Author: kib
Date: Sat Dec 29 15:55:44 2018
New Revision: 342595
URL: https://svnweb.freebsd.org/changeset/base/342595
Log:
For hw.{physmem,realmem,usermem} MIBs, clamp instead truncating.
If the memory size does not fit into u_long, current code truncates
the returned value and returns complete nonsense. Make the result
slightly more useful by clamping it at ULONG_MAX.
Reported and tested : pho
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Modified:
head/sys/kern/kern_mib.c
Modified: head/sys/kern/kern_mib.c
==============================================================================
--- head/sys/kern/kern_mib.c Sat Dec 29 15:49:03 2018 (r342594)
+++ head/sys/kern/kern_mib.c Sat Dec 29 15:55:44 2018 (r342595)
@@ -46,6 +46,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/jail.h>
#include <sys/kernel.h>
+#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
@@ -177,35 +178,45 @@ SYSCTL_PROC(_kern, KERN_ARND, arandom,
static int
sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
{
- u_long val;
+ u_long val, p;
- val = ctob(physmem);
+ p = SIZE_T_MAX >> PAGE_SHIFT;
+ if (physmem < p)
+ p = physmem;
+ val = ctob(p);
return (sysctl_handle_long(oidp, &val, 0, req));
}
-
SYSCTL_PROC(_hw, HW_PHYSMEM, physmem, CTLTYPE_ULONG | CTLFLAG_RD,
- 0, 0, sysctl_hw_physmem, "LU", "");
+ 0, 0, sysctl_hw_physmem, "LU", "");
static int
sysctl_hw_realmem(SYSCTL_HANDLER_ARGS)
{
- u_long val;
- val = ctob(realmem);
+ u_long val, p;
+
+ p = SIZE_T_MAX >> PAGE_SHIFT;
+ if (realmem < p)
+ p = realmem;
+ val = ctob(p);
return (sysctl_handle_long(oidp, &val, 0, req));
}
SYSCTL_PROC(_hw, HW_REALMEM, realmem, CTLTYPE_ULONG | CTLFLAG_RD,
- 0, 0, sysctl_hw_realmem, "LU", "");
+ 0, 0, sysctl_hw_realmem, "LU", "");
+
static int
sysctl_hw_usermem(SYSCTL_HANDLER_ARGS)
{
- u_long val;
+ u_long val, p, p1;
- val = ctob(physmem - vm_wire_count());
+ p1 = physmem - vm_wire_count();
+ p = SIZE_T_MAX >> PAGE_SHIFT;
+ if (p1 < p)
+ p = p1;
+ val = ctob(p);
return (sysctl_handle_long(oidp, &val, 0, req));
}
-
SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_ULONG | CTLFLAG_RD,
- 0, 0, sysctl_hw_usermem, "LU", "");
+ 0, 0, sysctl_hw_usermem, "LU", "");
SYSCTL_LONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &physmem, 0, "");
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