Hello, bpf developers. syzbot is reporting circular locking dependency because bpf program is hitting printk() path. To avoid this dependency, something like https://syzkaller.appspot.com/text?tag=Patch&x=121c92fe180000 is needed. Is it possible to call printk_deferred_{enter,exit}() from the bpf side (e.g. bpf_prog_run()) so that we don't need to add overhead on the scheduler side when bpf programs are not registered? printk_deferred_{enter,exit}() requires that printk_deferred_exit() is called on a CPU which printk_deferred_enter() was called, for percpu counter is used. Is migrate_{disable,enable}() also needed around printk_deferred_{enter,exit}() ? On 2023/10/08 15:28, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 7d730f1bf6f3 Add linux-next specific files for 20231005 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=172d36e9680000 > kernel config: https://syzkaller.appspot.com/x/.config?x=f532286be4fff4b5 > dashboard link: https://syzkaller.appspot.com/bug?extid=f78380e4eae53c64125c > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
