From: Kees Cook <keescook@chromium.org>
To: Shuah Khan <skhan@linuxfoundation.org>
Cc: johannes@sipsolutions.net, gregkh@linuxfoundation.org,
rafael@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 04/11] drivers/base/devcoredump: convert devcd_count to counter_atomic32
Date: Fri, 9 Oct 2020 11:02:31 -0700 [thread overview]
Message-ID: <202010091102.2E1886F8FD@keescook> (raw)
In-Reply-To: <9eee4448ec53e3a875e6785fa63bcda211e09d23.1602209970.git.skhan@linuxfoundation.org>
On Fri, Oct 09, 2020 at 09:55:59AM -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 wrap around to INT_MIN 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 <gregkh@linuxfoundation.org>
> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
next prev parent reply other threads:[~2020-10-09 18:02 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 15:55 [PATCH v3 00/11] Introduce Simple atomic counters Shuah Khan
2020-10-09 15:55 ` [PATCH v3 01/11] counters: Introduce counter_atomic* counters Shuah Khan
2020-10-09 18:00 ` Kees Cook
2020-10-09 19:49 ` Peter Zijlstra
2020-10-13 11:27 ` Mauro Carvalho Chehab
2020-10-15 1:11 ` Shuah Khan
2020-10-09 15:55 ` [PATCH v3 02/11] selftests:lib:test_counters: add new test for counters Shuah Khan
2020-10-09 18:02 ` Kees Cook
2020-10-09 15:55 ` [PATCH v3 03/11] drivers/base: convert deferred_trigger_count and probe_count to counter_atomic32 Shuah Khan
2020-10-09 15:55 ` [PATCH v3 04/11] drivers/base/devcoredump: convert devcd_count " Shuah Khan
2020-10-09 18:02 ` Kees Cook [this message]
2020-10-09 19:51 ` Peter Zijlstra
2020-10-09 15:56 ` [PATCH v3 05/11] drivers/acpi: convert seqno counter_atomic32 Shuah Khan
2020-10-09 15:56 ` [PATCH v3 06/11] drivers/acpi/apei: " Shuah Khan
2020-10-09 15:56 ` [PATCH v3 07/11] drivers/android/binder: convert stats, transaction_log to counter_atomic32 Shuah Khan
2020-10-09 15:56 ` [PATCH v3 08/11] drivers/base/test/test_async_driver_probe: convert to use counter_atomic32 Shuah Khan
2020-10-09 15:56 ` [PATCH v3 09/11] drivers/char/ipmi: convert stats " Shuah Khan
2020-10-09 15:56 ` [PATCH v3 10/11] drivers/misc/vmw_vmci: convert num guest devices counter to counter_atomic32 Shuah Khan
2020-10-09 15:56 ` [PATCH v3 11/11] drivers/edac: convert pci counters " Shuah Khan
2020-10-09 18:03 ` [PATCH v3 00/11] Introduce Simple atomic counters Kees Cook
2020-10-09 19:02 ` Shuah Khan
2020-10-09 19:37 ` Peter Zijlstra
2020-10-09 20:45 ` Kees Cook
2020-10-10 11:09 ` Peter Zijlstra
2020-10-14 2:12 ` Shuah Khan
2020-10-14 9:17 ` Peter Zijlstra
2020-10-14 23:31 ` Kees Cook
2020-10-16 10:53 ` Peter Zijlstra
2020-10-16 22:51 ` Kees Cook
2020-11-10 18:49 ` Dan Carpenter
2020-10-16 21:56 ` Shuah Khan
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