From nobody Sat Apr 4 04:34:59 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 363F33502A9; Fri, 20 Mar 2026 19:38:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774035529; cv=none; b=IyIORVaf3+jVA37UY6N4PL72ni4mY13bRAyqN67bswlo3bRp54EZhEe2Rftee4oMu8ooQxFzmVMIKcGyXJ2aVoa4VMlv9zTeYHoflA4BFiD+2df14Uh345XCxUsON1c6KlcGMQumqlMlDrv8jS8LwQLPw76VAeCsgx4Yzy/8gGs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774035529; c=relaxed/simple; bh=ioQTkBV6m3Y37Bfrju6maslIwd8eJKDuKdyHXU3PF84=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uRGQLyyl33WkhxEjf41L7jQXvGpWruPXIrnA1eb7NRhSNAgz4xT6fLrIvN2rRRdCRQZbyhcTxf/vWSwbc0AMVxAK//3ewk6CDWx5j8q7M6DNXMoOI/6PdKHES+8Cxv6dAD2UZxbdiMjQ2AhbnzELEc4qeXAkB06p2QzoposWJ6E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JLPa5D/8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JLPa5D/8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64789C4CEF7; Fri, 20 Mar 2026 19:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774035528; bh=ioQTkBV6m3Y37Bfrju6maslIwd8eJKDuKdyHXU3PF84=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JLPa5D/8a/lpeDSeloPdDrACck5k02GKPBWI7+D4njafMSn7rjrBTHddDGqU0MnPG 7bEotti4zoelK0VSxeeKJfCekl2UIeAawfpmNmr4tmnisptPH+pgmC58mj6lj29ju3 5vEUDsXS90jdc7fXQiWFL0fVMSSVGMBH3XGLb90DVUtxmEQ2KQMbW94wrwzm0u+uZa 2HeAepfK94bhZt204Wtqo+tRggWN25Z9xYV0W8aG2ItlTvvoa/iJ/9i+zROvJmBOVI r1dexFW/PSOCktuwQlMPWgD7bJzUaz1ZBNE7K7or5LafaYN0Xb7sjaZMEJW8lFaG2g vEAbJ0N97rIuQ== 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 01/25] mm/vma: add vma_flags_empty(), vma_flags_and(), vma_flags_diff_pair() Date: Fri, 20 Mar 2026 19:38:18 +0000 Message-ID: <53ab55b7da91425775e42c03177498ad6de88ef4.1774034900.git.ljs@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Firstly, add the ability to determine if VMA flags are empty, that is no flags are set in a vma_flags_t value. Next, add the ability to obtain the equivalent of the bitwise and of two vma_flags_t values, via vma_flags_and_mask(). Next, add the ability to obtain the difference between two sets of VMA flags, that is the equivalent to the exclusive bitwise OR of the two sets of flags, via vma_flags_diff_pair(). vma_flags_xxx_mask() typically operates on a pointer to a vma_flags_t value, which is assumed to be an lvalue of some kind (such as a field in a struct or a stack variable) and an rvalue of some kind (typically a constant set of VMA flags obtained e.g. via mk_vma_flags() or equivalent). However vma_flags_diff_pair() is intended to operate on two lvalues, so use the _pair() suffix to make this clear. Finally, update VMA userland tests to add these helpers. We also port bitmap_xor() and __bitmap_xor() to the tools/ headers and source to allow the tests to work with vma_flags_diff_pair(). Acked-by: Vlastimil Babka (SUSE) Signed-off-by: Lorenzo Stoakes (Oracle) --- include/linux/mm.h | 60 ++++++++++++++++++++++++++++----- include/linux/mm_types.h | 8 +++++ tools/include/linux/bitmap.h | 13 +++++++ tools/lib/bitmap.c | 10 ++++++ tools/testing/vma/include/dup.h | 36 +++++++++++++++++++- 5 files changed, 117 insertions(+), 10 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 70747b53c7da..6d2c4bd2c61d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1053,6 +1053,19 @@ static __always_inline vma_flags_t __mk_vma_flags(si= ze_t count, return flags; } =20 +/* + * Helper macro which bitwise-or combines the specified