- Rename tty_makedev() into tty_makedevf() and make it capable
to fail and return error. - Use make_dev_p() in tty_makedevf() instead of make_dev_cred(). - Always pass MAKEDEV_CHECKNAME flag. - Optionally pass MAKEDEV_REF flag. - Provide macro for compatibility with old API. This fixes races with simultaneous creation and desctruction of ttys, and makes it possible to call tty_makedevf() from device cloners. A race in tty_watermarks() still exist, since the latter drops lock for M_WAITOK allocation. This will be addressed in separate commit. Reviewed by: kib Sponsored by: Nginx, Inc.
This commit is contained in:
Gleb Smirnoff
parent
0f987f1f08
commit
e1e585a87c
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=259549
105
sys/kern/tty.c
105
sys/kern/tty.c
@ -289,7 +289,7 @@ ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
|
||||
goto done;
|
||||
|
||||
ttydisc_open(tp);
|
||||
tty_watermarks(tp);
|
||||
tty_watermarks(tp); /* XXXGL: drops lock */
|
||||
}
|
||||
|
||||
/* Wait for Carrier Detect. */
|
||||
@ -1174,16 +1174,18 @@ SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
|
||||
* the user.
|
||||
*/
|
||||
|
||||
void
|
||||
tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
|
||||
int
|
||||
tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
|
||||
const char *fmt, ...)
|
||||
{
|
||||
va_list ap;
|
||||
struct cdev *dev;
|
||||
struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
|
||||
const char *prefix = "tty";
|
||||
char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
|
||||
uid_t uid;
|
||||
gid_t gid;
|
||||
mode_t mode;
|
||||
int error;
|
||||
|
||||
/* Remove "tty" prefix from devices like PTY's. */
|
||||
if (tp->t_flags & TF_NOPREFIX)
|
||||
@ -1205,57 +1207,92 @@ tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
|
||||
mode = S_IRUSR|S_IWUSR|S_IWGRP;
|
||||
}
|
||||
|
||||
flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
|
||||
flags |= MAKEDEV_CHECKNAME;
|
||||
|
||||
/* Master call-in device. */
|
||||
dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
|
||||
uid, gid, mode, "%s%s", prefix, name);
|
||||
error = make_dev_p(flags, &dev, &ttydev_cdevsw, cred, uid, gid, mode,
|
||||
"%s%s", prefix, name);
|
||||
if (error)
|
||||
return (error);
|
||||
dev->si_drv1 = tp;
|
||||
wakeup(&dev->si_drv1);
|
||||
tp->t_dev = dev;
|
||||
|
||||
init = lock = cua = cinit = clock = NULL;
|
||||
|
||||
/* Slave call-in devices. */
|
||||
if (tp->t_flags & TF_INITLOCK) {
|
||||
dev = make_dev_cred(&ttyil_cdevsw, TTYUNIT_INIT, cred,
|
||||
uid, gid, mode, "%s%s.init", prefix, name);
|
||||
dev_depends(tp->t_dev, dev);
|
||||
dev->si_drv1 = tp;
|
||||
wakeup(&dev->si_drv1);
|
||||
dev->si_drv2 = &tp->t_termios_init_in;
|
||||
error = make_dev_p(flags, &init, &ttyil_cdevsw, cred, uid,
|
||||
gid, mode, "%s%s.init", prefix, name);
|
||||
if (error)
|
||||
goto fail;
|
||||
dev_depends(dev, init);
|
||||
dev2unit(init) = TTYUNIT_INIT;
|
||||
init->si_drv1 = tp;
|
||||
wakeup(&init->si_drv1);
|
||||
init->si_drv2 = &tp->t_termios_init_in;
|
||||
|
||||
dev = make_dev_cred(&ttyil_cdevsw, TTYUNIT_LOCK, cred,
|
||||
uid, gid, mode, "%s%s.lock", prefix, name);
|
||||
dev_depends(tp->t_dev, dev);
|
||||
