2022-08-22 15:39:58

by Liam R. Howlett

Subject: [PATCH v13 35/70] x86: remove vma linked list walks

From: "Matthew Wilcox (Oracle)" <[email protected]>

Use the VMA iterator instead.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Liam R. Howlett <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
---
arch/x86/entry/vdso/vma.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 1000d457c332..6292b960037b 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -127,17 +127,17 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
{
struct mm_struct *mm = task->mm;
struct vm_area_struct *vma;
+ VMA_ITERATOR(vmi, mm, 0);

mmap_read_lock(mm);
-
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ for_each_vma(vmi, vma) {
unsigned long size = vma->vm_end - vma->vm_start;

if (vma_is_special_mapping(vma, &vvar_mapping))
zap_page_range(vma, vma->vm_start, size);
}
-
mmap_read_unlock(mm);
+
return 0;
}
#else
@@ -354,6 +354,7 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
+ VMA_ITERATOR(vmi, mm, 0);

mmap_write_lock(mm);
/*
@@ -363,7 +364,7 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
* We could search vma near context.vdso, but it's a slowpath,
* so let's explicitly check all VMAs to be completely sure.
*/
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ for_each_vma(vmi, vma) {
if (vma_is_special_mapping(vma, &vdso_mapping) ||
vma_is_special_mapping(vma, &vvar_mapping)) {
mmap_write_unlock(mm);
--
2.35.1

2022-08-23 19:50:17

by Davidlohr Bueso

Subject: Re: [PATCH v13 35/70] x86: remove vma linked list walks

On Mon, 22 Aug 2022, Liam Howlett wrote:

>From: "Matthew Wilcox (Oracle)" <[email protected]>
>
>Use the VMA iterator instead.
>
>Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
>Signed-off-by: Liam R. Howlett <[email protected]>
>Acked-by: Vlastimil Babka <[email protected]>

Yeah all these are nice, I always hated the raw for-loop thing.

Reviewed-by: Davidlohr Bueso <[email protected]>