Add some FEATURE macros for various features (AUDIT/CAM/IPC/KTR/MAC/NFS/NTP/

PMC/SYSV/...).

No FreeBSD version bump, the userland application to query the features will
be committed last and can serve as an indication of the availablility if
needed.

Sponsored by:   Google Summer of Code 2010
Submitted by:   kibab
Reviewed by:    arch@ (parts by rwatson, trasz, jhb)
X-MFC after:    to be determined in last commit with code from this project

sys/cam/cam.c

@@ -51,6 +51,9 @@ __FBSDID("$FreeBSD$");
 #include <sys/libkern.h>
 #include <cam/cam_queue.h>
 #include <cam/cam_xpt.h>
+
+FEATURE(scbus, "SCSI devices support");
+
 #endif
 
 static int	camstatusentrycomp(const void *key, const void *member);

sys/fs/nfsclient/nfs_clvfsops.c

@@ -73,6 +73,8 @@ __FBSDID("$FreeBSD$");
 #include <fs/nfsclient/nfs.h>
 #include <fs/nfsclient/nfsdiskless.h>
 
+FEATURE(nfscl, "NFSv4 client");
+
 extern int nfscl_ticks;
 extern struct timeval nfsboottime;
 extern struct nfsstats	newnfsstats;

sys/fs/nfsserver/nfs_nfsdport.c

@@ -46,6 +46,8 @@ __FBSDID("$FreeBSD$");
 #include <nlm/nlm_prot.h>
 #include <nlm/nlm.h>
 
+FEATURE(nfsd, "NFSv4 server");
+
 extern u_int32_t newnfs_true, newnfs_false, newnfs_xdrneg1;
 extern int nfsrv_useacl;
 extern int newnfs_numnfsd;

sys/kern/kern_dtrace.c

@@ -37,10 +37,14 @@ __FBSDID("$FreeBSD$");
 #include <sys/malloc.h>
 #include <sys/proc.h>
 #include <sys/dtrace_bsd.h>
+#include <sys/sysctl.h>
 
 #define KDTRACE_PROC_SIZE	64
 #define	KDTRACE_THREAD_SIZE	256
 
+FEATURE(kdtrace_hooks,
+    "Kernel DTrace hooks which are required to load DTrace kernel modules");
+
 MALLOC_DEFINE(M_KDTRACE, "kdtrace", "DTrace hooks");
 
 /* Return the DTrace process data size compiled in the kernel hooks. */

sys/kern/kern_ktr.c

@@ -80,6 +80,8 @@ __FBSDID("$FreeBSD$");
 #define	KTR_CPU		PCPU_GET(cpuid)
 #endif
 
+FEATURE(ktr, "Kernel support for KTR kernel tracing facility");
+
 SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
 
 int	ktr_cpumask = KTR_CPUMASK;

sys/kern/kern_ktrace.c

@@ -83,6 +83,8 @@ static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
 
 #ifdef KTRACE
 
+FEATURE(ktrace, "Kernel support for system-call tracing");
+
 #ifndef KTRACE_REQUEST_POOL
 #define	KTRACE_REQUEST_POOL	100
 #endif

sys/kern/kern_lock.c

@@ -1299,6 +1299,10 @@ lockstatus(struct lock *lk)
 }
 
 #ifdef INVARIANT_SUPPORT
+
+FEATURE(invariant_support,
+    "Support for modules compiled with INVARIANTS option");
+
 #ifndef INVARIANTS
 #undef	_lockmgr_assert
 #endif

sys/kern/kern_ntptime.c

@@ -51,6 +51,10 @@ __FBSDID("$FreeBSD$");
 #include <sys/syscallsubr.h>
 #include <sys/sysctl.h>
 
+#ifdef PPS_SYNC
+FEATURE(pps_sync, "Support usage of external PPS signal by kernel PLL");
+#endif
+
 /*
  * Single-precision macros for 64-bit machines
  */

sys/kern/kern_pmc.c

@@ -37,8 +37,10 @@ __FBSDID("$FreeBSD$");
 #include <sys/pmc.h>
 #include <sys/pmckern.h>
 #include <sys/smp.h>
+#include <sys/sysctl.h>
 
 #ifdef	HWPMC_HOOKS
+FEATURE(hwpmc_hooks, "Kernel support for HW PMC");
 #define	PMC_KERNEL_VERSION	PMC_VERSION
 #else
 #define	PMC_KERNEL_VERSION	0

sys/kern/kern_prot.c

@@ -69,6 +69,11 @@ __FBSDID("$FreeBSD$");
 #include <sys/syscallsubr.h>
 #include <sys/sysctl.h>
 
+#ifdef REGRESSION
+FEATURE(regression,
+    "Kernel support for interfaces nessesary for regression testing (SECURITY RISK!)");
+#endif
+
 #if defined(INET) || defined(INET6)
 #include <netinet/in.h>
 #include <netinet/in_pcb.h>

sys/kern/ksched.c

@@ -41,12 +41,16 @@ __FBSDID("$FreeBSD$");
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/lock.h>
+#include <sys/sysctl.h>
+#include <sys/kernel.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
 #include <sys/posix4.h>
 #include <sys/resource.h>
 #include <sys/sched.h>
 
