firefox & flash9 patches - linprocfs patch for 6.x

[Juergen Lock]

On Wed, Oct 01, 2008 at 06:52:37PM +0200, Tijl Coosemans wrote:
> On Monday 29 September 2008 22:02:37 Chagin Dmitry wrote:
> > please, test following patches (just -current).
> > with them firefox && flash9 forks for me,
> > I tested only on ia32 at amd64 with 2.6.16 enabled,
> > firefox 2.0.0.16 and flash9 plugin.
> > 
> > If all is good, I will ask des@ and kib@ to review&commit them. thnx!
> 
> On 7.1-PRERELEASE, linux 2.4, fc4, the linprocfs patch seems to improve
> things a lot. I'm still having crashes from time to time, but overall
> flash9 works much better. Great work!
> 
> I've attached the patch for RELENG_7 (patch-linprocfs) and another
> patch for libflashsupport [1]. It should improve OSS support, A/V sync
> etc. For those without a linux box, I've attached a compiled version of
> the lib as well. You can drop it in /compat/linux/usr/lib.
> 
> [1] http://sourceforge.net/projects/flashsupport/

I still have one box on 6.3, so today I tried the updated RELENG_7
linprocfs_doprocmaps() and libflashsupport there (using linux-base-fc4),
and got youtube working on there as well.  I'll append the patch, which
should also apply on RELENG_6 and _6_4, tho with offset. (also at
	http://people.freebsd.org/~nox/linprocfs-6.3.patch
)

 Thanx again,
	Juergen

Index: linprocfs.c
@@ -934,48 +934,47 @@ linprocfs_doprocenviron(PFS_FILL_ARGS)
 static int
 linprocfs_doprocmaps(PFS_FILL_ARGS)
 {
-	char mebuffer[512];
 	vm_map_t map = &p->p_vmspace->vm_map;
-	vm_map_entry_t entry;
+	vm_map_entry_t entry, tmp_entry;
 	vm_object_t obj, tobj, lobj;
+	vm_offset_t saved_end;
 	vm_ooffset_t off = 0;
 	char *name = "", *freename = NULL;
-	size_t len;
 	ino_t ino;
+	unsigned int last_timestamp;
 	int ref_count, shadow_count, flags;
 	int error;
 	struct vnode *vp;
 	struct vattr vat;
 	int locked;
-	
+
 	PROC_LOCK(p);
 	error = p_candebug(td, p);
 	PROC_UNLOCK(p);
 	if (error)
 		return (error);
-	
+
 	if (uio->uio_rw != UIO_READ)
 		return (EOPNOTSUPP);
-	
-	if (uio->uio_offset != 0)
-		return (0);
-	
+
 	error = 0;
-	if (map != &curthread->td_proc->p_vmspace->vm_map)
-		vm_map_lock_read(map);
-        for (entry = map->header.next;
-	    ((uio->uio_resid > 0) && (entry != &map->header));
+	vm_map_lock_read(map);
+	for (entry = map->header.next; entry != &map->header;
 	    entry = entry->next) {
 		name = "";
 		freename = NULL;
 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
 			continue;
+		saved_end = entry->end;
 		obj = entry->object.vm_object;
-		for (lobj = tobj = obj; tobj; tobj = tobj->backing_object)
+		for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
+			VM_OBJECT_LOCK(tobj);
+			if (lobj != obj)
+				VM_OBJECT_UNLOCK(lobj);
 			lobj = tobj;
+		}
 		ino = 0;
 		if (lobj) {
-			VM_OBJECT_LOCK(lobj);
 			off = IDX_TO_OFF(lobj->size);
 			if (lobj->type == OBJT_VNODE) {
 				vp = lobj->handle;
@@ -984,10 +983,12 @@ linprocfs_doprocmaps(PFS_FILL_ARGS)
 			}
 			else
 				vp = NULL;
+			if (lobj != obj)
+				VM_OBJECT_UNLOCK(lobj);
 			flags = obj->flags;
 			ref_count = obj->ref_count;
 			shadow_count = obj->shadow_count;
-			VM_OBJECT_UNLOCK(lobj);
+			VM_OBJECT_UNLOCK(obj);
 			if (vp) {
 				vn_fullpath(td, vp, &name, &freename);
 				locked = VFS_LOCK_GIANT(vp->v_mount);
@@ -1007,7 +1008,7 @@ linprocfs_doprocmaps(PFS_FILL_ARGS)
 		 * format:
 		 *  start, end, access, offset, major, minor, inode, name.
 		 */
-		snprintf(mebuffer, sizeof mebuffer,
+		error = sbuf_printf(sb,
 		    "%08lx-%08lx %s%s%s%s %08lx %02x:%02x %lu%s%s\n",
 		    (u_long)entry->start, (u_long)entry->end,
 		    (entry->protection & VM_PROT_READ)?"r":"-",
@@ -1023,19 +1024,23 @@ linprocfs_doprocmaps(PFS_FILL_ARGS)
 		    );
 		if (freename)
 			free(freename, M_TEMP);
-		len = strlen(mebuffer);
-		if (len > uio->uio_resid)
-			len = uio->uio_resid; /*
-					       * XXX We should probably return
-					       * EFBIG here, as in procfs.
-					       */
-		error = uiomove(mebuffer, len, uio);
-		if (error)
-			break;
-	}
-	if (map != &curthread->td_proc->p_vmspace->vm_map)
+		last_timestamp = map->timestamp;
 		vm_map_unlock_read(map);
-	
+		if (error == -1)
+			return (0);
+		vm_map_lock_read(map);
+		if (last_timestamp + 1 != map->timestamp) {
+			/*
+			 * Look again for the entry because the map was
+			 * modified while it was unlocked.  Specifically,
+			 * the entry may have been clipped, merged, or deleted.
+			 */
+			vm_map_lookup_entry(map, saved_end - 1, &tmp_entry);
+			entry = tmp_entry;
+		}
+	}
+	vm_map_unlock_read(map);
+
 	return (error);
 }