android/android_kernel_samsung_sm8650
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ANDROID: mm: Fix __vma_adjust() writes for the maple tree

Browse Source 
Only write when necessary to the maple tree.  This should only occur
when the VMA changes.  In the __vma_adjust() case, it is either the vma
when it is expanded, the next vma when the boundary expands into 'vma',
writing the 'insert', or when vma expands/shrinks for shift_arg_pages().

The mas_preallocate() setup should track the intended write to ensure
the correct number of nodes are preallocated for the pending write.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Link: 61b337f650
[surenb: __vma_adjust was removed in 6.3, therefore these fixes are
not applicable upstream anymore. The patch was obtained from the
author's tree]

Bug: 274059236
Change-Id: I69d68a5b4ff11c40985f7b03b31eec4bb24dcbb6
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
This commit is contained in:
Liam R. Howlett 2023-05-01 20:27:52 -04:00 committed by Suren Baghdasaryan
parent b802573f44
commit aede79b81e
1 changed files with 11 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
mm/mmap.c
View File

@ -715,6 +715,13 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
}
}
if (adjust_next < 0)
mas_set_range(&mas, next->vm_start + adjust_next,
next->vm_end - 1);
else if (insert)
mas_set_range(&mas, insert->vm_start, insert->vm_end - 1);
if (mas_preallocate(&mas, vma, GFP_KERNEL))
return -ENOMEM;
@ -759,24 +766,23 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
}
if (start != vma->vm_start) {
if ((vma->vm_start < start) &&
(!insert || (insert->vm_end != start))) {
if ((vma->vm_start < start) && !insert) {
vma_mas_szero(&mas, vma->vm_start, start);
VM_WARN_ON(insert && insert->vm_start > vma->vm_start);
} else {
} else if (!insert) {
vma_changed = true;
}
vma->vm_start = start;
}
if (end != vma->vm_end) {
if (vma->vm_end > end) {
if (!insert || (insert->vm_start != end)) {
if (adjust_next >= 0 && !insert) {
vma_mas_szero(&mas, end, vma->vm_end);
mas_reset(&mas);
VM_WARN_ON(insert &&
insert->vm_end < vma->vm_end);
}
} else {
} else if (!insert) {
vma_changed = true;
}
vma->vm_end = end;