FAILED: patch "[PATCH] mm: /proc/pid/smaps_rollup: avoid skipping vma after getting" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] mm: /proc/pid/smaps_rollup: avoid skipping vma after getting" failed to apply to 6.1-stable tree

[gregkh]

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 6d065f507d82307d6161ac75c025111fb8b08a46
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024061335-lunchbox-playroom-cf81@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

6d065f507d82 ("mm: /proc/pid/smaps_rollup: avoid skipping vma after getting mmap_lock again")
250cb40f0afe ("task_mmu: convert to vma iterator")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6d065f507d82307d6161ac75c025111fb8b08a46 Mon Sep 17 00:00:00 2001
From: Yuanyuan Zhong <yzhong@purestorage.com>
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 <yzhong@purestorage.com>
Reviewed-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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);