From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E596CECE58C for ; Mon, 7 Oct 2019 15:47:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4FE420684 for ; Mon, 7 Oct 2019 15:47:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570463238; bh=MrH3F24vYjW41F7fKBrCf+P70nG/U3rnxCKTfYDPsi4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RAnmRdDrR05Un4gV+0WSIZj6Iild0pVxGyF3NpD2StVK7Xc3nNd6NOAExOCfgvM0y z6+1FUaIf2kA7zYBBrTpBH8Jy1kz18NTLyEarW/zGfO/wAr0Zb9mOEMMCTNYoZYKkH NU5oMfG72mZS4Vh+ZFAhJ3itA8/WFR8YbBQbuwEM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728837AbfJGPrS (ORCPT ); Mon, 7 Oct 2019 11:47:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:51660 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728691AbfJGPrQ (ORCPT ); Mon, 7 Oct 2019 11:47:16 -0400 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E34912173B; Mon, 7 Oct 2019 15:47:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570463235; bh=MrH3F24vYjW41F7fKBrCf+P70nG/U3rnxCKTfYDPsi4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fkEhxgOA27gPeytwCRag/UrLhInXu/74ihm8wXUvY6cjbkBctqGtIT6HQFH9L1+/i aLBGW1OPbz8N065sz1Df+ZjpLhyrCPfro0yNt+DnOwofeYFs/9eIHPWVY8D8RaURd4 Pu+IdTwNEmr304zcmdGk41WrZ+pY9G8zUd1jQh1M= From: Will Deacon To: linux-kernel@vger.kernel.org Cc: Will Deacon , Kees Cook , Ingo Molnar , Elena Reshetova , Peter Zijlstra , Ard Biesheuvel , Hanjun Guo , Jan Glauber Subject: [PATCH v3 03/10] lib/refcount: Remove unused refcount_*_checked() variants Date: Mon, 7 Oct 2019 16:46:56 +0100 Message-Id: <20191007154703.5574-4-will@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20191007154703.5574-1-will@kernel.org> References: <20191007154703.5574-1-will@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Cc: Ingo Molnar Cc: Elena Reshetova Cc: Peter Zijlstra Cc: Ard Biesheuvel Reviewed-by: Kees Cook Signed-off-by: Will Deacon --- include/linux/refcount.h | 25 ++++++------------- lib/refcount.c | 54 +++++++++++++++++++++------------------- 2 files changed, 36 insertions(+), 43 deletions(-) diff --git a/include/linux/refcount.h b/include/linux/refcount.h index 89066a1471dd..edd505d1a23b 100644 --- a/include/linux/refcount.h +++ b/include/linux/refcount.h @@ -44,32 +44,21 @@ static inline unsigned int refcount_read(const refcount_t *r) return atomic_read(&r->refs); } -extern __must_check bool refcount_add_not_zero_checked(int i, refcount_t *r); -extern void refcount_add_checked(int i, refcount_t *r); - -extern __must_check bool refcount_inc_not_zero_checked(refcount_t *r); -extern void refcount_inc_checked(refcount_t *r); - -extern __must_check bool refcount_sub_and_test_checked(int i, refcount_t *r); - -extern __must_check bool refcount_dec_and_test_checked(refcount_t *r); -extern void refcount_dec_checked(refcount_t *r); - #ifdef CONFIG_REFCOUNT_FULL #define REFCOUNT_MAX (UINT_MAX - 1) #define REFCOUNT_SATURATED UINT_MAX -#define refcount_add_not_zero refcount_add_not_zero_checked -#define refcount_add refcount_add_checked +extern __must_check bool refcount_add_not_zero(int i, refcount_t *r); +extern void refcount_add(int i, refcount_t *r); -#define refcount_inc_not_zero refcount_inc_not_zero_checked -#define refcount_inc refcount_inc_checked +extern __must_check bool refcount_inc_not_zero(refcount_t *r); +extern void refcount_inc(refcount_t *r); -#define refcount_sub_and_test refcount_sub_and_test_checked +extern __must_check bool refcount_sub_and_test(int i, refcount_t *r); -#define refcount_dec_and_test refcount_dec_and_test_checked -#define refcount_dec refcount_dec_checked +extern __must_check bool refcount_dec_and_test(refcount_t *r); +extern void refcount_dec(refcount_t *r); #else diff --git a/lib/refcount.c b/lib/refcount.c index 719b0bc42ab1..a2f670998cee 100644 --- a/lib/refcount.c +++ b/lib/refcount.c @@ -43,8 +43,10 @@ #include #include +#ifdef CONFIG_REFCOUNT_FULL + /** - * refcount_add_not_zero_checked - add a value to a refcount unless it is 0 + * refcount_add_not_zero - add a value to a refcount unless it is 0 * @i: the value to add to the refcount * @r: the refcount * @@ -61,7 +63,7 @@ * * Return: false if the passed refcount is 0, true otherwise */ -bool refcount_add_not_zero_checked(int i, refcount_t *r) +bool refcount_add_not_zero(int i, refcount_t *r) { unsigned int new, val = atomic_read(&r->refs); @@ -83,10 +85,10 @@ bool refcount_add_not_zero_checked(int i, refcount_t *r) return true; } -EXPORT_SYMBOL(refcount_add_not_zero_checked); +EXPORT_SYMBOL(refcount_add_not_zero); /** - * refcount_add_checked - add a value to a refcount + * refcount_add - add a value to a refcount * @i: the value to add to the refcount * @r: the refcount * @@ -101,14 +103,14 @@ EXPORT_SYMBOL(refcount_add_not_zero_checked); * cases, refcount_inc(), or one of its variants, should instead be used to * increment a reference count. */ -void refcount_add_checked(int i, refcount_t *r) +void refcount_add(int i, refcount_t *r) { - WARN_ONCE(!refcount_add_not_zero_checked(i, r), "refcount_t: addition on 0; use-after-free.