On 2024/03/20 16:12, Alexei Starovoitov wrote:
> On Wed, Mar 20, 2024 at 12:05 AM Tetsuo Handa
> <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>> On 2024/03/20 15:56, Alexei Starovoitov wrote:
>>> This has nothing to do with bpf.
>>> bpf never calls printk().
>>
>> Please see the Sample crash report in the dashboard.
>> bpf program is hitting printk() via report_bug().
>
> Exactly. local_bh_neable is simply asking for a splat.
> _this_ bug is in printk.
> It's a generic issue.
I can't catch. printk() is called due to report_bug().
If the reason report_bug() is called is that spin_unlock_bh() is bad,
this is a bug in sock_map_delete_elem() rather than a bug in printk(), isn't it.
>
> sockmap bug is orthogonal.
> It's already being looked at.
Then, can we expect that this bug is also fixed shortly?
>
>> -> #0 (console_owner){....}-{0:0}:
>> check_prev_add kernel/locking/lockdep.c:3134 [inline]
>> check_prevs_add kernel/locking/lockdep.c:3253 [inline]
>> validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
>> __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
>> lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
>> console_lock_spinning_enable kernel/printk/printk.c:1873 [inline]
>> console_emit_next_record kernel/printk/printk.c:2901 [inline]
>> console_flush_all+0x810/0xfd0 kernel/printk/printk.c:2973
>> console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3042
>> vprintk_emit+0x5a6/0x770 kernel/printk/printk.c:2342
>> _printk+0xd5/0x120 kernel/printk/printk.c:2367
>> __report_bug lib/bug.c:195 [inline]
>> report_bug+0x346/0x500 lib/bug.c:219
>> handle_bug+0x3e/0x70 arch/x86/kernel/traps.c:239
>> exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:260
>> asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
>> __local_bh_enable_ip+0x1be/0x200 kernel/softirq.c:362
>> spin_unlock_bh include/linux/spinlock.h:396 [inline]
>> __sock_map_delete net/core/sock_map.c:424 [inline]
>> sock_map_delete_elem+0xca/0x140 net/core/sock_map.c:446
>> bpf_prog_2c29ac5cdc6b1842+0x42/0x46
>> bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
>> __bpf_prog_run include/linux/filter.h:657 [inline]
>> bpf_prog_run include/linux/filter.h:664 [inline]
