AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2025-01-18 10:07:39 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

tty: Refactor tty_ldisc_reinit() for reuse

Browse Source 
At tty hangup, the line discipline instance is reinitialized by
closing the current ldisc instance and opening a new instance.
This operation is complicated by error recovery: if the attempt
to reinit the current line discipline fails, the line discipline
is reset to N_TTY (which should not but can fail).

Re-purpose tty_ldisc_reinit() to return a valid, open line discipline
instance, or otherwise, an error.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Hurley 2016-01-10 22:41:05 -08:00 committed by Greg Kroah-Hartman
parent c12da96f80
commit 7896f30d6f
1 changed files with 31 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
drivers/tty/tty_ldisc.c
View File

@ -641,26 +641,41 @@ static void tty_reset_termios(struct tty_struct *tty)
* @tty: tty to reinit
* @disc: line discipline to reinitialize
*
* Switch the tty to a line discipline and leave the ldisc
* state closed
* Completely reinitialize the line discipline state, by closing the
* current instance and opening a new instance. If an error occurs opening
* the new non-N_TTY instance, the instance is dropped and tty->ldisc reset
* to NULL. The caller can then retry with N_TTY instead.
*
* Returns 0 if successful, otherwise error code < 0
*/
static int tty_ldisc_reinit(struct tty_struct *tty, int disc)
{
struct tty_ldisc *ld = tty_ldisc_get(tty, disc);
struct tty_ldisc *ld;
int retval;
if (IS_ERR(ld))
return -1;
ld = tty_ldisc_get(tty, disc);
if (IS_ERR(ld)) {
BUG_ON(disc == N_TTY);
return PTR_ERR(ld);
}
tty_ldisc_close(tty, tty->ldisc);
tty_ldisc_put(tty->ldisc);
/*
* Switch the line discipline back
*/
if (tty->ldisc) {
tty_ldisc_close(tty, tty->ldisc);
tty_ldisc_put(tty->ldisc);
}
/* switch the line discipline */
tty->ldisc = ld;
tty_set_termios_ldisc(tty, disc);
return 0;
retval = tty_ldisc_open(tty, tty->ldisc);
if (retval) {
if (!WARN_ON(disc == N_TTY)) {
tty_ldisc_put(tty->ldisc);
tty->ldisc = NULL;
}
}
return retval;
}
/**
@ -716,19 +731,13 @@ void tty_ldisc_hangup(struct tty_struct *tty)
reopen a new ldisc. We could defer the reopen to the next
open but it means auditing a lot of other paths so this is
a FIXME */
if (reset == 0) {
if (reset == 0)
err = tty_ldisc_reinit(tty, tty->termios.c_line);
if (!tty_ldisc_reinit(tty, tty->termios.c_line))
err = tty_ldisc_open(tty, tty->ldisc);
else
err = 1;
}
/* If the re-open fails or we reset then go to N_TTY. The
N_TTY open cannot fail */
if (reset || err) {
BUG_ON(tty_ldisc_reinit(tty, N_TTY));
WARN_ON(tty_ldisc_open(tty, tty->ldisc));
}
if (reset || err < 0)
tty_ldisc_reinit(tty, N_TTY);
}
tty_ldisc_unlock(tty);
if (reset)