ci2 starts bisection 2024-07-03 12:14:47.392179948 +0000 UTC m=+28935.542443395 bisecting fixing commit since dcb09569bbff14d203a6b2ffa40da7b724665e31 building syzkaller on af24b0505c748561efb50f1d03c824d6642f6c0b ensuring issue is reproducible on original commit dcb09569bbff14d203a6b2ffa40da7b724665e31 testing commit dcb09569bbff14d203a6b2ffa40da7b724665e31 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 79db5651252130f28e45b9339a2e2ac0d2605af16d3b83d2a840debb550816ad run #0: crashed: BUG: scheduling while atomic in do_task_dead run #1: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #2: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #3: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #4: crashed: BUG: scheduling while atomic in do_task_dead run #5: crashed: BUG: scheduling while atomic in do_task_dead run #6: crashed: BUG: scheduling while atomic in ext4_buffered_write_iter run #7: crashed: UBSAN: array-index-out-of-bounds in bpf_bprintf_prepare run #8: crashed: BUG: scheduling while atomic in do_task_dead run #9: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #10: crashed: UBSAN: array-index-out-of-bounds in bpf_bprintf_prepare run #11: crashed: BUG: scheduling while atomic in folio_wait_bit_common run #12: crashed: BUG: scheduling while atomic in do_task_dead run #13: crashed: BUG: scheduling while atomic in do_task_dead run #14: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #15: crashed: BUG: scheduling while atomic in folio_wait_bit_common run #16: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #17: crashed: BUG: soft lockup in corrupted run #18: crashed: BUG: soft lockup in corrupted run #19: crashed: BUG: soft lockup in corrupted representative crash: BUG: scheduling while atomic in do_task_dead, types: [ATOMIC_SLEEP] check whether we can drop unnecessary instrumentation disabling configs for [LOCKDEP HANG LEAK UBSAN BUG KASAN], they are not needed testing commit dcb09569bbff14d203a6b2ffa40da7b724665e31 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 056a15a2f7323743c38a20481f2445b1da453df44f6e6a7c533c2a1ce937c486 run #0: crashed: BUG: scheduling while atomic in do_task_dead run #1: crashed: BUG: scheduling while atomic in do_task_dead run #2: crashed: BUG: scheduling while atomic in do_task_dead run #3: crashed: BUG: scheduling while atomic in do_task_dead run #4: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #5: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #6: crashed: BUG: workqueue lockup run #7: crashed: BUG: workqueue lockup run #8: crashed: BUG: workqueue lockup run #9: crashed: BUG: workqueue lockup representative crash: BUG: scheduling while atomic in do_task_dead, types: [ATOMIC_SLEEP UNKNOWN] the bug reproduces without the instrumentation disabling configs for [BUG KASAN LOCKDEP HANG LEAK UBSAN], they are not needed kconfig minimization: base=5179 full=6491 leaves diff=256 split chunks (needed=false): <256> split chunk #0 of len 256 into 5 parts testing without sub-chunk 1/5 disabling configs for [HANG LEAK UBSAN BUG KASAN LOCKDEP], they are not needed testing commit dcb09569bbff14d203a6b2ffa40da7b724665e31 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 17c78b21620f2b46c785cbf0fe91aa7b840bcb2c76385b3879c183b13389875f run #0: crashed: BUG: scheduling while atomic in do_task_dead run #1: crashed: BUG: scheduling while atomic in ext4_buffered_write_iter run #2: crashed: BUG: workqueue lockup run #3: crashed: BUG: workqueue lockup run #4: crashed: BUG: workqueue lockup run #5: crashed: BUG: workqueue lockup run #6: crashed: BUG: workqueue lockup run #7: crashed: BUG: workqueue lockup run #8: crashed: BUG: workqueue lockup run #9: crashed: BUG: workqueue lockup representative crash: BUG: workqueue lockup, types: [UNKNOWN] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [HANG