svn commit: r297493 - in head/sys: kern sys

[John Baldwin]

Author: jhb
Date: Fri Apr  1 18:29:38 2016
New Revision: 297493
URL: https://svnweb.freebsd.org/changeset/base/297493

Log:
  Cap IOSIZE_MAX to INT_MAX for 32-bit processes.
  
  Previously, freebsd32 binaries could submit read/write requests with lengths
  greater than INT_MAX that a native kernel would have rejected.
  
  Reviewed by:	kib
  Sponsored by:	Chelsio Communications
  Differential Revision:	https://reviews.freebsd.org/D5788

Modified:
  head/sys/kern/sys_generic.c
  head/sys/sys/systm.h

Modified: head/sys/kern/sys_generic.c
==============================================================================
--- head/sys/kern/sys_generic.c	Fri Apr  1 17:28:55 2016	(r297492)
+++ head/sys/kern/sys_generic.c	Fri Apr  1 18:29:38 2016	(r297493)
@@ -89,12 +89,14 @@ __FBSDID("$FreeBSD$");
 #define	SYS_IOCTL_SMALL_SIZE	128	/* bytes */
 #define	SYS_IOCTL_SMALL_ALIGN	8	/* bytes */
 
-int iosize_max_clamp = 0;
+#ifdef __LP64__
+static int iosize_max_clamp = 0;
 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;
+static 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");
+#endif
 
 /*
  * Assert that the return value of read(2) and write(2) syscalls fits
@@ -159,6 +161,24 @@ struct selfd {
 static uma_zone_t selfd_zone;
 static struct mtx_pool *mtxpool_select;
 
+#ifdef __LP64__
+size_t
+devfs_iosize_max(void)
+{
+
+	return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ?
+	    INT_MAX : SSIZE_MAX);
+}
+
+size_t
+iosize_max(void)
+{
+
+	return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ?
+	    INT_MAX : SSIZE_MAX);
+}
+#endif
+
 #ifndef _SYS_SYSPROTO_H_
 struct read_args {
 	int	fd;

Modified: head/sys/sys/systm.h
==============================================================================
--- head/sys/sys/systm.h	Fri Apr  1 17:28:55 2016	(r297492)
+++ head/sys/sys/systm.h	Fri Apr  1 18:29:38 2016	(r297493)
@@ -148,10 +148,14 @@ extern char **kenvp;
 extern const void *zero_region;	/* address space maps to a zeroed page	*/
 
 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)
+
+#ifdef __LP64__
+#define	IOSIZE_MAX		iosize_max()
+#define	DEVFS_IOSIZE_MAX	devfs_iosize_max()
+#else
+#define	IOSIZE_MAX		SSIZE_MAX
+#define	DEVFS_IOSIZE_MAX	SSIZE_MAX
+#endif
 
 /*
  * General function declarations.
@@ -403,6 +407,11 @@ struct cdev;
 dev_t dev2udev(struct cdev *x);
 const char *devtoname(struct cdev *cdev);
 
+#ifdef __LP64__
+size_t	devfs_iosize_max(void);
+size_t	iosize_max(void);
+#endif
+
 int poll_no_poll(int events);
 
 /* XXX: Should be void nanodelay(u_int nsec); */