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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 580D11099B35 for ; Fri, 20 Mar 2026 19:39:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=dZN40bzOwgfP54d8m0LVPICl9RFWnuWTvuCipJbm/ec=; b=rSjstxdhapgIPz+731BXpUqdox qhe5hRA3u4SHCwtf4jFHivi82f03tATZBjGy91jMxgHaHmCe/tGI/FnF4YeJ0t/Lpb7FJHBeQ9gMw +nsLBjX/zFS/kAssATFqboHhTQ93tsggTs5WV/K8BEA+YvcupRxfAhlBLvPwZlYKJvYIlfRRzQ+V7 Kq6F3mdvBzjrdI4ht8UUe4cpKoM0zwJI63UgVCySbOjL4inCO0R/xFERHplQOnrQyAdLLzNfHO1Zv bjMUi0Ys+S84bVa9Q6dwBwl7rM10HMKAdzK0W3gr7BMKOnywRQQdflFoth7++Mqt7dmmrJfjWl7i0 GaX8h//g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w3fh6-0000000DU5L-35TV; Fri, 20 Mar 2026 19:39:40 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w3fgs-0000000DThD-3Ycm; Fri, 20 Mar 2026 19:39:27 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:MIME-Version :References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=dZN40bzOwgfP54d8m0LVPICl9RFWnuWTvuCipJbm/ec=; b=pzAZTaC4D0dWf3mkYnzXTP5APJ RXWW3+SnXZkFJhu8/lBlMyiEk9GicAiPQA6UsflvBnQrcg/u0HYltioXFzdWuJ2yy6u+7HWDdF88v zl+tfyG43LYm9zbXKIiYVJld/0Bf3Wy70rwvCpc7KlRr0teXWUlK0R+QAtLxOvz76G9Gui389xllq L6gpIhJvym84NAVQkfSLG1UqcXTKQLJOA6KWVZodZSn0JJJx/H+Ie1ptU7GrwyEEYJsIIlfV+vaD+ yHHvgsQ7v0WVzxnuZClMuRy9SXWeXNhFTIWrDqFCRwlNUCTx36oj1Dkp8CZ11ivE7Mo2Xv/51U46D XCEKtP4Q==; Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by desiato.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w3fgo-0000000GMFf-02kB; Fri, 20 Mar 2026 19:39:24 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 8EE8A416D3; Fri, 20 Mar 2026 19:39:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE33FC4CEF7; Fri, 20 Mar 2026 19:39:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774035560; bh=frZGbChHfZDBR7/pCN2wWxe44RSqCYtYg/5HJ8X7rnk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bX82bPEa9dczbYZwn6vfhbeDK+Ajku+xA9x1MdDEsvLROP2EOfKP+e+ANeFkz5xMy OclEVmr33n+GqODBneGwuAlRCKiBQxo8WWqOYcdaJ0YNQOauhqIvhCCfI93kQ8a46t KIq0Ur5WXfClxDm8st4KHFzoN13nG4Ib+X8KOcASJfZyeyKJ8J09cIFVUNhA5Ky5Kf ixa08AIO4H+20X7qSKi4d7M9BaJbUJjkqKcNoQKgCcQCqDUz9SwTHZoO3X0dOZstu5 8a4GUv7HoIOWTOUPClkpq7+CPWVvfFpqdnmoqDEyyR6CSVjvESquXJk3FWcSTB3Ftg wSjHWNf9uxzBQ== From: "Lorenzo Stoakes (Oracle)" To: Andrew Morton Cc: David Hildenbrand , "Liam R . Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , Mike Rapoport , Suren Baghdasaryan , Kees Cook , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vineet Gupta , Russell King , Catalin Marinas , Will Deacon , Brian Cain , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , Dinh Nguyen , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Richard Weinberger , Anton Ivanov , Johannes Berg , Alexander Viro , Christian Brauner , Jan Kara , Xu Xin , Chengming Zhou , Michal Hocko , Paul Moore , Stephen Smalley , Ondrej Mosnacek , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-um@lists.infradead.org, linux-fsdevel@vger.kernel.org, selinux@vger.kernel.org Subject: [PATCH v4 15/25] mm: introduce vma_flags_count() and vma[_flags]_test_single_mask() Date: Fri, 20 Mar 2026 19:38:32 +0000 Message-ID: X-Mailer: git-send-email 2.53.