\n"); + WARN_ONCE(!refcount_add_not_zero(i, r), "refcount_t: addition on 0; use-after-free.\n"); } -EXPORT_SYMBOL(refcount_add_checked); +EXPORT_SYMBOL(refcount_add); /** - * refcount_inc_not_zero_checked - increment a refcount unless it is 0 + * refcount_inc_not_zero - increment a refcount unless it is 0 * @r: the refcount to increment * * Similar to atomic_inc_not_zero(), but will saturate at REFCOUNT_SATURATED @@ -120,7 +122,7 @@ EXPORT_SYMBOL(refcount_add_checked); * * Return: true if the increment was successful, false otherwise */ -bool refcount_inc_not_zero_checked(refcount_t *r) +bool refcount_inc_not_zero(refcount_t *r) { unsigned int new, val = atomic_read(&r->refs); @@ -140,10 +142,10 @@ bool refcount_inc_not_zero_checked(refcount_t *r) return true; } -EXPORT_SYMBOL(refcount_inc_not_zero_checked); +EXPORT_SYMBOL(refcount_inc_not_zero); /** - * refcount_inc_checked - increment a refcount + * refcount_inc - increment a refcount * @r: the refcount to increment * * Similar to atomic_inc(), but will saturate at REFCOUNT_SATURATED and WARN. @@ -154,14 +156,14 @@ EXPORT_SYMBOL(refcount_inc_not_zero_checked); * Will WARN if the refcount is 0, as this represents a possible use-after-free * condition. */ -void refcount_inc_checked(refcount_t *r) +void refcount_inc(refcount_t *r) { - WARN_ONCE(!refcount_inc_not_zero_checked(r), "refcount_t: increment on 0; use-after-free.\n"); + WARN_ONCE(!refcount_inc_not_zero(r), "refcount_t: increment on 0; use-after-free.\n"); } -EXPORT_SYMBOL(refcount_inc_checked); +EXPORT_SYMBOL(refcount_inc); /** - * refcount_sub_and_test_checked - subtract from a refcount and test if it is 0 + * refcount_sub_and_test - subtract from a refcount and test if it is 0 * @i: amount to subtract from the refcount * @r: the refcount * @@ -180,7 +182,7 @@ EXPORT_SYMBOL(refcount_inc_checked); * * Return: true if the resulting refcount is 0, false otherwise */ -bool refcount_sub_and_test_checked(int i, refcount_t *r) +bool refcount_sub_and_test(int i, refcount_t *r) { unsigned int new, val = atomic_read(&r->refs); @@ -203,10 +205,10 @@ bool refcount_sub_and_test_checked(int i, refcount_t *r) return false; } -EXPORT_SYMBOL(refcount_sub_and_test_checked); +EXPORT_SYMBOL(refcount_sub_and_test); /** - * refcount_dec_and_test_checked - decrement a refcount and test if it is 0 + * refcount_dec_and_test - decrement a refcount and test if it is 0 * @r: the refcount * * Similar to atomic_dec_and_test(), it will WARN on underflow and fail to @@ -218,14 +220,14 @@ EXPORT_SYMBOL(refcount_sub_and_test_checked); * * Return: true if the resulting refcount is 0, false otherwise */ -bool refcount_dec_and_test_checked(refcount_t *r) +bool refcount_dec_and_test(refcount_t *r) { - return refcount_sub_and_test_checked(1, r); + return refcount_sub_and_test(1, r); } -EXPORT_SYMBOL(refcount_dec_and_test_checked); +EXPORT_SYMBOL(refcount_dec_and_test); /** - * refcount_dec_checked - decrement a refcount + * refcount_dec - decrement a refcount * @r: the refcount * * Similar to atomic_dec(), it will WARN on underflow and fail to decrement @@ -234,11 +236,13 @@ EXPORT_SYMBOL(refcount_dec_and_test_checked); * Provides release memory ordering, such that prior loads and stores are done * before. */ -void refcount_dec_checked(refcount_t *r) +void refcount_dec(refcount_t *r) { - WARN_ONCE(refcount_dec_and_test_checked(r), "refcount_t: decrement hit 0; leaking memory.\n"); + WARN_ONCE(refcount_dec_and_test(r), "refcount_t: decrement hit 0; leaking memory.\n"); } -EXPORT_SYMBOL(refcount_dec_checked); +EXPORT_SYMBOL(refcount_dec); + +#endif /* CONFIG_REFCOUNT_FULL */ /** * refcount_dec_if_one - decrement a refcount if it is 1 -- 2.23.0.581.g78d2f28ef7-goog