From: Anshuman Khandual <anshuman.khandual@xxxxxxx> Subject: mm/vma: introduce VM_ACCESS_FLAGS There are many places where all basic VMA access flags (read, write, exec) are initialized or checked against as a group. One such example is during page fault. Existing vma_is_accessible() wrapper already creates the notion of VMA accessibility as a group access permissions. Hence lets just create VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which will not only reduce code duplication but also extend the VMA accessibility concept in general. Link: http://lkml.kernel.org/r/1583391014-8170-3-git-send-email-anshuman.khandual@xxxxxxx Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Mark Salter <msalter@xxxxxxxxxx> Cc: Nick Hu <nickhu@xxxxxxxxxxxxx> Cc: Ley Foon Tan <ley.foon.tan@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx> Cc: Guan Xuetao <gxt@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Rob Springer <rspringer@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/arm/mm/fault.c | 2 +- arch/arm64/mm/fault.c | 2 +- arch/nds32/mm/fault.c | 2 +- arch/powerpc/mm/book3s64/pkeys.c | 2 +- arch/s390/mm/fault.c | 2 +- arch/unicore32/mm/fault.c | 2 +- arch/x86/mm/pkeys.c | 2 +- drivers/staging/gasket/gasket_core.c | 2 +- include/linux/mm.h | 6 +++++- mm/mmap.c | 2 +- mm/mprotect.c | 4 ++-- 11 files changed, 16 insertions(+), 12 deletions(-) --- a/arch/arm64/mm/fault.c~mm-vma-introduce-vm_access_flags +++ a/arch/arm64/mm/fault.c @@ -445,7 +445,7 @@ static int __kprobes do_page_fault(unsig const struct fault_info *inf; struct mm_struct *mm = current->mm; vm_fault_t fault, major = 0; - unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC; + unsigned long vm_flags = VM_ACCESS_FLAGS; unsigned int mm_flags = FAULT_FLAG_DEFAULT; if (kprobe_page_fault(regs, esr)) --- a/arch/arm/mm/fault.c~mm-vma-introduce-vm_access_flags +++ a/arch/arm/mm/fault.c @@ -189,7 +189,7 @@ void do_bad_area(unsigned long addr, uns */ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) { - unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; + unsigned int mask = VM_ACCESS_FLAGS; if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) mask = VM_WRITE; --- a/arch/nds32/mm/fault.c~mm-vma-introduce-vm_access_flags +++ a/arch/nds32/mm/fault.c @@ -79,7 +79,7 @@ void do_page_fault(unsigned long entry, struct vm_area_struct *vma; int si_code; vm_fault_t fault; - unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; + unsigned int mask = VM_ACCESS_FLAGS; unsigned int flags = FAULT_FLAG_DEFAULT; error_code = error_code & (ITYPE_mskINST | ITYPE_mskETYPE); --- a/arch/powerpc/mm/book3s64/pkeys.c~mm-vma-introduce-vm_access_flags +++ a/arch/powerpc/mm/book3s64/pkeys.c @@ -315,7 +315,7 @@ int __execute_only_pkey(struct mm_struct static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma) { /* Do this check first since the vm_flags should be hot */ - if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC) + if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC) return false; return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey); --- a/arch/s390/mm/fault.c~mm-vma-introduce-vm_access_flags +++ a/arch/s390/mm/fault.c @@ -580,7 +580,7 @@ void do_dat_exception(struct pt_regs *re int access; vm_fault_t fault; - access = VM_READ | VM_EXEC | VM_WRITE; + access = VM_ACCESS_FLAGS; fault = do_exception(regs, access); if (unlikely(fault)) do_fault_error(regs, access, fault); --- a/arch/unicore32/mm/fault.c~mm-vma-introduce-vm_access_flags +++ a/arch/unicore32/mm/fault.c @@ -149,7 +149,7 @@ void do_bad_area(unsigned long addr, uns */ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) { - unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; + unsigned int mask = VM_ACCESS_FLAGS; if (!(fsr ^ 0x12)) /* write? */ mask = VM_WRITE; --- a/arch/x86/mm/pkeys.c~mm-vma-introduce-vm_access_flags +++ a/arch/x86/mm/pkeys.c @@ -63,7 +63,7 @@ int __execute_only_pkey(struct mm_struct static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma) { /* Do this check first since the vm_flags should be hot */ - if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC) + if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC) return false; if (vma_pkey(vma) != vma->vm_mm->context.execute_only_pkey) return false; --- a/drivers/staging/gasket/gasket_core.c~mm-vma-introduce-vm_access_flags +++ a/drivers/staging/gasket/gasket_core.c @@ -689,7 +689,7 @@ static bool gasket_mmap_has_permissions( /* Make sure that no wrong flags are set. */ requested_permissions = - (vma->vm_flags & (VM_WRITE | VM_READ | VM_EXEC)); + (vma->vm_flags & VM_ACCESS_FLAGS); if (requested_permissions & ~(bar_permissions)) { dev_dbg(gasket_dev->dev, "Attempting to map a region with requested permissions 0x%x, but region has permissions 0x%x.\n", --- a/include/linux/mm.h~mm-vma-introduce-vm_access_flags +++ a/include/linux/mm.h @@ -369,6 +369,10 @@ extern unsigned int kobjsize(const void #define VM_STACK_FLAGS (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT) +/* VMA basic access permission flags */ +#define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC) + + /* * Special vmas that are non-mergable, non-mlock()able. */ @@ -646,7 +650,7 @@ static inline bool vma_is_foreign(struct static inline bool vma_is_accessible(struct vm_area_struct *vma) { - return vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC); + return vma->vm_flags & VM_ACCESS_FLAGS; } #ifdef CONFIG_SHMEM --- a/mm/mmap.c~mm-vma-introduce-vm_access_flags +++ a/mm/mmap.c @@ -1224,7 +1224,7 @@ static int anon_vma_compatible(struct vm return a->vm_end == b->vm_start && mpol_equal(vma_policy(a), vma_policy(b)) && a->vm_file == b->vm_file && - !((a->vm_flags ^ b->vm_flags) & ~(VM_READ|VM_WRITE|VM_EXEC|VM_SOFTDIRTY)) && + !((a->vm_flags ^ b->vm_flags) & ~(VM_ACCESS_FLAGS | VM_SOFTDIRTY)) && b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT); } --- a/mm/mprotect.c~mm-vma-introduce-vm_access_flags +++ a/mm/mprotect.c @@ -419,7 +419,7 @@ mprotect_fixup(struct vm_area_struct *vm */ if (arch_has_pfn_modify_check() && (vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && - (newflags & (VM_READ|VM_WRITE|VM_EXEC)) == 0) { + (newflags & VM_ACCESS_FLAGS) == 0) { pgprot_t new_pgprot = vm_get_page_prot(newflags); error = walk_page_range(current->mm, start, end, @@ -598,7 +598,7 @@ static int do_mprotect_pkey(unsigned lon newflags |= (vma->vm_flags & ~mask_off_old_flags); /* newflags >> 4 shift VM_MAY% in place of VM_% */ - if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { + if ((newflags & ~(newflags >> 4)) & VM_ACCESS_FLAGS) { error = -EACCES; goto out; } _
