x86: rate-limit logging in do_xen{oprof,pmu}_op()

Some of the sub-ops are acessible to all guests, and hence should be
rate-limited. In the xenoprof case, just like for XSA-146, include them
only in debug builds. Since the vPMU code is rather new, allow them to
be always present, but downgrade them to (rate limited) guest messages.

This is CVE-2015-7971 / XSA-152.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/xen/arch/x86/cpu/vpmu.c b/xen/arch/x86/cpu/vpmu.c
index 8af3df1026d02669d0c0d5031e29cd043700705b..2f5156a7a07093ab08bb4508cd8596d4115a236d 100644 (file)
--- a/xen/arch/x86/cpu/vpmu.c
+++ b/xen/arch/x86/cpu/vpmu.c
@@ -682,8 +682,8 @@ long do_xenpmu_op(unsigned int op, XEN_GUEST_HANDLE_PARAM(xen_pmu_params_t) arg)
             vpmu_mode = pmu_params.val;
         else if ( vpmu_mode != pmu_params.val )
         {
-            printk(XENLOG_WARNING
-                   "VPMU: Cannot change mode while active VPMUs exist\n");
+            gprintk(XENLOG_WARNING,
+                    "VPMU: Cannot change mode while active VPMUs exist\n");
             ret = -EBUSY;
         }
 
@@ -714,8 +714,8 @@ long do_xenpmu_op(unsigned int op, XEN_GUEST_HANDLE_PARAM(xen_pmu_params_t) arg)
             vpmu_features = pmu_params.val;
         else
         {
-            printk(XENLOG_WARNING "VPMU: Cannot change features while"
-                                  " active VPMUs exist\n");
+            gprintk(XENLOG_WARNING,
+                    "VPMU: Cannot change features while active VPMUs exist\n");
             ret = -EBUSY;
         }
 

diff --git a/xen/common/xenoprof.c b/xen/common/xenoprof.c
index 53a803a551344029210980128a294bc81ab37fc1..19b4605895ffd16bb786e94e3797851ee2ab49dc 100644 (file)
--- a/xen/common/xenoprof.c
+++ b/xen/common/xenoprof.c
@@ -676,15 +676,13 @@ ret_t do_xenoprof_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
     
     if ( (op < 0) || (op > XENOPROF_last_op) )
     {
-        printk("xenoprof: invalid operation %d for domain %d\n",
-               op, current->domain->domain_id);
+        gdprintk(XENLOG_DEBUG, "invalid operation %d\n", op);
         return -EINVAL;
     }
 
     if ( !NONPRIV_OP(op) && (current->domain != xenoprof_primary_profiler) )
     {
-        printk("xenoprof: dom %d denied privileged operation %d\n",
-               current->domain->domain_id, op);
+        gdprintk(XENLOG_DEBUG, "denied privileged operation %d\n", op);
         return -EPERM;
     }
 
@@ -907,8 +905,7 @@ ret_t do_xenoprof_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
     spin_unlock(&xenoprof_lock);
 
     if ( ret < 0 )
-        printk("xenoprof: operation %d failed for dom %d (status : %d)\n",
-               op, current->domain->domain_id, ret);
+        gdprintk(XENLOG_DEBUG, "operation %d failed: %d\n", op, ret);
 
     return ret;
 }