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260320_193922_418472_9CDD7D63 X-CRM114-Status: GOOD ( 20.02 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org vma_flags_count() determines how many bits are set in VMA flags, using bitmap_weight(). vma_flags_test_single_mask() determines if a vma_flags_t set of flags contains a single flag specified as another vma_flags_t value, or if the sought flag mask is empty, it is defined to return false. This is useful when we want to declare a VMA flag as optionally a single flag in a mask or empty depending on kernel configuration. This allows us to have VM_NONE-like semantics when checking whether the flag is set. In a subsequent patch, we introduce the use of VMA_DROPPABLE of type vma_flags_t using precisely these semantics. It would be actively confusing to use vma_flags_test_any_single_mask() for this (and vma_flags_test_all_mask() is not correct to use here, as it trivially returns true when tested against an empty vma flags mask). We introduce vma_flags_count() to be able to assert that the compared flag mask is singular or empty, checked when CONFIG_DEBUG_VM is enabled. Also update the VMA tests as part of this change. Acked-by: Vlastimil Babka (SUSE) Signed-off-by: Lorenzo Stoakes (Oracle) --- include/linux/mm.h | 46 ++++++++++++++++++++++++++++++ tools/testing/vma/include/custom.h | 6 ---- tools/testing/vma/include/dup.h | 21 ++++++++++++++ tools/testing/vma/vma_internal.h | 6 ++++ 4 files changed, 73 insertions(+), 6 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 47bf9f166924..324b6e8a66fa 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1083,6 +1083,14 @@ static __always_inline vma_flags_t __mk_vma_flags(vma_flags_t flags, #define append_vma_flags(flags, ...) __mk_vma_flags(flags, \ COUNT_ARGS(__VA_ARGS__), (const vma_flag_t []){__VA_ARGS__}) +/* Calculates the number of set bits in the specified VMA flags. */ +static __always_inline int vma_flags_count(const vma_flags_t *flags) +{ + const unsigned long *bitmap = flags->__vma_flags; + + return bitmap_weight(bitmap, NUM_VMA_FLAG_BITS); +} + /* * Test whether a specific VMA flag is set, e.g.: * @@ -1158,6 +1166,26 @@ static __always_inline bool vma_flags_test_all_mask(const vma_flags_t *flags, #define vma_flags_test_all(flags, ...) \ vma_flags_test_all_mask(flags, mk_vma_flags(__VA_ARGS__)) +/* + * Helper to test that a flag mask of type vma_flags_t has a SINGLE flag set + * (returning false if flagmask has no flags set). + * + * This is defined to make the semantics clearer when testing an optionally + * defined VMA flags mask, e.g.: + * + * if (vma_flags_test_single_mask(&flags, VMA_DROPPABLE)) { ... } + * + * When VMA_DROPPABLE is defined if available, or set to EMPTY_VMA_FLAGS + * otherwise. + */ +static __always_inline bool vma_flags_test_single_mask(const vma_flags_t *flags, + vma_flags_t flagmask) +{ + VM_WARN_ON_ONCE(vma_flags_count(&flagmask) > 1); + + return vma_flags_test_any_mask(flags, flagmask); +} + /* Set each of the to_set flags in flags, non-atomically. */ static __always_inline void vma_flags_set_mask(vma_flags_t *flags, vma_flags_t to_set) @@ -1286,6 +1314,24 @@ static __always_inline bool vma_test_all_mask(const struct vm_area_struct *vma, #define vma_test_all(vma, ...) \ vma_test_all_mask(vma, mk_vma_flags(__VA_ARGS__)) +/* + * Helper to test that a flag mask of type vma_flags_t has a SINGLE flag set + * (returning false if flagmask has no flags set). + * + * This is useful when a flag needs to be either defined or not depending upon + * kernel