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708a507af0
Refresh kernel patches for generic kernel 5.15 due to new backport version of MGLRU patchset. Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
57 lines
1.7 KiB
Diff
57 lines
1.7 KiB
Diff
From c7dfefd4bdfba3d5171038d1cc2d4160288e6ee4 Mon Sep 17 00:00:00 2001
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From: Yu Zhao <yuzhao@google.com>
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Date: Sun, 15 Jan 2023 20:44:05 -0700
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Subject: [PATCH 16/29] mm: multi-gen LRU: fix crash during cgroup migration
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lru_gen_migrate_mm() assumes lru_gen_add_mm() runs prior to itself. This
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isn't true for the following scenario:
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CPU 1 CPU 2
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clone()
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cgroup_can_fork()
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cgroup_procs_write()
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cgroup_post_fork()
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task_lock()
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lru_gen_migrate_mm()
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task_unlock()
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task_lock()
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lru_gen_add_mm()
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task_unlock()
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And when the above happens, kernel crashes because of linked list
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corruption (mm_struct->lru_gen.list).
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Link: https://lore.kernel.org/r/20230115134651.30028-1-msizanoen@qtmlabs.xyz/
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Link: https://lkml.kernel.org/r/20230116034405.2960276-1-yuzhao@google.com
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Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks")
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Signed-off-by: Yu Zhao <yuzhao@google.com>
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Reported-by: msizanoen <msizanoen@qtmlabs.xyz>
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Tested-by: msizanoen <msizanoen@qtmlabs.xyz>
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Cc: <stable@vger.kernel.org> [6.1+]
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Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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---
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mm/vmscan.c | 5 ++++-
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1 file changed, 4 insertions(+), 1 deletion(-)
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--- a/mm/vmscan.c
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+++ b/mm/vmscan.c
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@@ -3024,13 +3024,16 @@ void lru_gen_migrate_mm(struct mm_struct
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if (mem_cgroup_disabled())
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return;
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+ /* migration can happen before addition */
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+ if (!mm->lru_gen.memcg)
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+ return;
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+
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rcu_read_lock();
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memcg = mem_cgroup_from_task(task);
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rcu_read_unlock();
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if (memcg == mm->lru_gen.memcg)
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return;
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- VM_WARN_ON_ONCE(!mm->lru_gen.memcg);
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VM_WARN_ON_ONCE(list_empty(&mm->lru_gen.list));
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lru_gen_del_mm(mm);
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