LEAK UBSAN BUG KASAN LOCKDEP], they are not needed testing commit dcb09569bbff14d203a6b2ffa40da7b724665e31 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 307b5134182782f4797a9cd3901c173d7e3cd9043299e154f8605fc598520bc6 run #0: crashed: BUG: scheduling while atomic in do_task_dead run #1: crashed: BUG: scheduling while atomic in do_task_dead run #2: crashed: BUG: scheduling while atomic in do_task_dead run #3: crashed: BUG: scheduling while atomic in do_task_dead run #4: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #5: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #6: crashed: BUG: workqueue lockup run #7: crashed: BUG: workqueue lockup run #8: crashed: BUG: workqueue lockup run #9: crashed: BUG: workqueue lockup representative crash: BUG: scheduling while atomic in do_task_dead, types: [ATOMIC_SLEEP UNKNOWN] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [UBSAN BUG KASAN LOCKDEP HANG LEAK], they are not needed testing commit dcb09569bbff14d203a6b2ffa40da7b724665e31 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 12358a66bfa522f59923e2391a304b4c9c20d9b26aa46f8f8b2233a270a0c6db run #0: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #1: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #2: crashed: BUG: scheduling while atomic in do_task_dead run #3: crashed: BUG: scheduling while atomic in do_task_dead run #4: crashed: BUG: scheduling while atomic in ext4_buffered_write_iter run #5: crashed: BUG: scheduling while atomic in do_task_dead run #6: crashed: BUG: workqueue lockup run #7: crashed: BUG: workqueue lockup run #8: crashed: BUG: workqueue lockup run #9: crashed: BUG: workqueue lockup representative crash: BUG: scheduling while atomic in exit_to_user_mode_loop, types: [ATOMIC_SLEEP UNKNOWN] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [LEAK UBSAN BUG KASAN LOCKDEP HANG], they are not needed testing commit dcb09569bbff14d203a6b2ffa40da7b724665e31 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 1a008faa534c031b5ff8f260b1c226e802e5493f5300e5109d2a64e9a4db3c00 run #0: crashed: BUG: scheduling while atomic in folio_wait_bit_common run #1: crashed: BUG: scheduling while atomic in do_task_dead run #2: crashed: BUG: scheduling while atomic in do_task_dead run #3: crashed: BUG: scheduling while atomic in ext4_buffered_write_iter run #4: crashed: BUG: scheduling while atomic in do_task_dead run #5: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #6: crashed: BUG: scheduling while atomic in ext4_buffered_write_iter run #7: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #8: crashed: BUG: workqueue lockup run #9: crashed: BUG: workqueue lockup representative crash: BUG: scheduling while atomic in folio_wait_bit_common, types: [ATOMIC_SLEEP] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [LEAK UBSAN BUG KASAN LOCKDEP HANG], they are not needed testing commit dcb09569bbff14d203a6b2ffa40da7b724665e31 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 failed building dcb09569bbff14d203a6b2ffa40da7b724665e31: net/socket.c:1245: undefined reference to `wext_handle_ioctl' net/socket.c:3442: undefined reference to `compat_wext_handle_ioctl' net/core/net-procfs.c:329: undefined reference to `wext_proc_init' net/core/net-procfs.c:345: undefined reference to `wext_proc_exit' minimized to 48 configs; suspects: [HID_ZEROPLUS USB_NET_NET1080 USB_NET_PLUSB USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD USB_OHCI_HCD_PCI USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_PRINTER USB_SERIAL_GENERIC USB_SERIAL_PL2303 USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_TRANCEVIBRATOR USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_WDM V4L2_ASYNC V4L2_FWNODE VIDEO_CAMERA_SENSOR WLAN WLAN_VENDOR_ATH WLAN_VENDOR_ATMEL WLAN_VENDOR_BROADCOM WLAN_VENDOR_INTERSIL WLAN_VENDOR_MARVELL