ELF uses more than 5 vmcmds by default, so grow the default vmcmd set size

to 8.

At the same time it seemed like a good idea to avoid to always malloc a
new vmcmd array, so put the default sized array into struct exec_vmcmd_set.

We might want to make a linked list of vmcmd arrays or exec_vmcmd_sets instead
of reallocating them some time in the future, but right now this seems like a
waste of time.

3 files changed, 33 insertions, 28 deletions

diff --git a/sys/kern/exec_subr.c b/sys/kern/exec_subr.c
index 36b2f4b13ea..cb731604d12 100644
--- a/sys/kern/exec_subr.c
+++ b/sys/kern/exec_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: exec_subr.c,v 1.9 2000/11/06 16:19:52 art Exp $	*/
+/*	$OpenBSD: exec_subr.c,v 1.10 2001/02/22 16:08:01 art Exp $	*/
 /*	$NetBSD: exec_subr.c,v 1.9 1994/12/04 03:10:42 mycroft Exp $	*/
 
 /*
@@ -94,18 +94,17 @@ vmcmdset_extend(evsp)
 		panic("vmcmdset_extend: not necessary");
 #endif
 
-	/* figure out number of entries in new set */
 	ocnt = evsp->evs_cnt;
-	evsp->evs_cnt += ocnt ? ocnt : EXEC_DEFAULT_VMCMD_SETSIZE;
+	KASSERT(ocnt > 0);
+	/* figure out number of entries in new set */
+	evsp->evs_cnt += ocnt;
 
-	/* allocate it */
+	/* reallocate the command set */
 	nvcp = malloc(evsp->evs_cnt * sizeof(struct exec_vmcmd), M_EXEC,
 		      M_WAITOK);
-	/* free the old struct, if there was one, and record the new one */
-	if (ocnt) {
-		bcopy(evsp->evs_cmds, nvcp, (ocnt * sizeof(struct exec_vmcmd)));
+	bcopy(evsp->evs_cmds, nvcp, (ocnt * sizeof(struct exec_vmcmd)));
+	if (evsp->evs_cmds != evsp->evs_start)
 		free(evsp->evs_cmds, M_EXEC);
-	}
 	evsp->evs_cmds = nvcp;
 }
 
@@ -116,16 +115,20 @@ kill_vmcmds(evsp)
 	struct exec_vmcmd *vcp;
 	int i;
 
-	if (evsp->evs_cnt == 0)
-		return;
-
 	for (i = 0; i < evsp->evs_used; i++) {
 		vcp = &evsp->evs_cmds[i];
 		if (vcp->ev_vp != NULLVP)
 			vrele(vcp->ev_vp);
 	}
-	evsp->evs_used = evsp->evs_cnt = 0;
-	free(evsp->evs_cmds, M_EXEC);
+
+	/*
+	 * Free old vmcmds and restet the array.
+	 */
+	evsp->evs_used = 0;
+	if (evsp->evs_cmds != evsp->evs_start)
+		free(evsp->evs_cmds, M_EXEC);
+	evsp->evs_cmds = evsp->evs_start;
+	evsp->evs_cnt = EXEC_DEFAULT_VMCMD_SETSIZE;
 }
 
 /*
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 71c068a9348..3344e664d33 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exec.c,v 1.46 2000/11/16 20:02:16 provos Exp $	*/
+/*	$OpenBSD: kern_exec.c,v 1.47 2001/02/22 16:08:01 art Exp $	*/
 /*	$NetBSD: kern_exec.c,v 1.75 1996/02/09 18:59:28 christos Exp $	*/
 
 /*-
@@ -269,7 +269,8 @@ sys_execve(p, v, retval)
 	pack.ep_hdrvalid = 0;
 	pack.ep_ndp = &nid;
 	pack.ep_emul_arg = NULL;
-	pack.ep_vmcmds.evs_cnt = 0;
+	pack.ep_vmcmds.evs_cnt = EXEC_DEFAULT_VMCMD_SETSIZE;
+	pack.ep_vmcmds.evs_cmds = pack.ep_vmcmds.evs_start;
 	pack.ep_vmcmds.evs_used = 0;
 	pack.ep_vap = &attr;
 	pack.ep_emul = &emul_native;
diff --git a/sys/sys/exec.h b/sys/sys/exec.h
index e2dfda8fcab..a95060bfe41 100644
--- a/sys/sys/exec.h
+++ b/sys/sys/exec.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: exec.h,v 1.8 1999/11/05 01:18:01 mickey Exp $	*/
+/*	$OpenBSD: exec.h,v 1.9 2001/02/22 16:08:01 art Exp $	*/
 /*	$NetBSD: exec.h,v 1.59 1996/02/09 18:25:09 christos Exp $	*/
 
 /*-
@@ -116,15 +116,26 @@ struct execsw {
 	exec_makecmds_fcn es_check;	/* function to check exec format */
 };
 
+struct exec_vmcmd {
+	int	(*ev_proc) __P((struct proc *p, struct exec_vmcmd *cmd));
+				/* procedure to run for region of vmspace */
+	u_long	ev_len;		/* length of the segment to map */
+	u_long	ev_addr;	/* address in the vmspace to place it at */
+	struct	vnode *ev_vp;	/* vnode pointer for the file w/the data */
+	u_long	ev_offset;	/* offset in the file for the data */
+	u_int	ev_prot;	/* protections for segment */
+};
+
+#define	EXEC_DEFAULT_VMCMD_SETSIZE	8	/* # of cmds in set to start */
+
 /* exec vmspace-creation command set; see below */
 struct exec_vmcmd_set {
 	u_int	evs_cnt;
 	u_int	evs_used;
 	struct	exec_vmcmd *evs_cmds;
+	struct	exec_vmcmd evs_start[EXEC_DEFAULT_VMCMD_SETSIZE];
 };
 
-#define	EXEC_DEFAULT_VMCMD_SETSIZE	5	/* # of cmds in set to start */
-
 struct exec_package {
 	char	*ep_name;		/* file's name */
 	void	*ep_hdr;		/* file's exec header */
@@ -157,16 +168,6 @@ struct exec_package {
 #define	EXEC_SKIPARG	0x0008		/* don't copy user-supplied argv[0] */
 #define	EXEC_DESTR	0x0010		/* destructive ops performed */
 
-struct exec_vmcmd {
-	int	(*ev_proc) __P((struct proc *p, struct exec_vmcmd *cmd));
-				/* procedure to run for region of vmspace */
-	u_long	ev_len;		/* length of the segment to map */
-	u_long	ev_addr;	/* address in the vmspace to place it at */
-	struct	vnode *ev_vp;	/* vnode pointer for the file w/the data */
-	u_long	ev_offset;	/* offset in the file for the data */
-	u_int	ev_prot;	/* protections for segment */
-};
-
 #ifdef _KERNEL
 /*
  * funtions used either by execve() or the various cpu-dependent execve()