diff mbox series

[1/5] mm/vma: move brk() internals to mm/vma.c

Message ID 3d24b9e67bb0261539ca921d1188a10a1b4d4357.1733248985.git.lorenzo.stoakes@oracle.com (mailing list archive)
State New
Headers show
Series mm/vma: make more mmap logic userland testable | expand

Commit Message

Lorenzo Stoakes Dec. 3, 2024, 6:05 p.m. UTC 
Now we have moved mmap_region() internals to mm/vma.c, making it available
to userland testing, it makes sense to do the same with brk().

This continues the pattern of VMA heavy lifting being done in mm/vma.c in
an environment where it can be subject to straightforward unit and
regression testing, with other VMA-adjacent files becoming wrappers around
this functionality.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
 mm/mmap.c                        | 85 +-------------------------------
 mm/vma.c                         | 82 ++++++++++++++++++++++++++++++
 mm/vma.h                         |  3 ++
 tools/testing/vma/vma_internal.h | 22 +++++++++
 4 files changed, 108 insertions(+), 84 deletions(-)

Comments

kernel test robot Dec. 4, 2024, 11:55 a.m. UTC | #1 
Hi Lorenzo,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Lorenzo-Stoakes/mm-vma-move-brk-internals-to-mm-vma-c/20241204-115150
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/3d24b9e67bb0261539ca921d1188a10a1b4d4357.1733248985.git.lorenzo.stoakes%40oracle.com
patch subject: [PATCH 1/5] mm/vma: move brk() internals to mm/vma.c
config: mips-allnoconfig (https://download.01.org/0day-ci/archive/20241204/202412041907.3DXYQrz6-lkp@intel.com/config)
compiler: mips-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241204/202412041907.3DXYQrz6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202412041907.3DXYQrz6-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from arch/mips/include/asm/cacheflush.h:13,
                    from include/linux/cacheflush.h:5,
                    from include/linux/highmem.h:8,
                    from include/linux/bvec.h:10,
                    from include/linux/blk_types.h:10,
                    from include/linux/writeback.h:13,
                    from include/linux/backing-dev.h:16,
                    from mm/vma_internal.h:12,
                    from mm/vma.c:7:
   mm/vma.c: In function 'do_brk_flags':
>> include/linux/mm.h:450:44: error: 'READ_IMPLIES_EXEC' undeclared (first use in this function)
     450 | #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
         |                                            ^~~~~~~~~~~~~~~~~
   include/linux/mm.h:453:55: note: in expansion of macro 'TASK_EXEC'
     453 | #define VM_DATA_FLAGS_TSK_EXEC  (VM_READ | VM_WRITE | TASK_EXEC | \
         |                                                       ^~~~~~~~~
   arch/mips/include/asm/page.h:215:33: note: in expansion of macro 'VM_DATA_FLAGS_TSK_EXEC'
     215 | #define VM_DATA_DEFAULT_FLAGS   VM_DATA_FLAGS_TSK_EXEC
         |                                 ^~~~~~~~~~~~~~~~~~~~~~
   mm/vma.c:2503:18: note: in expansion of macro 'VM_DATA_DEFAULT_FLAGS'
    2503 |         flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
         |                  ^~~~~~~~~~~~~~~~~~~~~
   include/linux/mm.h:450:44: note: each undeclared identifier is reported only once for each function it appears in
     450 | #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
         |                                            ^~~~~~~~~~~~~~~~~
   include/linux/mm.h:453:55: note: in expansion of macro 'TASK_EXEC'
     453 | #define VM_DATA_FLAGS_TSK_EXEC  (VM_READ | VM_WRITE | TASK_EXEC | \
         |                                                       ^~~~~~~~~
   arch/mips/include/asm/page.h:215:33: note: in expansion of macro 'VM_DATA_FLAGS_TSK_EXEC'
     215 | #define VM_DATA_DEFAULT_FLAGS   VM_DATA_FLAGS_TSK_EXEC
         |                                 ^~~~~~~~~~~~~~~~~~~~~~
   mm/vma.c:2503:18: note: in expansion of macro 'VM_DATA_DEFAULT_FLAGS'
    2503 |         flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
         |                  ^~~~~~~~~~~~~~~~~~~~~


