Merge tag 'stable/for-linus-3.7-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen bugfixes from Konrad Rzeszutek Wilk:
 - Use appropriate macros instead of hand-rolling our own (ARM).
 - Fixes if FB/KBD closed unexpectedly.
 - Fix memory leak in /dev/gntdev ioctl calls.
 - Fix overflow check in xenbus_file_write.
 - Document cleanup.
 - Performance optimization when migrating guests.

* tag 'stable/for-linus-3.7-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/mmu: Use Xen specific TLB flush instead of the generic one.
  xen/arm: use the __HVC macro
  xen/xenbus: fix overflow check in xenbus_file_write()
  xen-kbdfront: handle backend CLOSED without CLOSING
  xen-fbfront: handle backend CLOSED without CLOSING
  xen/gntdev: don't leak memory from IOCTL_GNTDEV_MAP_GRANT_REF
  x86: remove obsolete comment from asm/xen/hypervisor.h

8 files changed, 61 insertions, 31 deletions

diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
index 074f5ed101b..71f723984cb 100644
--- a/arch/arm/xen/hypercall.S
+++ b/arch/arm/xen/hypercall.S
@@ -48,20 +48,16 @@
 
 #include <linux/linkage.h>
 #include <asm/assembler.h>
+#include <asm/opcodes-virt.h>
 #include <xen/interface/xen.h>
 
 
-/* HVC 0xEA1 */
-#ifdef CONFIG_THUMB2_KERNEL
-#define xen_hvc .word 0xf7e08ea1
-#else
-#define xen_hvc .word 0xe140ea71
-#endif
+#define XEN_IMM 0xEA1
 
 #define HYPERCALL_SIMPLE(hypercall)             \
 ENTRY(HYPERVISOR_##hypercall)                   \
         mov r12, #__HYPERVISOR_##hypercall;     \
-        xen_hvc;                                                        \
+        __HVC(XEN_IMM);                                         \
         mov pc, lr;                                                     \
 ENDPROC(HYPERVISOR_##hypercall)
 
@@ -76,7 +72,7 @@ ENTRY(HYPERVISOR_##hypercall)			\
         stmdb sp!, {r4}                                         \
         ldr r4, [sp, #4]                                        \
         mov r12, #__HYPERVISOR_##hypercall;     \
-        xen_hvc                                                         \
+        __HVC(XEN_IMM);                                         \
         ldm sp!, {r4}                                           \
         mov pc, lr                                                      \
 ENDPROC(HYPERVISOR_##hypercall)
@@ -100,7 +96,7 @@ ENTRY(privcmd_call)
         mov r2, r3
         ldr r3, [sp, #8]
         ldr r4, [sp, #4]
-        xen_hvc
+        __HVC(XEN_IMM)
         ldm sp!, {r4}
         mov pc, lr
 ENDPROC(privcmd_call);
diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
index 66d0fff1ee8..125f344f06a 100644
--- a/arch/x86/include/asm/xen/hypervisor.h
+++ b/arch/x86/include/asm/xen/hypervisor.h
@@ -33,7 +33,6 @@
 #ifndef _ASM_X86_XEN_HYPERVISOR_H
 #define _ASM_X86_XEN_HYPERVISOR_H
 
-/* arch/i386/kernel/setup.c */
 extern struct shared_info *HYPERVISOR_shared_info;
 extern struct start_info *xen_start_info;
 
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 6226c99729b..dcf5f2dd91e 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1288,6 +1288,25 @@ unsigned long xen_read_cr2_direct(void)
         return this_cpu_read(xen_vcpu_info.arch.cr2);
 }
 
+void xen_flush_tlb_all(void)
+{
+        struct mmuext_op *op;
+        struct multicall_space mcs;
+
+        trace_xen_mmu_flush_tlb_all(0);
+
+        preempt_disable();
+
+        mcs = xen_mc_entry(sizeof(*op));
+
+        op = mcs.args;
+        op->cmd = MMUEXT_TLB_FLUSH_ALL;
+        MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+        xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+        preempt_enable();
+}
 static void xen_flush_tlb(void)
 {
         struct mmuext_op *op;
@@ -2518,7 +2537,7 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
         err = 0;
 out:
 
-        flush_tlb_all();
+        xen_flush_tlb_all();
 
         return err;
 }
diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 02ca8680ea5..6f7d9901303 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -311,7 +311,6 @@ static void xenkbd_backend_changed(struct xenbus_device *dev,
         case XenbusStateReconfiguring:
         case XenbusStateReconfigured:
         case XenbusStateUnknown:
-        case XenbusStateClosed:
                 break;
 
         case XenbusStateInitWait:
@@ -350,6 +349,10 @@ InitWait:
 
                 break;
 
