Messages in this thread | | | Date | Wed, 7 Oct 2020 11:13:27 -0700 | From | Kees Cook <> | Subject | Re: [PATCH v2 03/11] drivers/base: convert deferred_trigger_count and probe_count to counter_atomic32 |
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On Tue, Oct 06, 2020 at 02:44:34PM -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. > > deferred_trigger_count gets incremented and read. 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. > > probe_count gets incremented, decremented, read. It doesn't guard > object lifetimes, device usage counts, device open counts, and pm > states. There is very little chance of this counter overflowing. > This counter controls the wait for known devices to complete their > probing, and probe_count == 0 ends the wait. Other than that it > meets the other criteria to be converted. Convert it to use > counter_atomic32. > > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
With the "wrap around to 0" commit log detail fixed, look good:
Reviewed-by: Kees Cook <keescook@chromium.org>
-- Kees Cook
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