vim +/READ_IMPLIES_EXEC +450 include/linux/mm.h

a8bef8ff6ea15fa Mel Gorman        2010-05-24  449  
c62da0c35d58518 Anshuman Khandual 2020-04-10 @450  #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
c62da0c35d58518 Anshuman Khandual 2020-04-10  451
Lorenzo Stoakes Dec. 4, 2024, 12:08 p.m. UTC | #2 
On Tue, Dec 03, 2024 at 06:05:08PM +0000, Lorenzo Stoakes wrote:
> Now we have moved mmap_region() internals to mm/vma.c, making it available
> to userland testing, it makes sense to do the same with brk().
>
> This continues the pattern of VMA heavy lifting being done in mm/vma.c in
> an environment where it can be subject to straightforward unit and
> regression testing, with other VMA-adjacent files becoming wrappers around
> this functionality.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Hi Andrew,

Could you apply the below fix-patch? It seems we have another one of those
thorny header dependency things going on here.

Thanks,

Lorenzo

----8<----
From 0c61e8fe9f9ffe9fd7ac8e1fde6e8cad8bac2b30 Mon Sep 17 00:00:00 2001
From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Date: Wed, 4 Dec 2024 12:00:35 +0000
Subject: [PATCH] mm/vma: add missing personality header import

Some architectures have different header dependency chains, we incorrectly
failed to important linux/personality.h which broke MIPS. Fix this.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
 mm/vma_internal.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/vma_internal.h b/mm/vma_internal.h
index fc5f172a36bd..2f05735ff190 100644
--- a/mm/vma_internal.h
+++ b/mm/vma_internal.h
@@ -35,6 +35,7 @@
 #include <linux/mutex.h>
 #include <linux/pagemap.h>
 #include <linux/perf_event.h>
+#include <linux/personality.h>
 #include <linux/pfn.h>
 #include <linux/rcupdate.h>
 #include <linux/rmap.h>
--
2.47.1
Lorenzo Stoakes Dec. 4, 2024, 12:10 p.m. UTC | #3 
On Wed, Dec 04, 2024 at 07:55:16PM +0800, kernel test robot wrote:
> Hi Lorenzo,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on akpm-mm/mm-everything]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Lorenzo-Stoakes/mm-vma-move-brk-internals-to-mm-vma-c/20241204-115150
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link:    https://lore.kernel.org/r/3d24b9e67bb0261539ca921d1188a10a1b4d4357.1733248985.git.lorenzo.stoakes%40oracle.com
> patch subject: [PATCH 1/5] mm/vma: move brk() internals to mm/vma.c
> config: mips-allnoconfig (https://download.01.org/0day-ci/archive/20241204/202412041907.3DXYQrz6-lkp@intel.com/config)
> compiler: mips-linux-gcc (GCC) 14.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241204/202412041907.3DXYQrz6-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202412041907.3DXYQrz6-lkp@intel.com/

Thanks for the report!

Seems to be missing a header to include/uapi/linux/personality.h which declares
READ_IMPLES_EXEC, however the standard means of including this appears to be
including linux/personality.h which also imports this header.

I have sent a fixpatch separately.

