The patch titled
Subject: mm/vma: introduce VM_ACCESS_FLAGS
has been added to the -mm tree. Its filename is
mm-vma-introduce-vm_access_flags.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-vma-introduce-vm_access_flags.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-vma-introduce-vm_access_flags.patch
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------------------------------------------------------
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
@@ -452,7 +452,7 @@ 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_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
if (kprobe_page_fault(regs, esr))
--- a/arch/arm/mm/fault.c~mm-vma-introduce-vm_access_flags
+++ a/arch/arm/mm/fault.c
@@ -202,7 +202,7 @@ 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_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
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
@@ -585,7 +585,7 @@ 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.
*/
@@ -560,7 +564,7 @@ static inline bool vma_is_anonymous(stru
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;
}
static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
--- a/mm/mmap.c~mm-vma-introduce-vm_access_flags
+++ a/mm/mmap.c
@@ -1221,7 +1221,7 @@ 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
@@ -393,7 +393,7 @@ 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,
@@ -572,7 +572,7 @@ 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;
}
_
Patches currently in -mm which might be from anshuman.khandual@xxxxxxx are
mm-vma-add-missing-vma-flag-readable-name-for-vm_sync.patch
mm-vma-make-vma_is_accessible-available-for-general-use.patch
mm-vma-replace-all-remaining-open-encodings-with-is_vm_hugetlb_page.patch
mm-vma-replace-all-remaining-open-encodings-with-vma_is_anonymous.patch
mm-vma-append-unlikely-while-testing-vma-access-permissions.patch
mm-vma-move-vm_no_khugepaged-into-generic-header.patch
mm-vma-make-vma_is_foreign-available-for-general-use.patch
mm-vma-make-is_vma_temporary_stack-available-for-general-use.patch
mm-vma-define-a-default-value-for-vm_data_default_flags.patch
mm-vma-introduce-vm_access_flags.patch
mm-debug-add-tests-validating-architecture-page-table-helpers.patch