+FEATURE(kposix_priority_scheduling, "POSIX P1003.1B realtime extensions");
+
 /* ksched: Real-time extension to support POSIX priority scheduling.
  */
 

sys/kern/subr_mchain.c

@@ -32,6 +32,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#include <sys/sysctl.h>
 #include <sys/endian.h>
 #include <sys/errno.h>
 #include <sys/mbuf.h>
@@ -40,6 +41,8 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/mchain.h>
 
+FEATURE(libmchain, "mchain library");
+
 MODULE_VERSION(libmchain, 1);
 
 #define MBERROR(format, ...) printf("%s(%d): "format, __func__ , \

sys/kern/subr_stack.c

@@ -39,6 +39,9 @@ __FBSDID("$FreeBSD$");
 #include <sys/sbuf.h>
 #include <sys/stack.h>
 #include <sys/systm.h>
+#include <sys/sysctl.h>
+
+FEATURE(stack, "Support for capturing kernel stack");
 
 static MALLOC_DEFINE(M_STACK, "stack", "Stack Traces");
 

sys/kern/sysv_msg.c

@@ -72,6 +72,8 @@ __FBSDID("$FreeBSD$");
 
 #include <security/mac/mac_framework.h>
 
+FEATURE(sysv_msg, "System V message queues support");
+
 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
 
 static int msginit(void);

sys/kern/sysv_sem.c

@@ -62,6 +62,8 @@ __FBSDID("$FreeBSD$");
 
 #include <security/mac/mac_framework.h>
 
+FEATURE(sysv_sem, "System V semaphores support");
+
 static MALLOC_DEFINE(M_SEM, "sem", "SVID compatible semaphores");
 
 #ifdef SEM_DEBUG

sys/kern/sysv_shm.c

@@ -95,6 +95,8 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm_page.h>
 #include <vm/vm_pager.h>
 
+FEATURE(sysv_shm, "System V shared memory segments support");
+
 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
 
 static int shmget_allocate_segment(struct thread *td,

sys/kern/uipc_cow.c

@@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#include <sys/sysctl.h>
 #include <sys/kernel.h>
 #include <sys/proc.h>
 #include <sys/lock.h>
@@ -57,6 +58,7 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm_page.h>
 #include <vm/vm_object.h>
 
+FEATURE(zero_copy_sockets, "Zero copy sockets support");
 
 struct netsend_cow_stats {
 	int attempted;

sys/kern/uipc_mqueue.c

@@ -82,6 +82,8 @@ __FBSDID("$FreeBSD$");
 #include <sys/vnode.h>
 #include <machine/atomic.h>
 
+FEATURE(p1003_1b_mqueue, "POSIX P1003.1B message queues support");
+
 /*
  * Limits and constants
  */

sys/kern/uipc_sem.c

@@ -65,6 +65,7 @@ __FBSDID("$FreeBSD$");
 
 #include <security/mac/mac_framework.h>
 
+FEATURE(p1003_1b_semaphores, "POSIX1003.1B semaphores support");
 /*
  * TODO
  *

sys/nfsclient/nfs_vfsops.c

@@ -78,6 +78,8 @@ __FBSDID("$FreeBSD$");
 #include <nfsclient/nfsm_subs.h>
 #include <nfsclient/nfsdiskless.h>
 
+FEATURE(nfsclient, "NFS client");
+
 MALLOC_DEFINE(M_NFSREQ, "nfsclient_req", "NFS request header");
 MALLOC_DEFINE(M_NFSBIGFH, "nfsclient_bigfh", "NFS version 3 file handle");
 MALLOC_DEFINE(M_NFSDIROFF, "nfsclient_diroff", "NFS directory offset data");

sys/nfsserver/nfs_serv.c

@@ -97,6 +97,8 @@ __FBSDID("$FreeBSD$");
 #include <nfs/xdr_subs.h>
 #include <nfsserver/nfsm_subs.h>
 
+FEATURE(nfsserver, "NFS server");
+
 #ifdef NFSRV_DEBUG
 #define nfsdbprintf(info)	printf info
 #else

sys/security/audit/audit.c

@@ -72,6 +72,8 @@ __FBSDID("$FreeBSD$");
 
 #include <vm/uma.h>
 
+FEATURE(audit, "BSM audit support");
+
 static uma_zone_t	audit_record_zone;
 static MALLOC_DEFINE(M_AUDITCRED, "audit_cred", "Audit cred storage");
 MALLOC_DEFINE(M_AUDITDATA, "audit_data", "Audit data storage");

sys/security/mac/mac_syscalls.c

@@ -56,6 +56,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/mac.h>
 #include <sys/proc.h>
 #include <sys/systm.h>
+#include <sys/sysctl.h>
 #include <sys/sysproto.h>
 #include <sys/sysent.h>
 #include <sys/vnode.h>
@@ -72,6 +73,8 @@ __FBSDID("$FreeBSD$");
 
 #ifdef MAC
 
+FEATURE(mac, "Mandatory Access Control Framework support");
+
 int
 __mac_get_pid(struct thread *td, struct __mac_get_pid_args *uap)
 {