+        case XenbusStateClosed:
+                if (dev->state == XenbusStateClosed)
+                        break;
+                /* Missed the backend's CLOSING state -- fallthrough */
         case XenbusStateClosing:
                 xenbus_frontend_closed(dev);
                 break;
diff --git a/drivers/video/xen-fbfront.c b/drivers/video/xen-fbfront.c
index b7f5173ff9e..917bb568168 100644
--- a/drivers/video/xen-fbfront.c
+++ b/drivers/video/xen-fbfront.c
@@ -641,7 +641,6 @@ static void xenfb_backend_changed(struct xenbus_device *dev,
         case XenbusStateReconfiguring:
         case XenbusStateReconfigured:
         case XenbusStateUnknown:
-        case XenbusStateClosed:
                 break;
 
         case XenbusStateInitWait:
@@ -670,6 +669,10 @@ InitWait:
                 info->feature_resize = val;
                 break;
 
+        case XenbusStateClosed:
+                if (dev->state == XenbusStateClosed)
+                        break;
+                /* Missed the backend's CLOSING state -- fallthrough */
         case XenbusStateClosing:
                 xenbus_frontend_closed(dev);
                 break;
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 610bfc6be17..2e22df2f7a3 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -105,6 +105,21 @@ static void gntdev_print_maps(struct gntdev_priv *priv,
 #endif
 }
 
+static void gntdev_free_map(struct grant_map *map)
+{
+        if (map == NULL)
+                return;
+
+        if (map->pages)
+                free_xenballooned_pages(map->count, map->pages);
+        kfree(map->pages);
+        kfree(map->grants);
+        kfree(map->map_ops);
+        kfree(map->unmap_ops);
+        kfree(map->kmap_ops);
+        kfree(map);
+}
+
 static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
 {
         struct grant_map *add;
@@ -142,12 +157,7 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
         return add;
 
 err:
-        kfree(add->pages);
-        kfree(add->grants);
-        kfree(add->map_ops);
-        kfree(add->unmap_ops);
-        kfree(add->kmap_ops);
-        kfree(add);
+        gntdev_free_map(add);
         return NULL;
 }
 
@@ -198,17 +208,9 @@ static void gntdev_put_map(struct grant_map *map)
                 evtchn_put(map->notify.event);
         }
 
-        if (map->pages) {
-                if (!use_ptemod)
-                        unmap_grant_pages(map, 0, map->count);
-
-                free_xenballooned_pages(map->count, map->pages);
-        }
-        kfree(map->pages);
-        kfree(map->grants);
-        kfree(map->map_ops);
-        kfree(map->unmap_ops);
-        kfree(map);
+        if (map->pages && !use_ptemod)
+                unmap_grant_pages(map, 0, map->count);
+        gntdev_free_map(map);
 }
 
 /* ------------------------------------------------------------------ */
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index 89f76252a16..ac727028e65 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -458,7 +458,7 @@ static ssize_t xenbus_file_write(struct file *filp,
                 goto out;
 
         /* Can't write a xenbus message larger we can buffer */
-        if ((len + u->len) > sizeof(u->u.buffer)) {
+        if (len > sizeof(u->u.buffer) - u->len) {
                 /* On error, dump existing buffer */
                 u->len = 0;
                 rc = -EINVAL;
diff --git a/include/trace/events/xen.h b/include/trace/events/xen.h
index 15ba03bdd7c..d06b6da5c1e 100644
--- a/include/trace/events/xen.h
+++ b/include/trace/events/xen.h
@@ -377,6 +377,14 @@ DECLARE_EVENT_CLASS(xen_mmu_pgd,
 DEFINE_XEN_MMU_PGD_EVENT(xen_mmu_pgd_pin);
 DEFINE_XEN_MMU_PGD_EVENT(xen_mmu_pgd_unpin);
 
+TRACE_EVENT(xen_mmu_flush_tlb_all,
+            TP_PROTO(int x),
+            TP_ARGS(x),
+            TP_STRUCT__entry(__array(char, x, 0)),
+            TP_fast_assign((void)x),
+            TP_printk("%s", "")
+        );
+
 TRACE_EVENT(xen_mmu_flush_tlb,
             TP_PROTO(int x),
             TP_ARGS(x),