Previously, it was looping through sizeof(ev->valuators.mask) * 8
valuators, where valuators.mask is defined as an array of
(MAX_VALUATORS + 7) / 8 entries. Since MAX_VALUATORS is defined as 36,
this made it actually loop through 40 entries. The last 4 bits in this
array should never be set, so we should never access memory outside the
bounds of the arrays defined to be exactly MAX_VALUATORS in length, but
we can make the static analyzer happier and not waste time checking bits
that should never be set.
Found by Oracle Parfait 13.3 static analyzer:
Read outside array bounds [read-outside-array-bounds]:
In array dereference of ev->valuators.data[i] with index i
Array size is 36 elements (of 8 bytes each), index >= 0 and index <= 39
at line 741 of dix/eventconvert.c in function 'eventToDeviceEvent'.
Read outside array bounds [read-outside-array-bounds]:
In array dereference of ev->valuators.data[i] with index i
Array size is 36 elements (of 8 bytes each), index >= 0 and index <= 39
at line 808 of dix/eventconvert.c in function 'eventToRawEvent'.
Read outside array bounds [read-outside-array-bounds]:
In array dereference of ev->valuators.data_raw[i] with index i
Array size is 36 elements (of 8 bytes each), index >= 0 and index <= 39
at line 809 of dix/eventconvert.c in function 'eventToRawEvent'.
Fixes: b2ba77bac ("dix: add EventToXI2 and GetXI2Type.")
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1730>
8fa1ac2b50