Re: [discuss] Re: unregister_ioctl32_conversion and modules. ioct l32 revisited.

[Michael S. Tsirkin]

Hello!
Quoting r. Arnd Bergmann (arnd@xxxxxxxx) "Re: [discuss] Re: unregister_ioctl32_conversion and modules. ioct l32 revisited.":
> On Sünndag 26 Dezember 2004 23:26, Chris Wedgwood wrote:
> > > It's an internal error code as Arnd pointed out.
> > 
> > can we be sure this will never escape to userspace? i can think of
> > somewhere else we already do this (EFSCORRUPTED) and it does (somewhat
> > deliberately escape to userspace) and this causes confusion from time
> > to time when applications see 'errno == 990'
> 
> It's safe for the compat ioctl case. If someone wants to use the
> same function for the compat and native handler, it would be a bug
> to return -ENOIOCTLCMD from that handler with the current code.
> 
> To work around this, we could either convert -ENOIOCTLCMD to -EINVAL
> when returning from sys_ioctl(). Or we could WARN_ON(err ==
> -ENOIOCTLCMD)
> for the native path in order to make the intention clear.
> 
>  Arnd <><

You mean like this?

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxxxxxx>
--- linux-2.6.10/fs/ioctl.c.ok  2005-01-05 21:13:46.165718632 +0200
+++ linux-2.6.10/fs/ioctl.c     2005-01-05 21:14:09.341195424 +0200
@@ -162,7 +162,7 @@ asmlinkage long sys_ioctl(unsigned int f
 out:
        fput_light(filp, fput_needed);
 out2:
-       return error;
+       return error==-ENOIOCTLCMD?-ENOTTY:error;
 }

 /*
--- linux-2.6.10/fs/compat.c.ok 2005-01-05 21:15:34.221291688 +0200
+++ linux-2.6.10/fs/compat.c    2005-01-05 21:16:04.922624376 +0200
@@ -476,7 +476,7 @@ asmlinkage long compat_sys_ioctl(unsigne
 out:
        fput_light(filp, fput_needed);
 out2:
-       return error;
+       return error==-ENOIOCTLCMD?-ENOTTY:error;
 }

 static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
-
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