Re: [PATCH resend] define convenient securebits masks for prctl users

Quoting Stephen Rothwell (sfr@canb.auug.org.au):

Hi Serge,

On Wed, 28 Oct 2009 09:02:36 -0500 "Serge E. Hallyn" [off-list ref] wrote:

quoted

[ Are there any objections to exporting securebits.h?  If not,
can this patch be pushed to linux-next? ]

I am not sure which tree this belongs in?  Maybe security-testing (James
cc'd)?

I don't know why that didn't occur to me!  Thanks, I'll pursue
that :)

quoted

diff --git a/include/linux/securebits.h b/include/linux/securebits.h
index d2c5ed8..9ad109e 100644
--- a/include/linux/securebits.h
+++ b/include/linux/securebits.h

@@ -1,6 +1,13 @@
 #ifndef _LINUX_SECUREBITS_H
 #define _LINUX_SECUREBITS_H 1
 
+/* Each securesetting is implemented using two bits. One bit specifies
+   whether the setting is on or off. The other bit specify whether the
+   setting is locked or not. A setting which is locked cannot be
+   changed from user-level. */
+#define issecure_mask(X)	(1 << (X))
+#define issecure(X)		(issecure_mask(X) & current_cred_xxx(securebits))

You want this second define protected by ifdef __KERNEL__ ...

True, userspace doesn't need to see those.  Will sanitize and resend.

thanks,
-serge