mm/smaps_rollup: return empty file for kthreads instead of ESRCH

This restores the behavior prior to 258f669e7e88 ("mm:
/proc/pid/smaps_rollup: convert to single value seq_file"), making it once
again consistent with maps and smaps, and allowing patterns like awk
'$1=="Anonymous:"{x+=$2}END{print x}' /proc/*/smaps_rollup to work.
Searching all Debian packages for "smaps_rollup" did not find any programs
which would be affected by this change.

Link: https://lkml.kernel.org/r/20220413211357.26938-1-alex_y_xu@yahoo.ca
Fixes: 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file")
Signed-off-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f46060eb91b5cb1c4c64be687aa2c873de43ce20..d7de4584a27141677bb7a7e3fae945dd1b90f190 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -883,10 +883,8 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
                return -ESRCH;
 
        mm = priv->mm;
-       if (!mm || !mmget_not_zero(mm)) {
-               ret = -ESRCH;
+       if (!mm || !mmget_not_zero(mm))
                goto out_put_task;
-       }
 
        memset(&mss, 0, sizeof(mss));