From 6bc0987d0b508b3768808efafa1e90041713526b Mon Sep 17 00:00:00 2001 From: "Lorenzo Stoakes (Oracle)" Date: Fri, 20 Mar 2026 19:38:18 +0000 Subject: mm/vma: add vma_flags_empty(), vma_flags_and(), vma_flags_diff_pair() Patch series "mm/vma: convert vm_flags_t to vma_flags_t in vma code", v4. This series converts a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it. In order to do so it adds a number of additional helpers: * vma_flags_empty() - Determines whether a vma_flags_t value has no bits set. * vma_flags_and() - Performs a bitwise AND between two vma_flags_t values. * vma_flags_diff_pair() - Determines which flags are not shared between a pair of VMA flags (typically non-constant values) * append_vma_flags() - Similar to mk_vma_flags(), but allows a vma_flags_t value to be specified (typically a constant value) which will be copied and appended to to create a new vma_flags_t value, with additional flags specified to append to it. * vma_flags_same() - Determines if a vma_flags_t value is exactly equal to a set of VMA flags. * vma_flags_same_mask() - Determines if a vma_flags_t value is eactly equal to another vma_flags_t value (typically constant). * vma_flags_same_pair() - Determines if a pair of vma_flags_t values are exactly equal to one another (typically both non-constant). * vma_flags_to_legacy() - Converts a vma_flags_t value to a vm_flags_t value, used to enable more iterative introduction of the use of vma_flags_t. * legacy_to_vma_flags() - Converts a vm_flags_t value to a vma_flags-t value, for the same purpose. * vma_flags_test_single_mask() - Tests whether a vma_flags_t value contain the single flag specified in an input vma_flags_t flag mask, or if that flag mask is empty, is defined to return false. Useful for config-predicated VMA flag mask defines. * vma_test() - Tests whether a VMA's flags contain a specific singular VMA flag. * vma_test_any() - Tests whether a VMA's flags contain any of a set of VMA flags. * vma_test_any_mask() - Tests whether a VMA's flags contain any of the flags specified in another, typically constant, vma_flags_t value. * vma_test_single_mask() - Tests whether a VMA's flags contain the single flag specified in an input vma_flags_t flag mask, or if that flag mask is empty, is defined to return false. Useful for config-predicated VMA flag mask defines. * vma_clear_flags() - Clears a specific set of VMA flags from a vma_flags_t value. * vma_clear_flags_mask() - Clears those flag set in a vma_flags_t value (typically constant) from a (typically not constant) vma_flags_t value. The series mostly focuses on the the VMA specific code, especially that contained in mm/vma.c and mm/vma.h. It updates both brk() and mmap() logic to utils vma_flags_t values as much as is practiaclly possible at this point, changing surrounding logic to be able to do so. It also updates the vma_modify_xxx() functions where they interact with VMA flags directly to use vm_flags_t values where possible. There is extensive testing added in the VMA userland tests to assert that all of these new VMA flag functions work correctly. This patch (of 25): 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(). Link: https://lkml.kernel.org/r/cover.1774034900.git.ljs@kernel.org Link: https://lkml.kernel.org/r/53ab55b7da91425775e42c03177498ad6de88ef4.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) Acked-by: Vlastimil Babka (SUSE) Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Al Viro Cc: Anton Ivanov Cc: "Borislav Petkov (AMD)" Cc: Catalin Marinas Cc: Chengming Zhou Cc: Christian Borntraeger Cc: Christian Brauner Cc: David Hildenbrand Cc: Dinh Nguyen Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Jan Kara Cc: Jann Horn Cc: Johannes Berg Cc: Kees Cook Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Ondrej Mosnacek Cc: Palmer Dabbelt Cc: Paul Moore Cc: Pedro Falcato Cc: Richard Weinberger Cc: Russell King Cc: Stephen Smalley Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Cc: Vineet Gupta Cc: WANG Xuerui Cc: Will Deacon Cc: xu xin Signed-off-by: Andrew Morton --- tools/testing/vma/include/dup.h | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) (limited to 'tools/testing') diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.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) +static __always_inline bool vma_flags_empty(const vma_flags_t *flags) +{ + const unsigned long *bitmap = 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_flags_t *flags, return test_bit((__force int)bit, bitmap); } +static __always_inline vma_flags_t vma_flags_and_mask(const vma_flags_t *flags, + vma_flags_t to_and) +{ + vma_flags_t dst; + unsigned long *bitmap_dst = dst.__vma_flags; + const unsigned long *bitmap = flags->__vma_flags; + const unsigned long *bitmap_to_and = 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 *flags, vma_flags_t to_test) { @@ -901,8 +923,20 @@ static __always_inline void vma_flags_clear_mask(vma_flags_t *flags, vma_flags_t #define vma_flags_clear(flags, ...) \ vma_flags_clear_mask(flags, mk_vma_flags(__VA_ARGS__)) +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 = flags_other->__vma_flags; + const unsigned long *bitmap = flags->__vma_flags; + unsigned long *bitmap_dst = 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); } -- cgit v1.2.3