snd_timer_dev_register() walks snd_timer_list looking for the
ordered insertion point and on loop fall-through passes
&timer1->device_list to list_add_tail():
list_for_each_entry(timer1, &snd_timer_list, device_list) {
...
break; /* on found-position */
...
}
list_add_tail(&timer->device_list, &timer1->device_list);
When the loop walks all entries without break, timer1 is
past-the-end. &timer1->device_list aliases &snd_timer_list (the
list head) via container_of offset cancellation, so the insert
lands at the list tail. That is the intended behaviour, but the
access is undefined per C11 even though it works in practice.
Track an explicit insert_before pointer initialised to the list
head and overwritten to &timer1->device_list only when the loop
breaks early. The observable behaviour is unchanged.
Fixes: 9244b2c307 ("[ALSA] alsa core: convert to list_for_each_entry*")
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Link: https://patch.msgid.link/20260518194023.1667857-2-maoyixie.tju@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
snd_timer_check_slave() still walks all registered timers and all open
timer instances to find a matching master for a newly opened slave.
Maintain a global list of open master instances that can accept slave
links and use it for the slave lookup path instead. This keeps the
existing matching semantics while avoiding the nested walk over
snd_timer_list and each timer open_list_head.
The reverse path in snd_timer_check_master() already scans only the
pending slave list, so this makes both lookup paths closer in shape
without changing the master/slave linking logic.
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260316-alsa-timer-master-list-v1-1-fb95e547110a@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
We used to have a variable declaration with __free() initialized with
NULL. This was to keep the old coding style rule, but recently it's
relaxed and rather recommends to follow the new rule to declare in
place of use for __free() -- which avoids potential deadlocks or UAFs
with nested cleanups.
Although the current code has no bug, per se, let's follow the new
standard and move the declaration to the place of assignment (or
directly assign the allocated result) instead of NULL initializations.
Fixes: ed96f6394e ("ALSA: timer: Use automatic cleanup of kfree()")
Fixes: 37745918e0 ("ALSA: timer: Introduce virtual userspace-driven timers")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20251216140634.171890-8-tiwai@suse.de
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We used to wrap with no_free_ptr() for the return value from
memdup_user() with errors where the auto cleanup is applied. This was
a workaround because the initial implementation of kfree auto-cleanup
checked only NULL pointers.
Since recently, though, the kfree auto-cleanup checks with
IS_ERR_OR_NULL() (by the commit cd7eb8f83f ("mm/slab: make
__free(kfree) accept error pointers")), hence those workarounds became
superfluous. Let's drop them now.
Link: https://patch.msgid.link/20240902075246.3743-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Implement two ioctl calls in order to support virtual userspace-driven
ALSA timers.
The first ioctl is SNDRV_TIMER_IOCTL_CREATE, which gets the
snd_timer_uinfo struct as a parameter and puts a file descriptor of a
virtual timer into the `fd` field of the snd_timer_unfo structure. It
also updates the `id` field of the snd_timer_uinfo struct, which
provides a unique identifier for the timer (basically, the subdevice
number which can be used when creating timer instances).
This patch also introduces a tiny id allocator for the userspace-driven
timers, which guarantees that we don't have more than 128 of them in the
system.
Another ioctl is SNDRV_TIMER_IOCTL_TRIGGER, which allows us to trigger
the virtual timer (and calls snd_timer_interrupt for the timer under
the hood), causing all of the timer instances binded to this timer to
execute their callbacks.
The maximum amount of ticks available for the timer is 1 for the sake of
simplicity of the userspace API. 'start', 'stop', 'open' and 'close'
callbacks for the userspace-driven timers are empty since we don't
really do any hardware initialization here.
Suggested-by: Axel Holzinger <aholzinger@gmx.de>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20240813120701.171743-4-ivan.orlov0322@gmail.com
We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.
For making changes easier, some functions widen the application of
register_mutex, but those shouldn't influence on any actual
performance.
Also, one code block was factored out as a function so that guard()
can be applied cleanly without much indentation.
There are still a few remaining explicit spin_lock/unlock calls, and
those are for the places where we do temporary unlock/relock, which
doesn't fit well with the guard(), so far.
Only the code refactoring, and no functional changes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-4-tiwai@suse.de
There are common patterns where a temporary buffer is allocated and
freed at the exit, and those can be simplified with the recent cleanup
mechanism via __free(kfree).
No functional changes, only code refactoring.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240222111509.28390-5-tiwai@suse.de
When the timer instance was add into ack_list but was not currently in
process, the user could stop it via snd_timer_stop1() without delete it
from the ack_list. Then the user could free the timer instance and when
it was actually processed UAF occurred.
This issue could be reproduced via testcase snd_timer01 in ltp - running
several instances of that testcase at the same time.
What I actually met was that the ack_list of the timer broken and the
kernel went into deadloop with irqoff. That could be detected by
hardlockup detector on board or when we run it on qemu, we could use gdb
to dump the ack_list when the console has no response.
To fix this issue, we delete the timer instance from ack_list and
active_list unconditionally in snd_timer_stop1().
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Suggested-by: Takashi Iwai <tiwai@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211103033517.80531-1-wangwensheng4@huawei.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Maoyi XieandTakashi Iwai
Cássio GabrielandTakashi Iwai
Linus Torvalds
Kees Cook
Dewei MengandTakashi Iwai
Thorsten BlumandTakashi Iwai
Ingo MolnarandThomas Gleixner
Al ViroandLinus Torvalds
Jinjie RuanandTakashi Iwai
Ivan OrlovandTakashi Iwai
Oswald BuddenhagenandTakashi Iwai
Wang WenshengandTakashi Iwai