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| author |   Arnd Bergmann <arnd@arndb.de> | 2020-09-18 11:56:19 +0200 |
|---|---|---|
| committer |   Takashi Iwai <tiwai@suse.de> | 2020-09-21 10:37:07 +0200 |
| commit | 18d122c0287b29e70bc312a994c7ee79738cec77 (patch) | |
| tree | 5310fec9f6a909f465b97350cf4fda5105149361 /sound/core/control_compat.c | |
| parent | ALSA: asihpi: fix spellint typo in comments (diff) | |
| download | linux-dev-18d122c0287b29e70bc312a994c7ee79738cec77.tar.xz linux-dev-18d122c0287b29e70bc312a994c7ee79738cec77.zip | |
ALSA: compat_ioctl: avoid compat_alloc_user_space
Using compat_alloc_user_space() tends to add complexity
to the ioctl handling, so I am trying to remove it everywhere.
The two callers in sound/core can rewritten to just call
the same code that operates on a kernel pointer as the
native handler.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200918095642.1446243-1-arnd@arndb.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/control_compat.c')
| -rw-r--r-- | sound/core/control_compat.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/sound/core/control_compat.c b/sound/core/control_compat.c index 02df1d7db9a1..1d708aab9c98 100644 --- a/sound/core/control_compat.c +++ b/sound/core/control_compat.c @@ -22,24 +22,22 @@ struct snd_ctl_elem_list32 { static int snd_ctl_elem_list_compat(struct snd_card *card, struct snd_ctl_elem_list32 __user *data32) { - struct snd_ctl_elem_list __user *data; + struct snd_ctl_elem_list data = {}; compat_caddr_t ptr; int err; - data = compat_alloc_user_space(sizeof(*data)); - /* offset, space, used, count */ - if (copy_in_user(data, data32, 4 * sizeof(u32))) + if (copy_from_user(&data, data32, 4 * sizeof(u32))) return -EFAULT; /* pids */ - if (get_user(ptr, &data32->pids) || - put_user(compat_ptr(ptr), &data->pids)) + if (get_user(ptr, &data32->pids)) return -EFAULT; - err = snd_ctl_elem_list(card, data); + data.pids = compat_ptr(ptr); + err = snd_ctl_elem_list(card, &data); if (err < 0) return err; /* copy the result */ - if (copy_in_user(data32, data, 4 * sizeof(u32))) + if (copy_to_user(data32, &data, 4 * sizeof(u32))) return -EFAULT; return 0; } |