On Tue, Jan 02, 2024 at 03:45:10PM +0000, Stuart Henderson wrote: > panic: rw_enter: netlock locking against myself > Stopped at db_enter+0x14: popq %rbp > TID PID UID PRFLAGS PFLAGS CPU COMMAND > *388963 11506 755 0x2 0 0 snmpbulkwalk > 320140 61046 0 0x14000 0x200 1 reaper > db_enter() at db_enter+0x14 > panic(ffffffff820ebaaa) at panic+0xc3 > rw_enter(ffffffff824bd2d0,2) at rw_enter+0x252 > hv_kvp(ffffffff8248d738) at hv_kvp+0x705 > hv_event_intr(ffff80000008d000) at hv_event_intr+0x1ab > hv_intr() at hv_intr+0x1a > Xresume_hyperv_upcall() at Xresume_hyperv_upcall+0x27 > Xspllower() at Xspllower+0x1d > task_add(ffff800000036200,ffff8000001533c0) at task_add+0x83 > if_enqueue_ifq(ffff800000153060,fffffd80f6642900) at if_enqueue_ifq+0x6f > ether_output(ffff800000153060,fffffd80f6642900,fffffd80c8ef5c78,fffffd811e6414d8) > at ether_output+0x82 > if_output_tso(ffff800000153060,ffff800025395d08,fffffd80c8ef5c78,fffffd811e6414d8,5dc) > at if_output_tso+0xe1 > ip_output(fffffd80f6642900,0,fffffd80c8ef5c68,0,0,fffffd80c8ef5bf0,1da98542b9d8f733) > at ip_output+0x817 > udp_output(fffffd80c8ef5bf0,fffffd80b468b400,fffffd80ac452c00,0) at > udp_output+0x3be > end trace frame: 0xffff800025395ee0, count: 0 > https://www.openbsd.org/ddb.html describes the minimum info required in bug > reports. Insufficient info makes it difficult to find and fix bugs. > ddb{0}> Stopped at x86_ipi_db+0x16: leave > x86_ipi_db(ffff80002250dff0) at x86_ipi_db+0x16 > x86_ipi_handler() at x86_ipi_handler+0x80 > Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 > _kernel_lock() at _kernel_lock+0xc2 > reaper(ffff80002473c008) at reaper+0x133 > end trace frame: 0x0, count: 10
It is caused by this commit. ---------------------------- revision 1.20 date: 2023/09/23 13:01:12; author: mvs; state: Exp; lines: +5 -9; commitid: Gj5WdkySyube1RkO; Use shared netlock to protect if_list and ifa_list walkthrough and ifnet data access within kvp_get_ip_info(). ok bluhm ---------------------------- Net lock must not be acquired in interrupt context. It is wrong that hv tries to perform network operations from interrupt context. Actually it does not do much networking, it is just reads some interface addresses. The kernel lock that was used before is also questionable. Maybe some writers do not hold it anymore. There was much conversion from kernel to net lock. bluhm