input flags into a + * vma_flags_t bitmap value. E.g.: + * + * vma_flags_t flags =3D mk_vma_flags(VMA_IO_BIT, VMA_PFNMAP_BIT, + * VMA_DONTEXPAND_BIT, VMA_DONTDUMP_BIT); + * + * The compiler cleverly optimises away all of the work and this ends up b= eing + * equivalent to aggregating the values manually. + */ +#define mk_vma_flags(...) __mk_vma_flags(COUNT_ARGS(__VA_ARGS__), \ + (const vma_flag_t []){__VA_ARGS__}) + /* * Test whether a specific VMA flag is set, e.g.: * @@ -1067,17 +1080,30 @@ static __always_inline bool vma_flags_test(const vm= a_flags_t *flags, } =20 /* - * Helper macro which bitwise-or combines the specified input flags into a - * vma_flags_t bitmap value. E.g.: - * - * vma_flags_t flags =3D mk_vma_flags(VMA_IO_BIT, VMA_PFNMAP_BIT, - * VMA_DONTEXPAND_BIT, VMA_DONTDUMP_BIT); + * Obtain a set of VMA flags which contain the overlapping flags contained + * within flags and to_and. + */ +static __always_inline vma_flags_t vma_flags_and_mask(const vma_flags_t *f= lags, + vma_flags_t to_and) +{ + vma_flags_t dst; + unsigned long *bitmap_dst =3D dst.__vma_flags; + const unsigned long *bitmap =3D flags->__vma_flags; + const unsigned long *bitmap_to_and =3D to_and.__vma_flags; + + bitmap_and(bitmap_dst, bitmap, bitmap_to_and, NUM_VMA_FLAG_BITS); + return dst; +} + +/* + * Obtain a set of VMA flags which contains the specified overlapping flag= s, + * e.g.: * - * The compiler cleverly optimises away all of the work and this ends up b= eing - * equivalent to aggregating the values manually. + * vma_flags_t read_flags =3D vma_flags_and(&flags, VMA_READ_BIT, + * VMA_MAY_READ_BIT); */ -#define mk_vma_flags(...) __mk_vma_flags(COUNT_ARGS(__VA_ARGS__), \ - (const vma_flag_t []){__VA_ARGS__}) +#define vma_flags_and(flags, ...) \ + vma_flags_and_mask(flags, mk_vma_flags(__VA_ARGS__)) =20 /* Test each of to_test flags in flags, non-atomically. */ static __always_inline bool vma_flags_test_any_mask(const vma_flags_t *fla= gs, @@ -1151,6 +1177,22 @@ static __always_inline void vma_flags_clear_mask(vma= _flags_t *flags, #define vma_flags_clear(flags, ...) \ vma_flags_clear_mask(flags, mk_vma_flags(__VA_ARGS__)) =20 +/* + * Obtain a VMA flags value containing those flags that are present in fla= gs or + * flags_other but not in both. + */ +static __always_inline vma_flags_t vma_flags_diff_pair(const vma_flags_t *= flags, + const vma_flags_t *flags_other) +{ + vma_flags_t dst; + const unsigned long *bitmap_other =3D flags_other->__vma_flags; + const unsigned long *bitmap =3D flags->__vma_flags; + unsigned long *bitmap_dst =3D dst.__vma_flags; + + bitmap_xor(bitmap_dst, bitmap, bitmap_other, NUM_VMA_FLAG_BITS); + return dst; +} + /* * Helper to test that ALL specified flags are set in a VMA. * diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 3944b51ebac6..5584a0c7bcea 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -870,6 +870,14 @@ typedef struct { =20 #define EMPTY_VMA_FLAGS ((vma_flags_t){ }) =20 +/* Are no flags set in the specified VMA flags? */ +static __always_inline bool vma_flags_empty(const vma_flags_t *flags) +{ + const unsigned long *bitmap =3D flags->__vma_flags; + + return bitmap_empty(bitmap, NUM_VMA_FLAG_BITS); +} + /* * Describes a VMA that is about to be mmap()'ed. Drivers may choose to * manipulate mutable fields which will cause those fields to be updated i= n the diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h