[PATCH v12 50/69] bpf: remove VMA linked list

[Liam Howlett]

From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>

Use vma_next() and remove reference to the start of the linked list

Link: https://lkml.kernel.org/r/20220504011345.662299-35-Liam.Howlett@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20220621204632.3370049-51-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
 kernel/bpf/task_iter.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index 8c921799def4..1c8debd42dc9 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -299,8 +299,8 @@ struct bpf_iter_seq_task_vma_info {
 };
 
 enum bpf_task_vma_iter_find_op {
-	task_vma_iter_first_vma,   /* use mm->mmap */
-	task_vma_iter_next_vma,    /* use curr_vma->vm_next */
+	task_vma_iter_first_vma,   /* use find_vma() with addr 0 */
+	task_vma_iter_next_vma,    /* use vma_next() with curr_vma */
 	task_vma_iter_find_vma,    /* use find_vma() to find next vma */
 };
 
@@ -400,10 +400,10 @@ task_vma_seq_get_next(struct bpf_iter_seq_task_vma_info *info)
 
 	switch (op) {
 	case task_vma_iter_first_vma:
-		curr_vma = curr_task->mm->mmap;
+		curr_vma = find_vma(curr_task->mm, 0);
 		break;
 	case task_vma_iter_next_vma:
-		curr_vma = curr_vma->vm_next;
+		curr_vma = find_vma(curr_task->mm, curr_vma->vm_end);
 		break;
 	case task_vma_iter_find_vma:
 		/* We dropped mmap_lock so it is necessary to use find_vma
@@ -417,7 +417,7 @@ task_vma_seq_get_next(struct bpf_iter_seq_task_vma_info *info)
 		if (curr_vma &&
 		    curr_vma->vm_start == info->prev_vm_start &&
 		    curr_vma->vm_end == info->prev_vm_end)
-			curr_vma = curr_vma->vm_next;
+			curr_vma = find_vma(curr_task->mm, curr_vma->vm_end);
 		break;
 	}
 	if (!curr_vma) {
-- 
2.35.1