Module Name: src
Committed By: christos
Date: Fri Oct 17 20:49:22 UTC 2014
Modified Files:
src/sys/miscfs/procfs: procfs_map.c
Log Message:
Maps don't change that frequently between reads, so don't give up and
do what linux does (support reading from an offset).
To generate a diff of this commit:
cvs rdiff -u -r1.44 -r1.45 src/sys/miscfs/procfs/procfs_map.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/miscfs/procfs/procfs_map.c
diff -u src/sys/miscfs/procfs/procfs_map.c:1.44 src/sys/miscfs/procfs/procfs_map.c:1.45
--- src/sys/miscfs/procfs/procfs_map.c:1.44 Tue Mar 18 14:20:43 2014
+++ src/sys/miscfs/procfs/procfs_map.c Fri Oct 17 16:49:22 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: procfs_map.c,v 1.44 2014/03/18 18:20:43 riastradh Exp $ */
+/* $NetBSD: procfs_map.c,v 1.45 2014/10/17 20:49:22 christos Exp $ */
/*
* Copyright (c) 1993
@@ -76,7 +76,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: procfs_map.c,v 1.44 2014/03/18 18:20:43 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: procfs_map.c,v 1.45 2014/10/17 20:49:22 christos Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -126,15 +126,6 @@ procfs_domap(struct lwp *curl, struct pr
if (uio->uio_rw != UIO_READ)
return EOPNOTSUPP;
- if (uio->uio_offset != 0) {
- /*
- * we return 0 here, so that the second read returns EOF
- * we don't support reading from an offset because the
- * map could have changed between the two reads.
- */
- return 0;
- }
-
error = 0;
if (linuxmode != 0)
@@ -220,7 +211,16 @@ again:
vm_map_unlock_read(map);
uvmspace_free(vm);
- error = uiomove(buffer, pos, uio);
+ /*
+ * We support reading from an offset, because linux does.
+ * The map could have changed between the two reads, and
+ * that could result in junk, but typically it does not.
+ */
+ if (uio->uio_offset < pos)
+ error = uiomove(buffer + uio->uio_offset,
+ pos - uio->uio_offset, uio);
+ else
+ error = 0;
out:
if (path != NULL)
free(path, M_TEMP);