>
> All errors (new ones prefixed by >>):
>
>    In file included from arch/mips/include/asm/cacheflush.h:13,
>                     from include/linux/cacheflush.h:5,
>                     from include/linux/highmem.h:8,
>                     from include/linux/bvec.h:10,
>                     from include/linux/blk_types.h:10,
>                     from include/linux/writeback.h:13,
>                     from include/linux/backing-dev.h:16,
>                     from mm/vma_internal.h:12,
>                     from mm/vma.c:7:
>    mm/vma.c: In function 'do_brk_flags':
> >> include/linux/mm.h:450:44: error: 'READ_IMPLIES_EXEC' undeclared (first use in this function)
>      450 | #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
>          |                                            ^~~~~~~~~~~~~~~~~
>    include/linux/mm.h:453:55: note: in expansion of macro 'TASK_EXEC'
>      453 | #define VM_DATA_FLAGS_TSK_EXEC  (VM_READ | VM_WRITE | TASK_EXEC | \
>          |                                                       ^~~~~~~~~
>    arch/mips/include/asm/page.h:215:33: note: in expansion of macro 'VM_DATA_FLAGS_TSK_EXEC'
>      215 | #define VM_DATA_DEFAULT_FLAGS   VM_DATA_FLAGS_TSK_EXEC
>          |                                 ^~~~~~~~~~~~~~~~~~~~~~
>    mm/vma.c:2503:18: note: in expansion of macro 'VM_DATA_DEFAULT_FLAGS'
>     2503 |         flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
>          |                  ^~~~~~~~~~~~~~~~~~~~~
>    include/linux/mm.h:450:44: note: each undeclared identifier is reported only once for each function it appears in
>      450 | #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
>          |                                            ^~~~~~~~~~~~~~~~~
>    include/linux/mm.h:453:55: note: in expansion of macro 'TASK_EXEC'
>      453 | #define VM_DATA_FLAGS_TSK_EXEC  (VM_READ | VM_WRITE | TASK_EXEC | \
>          |                                                       ^~~~~~~~~
>    arch/mips/include/asm/page.h:215:33: note: in expansion of macro 'VM_DATA_FLAGS_TSK_EXEC'
>      215 | #define VM_DATA_DEFAULT_FLAGS   VM_DATA_FLAGS_TSK_EXEC
>          |                                 ^~~~~~~~~~~~~~~~~~~~~~
>    mm/vma.c:2503:18: note: in expansion of macro 'VM_DATA_DEFAULT_FLAGS'
>     2503 |         flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
>          |                  ^~~~~~~~~~~~~~~~~~~~~
>
>
> vim +/READ_IMPLIES_EXEC +450 include/linux/mm.h
>
> a8bef8ff6ea15fa Mel Gorman        2010-05-24  449
> c62da0c35d58518 Anshuman Khandual 2020-04-10 @450  #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
> c62da0c35d58518 Anshuman Khandual 2020-04-10  451
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
kernel test robot Dec. 4, 2024, 1:10 p.m. UTC | #4 
Hi Lorenzo,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Lorenzo-Stoakes/mm-vma-move-brk-internals-to-mm-vma-c/20241204-115150
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/3d24b9e67bb0261539ca921d1188a10a1b4d4357.1733248985.git.lorenzo.stoakes%40oracle.com
patch subject: [PATCH 1/5] mm/vma: move brk() internals to mm/vma.c
config: mips-ath25_defconfig (https://download.01.org/0day-ci/archive/20241204/202412042012.zymuBpfD-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 592c0fe55f6d9a811028b5f3507be91458ab2713)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241204/202412042012.zymuBpfD-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202412042012.zymuBpfD-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from mm/vma.c:7:
   In file included from mm/vma_internal.h:12:
   In file included from include/linux/backing-dev.h:16:
   In file included from include/linux/writeback.h:13:
   In file included from include/linux/blk_types.h:10:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:8:
   In file included from include/linux/cacheflush.h:5:
   In file included from arch/mips/include/asm/cacheflush.h:13:
   In file included from include/linux/mm.h:2223:
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   In file included from mm/vma.c:7:
   In file included from mm/vma_internal.h:29:
   include/linux/mm_inline.h:47:41: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
      47 |         __mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
         |                                    ~~~~~~~~~~~ ^ ~~~
   include/linux/mm_inline.h:49:22: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
      49 |                                 NR_ZONE_LRU_BASE + lru, nr_pages);
         |                                 ~~~~~~~~~~~~~~~~ ^ ~~~
>> mm/vma.c:2503:11: error: use of undeclared identifier 'READ_IMPLIES_EXEC'
    2503 |         flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
         |                  ^
   arch/mips/include/asm/page.h:215:31: note: expanded from macro 'VM_DATA_DEFAULT_FLAGS'
     215 | #define VM_DATA_DEFAULT_FLAGS   VM_DATA_FLAGS_TSK_EXEC
         |                                 ^
   include/linux/mm.h:453:54: note: expanded from macro 'VM_DATA_FLAGS_TSK_EXEC'
     453 | #define VM_DATA_FLAGS_TSK_EXEC  (VM_READ | VM_WRITE | TASK_EXEC | \
         |                                                       ^
   include/linux/mm.h:450:44: note: expanded from macro 'TASK_EXEC'
     450 | #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
         |                                            ^
   3 warnings and 1 error generated.


