git: kernel - Fix panic when X11 intercepts console (II)

Matthew Dillon dillon at
Sun Sep 5 11:19:11 PDT 2010

commit 28d7e704b1a949e1b01af023e51b33e2f87ce626
Author: Matthew Dillon <dillon at>
Date:   Sun Sep 5 11:14:49 2010 -0700

    kernel - Fix panic when X11 intercepts console (II)
    * There is a secondary issue when the console is runs through a pty or
      other device and kqueue is used, the tty_token is not enough.
    * Rewrite kputchar() and shift all constty intercepts over to their own
      kernel thread.  kputchar() will write to the dmesg buffer and will call
      cnputc() to write to the real console, and (for tprintf()) it will
      output a specified tty.  But it will no longer attempt to write to
      the console tty via the kprintf() path.
      Instead kputchar() simply wakes up the monitoring kernel thread and
      the monitoring kernel thread tracks and copies the dmesg buffer to
      the constty.
    * This completely fixes the constty intercept issue.  'xconsole' now works
      perfectly.  Nothing can go wrong.  Go wrong.  Go wrong.

Summary of changes:
 sys/kern/subr_prf.c |  114 +++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 93 insertions(+), 21 deletions(-)

DragonFly BSD source repository

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