[PATCH] KVM: PPC: Book3S: Ratelimit copy data failure error messages

Vipin K Parashar vipin at linux.vnet.ibm.com
Tue Feb 14 05:56:30 AEDT 2017


kvm_ppc_mmu_book3s_32/64 xlat() log "KVM can't copy data" error
upon failing to copy user data to kernel space. This floods kernel
log once such fails occur in short time period. Ratelimit this
error to avoid flooding kernel logs upon copy data failures.

Signed-off-by: Vipin K Parashar <vipin at linux.vnet.ibm.com>
---
 arch/powerpc/kvm/book3s_32_mmu.c | 3 ++-
 arch/powerpc/kvm/book3s_64_mmu.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_32_mmu.c b/arch/powerpc/kvm/book3s_32_mmu.c
index a2eb6d3..ca8f960 100644
--- a/arch/powerpc/kvm/book3s_32_mmu.c
+++ b/arch/powerpc/kvm/book3s_32_mmu.c
@@ -224,7 +224,8 @@ static int kvmppc_mmu_book3s_32_xlate_pte(struct kvm_vcpu *vcpu, gva_t eaddr,
 	ptem = kvmppc_mmu_book3s_32_get_ptem(sre, eaddr, primary);
 
 	if(copy_from_user(pteg, (void __user *)ptegp, sizeof(pteg))) {
-		printk(KERN_ERR "KVM: Can't copy data from 0x%lx!\n", ptegp);
+		if (printk_ratelimit())
+			printk(KERN_ERR "KVM: Can't copy data from 0x%lx!\n", ptegp);
 		goto no_page_found;
 	}
 
diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index b9131aa..b420aca 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -265,7 +265,8 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 		goto no_page_found;
 
 	if(copy_from_user(pteg, (void __user *)ptegp, sizeof(pteg))) {
-		printk(KERN_ERR "KVM can't copy data from 0x%lx!\n", ptegp);
+		if (printk_ratelimit())
+			printk(KERN_ERR "KVM can't copy data from 0x%lx!\n", ptegp);
 		goto no_page_found;
 	}
 
-- 
2.7.4



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