kernel/linux.git/sound/core/info.c, branch v6.19.12

ALSA: info: Use guard() for locking

2024-02-28T14:01:21+00:00

We can simplify the code gracefully with new guard() macro and co for automatic cleanup of locks. Only the code refactoring, and no functional changes. Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20240227085306.9764-7-tiwai@suse.de

ALSA: info: Fix potential deadlock at disconnection

2023-11-09T15:06:33+00:00

As reported recently, ALSA core info helper may cause a deadlock at the forced device disconnection during the procfs operation. The proc_remove() (that is called from the snd_card_disconnect() helper) has a synchronization of the pending procfs accesses via wait_for_completion(). Meanwhile, ALSA procfs helper takes the global mutex_lock(&info_mutex) at both the proc_open callback and snd_card_info_disconnect() helper. Since the proc_open can't finish due to the mutex lock, wait_for_completion() never returns, either, hence it deadlocks. TASK#1 TASK#2 proc_reg_open() takes use_pde() snd_info_text_entry_open() snd_card_disconnect() snd_info_card_disconnect() takes mutex_lock(&info_mutex) proc_remove() wait_for_completion(unused_pde) ... waiting task#1 closes mutex_lock(&info_mutex) => DEADLOCK This patch is a workaround for avoiding the deadlock scenario above. The basic strategy is to move proc_remove() call outside the mutex lock. proc_remove() can work gracefully without extra locking, and it can delete the tree recursively alone. So, we call proc_remove() at snd_info_card_disconnection() at first, then delete the rest resources recursively within the info_mutex lock. After the change, the function snd_info_disconnect() doesn't do disconnection by itself any longer, but it merely clears the procfs pointer. So rename the function to snd_info_clear_entries() for avoiding confusion. The similar change is applied to snd_info_free_entry(), too. Since the proc_remove() is called only conditionally with the non-NULL entry->p, it's skipped after the snd_info_clear_entries() call. Reported-by: Shinhyung Kang Closes: https://lore.kernel.org/r/664457955.21699345385931.JavaMail.epsvc@epcpadp4 Reviewed-by: Jaroslav Kysela Cc: Link: https://lore.kernel.org/r/20231109141954.4283-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: info: Fix llseek return value when using callback

2022-08-17T13:13:30+00:00

When using callback there was a flow of ret = -EINVAL if (callback) { offset = callback(); goto out; } ... offset = some other value in case of no callback; ret = offset; out: return ret; which causes the snd_info_entry_llseek() to return -EINVAL when there is callback handler. Fix this by setting "ret" directly to callback return value before jumping to "out". Fixes: 73029e0ff18d ("ALSA: info - Implement common llseek for binary mode") Signed-off-by: Amadeusz Sławiński Cc: Link: https://lore.kernel.org/r/20220817124924.3974577-1-amadeuszx.slawinski@linux.intel.com Signed-off-by: Takashi Iwai

ALSA: core: Fix missing return value comments for kernel docs

2022-07-13T11:42:38+00:00

Each kernel doc comment expects the definition of the return value in a proper format. This patch adds or fixes the missing entries for the remaining ALSA core API functions. Link: https://lore.kernel.org/r/20220713104759.4365-8-tiwai@suse.de Signed-off-by: Takashi Iwai

proc: remove PDE_DATA() completely

2022-01-22T06:33:37+00:00

Remove PDE_DATA() completely and replace it with pde_data(). [akpm@linux-foundation.org: fix naming clash in drivers/nubus/proc.c] [akpm@linux-foundation.org: now fix it properly] Link: https://lkml.kernel.org/r/20211124081956.87711-2-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Christian Brauner Cc: Alexey Dobriyan Cc: Alexey Gladkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

isystem: trim/fixup stdarg.h and other headers

2021-08-19T00:02:55+00:00

Delete/fixup few includes in anticipation of global -isystem compile option removal. Note: crypto/aegis128-neon-inner.c keeps due to redefinition of uintptr_t error (one definition comes from , another from ). Signed-off-by: Alexey Dobriyan Signed-off-by: Masahiro Yamada

ALSA: info: Drop WARN_ON() from buffer NULL sanity check

2020-07-17T08:59:38+00:00

snd_info_get_line() has a sanity check of NULL buffer -- both buffer itself being NULL and buffer->buffer being NULL. Basically both checks are valid and necessary, but the problem is that it's with snd_BUG_ON() macro that triggers WARN_ON(). The latter condition (NULL buffer->buffer) can be met arbitrarily by user since the buffer is allocated at the first write, so it means that user can trigger WARN_ON() at will. This patch addresses it by simply moving buffer->buffer NULL check out of snd_BUG_ON() so that spurious WARNING is no longer triggered. Reported-by: syzbot+e42d0746c3c3699b6061@syzkaller.appspotmail.com Cc: Link: https://lore.kernel.org/r/20200717084023.5928-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: info: remove redundant assignment to variable c

2020-02-10T07:30:02+00:00

Variable c is being assigned with the value -1 that is never read, it is assigned a new value in a following while-loop. The assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20200208224206.38540-1-colin.king@canonical.com Signed-off-by: Takashi Iwai

proc: convert everything to "struct proc_ops"

2020-02-04T03:05:26+00:00

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ALSA: info: More constifications

2020-01-05T15:14:57+00:00

Apply const prefix to the string array and its callers. Just for minor optimization and no functional changes. Link: https://lore.kernel.org/r/20200105144823.29547-39-tiwai@suse.de Signed-off-by: Takashi Iwai