# TCSBRK implementation for linux compat



## willyvmm (Oct 25, 2012)

Hi.

I needed suport for this feature in FreeBSD linux emulation, because I have to use precompiled linux library/binary that uses it. There was a lot of errors in logs like:


```
... ioctl fd=52, cmd=0x5409 ('T',9) is not implemented
```

I could not find any help so I had to do that by myself 

I found implementation in NetBSD sources, and just 'translated' it to the FreeBSD :e

There is my work:


```
--- linux_ioctl.orig    2012-08-06 01:54:33.000000000 +0200
+++ linux_ioctl.c       2012-10-25 13:59:12.000000000 +0200
@@ -778,8 +778,26 @@
                    td));
                break;

-       /* LINUX_TCSBRK */
-
+       case LINUX_TCSBRK:
+               if (args->arg)
+                   {
+                       args->cmd = TIOCDRAIN;
+                       error = (sys_ioctl(td, (struct ioctl_args *)args));
+                       break;
+                   }
+               else
+                   {
+                       if ((error = fo_ioctl(fp, TIOCSBRK, NULL, td->td_ucred,td)) != 0)
+                           break;
+                       error = tsleep(&args->arg, PZERO | PCATCH, "linux_tcsbrk", hz / 4);
+                       if (error == EINTR || error == ERESTART) {
+                           fo_ioctl(fp, TIOCCBRK, NULL, td->td_ucred, td);
+                           error = EINTR;
+                       } else
+                           error = fo_ioctl (fp, TIOCCBRK, NULL, td->td_ucred, td);
+                       break;
+                   }
+
        case LINUX_TCXONC: {
                switch (args->arg) {
                case LINUX_TCOOFF:
```

Could someone have a look at this if the code is correct?
Sorry but I do not have kernel developing experience and this is my first patch :stud
I'm testing this patch for over 12 hours now and it seems to work well. No errors, load average dropped from 2.5 to 0.5 
And sorry for my bad english...


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## SirDice (Oct 25, 2012)

I suggest emailing the freebsd-emulation@ mailing list. There aren't a lot of developers on this board.


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