vim +/READ_IMPLIES_EXEC +2503 mm/vma.c

  2481	
  2482	/*
  2483	 * do_brk_flags() - Increase the brk vma if the flags match.
  2484	 * @vmi: The vma iterator
  2485	 * @addr: The start address
  2486	 * @len: The length of the increase
  2487	 * @vma: The vma,
  2488	 * @flags: The VMA Flags
  2489	 *
  2490	 * Extend the brk VMA from addr to addr + len.  If the VMA is NULL or the flags
  2491	 * do not match then create a new anonymous VMA.  Eventually we may be able to
  2492	 * do some brk-specific accounting here.
  2493	 */
  2494	int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
  2495			 unsigned long addr, unsigned long len, unsigned long flags)
  2496	{
  2497		struct mm_struct *mm = current->mm;
  2498	
  2499		/*
  2500		 * Check against address space limits by the changed size
  2501		 * Note: This happens *after* clearing old mappings in some code paths.
  2502		 */
> 2503		flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
diff mbox series

Patch

diff --git a/mm/mmap.c b/mm/mmap.c
index 16f8e8be01f8..93188ef46dae 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -111,8 +111,7 @@  static int check_brk_limits(unsigned long addr, unsigned long len)
 	return mlock_future_ok(current->mm, current->mm->def_flags, len)
 		? 0 : -EAGAIN;
 }
-static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *brkvma,
-		unsigned long addr, unsigned long request, unsigned long flags);
+
 SYSCALL_DEFINE1(brk, unsigned long, brk)
 {
 	unsigned long newbrk, oldbrk, origbrk;
@@ -1512,88 +1511,6 @@  SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 	return ret;
 }
 
