Messages in this thread | | | Date | Thu, 17 Jun 2010 16:43:01 -0700 | From | Howard Chu <> | Subject | Re: [PATCH] tty: Add EXTPROC support for LINEMODE |
| |
Howard Chu wrote: > Alan Cox wrote: >>>>> For Alpha this value should match OSF if possible. >>> >>> OSF didn't define this flag, nor did it assign that particular bit to any >>> purpose. Is that good enough? >> >> Fine >> >>>> Are you suggesting that this is completely unfixable/unworkable? Would it be >>>> sufficient to use kernel_termios_to_user_termios() ? >> >> I don't see a way to fix it sanely >> >>>> >>> Actually using kernel_termios_to_user_termios_1(). In all supported >>> architectures this structure is basically aligned with but smaller than the >>> userland struct termios. >> >> The relationship isn't quite so simple and it may change in the future, >> so this seems to be a very bad idea. Besides which syscalls are *cheap* >> so simply notifying someone to reread the terminal data they care about >> should be fine. In that sense it seems SVR4 got it right.
> OK. I'm fine with only setting a bit in the packet header, and letting the > application do an ioctl/tcgetattr to discover the actual state.
Just deleting that part of the patch was simple enough. The TIOCPKT_IOCTL bit still gets set in the packet header byte; userspace apps will just have to do an ioctl to retrieve the state when the bit is set.
I've also added locking to the pty_signal() function. The check for tty->link seems a bit paranoid, but a few other functions do it as well.
/* Send a signal to the slave */ static int pty_signal(struct tty_struct *tty, int sig) { unsigned long flags; struct pid *pgrp;
if (tty->link) { spin_lock_irqsave(&tty->link->ctrl_lock, flags); pgrp = get_pid(tty->link->pgrp); spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
kill_pgrp(pgrp, sig, 1); put_pid(pgrp); } return 0; }
That covers all the feedback so far. I'll be reposting the entire patch again shortly, unless you have any additional thoughts.
-- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/
| |