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361e0ff456
When forward-porting Rust Binder to 6.18, I neglected to take commitfb56fdf8b9("mm/list_lru: split the lock to per-cgroup scope") into account, and apparently I did not end up running the shrinker callback when I sanity tested the driver before submission. This leads to crashes like the following: ============================================ WARNING: possible recursive locking detected 6.18.0-mainline-maybe-dirty #1 Tainted: G IO -------------------------------------------- kswapd0/68 is trying to acquire lock: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: lock_list_lru_of_memcg+0x128/0x230 but task is already holding lock: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&l->lock); lock(&l->lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kswapd0/68: #0: ffffffff90d2e260 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x597/0x1160 #1: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20 #2: ffffffff90cf3680 (rcu_read_lock){....}-{1:2}, at: lock_list_lru_of_memcg+0x2d/0x230 To fix this, remove the spin_lock() call from rust_shrink_free_page(). Cc: stable <stable@kernel.org> Fixes:eafedbc7c0("rust_binder: add Rust Binder driver") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20251202-binder-shrink-unspin-v1-1-263efb9ad625@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>