mirror of
https://github.com/torvalds/linux.git
synced 2026-08-30 04:26:02 +02:00
bee6741ca0
Only the N_TTY line discipline implements the signal-driven i/o notification enabled/disabled by fcntl(F_SETFL, O_ASYNC). The ldisc fasync() notification is sent to the ldisc when the enable state has changed (the tty core is notified via the fasync() VFS file operation). The N_TTY line discipline used the enable state to change the wakeup condition (minimum_to_wake = 1) for notifying the signal handler i/o is available. However, just the presence of data is sufficient and necessary to signal i/o is available, so changing minimum_to_wake is unnecessary (and creates a race condition with read() and poll() which may be concurrently updating minimum_to_wake). Furthermore, since the kill_fasync() VFS helper performs no action if the fasync list is empty, calling unconditionally is preferred; if signal driven i/o just has been disabled, no signal will be sent by kill_fasync() anyway so notification of the change via the ldisc fasync() method is superfluous. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|---|---|---|
| .. | ||
| hvc | ||
| ipwireless | ||
| serial | ||
| vt | ||
| amiserial.c | ||
| bfin_jtag_comm.c | ||
| cyclades.c | ||
| ehv_bytechan.c | ||
| goldfish.c | ||
| isicom.c | ||
| Kconfig | ||
| Makefile | ||
| metag_da.c | ||
| mips_ejtag_fdc.c | ||
| moxa.c | ||
| moxa.h | ||
| mxser.c | ||
| mxser.h | ||
| n_gsm.c | ||
| n_hdlc.c | ||
| n_r3964.c | ||
| n_tracerouter.c | ||
| n_tracesink.c | ||
| n_tracesink.h | ||
| n_tty.c | ||
| nozomi.c | ||
| pty.c | ||
| rocket_int.h | ||
| rocket.c | ||
| rocket.h | ||
| synclink_gt.c | ||
| synclink.c | ||
| synclinkmp.c | ||
| sysrq.c | ||
| tty_audit.c | ||
| tty_buffer.c | ||
| tty_io.c | ||
| tty_ioctl.c | ||
| tty_ldisc.c | ||
| tty_ldsem.c | ||
| tty_mutex.c | ||
| tty_port.c | ||