From 78ddaa358ec4cdd60bd0e243ced1c83a52c30241 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Wed, 18 Jun 2025 20:42:52 +0100 Subject: [PATCH] mm: change vm_get_page_prot() to accept vm_flags_t argument Patch series "use vm_flags_t consistently". The VMA flags field vma->vm_flags is of type vm_flags_t. Right now this is exactly equivalent to unsigned long, but it should not be assumed to be. Much code that references vma->vm_flags already correctly uses vm_flags_t, but a fairly large chunk of code simply uses unsigned long and assumes that the two are equivalent. This series corrects that and has us use vm_flags_t consistently. This series is motivated by the desire to, in a future series, adjust vm_flags_t to be a u64 regardless of whether the kernel is 32-bit or 64-bit in order to deal with the VMA flag exhaustion issue and avoid all the various problems that arise from it (being unable to use certain features in 32-bit, being unable to add new flags except for 64-bit, etc.) This is therefore a critical first step towards that goal. At any rate, using the correct type is of value regardless. We additionally take the opportunity to refer to VMA flags as vm_flags where possible to make clear what we're referring to. Overall, this series does not introduce any functional change. This patch (of 3): We abstract the type of the VMA flags to vm_flags_t, however in may places it is simply assumed this is unsigned long, which is simply incorrect. At the moment this is simply an incongruity, however in future we plan to change this type and therefore this change is a critical requirement for doing so. Overall, this patch does not introduce any functional change. [lorenzo.stoakes@oracle.com: add missing vm_get_page_prot() instance, remove include] Link: https://lkml.kernel.org/r/552f88e1-2df8-4e95-92b8-812f7c8db829@lucifer.local Link: https://lkml.kernel.org/r/cover.1750274467.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/a12769720a2743f235643b158c4f4f0a9911daf0.1750274467.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Acked-by: Mike Rapoport (Microsoft) Acked-by: Christian Brauner Reviewed-by: Vlastimil Babka Reviewed-by: Oscar Salvador Reviewed-by: Pedro Falcato Acked-by: Catalin Marinas [arm64] Acked-by: Zi Yan Acked-by: David Hildenbrand Reviewed-by: Anshuman Khandual Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Jann Horn Cc: Kees Cook Cc: Jan Kara Cc: Jarkko Sakkinen Signed-off-by: Andrew Morton --- arch/arm64/mm/mmap.c | 2 +- arch/powerpc/include/asm/book3s/64/pkeys.h | 2 +- arch/powerpc/mm/book3s64/pgtable.c | 2 +- arch/sparc/mm/init_64.c | 2 +- arch/x86/mm/pgprot.c | 2 +- include/linux/mm.h | 4 ++-- include/linux/pgtable.h | 2 +- tools/testing/vma/vma_internal.h | 2 +- 8 files changed, 9 insertions(+), 9 deletions(-) diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index c86c348857c40..08ee177432c2f 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -81,7 +81,7 @@ static int __init adjust_protection_map(void) } arch_initcall(adjust_protection_map); -pgprot_t vm_get_page_prot(unsigned long vm_flags) +pgprot_t vm_get_page_prot(vm_flags_t vm_flags) { ptdesc_t prot; diff --git a/arch/powerpc/include/asm/book3s/64/pkeys.h b/arch/powerpc/include/asm/book3s/64/pkeys.h index 5b178139f3c08..ff911b4251d97 100644 --- a/arch/powerpc/include/asm/book3s/64/pkeys.h +++ b/arch/powerpc/include/asm/book3s/64/pkeys.h @@ -5,7 +5,7 @@ #include -static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags) +static inline u64 vmflag_to_pte_pkey_bits(vm_flags_t vm_flags) { if (!mmu_has_feature(MMU_FTR_PKEY)) return 0x0UL; diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c index 0db01e10a3f84..a89ef89101fc6 100644 --- a/arch/powerpc/mm/book3s64/pgtable.c +++ b/arch/powerpc/mm/book3s64/pgtable.c @@ -644,7 +644,7 @@ unsigned long memremap_compat_align(void) EXPORT_SYMBOL_GPL(memremap_compat_align); #endif -pgprot_t vm_get_page_prot(unsigned long vm_flags) +pgprot_t vm_get_page_prot(vm_flags_t vm_flags) { unsigned long prot; diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index 25ae4c897aae7..7ed58bf3aacaa 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -3201,7 +3201,7 @@ void copy_highpage(struct page *to, struct page *from) } EXPORT_SYMBOL(copy_highpage); -pgprot_t vm_get_page_prot(unsigned long vm_flags) +pgprot_t vm_get_page_prot(vm_flags_t vm_flags) { unsigned long prot = pgprot_val(protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]); diff --git a/arch/x86/mm/pgprot.c b/arch/x86/mm/pgprot.c index c84bd9540b163..dc1afd5c839de 100644 --- a/arch/x86/mm/pgprot.c +++ b/arch/x86/mm/pgprot.c @@ -32,7 +32,7 @@ void add_encrypt_protection_map(void) protection_map[i] = pgprot_encrypted(protection_map[i]); } -pgprot_t vm_get_page_prot(unsigned long vm_flags) +pgprot_t vm_get_page_prot(vm_flags_t vm_flags) { unsigned long val = pgprot_val(protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]); diff --git a/include/linux/mm.h b/include/linux/mm.h index b7e2abd8ce0df..78bb177ba55f6 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3489,10 +3489,10 @@ static inline bool range_in_vma(struct vm_area_struct *vma, } #ifdef CONFIG_MMU -pgprot_t vm_get_page_prot(unsigned long vm_flags); +pgprot_t vm_get_page_prot(vm_flags_t vm_flags); void vma_set_page_prot(struct vm_area_struct *vma); #else -static inline pgprot_t vm_get_page_prot(unsigned long vm_flags) +static inline pgprot_t vm_get_page_prot(vm_flags_t vm_flags) { return __pgprot(0); } diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index e4a3895c043be..d05e35a0facff 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -2016,7 +2016,7 @@ typedef unsigned int pgtbl_mod_mask; * x: (yes) yes */ #define DECLARE_VM_GET_PAGE_PROT \ -pgprot_t vm_get_page_prot(unsigned long vm_flags) \ +pgprot_t vm_get_page_prot(vm_flags_t vm_flags) \ { \ return protection_map[vm_flags & \ (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)]; \ diff --git a/tools/testing/vma/vma_internal.h b/tools/testing/vma/vma_internal.h index 0f013784da897..3b1b45256d562 100644 --- a/tools/testing/vma/vma_internal.h +++ b/tools/testing/vma/vma_internal.h @@ -576,7 +576,7 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) return __pgprot(pgprot_val(oldprot) | pgprot_val(newprot)); } -static inline pgprot_t vm_get_page_prot(unsigned long vm_flags) +static inline pgprot_t vm_get_page_prot(vm_flags_t vm_flags) { return __pgprot(vm_flags); } -- 2.47.2