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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.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Springer <rspringer@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/1583391014-8170-3-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alistair/sensors
Anshuman Khandual 2020-04-10 14:33:09 -07:00 committed by Linus Torvalds
parent c62da0c35d
commit 6cb4d9a287
11 changed files with 16 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm/mm/fault.c
View File

@ -189,7 +189,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
*/
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;

2
arch/arm64/mm/fault.c
View File

@ -445,7 +445,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
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))

2
arch/nds32/mm/fault.c
View File

@ -79,7 +79,7 @@ void do_page_fault(unsigned long entry, unsigned long addr,
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);

2
arch/powerpc/mm/book3s64/pkeys.c
View File

@ -315,7 +315,7 @@ int __execute_only_pkey(struct mm_struct *mm)
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);

2
arch/s390/mm/fault.c
View File

@ -580,7 +580,7 @@ void do_dat_exception(struct pt_regs *regs)
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);

2
arch/unicore32/mm/fault.c
View File

@ -149,7 +149,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
*/
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;

2
arch/x86/mm/pkeys.c
View File

@ -63,7 +63,7 @@ int __execute_only_pkey(struct mm_struct *mm)
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;

2
drivers/staging/gasket/gasket_core.c
View File

@ -689,7 +689,7 @@ static bool gasket_mmap_has_permissions(struct gasket_dev *gasket_dev,
/* 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",

6
include/linux/mm.h
View File

@ -369,6 +369,10 @@ extern unsigned int kobjsize(const void *objp);
#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 vm_area_struct *vma)
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

2
mm/mmap.c
View File

@ -1224,7 +1224,7 @@ static int anon_vma_compatible(struct vm_area_struct *a, struct vm_area_struct *
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);
}

4
mm/mprotect.c
View File

@ -419,7 +419,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
*/
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 long start, size_t len,
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;
}