From 7ec1885a7e283caaf6566aedc1eea5988d545f97 Mon Sep 17 00:00:00 2001 From: "Lorenzo Stoakes (Oracle)" Date: Fri, 20 Mar 2026 19:38:22 +0000 Subject: mm/vma: use new VMA flags for sticky flags logic Use the new vma_flags_t flags implementation to perform the logic around sticky flags and what flags are ignored on VMA merge. We make use of the new vma_flags_empty(), vma_flags_diff_pair(), and vma_flags_and_mask() functionality. Also update the VMA tests accordingly. Link: https://lkml.kernel.org/r/369574f06360ffa44707047e3b58eb4897345fba.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 --- include/linux/mm.h | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/include/linux/mm.h b/include/linux/mm.h index 7954a7a2b811..d7e647e31742 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -540,6 +540,7 @@ enum { /* VMA basic access permission flags */ #define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC) +#define VMA_ACCESS_FLAGS mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT) /* * Special vmas that are non-mergable, non-mlock()able. @@ -585,27 +586,32 @@ enum { * possesses it but the other does not, the merged VMA should nonetheless have * applied to it: * - * VM_SOFTDIRTY - if a VMA is marked soft-dirty, that is has not had its - * references cleared via /proc/$pid/clear_refs, any merged VMA - * should be considered soft-dirty also as it operates at a VMA - * granularity. + * VMA_SOFTDIRTY_BIT - if a VMA is marked soft-dirty, that is has not had its + * references cleared via /proc/$pid/clear_refs, any + * merged VMA should be considered soft-dirty also as it + * operates at a VMA granularity. * - * VM_MAYBE_GUARD - If a VMA may have guard regions in place it implies that - * mapped page tables may contain metadata not described by the - * VMA and thus any merged VMA may also contain this metadata, - * and thus we must make this flag sticky. + * VMA_MAYBE_GUARD_BIT - If a VMA may have guard regions in place it implies + * that mapped page tables may contain metadata not + * described by the VMA and thus any merged VMA may also + * contain this metadata, and thus we must make this flag + * sticky. */ -#define VM_STICKY (VM_SOFTDIRTY | VM_MAYBE_GUARD) +#ifdef CONFIG_MEM_SOFT_DIRTY +#define VMA_STICKY_FLAGS mk_vma_flags(VMA_SOFTDIRTY_BIT, VMA_MAYBE_GUARD_BIT) +#else +#define VMA_STICKY_FLAGS mk_vma_flags(VMA_MAYBE_GUARD_BIT) +#endif /* * VMA flags we ignore for the purposes of merge, i.e. one VMA possessing one * of these flags and the other not does not preclude a merge. * - * VM_STICKY - When merging VMAs, VMA flags must match, unless they are - * 'sticky'. If any sticky flags exist in either VMA, we simply - * set all of them on the merged VMA. + * VMA_STICKY_FLAGS - When merging VMAs, VMA flags must match, unless they + * are 'sticky'. If any sticky flags exist in either VMA, + * we simply set all of them on the merged VMA. */ -#define VM_IGNORE_MERGE VM_STICKY +#define VMA_IGNORE_MERGE_FLAGS VMA_STICKY_FLAGS /* * Flags which should result in page tables being copied on fork. These are -- cgit v1.2.3