On Mon, Jan 3, 2022 at 5:33 PM Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx> wrote:
>
> The commit 04c7820b776f ("bpf: tcp: Bpf iter batching and lock_sock")
> introduces the batching algorithm to iterate TCP sockets with more
> consistency.
>
> This patch uses the same algorithm to iterate AF_UNIX sockets.
>
> Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx>
There is something wrong in this patch:
./test_progs -t bpf_iter_setsockopt_unix
[ 14.993474] bpf_testmod: loading out-of-tree module taints kernel.
[ 15.068986]
[ 15.069203] =====================================
[ 15.069698] WARNING: bad unlock balance detected!
[ 15.070187] 5.16.0-rc7-01992-g15d8ab86952d #3780 Tainted: G O
[ 15.070937] -------------------------------------
[ 15.071441] test_progs/1438 is trying to release lock
(&unix_table_locks[i]) at:
[ 15.072209] [<ffffffff831b7ae9>] unix_next_socket+0x169/0x460
[ 15.072825] but there are no more locks to release!
[ 15.073329]
[ 15.073329] other info that might help us debug this:
[ 15.074004] 1 lock held by test_progs/1438:
[ 15.074441] #0: ffff8881072c81c8 (&p->lock){+.+.}-{3:3}, at:
bpf_seq_read+0x61/0xfa0
[ 15.075279]
[ 15.075279] stack backtrace:
[ 15.075744] CPU: 0 PID: 1438 Comm: test_progs Tainted: G
O 5.16.0-rc7-01992-g15d8ab86952d #3780
[ 15.076792] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[ 15.077986] Call Trace:
[ 15.078250] <TASK>
[ 15.078476] dump_stack_lvl+0x44/0x57
[ 15.078873] lock_release+0x48e/0x650
[ 15.079262] ? unix_next_socket+0x169/0x460
[ 15.079712] ? lock_downgrade+0x690/0x690
[ 15.080131] ? lock_downgrade+0x690/0x690
[ 15.080559] _raw_spin_unlock+0x17/0x40
[ 15.080979] unix_next_socket+0x169/0x460
[ 15.081402] ? bpf_iter_unix_seq_show+0x20b/0x270
[ 15.081898] bpf_iter_unix_batch+0xf7/0x580
[ 15.082337] ? trace_kmalloc_node+0x29/0xd0
[ 15.082786] bpf_seq_read+0x4a1/0xfa0
[ 15.083176] ? up_read+0x1a1/0x720
[ 15.083538] vfs_read+0x128/0x4e0
[ 15.083902] ksys_read+0xe7/0x1b0
[ 15.084253] ? vfs_write+0x8b0/0x8b0
[ 15.084638] do_syscall_64+0x34/0x80
[ 15.085016] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 15.085545] RIP: 0033:0x7f2c4a5ad8b2
[ 15.085931] Code: 97 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb
b6 0f 1f 80 00 00 00 00 f3 0f 1e fa 8b 05 96 db 20 00 85 c0 75 12 31
c0 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 41 54 49 89 d4 55
48 89
[ 15.087875] RSP: 002b:00007fff4c8c24b8 EFLAGS: 00000246 ORIG_RAX:
0000000000000000
[ 15.088658] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2c4a5ad8b2
[ 15.089396] RDX: 0000000000000001 RSI: 00007fff4c8c24cb RDI: 000000000000000a
[ 15.090132] RBP: 00007fff4c8c2550 R08: 0000000000000000 R09: 00007fff4c8c2397
[ 15.090870] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000040d910
[ 15.091618] R13: 00007fff4c8c2750 R14: 0000000000000000 R15: 0000000000000000
[ 15.092403] </TASK>
I've applied patches 1 and 2 to bpf-next.
