Date: Fri, 22 May 2009 00:48:25 +1000 (EST) From: Emil Mikulic <emikulic@gmail.com> To: FreeBSD-gnats-submit@FreeBSD.org Subject: amd64/134786: [patch] vfs.bufspace sysctl wideness on amd64 Message-ID: <20090521144825.5E65F5C40@ppp154-240.static.internode.on.net> Resent-Message-ID: <200905211450.n4LEo4P6065698@freefall.freebsd.org>
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>Number: 134786
>Category: amd64
>Synopsis: [patch] vfs.bufspace sysctl wideness on amd64
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-amd64
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Thu May 21 14:50:04 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator: Emil Mikulic
>Release: FreeBSD 8-CURRENT
>Organization:
>Environment:
>Description:
On amd64, providing a 64-bit buffer to get the vfs.bufspace sysctl will
return a 64-bit (long) quantity, but providing a *larger* buffer will
only yield a 32-bit (int) quantity.
>How-To-Repeat:
len = 8;
sysctlbyname("vfs.bufspace", &buf, &len, NULL, 0);
/* len is still 8 */
len = 10;
sysctlbyname("vfs.bufspace", &buf, &len, NULL, 0);
/* len is 4! */
>Fix:
--- sys/kern/vfs_bio.c 2009-04-17 10:01:39.000000000 +0000
+++ sys/kern/vfs_bio.c.2 2009-05-09 09:27:16.000000000 +0000
@@ -288,15 +288,15 @@
defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
static int
sysctl_bufspace(SYSCTL_HANDLER_ARGS)
{
long lvalue;
int ivalue;
- if (sizeof(int) == sizeof(long) || req->oldlen == sizeof(long))
+ if (sizeof(int) == sizeof(long) || req->oldlen >= sizeof(long))
return (sysctl_handle_long(oidp, arg1, arg2, req));
lvalue = *(long *)arg1;
if (lvalue > INT_MAX)
/* On overflow, still write out a long to trigger ENOMEM. */
return (sysctl_handle_long(oidp, &lvalue, 0, req));
ivalue = lvalue;
return (sysctl_handle_int(oidp, &ivalue, 0, req));
>Release-Note:
>Audit-Trail:
>Unformatted:
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