-/*
- * do_brk_flags() - Increase the brk vma if the flags match.
- * @vmi: The vma iterator
- * @addr: The start address
- * @len: The length of the increase
- * @vma: The vma,
- * @flags: The VMA Flags
- *
- * Extend the brk VMA from addr to addr + len.  If the VMA is NULL or the flags
- * do not match then create a new anonymous VMA.  Eventually we may be able to
- * do some brk-specific accounting here.
- */
-static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
-		unsigned long addr, unsigned long len, unsigned long flags)
-{
-	struct mm_struct *mm = current->mm;
-
-	/*
-	 * Check against address space limits by the changed size
-	 * Note: This happens *after* clearing old mappings in some code paths.
-	 */
-	flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
-	if (!may_expand_vm(mm, flags, len >> PAGE_SHIFT))
-		return -ENOMEM;
-
-	if (mm->map_count > sysctl_max_map_count)
-		return -ENOMEM;
-
-	if (security_vm_enough_memory_mm(mm, len >> PAGE_SHIFT))
-		return -ENOMEM;
-
-	/*
-	 * Expand the existing vma if possible; Note that singular lists do not
-	 * occur after forking, so the expand will only happen on new VMAs.
-	 */
-	if (vma && vma->vm_end == addr) {
-		VMG_STATE(vmg, mm, vmi, addr, addr + len, flags, PHYS_PFN(addr));
-
-		vmg.prev = vma;
-		/* vmi is positioned at prev, which this mode expects. */
-		vmg.merge_flags = VMG_FLAG_JUST_EXPAND;
-
-		if (vma_merge_new_range(&vmg))
-			goto out;
-		else if (vmg_nomem(&vmg))
-			goto unacct_fail;
-	}
-
-	if (vma)
-		vma_iter_next_range(vmi);
-	/* create a vma struct for an anonymous mapping */
-	vma = vm_area_alloc(mm);
-	if (!vma)
-		goto unacct_fail;
-
-	vma_set_anonymous(vma);
-	vma_set_range(vma, addr, addr + len, addr >> PAGE_SHIFT);
-	vm_flags_init(vma, flags);
-	vma->vm_page_prot = vm_get_page_prot(flags);
-	vma_start_write(vma);
-	if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL))
-		goto mas_store_fail;
-
-	mm->map_count++;
-	validate_mm(mm);
-	ksm_add_vma(vma);
-out:
-	perf_event_mmap(vma);
-	mm->total_vm += len >> PAGE_SHIFT;
-	mm->data_vm += len >> PAGE_SHIFT;
-	if (flags & VM_LOCKED)
-		mm->locked_vm += (len >> PAGE_SHIFT);
-	vm_flags_set(vma, VM_SOFTDIRTY);
-	return 0;
-
-mas_store_fail:
-	vm_area_free(vma);
-unacct_fail:
-	vm_unacct_memory(len >> PAGE_SHIFT);
-	return -ENOMEM;
-}
-
 int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
 {
 	struct mm_struct *mm = current->mm;
diff --git a/mm/vma.c b/mm/vma.c
index 8e31b7e25aeb..9955b5332ca2 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -2478,3 +2478,85 @@  unsigned long __mmap_region(struct file *file, unsigned long addr,
 	vms_abort_munmap_vmas(&map.vms, &map.mas_detach);
 	return error;
 }
+
+/*
+ * do_brk_flags() - Increase the brk vma if the flags match.
+ * @vmi: The vma iterator
+ * @addr: The start address
+ * @len: The length of the increase
+ * @vma: The vma,
+ * @flags: The VMA Flags
+ *
+ * Extend the brk VMA from addr to addr + len.  If the VMA is NULL or the flags
+ * do not match then create a new anonymous VMA.  Eventually we may be able to
+ * do some brk-specific accounting here.
+ */
+int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
+		 unsigned long addr, unsigned long len, unsigned long flags)
+{
+	struct mm_struct *mm = current->mm;
+
+	/*
+	 * Check against address space limits by the changed size
+	 * Note: This happens *after* clearing old mappings in some code paths.
+	 */
+	flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
+	if (!may_expand_vm(mm, flags, len >> PAGE_SHIFT))
+		return -ENOMEM;
+
+	if (mm->map_count > sysctl_max_map_count)
+		return -ENOMEM;
+
+	if (security_vm_enough_memory_mm(mm, len >> PAGE_SHIFT))
+		return -ENOMEM;
+
+	/*
+	 * Expand the existing vma if possible; Note that singular lists do not
+	 * occur after forking, so the expand will only happen on new VMAs.
+	 */
+	if (vma && vma->vm_end == addr) {
+		VMG_STATE(vmg, mm, vmi, addr, addr + len, flags, PHYS_PFN(addr));
+
+		vmg.prev = vma;
+		/* vmi is positioned at prev, which this mode expects. */
+		vmg.merge_flags = VMG_FLAG_JUST_EXPAND;
+
+		if (vma_merge_new_range(&vmg))
+			goto out;
+		else if (vmg_nomem(&vmg))
+			goto unacct_fail;
+	}
+
+	if (vma)
+		vma_iter_next_range(vmi);
+	/* create a vma struct for an anonymous mapping */
+	vma = vm_area_alloc(mm);
+	if (!vma)
+		goto unacct_fail;
+
+	vma_set_anonymous(vma);
+	vma_set_range(vma, addr, addr + len, addr >> PAGE_SHIFT);
+	vm_flags_init(vma, flags);
+	vma->vm_page_prot = vm_get_page_prot(flags);
+	vma_start_write(vma);
+	if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL))
+		goto mas_store_fail;
+
+	mm->map_count++;
+	validate_mm(mm);
+	ksm_add_vma(vma);
+out:
+	perf_event_mmap(vma);
+	mm->total_vm += len >> PAGE_SHIFT;
+	mm->data_vm += len >> PAGE_SHIFT;
+	if (flags & VM_LOCKED)
+		mm->locked_vm += (len >> PAGE_SHIFT);
+	vm_flags_set(vma, VM_SOFTDIRTY);
+	return 0;
+
+mas_store_fail:
+	vm_area_free(vma);
+unacct_fail:
+	vm_unacct_memory(len >> PAGE_SHIFT);
+	return -ENOMEM;
+}
diff --git a/mm/vma.h b/mm/vma.h
index 388d34748674..83a15d3a8285 100644
--- a/mm/vma.h
+++ b/mm/vma.h
@@ -247,6 +247,9 @@  unsigned long __mmap_region(struct file *file, unsigned long addr,
 		unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
 		struct list_head *uf);
 
