vmstate.h: Type check VMSTATE_STRUCT_VARRAY macros

The VMSTATE_STRUCT_VARRAY_UINT32 macro is intended to handle
migrating a field which is an array of structs, but where instead of
migrating the entire array we only migrate a variable number of
elements of it.

The VMSTATE_STRUCT_VARRAY_POINTER_UINT32 macro is intended to handle
migrating a field which is of pointer type, and points to a
dynamically allocated array of structs of variable size.

We weren't actually checking that the field passed to
VMSTATE_STRUCT_VARRAY_UINT32 really is an array, with the result that
accidentally using it where the _POINTER_ macro was intended would
compile but silently corrupt memory on migration.

Add type-checking that enforces that the field passed in is
really of the right array type. This applies to all the VMSTATE
macros which use flags including VMS_VARRAY_* but not VMS_POINTER.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Damien Hedde <damien.hedde@greensocs.com>
Tested-by: Damien Hedde <damien.hedde@greensocs.com>
Message-id: 20190725163710.11703-3-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2019-07-26 15:40:28 +01:00
parent 372e458ebc
commit 0c413ba0d8
1 changed files with 24 additions and 6 deletions

View File

@ -227,8 +227,22 @@ extern const VMStateInfo vmstate_info_bitmap;
extern const VMStateInfo vmstate_info_qtailq;
#define type_check_2darray(t1,t2,n,m) ((t1(*)[n][m])0 - (t2*)0)
/*
* Check that type t2 is an array of type t1 of size n,
* e.g. if t1 is 'foo' and n is 32 then t2 must be 'foo[32]'
*/
#define type_check_array(t1,t2,n) ((t1(*)[n])0 - (t2*)0)
#define type_check_pointer(t1,t2) ((t1**)0 - (t2*)0)
/*
* type of element 0 of the specified (array) field of the type.
* Note that if the field is a pointer then this will return the
* pointed-to type rather than complaining.
*/
#define typeof_elt_of_field(type, field) typeof(((type *)0)->field[0])
/* Check that field f in struct type t2 is an array of t1, of any size */
#define type_check_varray(t1, t2, f) \
(type_check(t1, typeof_elt_of_field(t2, f)) \
+ QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(((t2 *)0)->f)))
#define vmstate_offset_value(_state, _field, _type) \
(offsetof(_state, _field) + \
@ -253,6 +267,10 @@ extern const VMStateInfo vmstate_info_qtailq;
vmstate_offset_array(_state, _field, uint8_t, \
sizeof(typeof_field(_state, _field)))
#define vmstate_offset_varray(_state, _field, _type) \
(offsetof(_state, _field) + \
type_check_varray(_type, _state, _field))
/* In the macros below, if there is a _version, that means the macro's
* field will be processed only if the version being received is >=
* the _version specified. In general, if you add a new field, you
@ -347,7 +365,7 @@ extern const VMStateInfo vmstate_info_qtailq;
.info = &(_info), \
.size = sizeof(_type), \
.flags = VMS_VARRAY_UINT32|VMS_MULTIPLY_ELEMENTS, \
.offset = offsetof(_state, _field), \
.offset = vmstate_offset_varray(_state, _field, _type), \
}
#define VMSTATE_ARRAY_TEST(_field, _state, _num, _test, _info, _type) {\
@ -376,7 +394,7 @@ extern const VMStateInfo vmstate_info_qtailq;
.info = &(_info), \
.size = sizeof(_type), \
.flags = VMS_VARRAY_INT32, \
.offset = offsetof(_state, _field), \
.offset = vmstate_offset_varray(_state, _field, _type), \
}
#define VMSTATE_VARRAY_INT32(_field, _state, _field_num, _version, _info, _type) {\
@ -416,7 +434,7 @@ extern const VMStateInfo vmstate_info_qtailq;
.info = &(_info), \
.size = sizeof(_type), \
.flags = VMS_VARRAY_UINT16, \
.offset = offsetof(_state, _field), \
.offset = vmstate_offset_varray(_state, _field, _type), \
}
#define VMSTATE_VSTRUCT_TEST(_field, _state, _test, _version, _vmsd, _type, _struct_version) { \
@ -520,7 +538,7 @@ extern const VMStateInfo vmstate_info_qtailq;
.vmsd = &(_vmsd), \
.size = sizeof(_type), \
.flags = VMS_STRUCT|VMS_VARRAY_UINT8, \
.offset = offsetof(_state, _field), \
.offset = vmstate_offset_varray(_state, _field, _type), \
}
/* a variable length array (i.e. _type *_field) but we know the
@ -573,7 +591,7 @@ extern const VMStateInfo vmstate_info_qtailq;
.vmsd = &(_vmsd), \
.size = sizeof(_type), \
.flags = VMS_STRUCT|VMS_VARRAY_INT32, \
.offset = offsetof(_state, _field), \
.offset = vmstate_offset_varray(_state, _field, _type), \
}
#define VMSTATE_STRUCT_VARRAY_UINT32(_field, _state, _field_num, _version, _vmsd, _type) { \
@ -583,7 +601,7 @@ extern const VMStateInfo vmstate_info_qtailq;
.vmsd = &(_vmsd), \
.size = sizeof(_type), \
.flags = VMS_STRUCT|VMS_VARRAY_UINT32, \
.offset = offsetof(_state, _field), \
.offset = vmstate_offset_varray(_state, _field, _type), \
}
#define VMSTATE_STRUCT_VARRAY_ALLOC(_field, _state, _field_num, _version, _vmsd, _type) {\