From: David Sterba <dsterba@suse.cz>
To: Will Deacon <will@kernel.org>
Cc: linux-kernel@vger.kernel.org, Kees Cook <keescook@chromium.org>,
Ingo Molnar <mingo@kernel.org>,
Elena Reshetova <elena.reshetova@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Hanjun Guo <guohanjun@huawei.com>
Subject: Re: [RESEND PATCH v4 03/10] lib/refcount: Remove unused refcount_*_checked() variants
Date: Thu, 21 Nov 2019 15:55:33 +0100 [thread overview]
Message-ID: <20191121145533.GZ3001@twin.jikos.cz> (raw)
In-Reply-To: <20191121115902.2551-4-will@kernel.org>
On Thu, Nov 21, 2019 at 11:58:55AM +0000, Will Deacon wrote:
> The full-fat refcount implementation is exposed via a set of functions
> suffixed with "_checked()", the idea being that code can choose to use
> the more expensive, yet more secure implementation on a case-by-case
> basis.
>
> In reality, this hasn't happened, so with a grand total of zero users,
> let's remove the checked variants for now by simply dropping the suffix
> and predicating the out-of-line functions on CONFIG_REFCOUNT_FULL=y.
I am still interested in the _checked versions and have a WIP patch that
adds that to btrfs (that was my original plan) but haven't had enough
time to finalize it. The patch itself is simple, the missing part is to
understand and document what the saturated counters would do with the
structures.
If the _checked helpers are really bothering for you, then well remove
it, but I think it's a good API extension that makes the full-refcount
semantics independent of the config.
next prev parent reply other threads:[~2019-11-21 14:55 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-21 11:58 [RESEND PATCH v4 00/10] Rework REFCOUNT_FULL using atomic_fetch_* operations Will Deacon
2019-11-21 11:58 ` [RESEND PATCH v4 01/10] lib/refcount: Define constants for saturation and max refcount values Will Deacon
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: " tip-bot2 for Will Deacon
2019-11-21 11:58 ` [RESEND PATCH v4 02/10] lib/refcount: Ensure integer operands are treated as signed Will Deacon
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: " tip-bot2 for Will Deacon
2019-11-21 11:58 ` [RESEND PATCH v4 03/10] lib/refcount: Remove unused refcount_*_checked() variants Will Deacon
2019-11-21 14:55 ` David Sterba [this message]
2019-11-21 17:11 ` Kees Cook
2019-11-21 17:17 ` David Sterba
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: " tip-bot2 for Will Deacon
2019-11-21 11:58 ` [RESEND PATCH v4 04/10] lib/refcount: Move bulk of REFCOUNT_FULL implementation into header Will Deacon
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the <linux/refcount.h> header tip-bot2 for Will Deacon
2019-11-21 11:58 ` [RESEND PATCH v4 05/10] lib/refcount: Improve performance of generic REFCOUNT_FULL code Will Deacon
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: " tip-bot2 for Will Deacon
2020-02-26 4:10 ` [RESEND PATCH v4 05/10] lib/refcount: " Jann Horn
2020-02-26 4:10 ` Jann Horn
2020-02-28 10:43 ` Will Deacon
2020-03-02 13:06 ` Jann Horn
2020-03-02 13:06 ` Jann Horn
2019-11-21 11:58 ` [RESEND PATCH v4 06/10] lib/refcount: Move saturation warnings out of line Will Deacon
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: " tip-bot2 for Will Deacon
2019-11-21 11:58 ` [RESEND PATCH v4 07/10] lib/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions Will Deacon
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: " tip-bot2 for Will Deacon
2019-11-21 11:59 ` [RESEND PATCH v4 08/10] refcount: Consolidate implementations of refcount_t Will Deacon
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: " tip-bot2 for Will Deacon
2019-12-01 15:49 ` [refcount] d2d337b185: WARNING:at_lib/refcount.c:#refcount_warn_saturate kernel test robot
2019-12-01 15:49 ` kernel test robot
2019-12-02 9:43 ` Ard Biesheuvel
2019-12-02 9:43 ` Ard Biesheuvel
2019-12-03 8:01 ` [LKP] " Rong Chen
2019-12-03 8:01 ` Rong Chen
2019-12-03 8:09 ` [LKP] " Will Deacon
2019-12-03 8:09 ` Will Deacon
2019-12-03 8:42 ` [LKP] " Rong Chen
2019-12-03 8:42 ` Rong Chen
2019-11-21 11:59 ` [RESEND PATCH v4 09/10] lib/refcount: Remove unused 'refcount_error_report()' function Will Deacon
2019-11-25 8:19 ` [tip: locking/core] locking/refcount: " tip-bot2 for Will Deacon
2019-11-21 11:59 ` [RESEND PATCH v4 10/10] drivers/lkdtm: Remove references to CONFIG_REFCOUNT_FULL Will Deacon
2019-11-25 8:19 ` [tip: locking/core] lkdtm: " tip-bot2 for Will Deacon
2019-11-21 12:07 ` [RESEND PATCH v4 00/10] Rework REFCOUNT_FULL using atomic_fetch_* operations Ard Biesheuvel
2019-11-22 3:44 ` Hanjun Guo
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