dev->si_drv1 = tp;
|
||||
wakeup(&dev->si_drv1);
|
||||
dev->si_drv2 = &tp->t_termios_lock_in;
|
||||
error = make_dev_p(flags, &lock, &ttyil_cdevsw, cred, uid,
|
||||
gid, mode, "%s%s.lock", prefix, name);
|
||||
if (error)
|
||||
goto fail;
|
||||
dev_depends(dev, lock);
|
||||
dev2unit(lock) = TTYUNIT_LOCK;
|
||||
lock->si_drv1 = tp;
|
||||
wakeup(&lock->si_drv1);
|
||||
lock->si_drv2 = &tp->t_termios_lock_in;
|
||||
}
|
||||
|
||||
/* Call-out devices. */
|
||||
if (tp->t_flags & TF_CALLOUT) {
|
||||
dev = make_dev_cred(&ttydev_cdevsw, TTYUNIT_CALLOUT, cred,
|
||||
error = make_dev_p(flags, &cua, &ttydev_cdevsw, cred,
|
||||
UID_UUCP, GID_DIALER, 0660, "cua%s", name);
|
||||
dev_depends(tp->t_dev, dev);
|
||||
dev->si_drv1 = tp;
|
||||
wakeup(&dev->si_drv1);
|
||||
if (error)
|
||||
goto fail;
|
||||
dev_depends(dev, cua);
|
||||
dev2unit(cua) = TTYUNIT_CALLOUT;
|
||||
cua->si_drv1 = tp;
|
||||
wakeup(&cua->si_drv1);
|
||||
|
||||
/* Slave call-out devices. */
|
||||
if (tp->t_flags & TF_INITLOCK) {
|
||||
dev = make_dev_cred(&ttyil_cdevsw,
|
||||
TTYUNIT_CALLOUT | TTYUNIT_INIT, cred,
|
||||
error = make_dev_p(flags, &cinit, &ttyil_cdevsw, cred,
|
||||
UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
|
||||
dev_depends(tp->t_dev, dev);
|
||||
dev->si_drv1 = tp;
|
||||
wakeup(&dev->si_drv1);
|
||||
dev->si_drv2 = &tp->t_termios_init_out;
|
||||
if (error)
|
||||
goto fail;
|
||||
dev_depends(dev, cinit);
|
||||
dev2unit(cinit) = TTYUNIT_CALLOUT | TTYUNIT_INIT;
|
||||
cinit->si_drv1 = tp;
|
||||
wakeup(&cinit->si_drv1);
|
||||
cinit->si_drv2 = &tp->t_termios_init_out;
|
||||
|
||||
dev = make_dev_cred(&ttyil_cdevsw,
|
||||
TTYUNIT_CALLOUT | TTYUNIT_LOCK, cred,
|
||||
error = make_dev_p(flags, &clock, &ttyil_cdevsw, cred,
|
||||
UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
|
||||
dev_depends(tp->t_dev, dev);
|
||||
dev->si_drv1 = tp;
|
||||
wakeup(&dev->si_drv1);
|
||||
dev->si_drv2 = &tp->t_termios_lock_out;
|
||||
if (error)
|
||||
goto fail;
|
||||
dev_depends(dev, clock);
|
||||
dev2unit(clock) = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
|
||||
clock->si_drv1 = tp;
|
||||
wakeup(&clock->si_drv1);
|
||||
clock->si_drv2 = &tp->t_termios_lock_out;
|
||||
}
|
||||
}
|
||||
|
||||
return (0);
|
||||
|
||||
fail:
|
||||
destroy_dev(dev);
|
||||
if (init)
|
||||
destroy_dev(init);
|
||||
if (lock)
|
||||
destroy_dev(lock);
|
||||
if (cinit)
|
||||
destroy_dev(cinit);
|
||||
if (clock)
|
||||
destroy_dev(clock);
|
||||
|
||||
return (error);
|
||||
}
|
||||
|
||||
/*
|
||||
|
||||
@ -171,8 +171,11 @@ void tty_rel_gone(struct tty *tp);
|
||||
#define tty_getlock(tp) ((tp)->t_mtx)
|
||||
|
||||
/* Device node creation. */
|
||||
void tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
|
||||
__printflike(3, 4);
|
||||
int tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
|
||||
const char *fmt, ...) __printflike(4, 5);
|
||||
#define TTYMK_CLONING 0x1
|
||||
#define tty_makedev(tp, cred, fmt, ...) \
|
||||
(void )tty_makedevf((tp), (cred), 0, (fmt), ## __VA_ARGS__)
|
||||
#define tty_makealias(tp,fmt,...) \
|
||||
make_dev_alias((tp)->t_dev, fmt, ## __VA_ARGS__)
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user