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>
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index b598e69..2dd5c41 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -189,7 +189,7 @@
*/
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;
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 1027851..c9cedc0 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -445,7 +445,7 @@
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))
diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c
index 0cf0c08..f331e53 100644
--- a/arch/nds32/mm/fault.c
+++ b/arch/nds32/mm/fault.c
@@ -79,7 +79,7 @@
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);
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 07527f1..1199fc2 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -315,7 +315,7 @@
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);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index d56f677..9822a1f 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -580,7 +580,7 @@
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);
diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c
index a9bd08f..3022104 100644
--- a/arch/unicore32/mm/fault.c
+++ b/arch/unicore32/mm/fault.c
@@ -149,7 +149,7 @@
*/
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;
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index c6f84c0..8873ed1 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -63,7 +63,7 @@
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;
diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c
index cd181a6..8e0575f 100644
--- a/drivers/staging/gasket/gasket_core.c
+++ b/drivers/staging/gasket/gasket_core.c
@@ -689,7 +689,7 @@
/* 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",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 33076fa1..4db1522 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -369,6 +369,10 @@
#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_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
diff --git a/mm/mmap.c b/mm/mmap.c
index de07bbc..f609e9e 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1224,7 +1224,7 @@
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);
}
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 1d823b05..494192ca 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -419,7 +419,7 @@
*/
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 @@
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;
}
