From ddda35b8f6e8e19330a383f856c0775c092b3cbc Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Mon, 2 Apr 2007 13:53:26 +0000
Subject: [PATCH] - Split out the part of SYSCALL_MODULE_HELPER() that builds a
 'struct   sysent' for a new system call into a new MAKE_SYSENT() macro. - Use
 MAKE_SYSENT() to build a full sysent for the nfssvc system call in   the NFS
 server and use syscall_register() and syscall_deregister() to   manage the
 nfssvc system call entry instead of manually frobbing the   sysent[] array.

---
 sys/nfsserver/nfs_srvsubs.c | 21 ++++++++++++---------
 sys/sys/sysent.h            | 15 +++++++++------
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/sys/nfsserver/nfs_srvsubs.c b/sys/nfsserver/nfs_srvsubs.c
index b064fb32e633..374bf267718a 100644
--- a/sys/nfsserver/nfs_srvsubs.c
+++ b/sys/nfsserver/nfs_srvsubs.c
@@ -98,8 +98,9 @@ int nfssvc_sockhead_flag;
 struct nfsd_head nfsd_head;
 int nfsd_head_flag;
 
-static int nfs_prev_nfssvc_sy_narg;
-static sy_call_t *nfs_prev_nfssvc_sy_call;
+static int nfssvc_offset = SYS_nfssvc;
+static struct sysent nfssvc_prev_sysent;
+MAKE_SYSENT(nfssvc);
 
 struct mtx nfsd_mtx;
 
@@ -522,6 +523,7 @@ static const short *nfsrv_v3errmap[] = {
 static int
 nfsrv_modevent(module_t mod, int type, void *data)
 {
+	static int registered;
 	int error = 0;
 
 	NET_LOCK_GIANT();
@@ -554,11 +556,11 @@ nfsrv_modevent(module_t mod, int type, void *data)
 		NFSD_UNLOCK();
 		nfsrv_timer(0);
 
-		/* XXX: Should use SYSCALL_MODULE() */
-		nfs_prev_nfssvc_sy_narg = sysent[SYS_nfssvc].sy_narg;
-		sysent[SYS_nfssvc].sy_narg = 2;
-		nfs_prev_nfssvc_sy_call = sysent[SYS_nfssvc].sy_call;
-		sysent[SYS_nfssvc].sy_call = (sy_call_t *)nfssvc;
+		error = syscall_register(&nfssvc_offset, &nfssvc_sysent,
+		    &nfssvc_prev_sysent);
+		if (error)
+			break;
+		registered = 1;
 		break;
 
 	case MOD_UNLOAD:
@@ -567,9 +569,10 @@ nfsrv_modevent(module_t mod, int type, void *data)
 			break;
 		}
 
+		if (registered)
+			syscall_deregister(&nfssvc_offset, &nfssvc_prev_sysent);
 		callout_drain(&nfsrv_callout);
-		sysent[SYS_nfssvc].sy_narg = nfs_prev_nfssvc_sy_narg;
-		sysent[SYS_nfssvc].sy_call = nfs_prev_nfssvc_sy_call;
+		nfsrv_destroycache();	/* Free the server request cache */
 		nfsrv_destroycache();	/* Free the server request cache */
 		mtx_destroy(&nfsd_mtx);
 		break;
diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h
index e631f04d7a0f..edf171722b2f 100644
--- a/sys/sys/sysent.h
+++ b/sys/sys/sysent.h
@@ -119,6 +119,14 @@ struct syscall_module_data {
        struct  sysent old_sysent; /* old sysent */
 };
 
+#define MAKE_SYSENT(syscallname)                        \
+static struct sysent syscallname##_sysent = {           \
+    (sizeof(struct syscallname ## _args )               \
+     / sizeof(register_t)),                             \
+    (sy_call_t *)& syscallname,                         \
+    SYS_AUE_##syscallname                               \
+}
+	
 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg)     \
 static struct syscall_module_data name##_syscall_mod = {       \
        evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL }     \
@@ -133,12 +141,7 @@ DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE)
 
 #define SYSCALL_MODULE_HELPER(syscallname)              \
 static int syscallname##_syscall = SYS_##syscallname;   \
-static struct sysent syscallname##_sysent = {           \
-    (sizeof(struct syscallname ## _args )               \
-     / sizeof(register_t)),                             \
-    (sy_call_t *)& syscallname,                         \
-    SYS_AUE_##syscallname                               \
-};                                                      \
+MAKE_SYSENT(syscallname);                               \
 SYSCALL_MODULE(syscallname,                             \
     & syscallname##_syscall, & syscallname##_sysent,    \
     NULL, NULL);