[PATCH 1/3] kvm-s390: Fix printk on SIGP set arch

Christian Borntraeger
2009-01-22T09:30:28Z

From: Christian Borntraeger <borntraeger@de.ibm.com>

KVM on s390 does not support the ESA/390 architecture. We refuse to
change the architecture mode and print a warning. While testing a
crashme for kvm, I spotted two problems with the printk:

o A malicious can flood host dmesg
o There was no newline at the end of the printk

This patch fixes both problems.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
arch/s390/kvm/sigp.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

Index: kvm/arch/s390/kvm/sigp.c
===================================================================
--- kvm.orig/arch/s390/kvm/sigp.c
+++ kvm/arch/s390/kvm/sigp.c
@@ -153,8 +153,9 @@ static int __sigp_set_arch(struct kvm_vc

switch (parameter & 0xff) {
case 0:
- printk(KERN_WARNING "kvm: request to switch to ESA/390 mode"
- " not supported");
+ if (printk_ratelimit())
+ printk(KERN_WARNING "kvm: request to switch to ESA/390"
+ " mode not supported\n");
rc = 3; /* not operational */
break;
case 1: