ALSA: seq: fix function cast warnings

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[ Upstream commit d7bf738098 ]

clang-16 points out a control flow integrity (kcfi) issue when event
callbacks get converted to incompatible types:

sound/core/seq/seq_midi.c:135:30: error: cast from 'int (*)(struct snd_rawmidi_substream *, const char *, int)' to 'snd_seq_dump_func_t' (aka 'int (*)(void *, void *, int)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
  135 |                 snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream);
      |                                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sound/core/seq/seq_virmidi.c:83:31: error: cast from 'int (*)(struct snd_rawmidi_substream *, const unsigned char *, int)' to 'snd_seq_dump_func_t' (aka 'int (*)(void *, void *, int)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
   83 |                         snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream);
      |                                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

For addressing those errors, introduce wrapper functions that are used
for callbacks and bridge to the actual function call with pointer
cast.

The code was originally added with the initial ALSA merge in linux-2.5.4.

[ the patch description shamelessly copied from Arnd's original patch
  -- tiwai ]

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240213101020.459183-1-arnd@kernel.org
Link: https://lore.kernel.org/r/20240213135343.16411-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Takashi Iwai 2024-02-13 14:53:43 +01:00 • committed by Sasha Levin

parent 7378234eee

commit 3cae4f4153

2 changed files with 15 additions and 2 deletions

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8

sound/core/seq/seq_midi.c

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9

sound/core/seq/seq_virmidi.c

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