2007-10-17 04:20:24

by Coly Li

Subject: [PATCH] setup vma->vm_page_prot by vm_get_page_prot()

This patch uses vm_get_page_prot() to setup vma->vm_page_prot.
use-vm_read-write-exec-to-set-vm_page_prot.patch just only replaces "& 0x7" with "&
(VM_READ|VM_WRITE|VM_EXEC)". This is a non-unified method, because there is a vm_get_page_prot() in
mm/mmap.c and exported to kerenl.
Though inside vm_get_page_prot() the protection flags is AND with
(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED), it does not hurt correct code.

This patch can replace use-vm_read-write-exec-to-set-vm_page_prot.patch.

Signed-off-by: Coly Li <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Andrew Morton <[email protected]>
---
arch/ia64/mm/init.c | 2 +-
fs/exec.c | 2 +-
mm/mmap.c | 11 ++++-------
mm/mprotect.c | 6 ++----
4 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index c14abef..4065280 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -130,8 +130,8 @@ ia64_init_addr_space (void)
vma->vm_mm = current->mm;
vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
vma->vm_end = vma->vm_start + PAGE_SIZE;
- vma->vm_page_prot = protection_map[VM_DATA_DEFAULT_FLAGS & 0x7];
vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
+ vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
down_write(&current->mm->mmap_sem);
if (insert_vm_struct(current->mm, vma)) {
up_write(&current->mm->mmap_sem);
diff --git a/fs/exec.c b/fs/exec.c
index 073b0b8..2794fee 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -260,7 +260,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
vma->vm_start = vma->vm_end - PAGE_SIZE;

vma->vm_flags = VM_STACK_FLAGS;
- vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
+ vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
err = insert_vm_struct(mm, vma);
if (err) {
up_write(&mm->mmap_sem);
diff --git a/mm/mmap.c b/mm/mmap.c
index 0d40e66..57f5628 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1049,8 +1049,7 @@ int vma_wants_writenotify(struct vm_area_struct *vma)

/* The open routine did something to the protections already? */
if (pgprot_val(vma->vm_page_prot) !=
- pgprot_val(protection_map[vm_flags &
- (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]))
+ pgprot_val(vm_get_page_prot(vm_flags)))
return 0;

/* Specialty mapping? */
@@ -1131,8 +1130,7 @@ munmap_back:
vma->vm_start = addr;
vma->vm_end = addr + len;
vma->vm_flags = vm_flags;
- vma->vm_page_prot = protection_map[vm_flags &
- (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
+ vma->vm_page_prot = vm_get_page_prot(vm_flags);
vma->vm_pgoff = pgoff;

if (file) {
@@ -2003,8 +2001,7 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
vma->vm_end = addr + len;
vma->vm_pgoff = pgoff;
vma->vm_flags = flags;
- vma->vm_page_prot = protection_map[flags &
- (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
+ vma->vm_page_prot = vm_get_page_prot(flags);
vma_link(mm, vma, prev, rb_link, rb_parent);
out:
mm->total_vm += len >> PAGE_SHIFT;
@@ -2210,7 +2207,7 @@ int install_special_mapping(struct mm_struct *mm,
vma->vm_end = addr + len;

vma->vm_flags = vm_flags | mm->def_flags;
- vma->vm_page_prot = protection_map[vma->vm_flags & 7];
+ vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);

vma->vm_ops = &special_mapping_vmops;
vma->vm_private_data = pages;
diff --git a/mm/mprotect.c b/mm/mprotect.c
index e8346c3..d21c358 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -193,11 +193,9 @@ success:
* held in write mode.
*/
vma->vm_flags = newflags;
- vma->vm_page_prot = protection_map[newflags &
- (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
+ vma->vm_page_prot = vm_get_page_prot(newflags);
if (vma_wants_writenotify(vma)) {
- vma->vm_page_prot = protection_map[newflags &
- (VM_READ|VM_WRITE|VM_EXEC)];
+ vma->vm_page_prot = vm_get_page_prot(newflags);
dirty_accountable = 1;
}




--
Coly Li
SuSE PRC Labs