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author | Jiri Slaby (SUSE) <jirislaby@kernel.org> | 2024-01-22 14:03:18 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-28 05:08:52 +0300 |
commit | b3dd9bef75b626cebc3b4720df3c5c010d6a29aa (patch) | |
tree | b32419f30c4677566b848d608524d9ae7ad7c652 /drivers | |
parent | 0e6a92f67c8a94707f7bb27ac29e2bdf3e7c167d (diff) | |
download | linux-b3dd9bef75b626cebc3b4720df3c5c010d6a29aa.tar.xz |
tty: vt: expect valid vc when in tty ops
At least since commits feebed6515a1 ("tty: shutdown method") and
bc1e99d93f09 ("TTY: vt, add ->install"), tty->driver_data in vc is
expected to be set since tty_operations::install() till ::cleanup().
So the checks of !tty->driver_data (aka !vc) in:
* vc_do_resize() by tty -> ioctl(TIOCSWINSZ) -> vt_resize()
* do_con_write() by tty -> tty_operations::write()/::put_char()
* con_flush_chars() by tty -> ::flush_chars()
are all superfluous. And also, holding a console lock is not needed to
fetch tty->driver_data.
Note there is even a stale comment in con_flush_chars() about a race
between that and con_close(). But con_close() does not set
tty->driver_data to NULL for years already.
Drop all these in a hope I am not terribly mistaken.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/tty/vt/vt.c | 19 |
1 files changed, 3 insertions, 16 deletions
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 55ce6cdecbca..e131edea00da 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -1154,9 +1154,6 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc, WARN_CONSOLE_UNLOCKED(); - if (!vc) - return -ENXIO; - user = vc->vc_resize_user; vc->vc_resize_user = 0; @@ -2852,7 +2849,7 @@ static int do_con_write(struct tty_struct *tty, const u8 *buf, int count) }; int c, tc, n = 0; unsigned int currcons; - struct vc_data *vc; + struct vc_data *vc = tty->driver_data; struct vt_notifier_param param; bool rescan; @@ -2860,13 +2857,6 @@ static int do_con_write(struct tty_struct *tty, const u8 *buf, int count) return count; console_lock(); - vc = tty->driver_data; - if (vc == NULL) { - pr_err("vt: argh, driver_data is NULL !\n"); - console_unlock(); - return 0; - } - currcons = vc->vc_num; if (!vc_cons_allocated(currcons)) { /* could this happen? */ @@ -3312,16 +3302,13 @@ static void con_start(struct tty_struct *tty) static void con_flush_chars(struct tty_struct *tty) { - struct vc_data *vc; + struct vc_data *vc = tty->driver_data; if (in_interrupt()) /* from flush_to_ldisc */ return; - /* if we race with con_close(), vt may be null */ console_lock(); - vc = tty->driver_data; - if (vc) - set_cursor(vc); + set_cursor(vc); console_unlock(); } |