KVM: fix userspace ABI breakage
authorAdrian Bunk <bunk@kernel.org>
Tue, 5 Aug 2008 22:36:09 +0000 (01:36 +0300)
committerAvi Kivity <avi@qumranet.com>
Mon, 25 Aug 2008 14:28:25 +0000 (17:28 +0300)
The following part of commit 9ef621d3be56e1188300476a8102ff54f7b6793f
(KVM: Support mixed endian machines) changed on the size of a struct
that is exported to userspace:

include/linux/kvm.h:

@@ -318,14 +318,14 @@ struct kvm_trace_rec {
  __u32 vcpu_id;
  union {
  struct {
- __u32 cycle_lo, cycle_hi;
+ __u64 cycle_u64;
  __u32 extra_u32[KVM_TRC_EXTRA_MAX];
  } cycle;
  struct {
  __u32 extra_u32[KVM_TRC_EXTRA_MAX];
  } nocycle;
  } u;
-};
+} __attribute__((packed));

Packing a struct was the correct idea, but it packed the wrong struct.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
include/linux/kvm.h

index 69511f74f912682e69e4d49a9abf5198c0a4bfa3..70a30651cd128cd3dbaf91a366886764abdede33 100644 (file)
@@ -320,12 +320,12 @@ struct kvm_trace_rec {
                struct {
                        __u64 cycle_u64;
                        __u32 extra_u32[KVM_TRC_EXTRA_MAX];
-               } cycle;
+               } __attribute__((packed)) cycle;
                struct {
                        __u32 extra_u32[KVM_TRC_EXTRA_MAX];
                } nocycle;
        } u;
-} __attribute__((packed));
+};
 
 #define KVMIO 0xAE