+ mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch added to mm-unstable branch

+ mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/mmap: fix return on maple tree expand fail in brk()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Liam Howlett <liam.howlett@oracle.com>
Subject: mm/mmap: fix return on maple tree expand fail in brk()
Date: Tue, 12 Jul 2022 14:51:08 +0000

When do_brk_flags() fails, ensure the necessary locking is undone.

Link: https://lkml.kernel.org/r/20220712145059.4191132-1-Liam.Howlett@oracle.com
Fixes: e9bad648fe05 (mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap())
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mmap.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/mm/mmap.c~mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix
+++ a/mm/mmap.c
@@ -2965,7 +2965,7 @@ static int do_brk_flags(struct ma_state
 		vma->vm_end = addr + len;
 		vma->vm_flags |= VM_SOFTDIRTY;
 		if (mas_store_gfp(mas, vma, GFP_KERNEL))
-			return -ENOMEM;
+			goto mas_expand_failed;
 
 		if (vma->anon_vma) {
 			anon_vma_interval_tree_post_update_vma(vma);
@@ -3013,6 +3013,13 @@ mas_store_fail:
 vma_alloc_fail:
 	vm_unacct_memory(len >> PAGE_SHIFT);
 	return -ENOMEM;
+
+mas_expand_failed:
+	if (vma->anon_vma) {
+		anon_vma_interval_tree_post_update_vma(vma);
+		anon_vma_unlock_write(vma->anon_vma);
+	}
+	return -ENOMEM;
 }
 
 int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
_

Patches currently in -mm which might be from liam.howlett@oracle.com are

android-binder-fix-lockdep-check-on-clearing-vma.patch
maple-tree-add-new-data-structure-fix.patch
maple-tree-add-new-data-structure-fix-2.patch
maple-tree-add-new-data-structure-fix-3.patch
maple-tree-add-new-data-structure-fix-4.patch
lib-test_maple_tree-add-testing-for-maple-tree-fix.patch
lib-test_maple_tree-add-testing-for-maple-tree-fix-2.patch
lib-test_maple_tree-add-testing-for-maple-tree-fix-3.patch
mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch
mm-remove-the-vma-linked-list-fix-3.patch
mm-mlock-drop-dead-code-in-count_mm_mlocked_page_nr.patch

+ mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mmap: remove do_brk_munmap() optimization
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Liam Howlett <liam.howlett@oracle.com>
Subject: mmap: remove do_brk_munmap() optimization
Date: Tue, 19 Jul 2022 19:14:01 +0000

This optimization does not work with the locking.

Link: https://lkml.kernel.org/r/20220719191352.3366482-2-Liam.Howlett@oracle.com
Fixes: f12fee814843 (mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap())
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mmap.c |   61 +---------------------------------------------------
 1 file changed, 2 insertions(+), 59 deletions(-)

--- a/mm/mmap.c~mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix
+++ a/mm/mmap.c
@@ -2809,67 +2809,10 @@ static int do_brk_munmap(struct ma_state
 			 struct list_head *uf)
 {
 	struct mm_struct *mm = vma->vm_mm;
-	struct vm_area_struct unmap;
-	unsigned long unmap_pages;
-	int ret = 1;
+	int ret;
 
 	arch_unmap(mm, newbrk, oldbrk);
-
-	if (likely((vma->vm_end < oldbrk) ||
-		   ((vma->vm_start == newbrk) && (vma->vm_end == oldbrk)))) {
-		/* remove entire mapping(s) */
-		mas_set(mas, newbrk);
-		if (vma->vm_start != newbrk)
-			mas_reset(mas); /* cause a re-walk for the first overlap. */
-		ret = __do_munmap(mm, newbrk, oldbrk - newbrk, uf, true);
-		goto munmap_full_vma;
-	}
-
-	vma_init(&unmap, mm);
-	unmap.vm_start = newbrk;
-	unmap.vm_end = oldbrk;
-	ret = userfaultfd_unmap_prep(&unmap, newbrk, oldbrk, uf);
-	if (ret)
-		return ret;
-	ret = 1;
-
-	/* Change the oldbrk of vma to the newbrk of the munmap area */
-	vma_adjust_trans_huge(vma, vma->vm_start, newbrk, 0);
-	if (mas_preallocate(mas, vma, GFP_KERNEL))
-		return -ENOMEM;
-
-	if (vma->anon_vma) {
-		anon_vma_lock_write(vma->anon_vma);
-		anon_vma_interval_tree_pre_update_vma(vma);
-	}
-
-	vma->vm_end = newbrk;
-	vma_init(&unmap, mm);
-	unmap.vm_start = newbrk;
-	unmap.vm_end = oldbrk;
-	if (vma->anon_vma)
-		vma_set_anonymous(&unmap);
-
-	vma_mas_remove(&unmap, mas);
-
-	vmacache_invalidate(vma->vm_mm);
-	if (vma->anon_vma) {
-		anon_vma_interval_tree_post_update_vma(vma);
-		anon_vma_unlock_write(vma->anon_vma);
-	}
-
-	unmap_pages = vma_pages(&unmap);
-	if (vma->vm_flags & VM_LOCKED)
-		mm->locked_vm -= unmap_pages;
-
-	mmap_write_downgrade(mm);
-	unmap_region(mm, &unmap, vma, newbrk, oldbrk);
-	/* Statistics */
-	vm_stat_account(mm, vma->vm_flags, -unmap_pages);
-	if (vma->vm_flags & VM_ACCOUNT)
-		vm_unacct_memory(unmap_pages);
-
-munmap_full_vma:
+	ret = __do_munmap(mm, newbrk, oldbrk - newbrk, uf, true);
 	validate_mm_mt(mm);
 	return ret;
 }
_

Patches currently in -mm which might be from liam.howlett@oracle.com are

android-binder-fix-lockdep-check-on-clearing-vma.patch
maple-tree-add-new-data-structure-fix.patch
maple-tree-add-new-data-structure-fix-2.patch
mm-start-tracking-vmas-with-maple-tree-fix.patch
mm-mmap-use-maple-tree-for-unmapped_area_topdown-fix.patch
mm-mmap-change-do_brk_flags-to-expand-existing-vma-and-add-do_brk_munmap-fix.patch
mm-mmap-use-advanced-maple-tree-api-for-mmap_region-fix.patch
mm-mlock-drop-dead-code-in-count_mm_mlocked_page_nr.patch