index 250883090a5d..845eda759f67 100644 --- a/tools/include/linux/bitmap.h +++ b/tools/include/linux/bitmap.h @@ -28,6 +28,8 @@ bool __bitmap_subset(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); +void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); =20 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG -= 1))) #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG -= 1))) @@ -209,4 +211,15 @@ static inline void bitmap_clear(unsigned long *map, un= signed int start, else __bitmap_clear(map, start, nbits); } + +static __always_inline +void bitmap_xor(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst =3D *src1 ^ *src2; + else + __bitmap_xor(dst, src1, src2, nbits); +} + #endif /* _TOOLS_LINUX_BITMAP_H */ diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c index aa83d22c45e3..fedc9070f0e4 100644 --- a/tools/lib/bitmap.c +++ b/tools/lib/bitmap.c @@ -169,3 +169,13 @@ bool __bitmap_subset(const unsigned long *bitmap1, return false; return true; } + +void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int bits) +{ + unsigned int k; + unsigned int nr =3D BITS_TO_LONGS(bits); + + for (k =3D 0; k < nr; k++) + dst[k] =3D bitmap1[k] ^ bitmap2[k]; +} diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/du= p.h index 8865ffe046d8..8091a5caaeb8 100644 --- a/tools/testing/vma/include/dup.h +++ b/tools/testing/vma/include/dup.h @@ -422,6 +422,13 @@ struct vma_iterator { #define MAPCOUNT_ELF_CORE_MARGIN (5) #define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN) =20 +static __always_inline bool vma_flags_empty(const vma_flags_t *flags) +{ + const unsigned long *bitmap =3D flags->__vma_flags; + + return bitmap_empty(bitmap, NUM_VMA_FLAG_BITS); +} + /* What action should be taken after an .mmap_prepare call is complete? */ enum mmap_action_type { MMAP_NOTHING, /* Mapping is complete, no further action. */ @@ -855,6 +862,21 @@ static __always_inline bool vma_flags_test(const vma_f= lags_t *flags, return test_bit((__force int)bit, bitmap); } =20 +static __always_inline vma_flags_t vma_flags_and_mask(const vma_flags_t *f= lags, + vma_flags_t to_and) +{ + vma_flags_t dst; + unsigned long *bitmap_dst =3D dst.__vma_flags; + const unsigned long *bitmap =3D flags->__vma_flags; + const unsigned long *bitmap_to_and =3D to_and.__vma_flags; + + bitmap_and(bitmap_dst, bitmap, bitmap_to_and, NUM_VMA_FLAG_BITS); + return dst; +} + +#define vma_flags_and(flags, ...) \ + vma_flags_and_mask(flags, mk_vma_flags(__VA_ARGS__)) + static __always_inline bool vma_flags_test_any_mask(const vma_flags_t *fla= gs, vma_flags_t to_test) { @@ -901,8 +923,20 @@ static __always_inline void vma_flags_clear_mask(vma_f= lags_t *flags, vma_flags_t #define vma_flags_clear(flags, ...) \ vma_flags_clear_mask(flags, mk_vma_flags(__VA_ARGS__)) =20 +static __always_inline vma_flags_t vma_flags_diff_pair(const vma_flags_t *= flags, + const vma_flags_t *flags_other) +{ + vma_flags_t dst; + const unsigned long *bitmap_other =3D flags_other->__vma_flags; + const unsigned long *bitmap =3D flags->__vma_flags; + unsigned long *bitmap_dst =3D dst.__vma_flags; + + bitmap_xor(bitmap_dst, bitmap, bitmap_other, NUM_VMA_FLAG_BITS); + return dst; +} + static inline bool vma_test_all_mask(const struct vm_area_struct *vma, - vma_flags_t flags) + vma_flags_t flags) { return vma_flags_test_all_mask(&vma->flags, flags); } --=20 2.53.0