+int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *brkvma,
+		 unsigned long addr, unsigned long request, unsigned long flags);
+
 static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma)
 {
 	/*
diff --git a/tools/testing/vma/vma_internal.h b/tools/testing/vma/vma_internal.h
index e76ff579e1fd..7c3c15135c5b 100644
--- a/tools/testing/vma/vma_internal.h
+++ b/tools/testing/vma/vma_internal.h
@@ -39,6 +39,7 @@ 
 #define VM_SHARED	0x00000008
 #define VM_MAYREAD	0x00000010
 #define VM_MAYWRITE	0x00000020
+#define VM_MAYEXEC	0x00000040
 #define VM_GROWSDOWN	0x00000100
 #define VM_PFNMAP	0x00000400
 #define VM_LOCKED	0x00002000
@@ -58,6 +59,13 @@ 
 /* This mask represents all the VMA flag bits used by mlock */
 #define VM_LOCKED_MASK	(VM_LOCKED | VM_LOCKONFAULT)
 
+#define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
+
+#define VM_DATA_FLAGS_TSK_EXEC	(VM_READ | VM_WRITE | TASK_EXEC | \
+				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
+
 #ifdef CONFIG_64BIT
 /* VM is sealed, in vm_flags */
 #define VM_SEALED	_BITUL(63)
@@ -122,10 +130,22 @@  enum {
 	TASK_COMM_LEN = 16,
 };
 
+/*
+ * Flags for bug emulation.
+ *
+ * These occupy the top three bytes.
+ */
+enum {
+	READ_IMPLIES_EXEC =	0x0400000,
+};
+
 struct task_struct {
 	char comm[TASK_COMM_LEN];
 	pid_t pid;
 	struct mm_struct *mm;
+
+	/* Used for emulating ABI behavior of previous Linux versions: */
+	unsigned int			personality;
 };
 
 struct task_struct *get_current(void);
@@ -186,6 +206,8 @@  struct mm_struct {
 	unsigned long data_vm;	   /* VM_WRITE & ~VM_SHARED & ~VM_STACK */
 	unsigned long exec_vm;	   /* VM_EXEC & ~VM_WRITE & ~VM_STACK */
 	unsigned long stack_vm;	   /* VM_STACK */
+
+	unsigned long def_flags;
 };
 
 struct vma_lock {