The patch titled
revoke: special mmap handling
has been added to the -mm tree. Its filename is
revoke-special-mmap-handling.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: revoke: special mmap handling
From: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
This adds special handling for revoked memory mappings. We want to raise
SIGBUS when accessing revoked mappings and return ENODEV when trying to remap
with mmap(2).
Acked-by: Alan Cox <alan@xxxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 1 +
mm/memory.c | 3 +++
mm/mmap.c | 12 ++++++++----
3 files changed, 12 insertions(+), 4 deletions(-)
diff -puN include/linux/mm.h~revoke-special-mmap-handling include/linux/mm.h
--- a/include/linux/mm.h~revoke-special-mmap-handling
+++ a/include/linux/mm.h
@@ -171,6 +171,7 @@ extern unsigned int kobjsize(const void
#define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */
#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */
#define VM_ALWAYSDUMP 0x04000000 /* Always include in core dumps */
+#define VM_REVOKED 0x08000000 /* Mapping has been revoked */
#define VM_CAN_INVALIDATE 0x08000000 /* The mapping may be invalidated,
* eg. truncate or invalidate_inode_*.
diff -puN mm/memory.c~revoke-special-mmap-handling mm/memory.c
--- a/mm/memory.c~revoke-special-mmap-handling
+++ a/mm/memory.c
@@ -2470,6 +2470,9 @@ int __handle_mm_fault(struct mm_struct *
if (unlikely(is_vm_hugetlb_page(vma)))
return hugetlb_fault(mm, vma, address, write_access);
+ if (unlikely(vma->vm_flags & VM_REVOKED))
+ return VM_FAULT_SIGBUS;
+
pgd = pgd_offset(mm, address);
pud = pud_alloc(mm, pgd, address);
if (!pud)
diff -puN mm/mmap.c~revoke-special-mmap-handling mm/mmap.c
--- a/mm/mmap.c~revoke-special-mmap-handling
+++ a/mm/mmap.c
@@ -1030,10 +1030,14 @@ unsigned long do_mmap_pgoff(struct file
error = -ENOMEM;
munmap_back:
vma = find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent);
- if (vma && vma->vm_start < addr + len) {
- if (do_munmap(mm, addr, len))
- return -ENOMEM;
- goto munmap_back;
+ if (vma) {
+ if (unlikely(vma->vm_flags & VM_REVOKED))
+ return -ENODEV;
+ if (vma->vm_start < addr + len) {
+ if (do_munmap(mm, addr, len))
+ return -ENOMEM;
+ goto munmap_back;
+ }
}
/* Check against address space limit. */
_
Patches currently in -mm which might be from penberg@xxxxxxxxxxxxxx are
slab-introduce-krealloc.patch
slab-introduce-krealloc-fix.patch
unionfs-fix-slab-abuses-with-krealloc.patch
slab-ensure-cache_alloc_refill-terminates.patch
module-use-krealloc.patch
slab-use-cpu_lock_.patch
revoke-special-mmap-handling.patch
revoke-core-code.patch
revoke-support-for-ext2-and-ext3.patch
revoke-add-documentation.patch
revoke-wire-up-i386-system-calls.patch
slab-leaks3-default-y.patch
-
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