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From: Yuanyuan Zhong <yzhong@purestorage.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	David Hildenbrand <david@redhat.com>,
	Matthew Wilcox <willy@infradead.org>
Cc: linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org,
	Yuanyuan Zhong <yzhong@purestorage.com>,
	Mohamed Khalfella <mkhalfella@purestorage.com>
Subject: [PATCH] mm: /proc/pid/smaps_rollup: avoid skipping vma after getting mmap_lock again
Date: Thu, 23 May 2024 12:35:31 -0600
Message-Id: <20240523183531.2535436-1-yzhong@purestorage.com>
Precedence: bulk
MIME-Version: 1.0
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After switching smaps_rollup to use VMA iterator, searching for next
entry is part of the condition expression of the do-while loop. So the
current VMA needs to be addressed before the continue statement.

Fixes: c4c84f06285e ("fs/proc/task_mmu: stop using linked list and highest_vm_end")
Signed-off-by: Yuanyuan Zhong <yzhong@purestorage.com>
Reviewed-by: Mohamed Khalfella <mkhalfella@purestorage.com>
---
 fs/proc/task_mmu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index e5a5f015ff03..f8d35f993fe5 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -970,12 +970,17 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
 				break;
 
 			/* Case 1 and 2 above */
-			if (vma->vm_start >= last_vma_end)
+			if (vma->vm_start >= last_vma_end) {
+				smap_gather_stats(vma, &mss, 0);
+				last_vma_end = vma->vm_end;
 				continue;
+			}
 
 			/* Case 4 above */
-			if (vma->vm_end > last_vma_end)
+			if (vma->vm_end > last_vma_end) {
 				smap_gather_stats(vma, &mss, last_vma_end);
+				last_vma_end = vma->vm_end;
+			}
 		}
 	} for_each_vma(vmi, vma);
 
-- 
2.34.1