configuration, e.g.: + * + * if (vma_test_single_mask(vma, VMA_DROPPABLE)) { ... } + * + * When VMA_DROPPABLE is defined if available, or set to EMPTY_VMA_FLAGS + * otherwise. + */ +static __always_inline bool +vma_test_single_mask(const struct vm_area_struct *vma, vma_flags_t flagmask) +{ + return vma_flags_test_single_mask(&vma->flags, flagmask); +} + /* * Helper to set all VMA flags in a VMA. * diff --git a/tools/testing/vma/include/custom.h b/tools/testing/vma/include/custom.h index 2c498e713fbd..b7d9eb0a44e4 100644 --- a/tools/testing/vma/include/custom.h +++ b/tools/testing/vma/include/custom.h @@ -15,12 +15,6 @@ extern unsigned long dac_mmap_min_addr; #define dac_mmap_min_addr 0UL #endif -#define VM_WARN_ON(_expr) (WARN_ON(_expr)) -#define VM_WARN_ON_ONCE(_expr) (WARN_ON_ONCE(_expr)) -#define VM_WARN_ON_VMG(_expr, _vmg) (WARN_ON(_expr)) -#define VM_BUG_ON(_expr) (BUG_ON(_expr)) -#define VM_BUG_ON_VMA(_expr, _vma) (BUG_ON(_expr)) - #define TASK_SIZE ((1ul << 47)-PAGE_SIZE) /* diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h index f9fe07a8a443..244ee02dc21d 100644 --- a/tools/testing/vma/include/dup.h +++ b/tools/testing/vma/include/dup.h @@ -905,6 +905,13 @@ static __always_inline vma_flags_t __mk_vma_flags(vma_flags_t flags, #define append_vma_flags(flags, ...) __mk_vma_flags(flags, \ COUNT_ARGS(__VA_ARGS__), (const vma_flag_t []){__VA_ARGS__}) +static __always_inline int vma_flags_count(const vma_flags_t *flags) +{ + const unsigned long *bitmap = flags->__vma_flags; + + return bitmap_weight(bitmap, NUM_VMA_FLAG_BITS); +} + static __always_inline bool vma_flags_test(const vma_flags_t *flags, vma_flag_t bit) { @@ -952,6 +959,14 @@ static __always_inline bool vma_flags_test_all_mask(const vma_flags_t *flags, #define vma_flags_test_all(flags, ...) \ vma_flags_test_all_mask(flags, mk_vma_flags(__VA_ARGS__)) +static __always_inline bool vma_flags_test_single_mask(const vma_flags_t *flags, + vma_flags_t flagmask) +{ + VM_WARN_ON_ONCE(vma_flags_count(&flagmask) > 1); + + return vma_flags_test_any_mask(flags, flagmask); +} + static __always_inline void vma_flags_set_mask(vma_flags_t *flags, vma_flags_t to_set) { unsigned long *bitmap = flags->__vma_flags; @@ -1031,6 +1046,12 @@ static __always_inline bool vma_test_all_mask(const struct vm_area_struct *vma, #define vma_test_all(vma, ...) \ vma_test_all_mask(vma, mk_vma_flags(__VA_ARGS__)) +static __always_inline bool +vma_test_single_mask(const struct vm_area_struct *vma, vma_flags_t flagmask) +{ + return vma_flags_test_single_mask(&vma->flags, flagmask); +} + static __always_inline void vma_set_flags_mask(struct vm_area_struct *vma, vma_flags_t flags) { diff --git a/tools/testing/vma/vma_internal.h b/tools/testing/vma/vma_internal.h index 0e1121e2ef23..e12ab2c80f95 100644 --- a/tools/testing/vma/vma_internal.h +++ b/tools/testing/vma/vma_internal.h @@ -51,6 +51,12 @@ typedef unsigned long pgprotval_t; typedef struct pgprot { pgprotval_t pgprot; } pgprot_t; typedef __bitwise unsigned int vm_fault_t; +#define VM_WARN_ON(_expr) (WARN_ON(_expr)) +#define VM_WARN_ON_ONCE(_expr) (WARN_ON_ONCE(_expr)) +#define VM_WARN_ON_VMG(_expr, _vmg) (WARN_ON(_expr)) +#define VM_BUG_ON(_expr) (BUG_ON(_expr)) +#define VM_BUG_ON_VMA(_expr, _vma) (BUG_ON(_expr)) + #include "include/stubs.h" #include "include/dup.h" #include "include/custom.h" -- 2.53.0