From 6d065f507d82307d6161ac75c025111fb8b08a46 Mon Sep 17 00:00:00 2001 From: Yuanyuan Zhong Date: Thu, 23 May 2024 12:35:31 -0600 Subject: [PATCH] mm: /proc/pid/smaps_rollup: avoid skipping vma after getting mmap_lock again 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. Otherwise, with some VMAs skipped, userspace observed memory consumption from /proc/pid/smaps_rollup will be smaller than the sum of the corresponding fields from /proc/pid/smaps. Link: https://lkml.kernel.org/r/20240523183531.2535436-1-yzhong@purestorage.com Fixes: c4c84f06285e ("fs/proc/task_mmu: stop using linked list and highest_vm_end") Signed-off-by: Yuanyuan Zhong Reviewed-by: Mohamed Khalfella Cc: David Hildenbrand Cc: Matthew Wilcox (Oracle) Cc: Signed-off-by: Andrew Morton --- 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);