From 90cb921c4d7bf92854344d3e76561f48784c613e Mon Sep 17 00:00:00 2001 From: "Lorenzo Stoakes (Oracle)" Date: Fri, 20 Mar 2026 19:38:41 +0000 Subject: mm/vma: convert __mmap_region() to use vma_flags_t Update the mmap() implementation logic implemented in __mmap_region() and functions invoked by it. The mmap_region() function converts its input vm_flags_t parameter to a vma_flags_t value which it then passes to __mmap_region() which uses the vma_flags_t value consistently from then on. As part of the change, we convert map_deny_write_exec() to using vma_flags_t (it was incorrectly using unsigned long before), and place it in vma.h, as it is only used internal to mm. With this change, we eliminate the legacy is_shared_maywrite_vm_flags() helper function which is now no longer required. We are also able to update the MMAP_STATE() and VMG_MMAP_STATE() macros to use the vma_flags_t value. Finally, we update the VMA tests to reflect the change. Link: https://lkml.kernel.org/r/1fc33a404c962f02da778da100387cc19bd62153.1774034900.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 | 18 ++++++++++++------ include/linux/mman.h | 49 ------------------------------------------------- 2 files changed, 12 insertions(+), 55 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index 72bc5016094b..9472b3c9a22b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1522,12 +1522,6 @@ static inline bool vma_is_accessible(const struct vm_area_struct *vma) return vma->vm_flags & VM_ACCESS_FLAGS; } -static inline bool is_shared_maywrite_vm_flags(vm_flags_t vm_flags) -{ - return (vm_flags & (VM_SHARED | VM_MAYWRITE)) == - (VM_SHARED | VM_MAYWRITE); -} - static inline bool is_shared_maywrite(const vma_flags_t *flags) { return vma_flags_test_all(flags, VMA_SHARED_BIT, VMA_MAYWRITE_BIT); @@ -4335,12 +4329,24 @@ static inline bool range_in_vma(const struct vm_area_struct *vma, #ifdef CONFIG_MMU pgprot_t vm_get_page_prot(vm_flags_t vm_flags); + +static inline pgprot_t vma_get_page_prot(vma_flags_t vma_flags) +{ + const vm_flags_t vm_flags = vma_flags_to_legacy(vma_flags); + + return vm_get_page_prot(vm_flags); +} + void vma_set_page_prot(struct vm_area_struct *vma); #else static inline pgprot_t vm_get_page_prot(vm_flags_t vm_flags) { return __pgprot(0); } +static inline pgprot_t vma_get_page_prot(vma_flags_t vma_flags) +{ + return __pgprot(0); +} static inline void vma_set_page_prot(struct vm_area_struct *vma) { vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); diff --git a/include/linux/mman.h b/include/linux/mman.h index 0ba8a7e8b90a..389521594c69 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -170,53 +170,4 @@ static inline bool arch_memory_deny_write_exec_supported(void) } #define arch_memory_deny_write_exec_supported arch_memory_deny_write_exec_supported #endif - -/* - * Denies creating a writable executable mapping or gaining executable permissions. - * - * This denies the following: - * - * a) mmap(PROT_WRITE | PROT_EXEC) - * - * b) mmap(PROT_WRITE) - * mprotect(PROT_EXEC) - * - * c) mmap(PROT_WRITE) - * mprotect(PROT_READ) - * mprotect(PROT_EXEC) - * - * But allows the following: - * - * d) mmap(PROT_READ | PROT_EXEC) - * mmap(PROT_READ | PROT_EXEC | PROT_BTI) - * - * This is only applicable if the user has set the Memory-Deny-Write-Execute - * (MDWE) protection mask for the current process. - * - * @old specifies the VMA flags the VMA originally possessed, and @new the ones - * we propose to set. - * - * Return: false if proposed change is OK, true if not ok and should be denied. - */ -static inline bool map_deny_write_exec(unsigned long old, unsigned long new) -{ - /* If MDWE is disabled, we have nothing to deny. */ - if (!mm_flags_test(MMF_HAS_MDWE, current->mm)) - return false; - - /* If the new VMA is not executable, we have nothing to deny. */ - if (!(new & VM_EXEC)) - return false; - - /* Under MDWE we do not accept newly writably executable VMAs... */ - if (new & VM_WRITE) - return true; - - /* ...nor previously non-executable VMAs becoming executable. */ - if (!(old & VM_EXEC)) - return true; - - return false; -} - #endif /* _LINUX_MMAN_H */ -- cgit v1.2.3