On Tue, Oct 06, 2020 at 02:44:35PM -0600, Shuah Khan wrote: > counter_atomic* is introduced to be used when a variable is used as > a simple counter and doesn't guard object lifetimes. This clearly > differentiates atomic_t usages that guard object lifetimes. > > counter_atomic* variables will wrap around to 0 when it overflows and > should not be used to guard resource lifetimes, device usage and > open counts that control state changes, and pm states. > > devcd_count is used to track dev_coredumpm device count and used in > device name string. It doesn't guard object lifetimes, device usage > counts, device open counts, and pm states. There is very little chance > of this counter overflowing. Convert it to use counter_atomic32. > > This conversion doesn't change the overflow wrap around behavior. > > Reviewed-by: Greg Kroah-Hartman <[email protected]> > Signed-off-by: Shuah Khan <[email protected]>
I actually wonder if this should use refcount_t just because it is designed to be an alway-unique value. It is hard to imagine ever causing this to overflow, but why not let it be protected? -- Kees Cook
