svn commit: r256502 - in head/sys: fs/devfs kern sys

[Konstantin Belousov]

Author: kib
Date: Tue Oct 15 06:33:10 2013
New Revision: 256502
URL: http://svnweb.freebsd.org/changeset/base/256502

Log:
  Similar to debug.iosize_max_clamp sysctl, introduce
  devfs_iosize_max_clamp sysctl, which allows/disables SSIZE_MAX-sized
  i/o requests on the devfs files.
  
  Sponsored by:	The FreeBSD Foundation
  Reminded by:	Dmitry Sivachenko <trtrmitya at gmail.com>
  MFC after:	1 week

Modified:
  head/sys/fs/devfs/devfs_vnops.c
  head/sys/kern/sys_generic.c
  head/sys/sys/systm.h

Modified: head/sys/fs/devfs/devfs_vnops.c
==============================================================================
--- head/sys/fs/devfs/devfs_vnops.c	Tue Oct 15 06:28:11 2013	(r256501)
+++ head/sys/fs/devfs/devfs_vnops.c	Tue Oct 15 06:33:10 2013	(r256502)
@@ -1178,6 +1178,8 @@ devfs_read_f(struct file *fp, struct uio
 	struct cdevsw *dsw;
 	struct file *fpop;
 
+	if (uio->uio_resid > DEVFS_IOSIZE_MAX)
+		return (EINVAL);
 	fpop = td->td_fpop;
 	error = devfs_fp_check(fp, &dev, &dsw, &ref);
 	if (error)
@@ -1653,6 +1655,8 @@ devfs_write_f(struct file *fp, struct ui
 	struct cdevsw *dsw;
 	struct file *fpop;
 
+	if (uio->uio_resid > DEVFS_IOSIZE_MAX)
+		return (EINVAL);
 	fpop = td->td_fpop;
 	error = devfs_fp_check(fp, &dev, &dsw, &ref);
 	if (error)

Modified: head/sys/kern/sys_generic.c
==============================================================================
--- head/sys/kern/sys_generic.c	Tue Oct 15 06:28:11 2013	(r256501)
+++ head/sys/kern/sys_generic.c	Tue Oct 15 06:33:10 2013	(r256502)
@@ -78,6 +78,10 @@ __FBSDID("$FreeBSD$");
 int iosize_max_clamp = 1;
 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW,
     &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX");
+int devfs_iosize_max_clamp = 1;
+SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW,
+    &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices");
+
 /*
  * Assert that the return value of read(2) and write(2) syscalls fits
  * into a register.  If not, an architecture will need to provide the

Modified: head/sys/sys/systm.h
==============================================================================
--- head/sys/sys/systm.h	Tue Oct 15 06:28:11 2013	(r256501)
+++ head/sys/sys/systm.h	Tue Oct 15 06:33:10 2013	(r256502)
@@ -146,7 +146,9 @@ extern const void *zero_region;	/* addre
 
 extern int unmapped_buf_allowed;
 extern int iosize_max_clamp;
+extern int devfs_iosize_max_clamp;
 #define	IOSIZE_MAX	(iosize_max_clamp ? INT_MAX : SSIZE_MAX)
+#define	DEVFS_IOSIZE_MAX	(devfs_iosize_max_clamp ? INT_MAX : SSIZE_MAX)
 
 /*
  * General function declarations.