mem_event: use C99 initializers for mem_event_request_t users

Use C99 initializers for mem_event_request_t users to make sure req is
always cleared, even with local debug patches that shuffle code around
to have a single exit point.
The common case is to use and send req, so it does not add significant
overhead to always clear req.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Tim Deegan <tim@xen.org>
Committed-by: Tim Deegan <tim@xen.org>

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index d00eaf5fed7909931e00ff46e32deb8471a8fb72..de90f6183ef62256b137f5c992ca49a082d71581 100644 (file)
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4302,7 +4302,7 @@ static int hvm_memory_event_traps(long p, uint32_t reason,
 {
     struct vcpu* v = current;
     struct domain *d = v->domain;
-    mem_event_request_t req;
+    mem_event_request_t req = { .reason = reason };
     int rc;
 
     if ( !(p & HVMPME_MODE_MASK) ) 
@@ -4321,9 +4321,6 @@ static int hvm_memory_event_traps(long p, uint32_t reason,
     else if ( rc < 0 )
         return rc;
 
-    memset(&req, 0, sizeof(req));
-    req.reason = reason;
-
     if ( (p & HVMPME_MODE_MASK) == HVMPME_mode_sync ) 
     {
         req.flags |= MEM_EVENT_FLAG_VCPU_PAUSED;    

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 9eb0ba5f351e394e5f690173b0e7e774f304e469..45ed6e2766def6040e26c3903002af0118c27345 100644 (file)
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -913,7 +913,7 @@ int p2m_mem_paging_evict(struct domain *d, unsigned long gfn)
 void p2m_mem_paging_drop_page(struct domain *d, unsigned long gfn,
                                 p2m_type_t p2mt)
 {
-    mem_event_request_t req;
+    mem_event_request_t req = { .gfn = gfn };
 
     /* We allow no ring in this unique case, because it won't affect
      * correctness of the guest execution at this point.  If this is the only
@@ -924,8 +924,6 @@ void p2m_mem_paging_drop_page(struct domain *d, unsigned long gfn,
         return;
 
     /* Send release notification to pager */
-    memset(&req, 0, sizeof(req));
-    req.gfn = gfn;
     req.flags = MEM_EVENT_FLAG_DROP_PAGE;
 
     /* Update stats unless the page hasn't yet been evicted */
@@ -962,7 +960,7 @@ void p2m_mem_paging_drop_page(struct domain *d, unsigned long gfn,
 void p2m_mem_paging_populate(struct domain *d, unsigned long gfn)
 {
     struct vcpu *v = current;
-    mem_event_request_t req;
+    mem_event_request_t req = { .gfn = gfn };
     p2m_type_t p2mt;
     p2m_access_t a;
     mfn_t mfn;
@@ -980,8 +978,6 @@ void p2m_mem_paging_populate(struct domain *d, unsigned long gfn)
     else if ( rc < 0 )
         return;
 
-    memset(&req, 0, sizeof(req));
-
     /* Fix p2m mapping */
     gfn_lock(p2m, gfn, 0);
     mfn = p2m->get_entry(p2m, gfn, &p2mt, &a, p2m_query, NULL);
@@ -1011,7 +1007,6 @@ void p2m_mem_paging_populate(struct domain *d, unsigned long gfn)
     }
 
     /* Send request to pager */
-    req.gfn = gfn;
     req.p2mt = p2mt;
     req.vcpu_id = v->vcpu_id;