-in or not.  Namely, when only the sound core is built-in
(CONFIG_SND=y) while the driver is a module (CONFIG_SND_USB_AUDIO=m),
the passed module pointer is ignored even if it's non-NULL, and
card->module remains as NULL.  This would result in the missing module
reference up/down at the device open/close, leading to a race with the
code execution after the module removal.

For addressing the bug, move the assignment of card->module again out
of ifdef.  The WARN_ON() is still wrapped with ifdef because the
module can be really NULL when all sound drivers are built-in.

Note that we keep 'ifdef MODULE' for WARN_ON(), otherwise it would
lead to a false-positive NULL module check.  Admittedly it won't catch
perfectly, i.e. no check is performed when CONFIG_SND=y.  But, it's no
real problem as it's only for debugging, and the condition is pretty
rare.

Fixes: 81033c6b ("ALSA: core: Warn on empty module")
Reported-by: default avatarXu Yang <xu.yang_2@nxp.com>
Closes: https://lore.kernel.org/r/20240520170349.2417900-1-xu.yang_2@nxp.com
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Tested-by: default avatarXu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240522070442.17786-1-tiwai@suse.de
      39381fe7
  5. 21 May, 2024 2 commits
  7. 20 May, 2024 2 commits
  9. 16 May, 2024 3 commits
  11. 15 May, 2024 1 commit
  13. 14 May, 2024 2 commits
  15. 13 May, 2024 4 commits
  17. 12 May, 2024 2 commits
  19. 10 May, 2024 20 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7