WLAN_VENDOR_MEDIATEK WLAN_VENDOR_MICROCHIP WLAN_VENDOR_PURELIFI WLAN_VENDOR_RALINK WLAN_VENDOR_REALTEK WLAN_VENDOR_RSI WLAN_VENDOR_SILABS WLAN_VENDOR_ZYDAS X86_X32_ABI ZEROPLUS_FF] disabling configs for [HANG LEAK UBSAN BUG KASAN LOCKDEP], they are not needed testing current HEAD 04685279357fb894d1dda3ab734c9052ecb2051a testing commit 04685279357fb894d1dda3ab734c9052ecb2051a gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 591ac96948217f93eeac38792d082ef39883f0d01fce87092b7a2fe82e4f5b7b all runs: OK false negative chance: 0.000 # git bisect start 04685279357fb894d1dda3ab734c9052ecb2051a dcb09569bbff14d203a6b2ffa40da7b724665e31 Bisecting: 1060 revisions left to test after this (roughly 10 steps) [f0acafd6f79fa6068b7fc4af7980ac9bbd14f1d1] x86/efistub: Simplify and clean up handover entry code determine whether the revision contains the guilty commit checking the merge base 883d1a9562083922c6d293e9adad8cca4626adf3 no existing result, test the revision testing commit 883d1a9562083922c6d293e9adad8cca4626adf3 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 042751544423bcc9200ff389bdabf06f029e0db9233f63fd452a2a146108d584 run #0: crashed: BUG: scheduling while atomic in do_task_dead run #1: crashed: BUG: scheduling while atomic in do_task_dead run #2: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #3: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #4: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #5: crashed: BUG: scheduling while atomic in do_task_dead run #6: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #7: crashed: BUG: workqueue lockup run #8: crashed: BUG: workqueue lockup run #9: crashed: BUG: workqueue lockup representative crash: BUG: scheduling while atomic in do_task_dead, types: [ATOMIC_SLEEP UNKNOWN] testing commit f0acafd6f79fa6068b7fc4af7980ac9bbd14f1d1 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 48dec95664e31f2122c9c2abc15d6bff9f0147919e6a562441e5d3e69d02a81b all runs: OK false negative chance: 0.000 # git bisect bad f0acafd6f79fa6068b7fc4af7980ac9bbd14f1d1 Bisecting: 530 revisions left to test after this (roughly 9 steps) [be76ad74a43f90f340f9f479e6b04f02125f6aef] media: ir_toy: fix a memleak in irtoy_tx determine whether the revision contains the guilty commit revision 883d1a9562083922c6d293e9adad8cca4626adf3 crashed and is reachable testing commit be76ad74a43f90f340f9f479e6b04f02125f6aef gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 86962240806e6203af25fccd3af9fa1e8c4fa708b3e5176db5213e31348bc3cc run #0: crashed: BUG: scheduling while atomic in folio_wait_bit_common run #1: crashed: BUG: scheduling while atomic in do_task_dead run #2: crashed: BUG: scheduling while atomic in do_task_dead run #3: crashed: BUG: scheduling while atomic in do_task_dead run #4: crashed: BUG: scheduling while atomic in do_epoll_wait run #5: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #6: crashed: BUG: workqueue lockup run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine representative crash: BUG: scheduling while atomic in folio_wait_bit_common, types: [ATOMIC_SLEEP UNKNOWN] # git bisect good be76ad74a43f90f340f9f479e6b04f02125f6aef Bisecting: 265 revisions left to test after this (roughly 8 steps) [786f089086b505372fb3f4f008d57e7845fff0d8] ARM: ep93xx: Add terminator to gpiod_lookup_table determine whether the revision contains the guilty commit revision 883d1a9562083922c6d293e9adad8cca4626adf3 crashed and is reachable testing commit 786f089086b505372fb3f4f008d57e7845fff0d8 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: e34ded51290b2c71eb858c44294bb95e918815c1a39cc79aa7c5d0d9d7615aa4 all runs: OK false negative chance: 0.000 # git bisect bad 786f089086b505372fb3f4f008d57e7845fff0d8 Bisecting: 132 revisions left to test after this (roughly 7 steps) [51a8f31b939c21994f43e2d01e1a97719c8685df] nfsd: don't take fi_lock in nfsd_break_deleg_cb() determine whether the revision contains the guilty commit revision be76ad74a43f90f340f9f479e6b04f02125f6aef crashed and is reachable testing commit 51a8f31b939c21994f43e2d01e1a97719c8685df gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 0464e5093e18fbb8f167222edca717b8163541c212a3d260b2c99c9cf048c206 run #0: crashed: BUG: scheduling while atomic in do_task_dead run #1: crashed: BUG: scheduling while atomic in do_task_dead run #2: crashed: BUG: scheduling while atomic in do_task_dead run #3: crashed: BUG: scheduling while atomic in do_task_dead run #4: crashed: BUG: scheduling while atomic in folio_wait_bit_common run #5: crashed: BUG: workqueue lockup run #6: crashed: BUG: workqueue lockup run #7: crashed: BUG: workqueue lockup run #8: crashed: no output from test machine run #9: crashed: no output from test machine representative crash: BUG: scheduling while atomic in do_task_dead, types: [ATOMIC_SLEEP UNKNOWN] # git bisect good 51a8f31b939c21994f43e2d01e1a97719c8685df Bisecting: 66 revisions left to test after this (roughly 6 steps) [16b2b31ba886694d9fc06950a1a230adc4357350] nvmet-fcloop: swap the list_add_tail arguments determine whether the revision contains the guilty commit revision be76ad74a43f90f340f9f479e6b04f02125f6aef crashed and is reachable testing commit 16b2b31ba886694d9fc06950a1a230adc4357350 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 9ed2c5120fd0534b9d77065178a56072836d874143bcfcfbb3fcfb07ce39eaef all runs: OK false negative chance: 0.000 # git bisect bad 16b2b31ba886694d9fc06950a1a230adc4357350 Bisecting: 32 revisions left to test after this (roughly 5 steps) [8dda42b1f2e40b7fdd6a039de8558448b9016748] dmaengine: shdma: increase size of 'dev_id' determine whether the revision contains the guilty commit revision 883d1a9562083922c6d293e9adad8cca4626adf3 crashed and is reachable testing commit 8dda42b1f2e40b7fdd6a039de8558448b9016748 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 72dc4f9f1f80ebf317883504c34ff2ecd68b1521a1cfb8ae90c9c01f0de9f737 all runs: OK false negative chance: 0.000 # git bisect bad 8dda42b1f2e40b7fdd6a039de8558448b9016748 Bisecting: 16 revisions left to test after this (roughly 4 steps) [6589f0f72f8edd1fa11adce4eedbd3615f2e78ab] nilfs2: fix potential bug in end_buffer_async_write determine whether the revision contains the guilty commit revision 883d1a9562083922c6d293e9adad8cca4626adf3 crashed and is reachable testing commit 6589f0f72f8edd1fa11adce4eedbd3615f2e78ab gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 243089b9bd2cacdba4089145b6c104483f12d2b4d700f6424527e1f48b0dcbd4 all runs: OK false negative chance: 0.000 # git bisect bad 6589f0f72f8edd1fa11adce4eedbd3615f2e78ab Bisecting: 7 revisions left to test after this (roughly 3 steps) [f3e975828636794a9d4cc27adb14a2f66592d414] bpf: Remove trace_printk_lock determine whether the revision contains the guilty commit revision 883d1a9562083922c6d293e9adad8cca4626adf3 crashed and is reachable testing commit f3e975828636794a9d4cc27adb14a2f66592d414 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 4eaa746b5882c920ad39a6441ada1715a00bc536d604198a549f551d77b4af1a all runs: OK false negative chance: 0.000 # git bisect bad f3e975828636794a9d4cc27adb14a2f66592d414 Bisecting: 3 revisions left to test after this (roughly 2 steps) [380aeff204b903502582019ff067caccbd3399b3] smb: client: fix parsing of SMB3.1.1 POSIX create context determine whether the revision contains the guilty commit revision 883d1a9562083922c6d293e9adad8cca4626adf3 crashed and is reachable testing commit 380aeff204b903502582019ff067caccbd3399b3 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: a228c3be3c00d198ae60c00b90fa9775313918835d5f4e09c07c6c0a8b5c66b9 run #0: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #1: crashed: BUG: scheduling while atomic in folio_wait_bit_common run #2: crashed: BUG: scheduling while atomic in do_task_dead run #3: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #4: crashed: BUG: workqueue lockup run #5: crashed: BUG: workqueue lockup run #6: crashed: BUG: workqueue lockup run #7: crashed: BUG: workqueue lockup run #8: crashed: no output from test machine run #9: crashed: no output from test machine representative crash: BUG: workqueue lockup, types: [UNKNOWN ATOMIC_SLEEP] # git bisect good 380aeff204b903502582019ff067caccbd3399b3 Bisecting: 1 revision left to test after this (roughly 1 step) [f7bbad9561f32dda2c13f6c4d0ca77d301f1c123] bpf: Add struct for bin_args arg in bpf_bprintf_prepare determine whether the revision contains the guilty commit revision be76ad74a43f90f340f9f479e6b04f02125f6aef crashed and is reachable testing commit f7bbad9561f32dda2c13f6c4d0ca77d301f1c123 gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: a2298a0dc919979dd9fca4f2015f56517b95e2abf354a932d7b8b9aff2c9f8be run #0: crashed: BUG: scheduling while atomic in ext4_orphan_del run #1: crashed: BUG: scheduling while atomic in do_task_dead run #2: crashed: BUG: scheduling while atomic in do_task_dead run #3: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #4: crashed: BUG: scheduling while atomic in exit_to_user_mode_loop run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: basic kernel testing failed: failed to copy binary to VM: failed to run ["scp" "-P" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "IdentitiesOnly=yes" "-o" "BatchMode=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "-v" "/tmp/syz-executor3900423640" "root@10.128.1.247:./syz-executor3900423640"]: exit status 255 Executing: program /usr/bin/ssh host 10.128.1.247, user root, command sftp OpenSSH_9.2p1 Debian-2+deb12u2, OpenSSL 3.0.11 19 Sep 2023 debug1: Reading configuration data /dev/null debug1: Connecting to 10.128.1.247 [10.128.1.247] port 22. debug1: fd 3 clearing O_NONBLOCK debug1: Connection established. debug1: identity file /root/.ssh/id_rsa type -1 debug1: identity file /root/.ssh/id_rsa-cert type -1 debug1: identity file /root/.ssh/id_ecdsa type -1 debug1: identity file /root/.ssh/id_ecdsa-cert type -1 debug1: identity file /root/.ssh/id_ecdsa_sk type -1 debug1: identity file /root/.ssh/id_ecdsa_sk-cert type -1 debug1: identity file /root/.ssh/id_ed25519 type -1 debug1: identity file /root/.ssh/id_ed25519-cert type -1 debug1: identity file /root/.ssh/id_ed25519_sk type -1 debug1: identity file /root/.ssh/id_ed25519_sk-cert type -1 debug1: identity file /root/.ssh/id_xmss type -1 debug1: identity file /root/.ssh/id_xmss-cert type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: identity file /root/.ssh/id_dsa-cert type -1 debug1: Local version string SSH-2.0-OpenSSH_9.2p1 Debian-2+deb12u2 Connection timed out during banner exchange Connection to 10.128.1.247 port 22 timed out scp: Connection closed representative crash: BUG: scheduling while atomic in ext4_orphan_del, types: [ATOMIC_SLEEP UNKNOWN] # git bisect good f7bbad9561f32dda2c13f6c4d0ca77d301f1c123 Bisecting: 0 revisions left to test after this (roughly 0 steps) [95b7476f6f68d725c474e3348e89436b0abde62a] bpf: Do cleanup in bpf_bprintf_cleanup only when needed determine whether the revision contains the guilty commit revision f7bbad9561f32dda2c13f6c4d0ca77d301f1c123 crashed and is reachable testing commit 95b7476f6f68d725c474e3348e89436b0abde62a gcc compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: b954b1e95073472d8db03d848059093a7caed8d2bbf097b3ac7c3a3e5c3c0f7b run #0: crashed: lost connection to test machine run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK representative crash: lost connection to test machine, types: [UNKNOWN] # git bisect good 95b7476f6f68d725c474e3348e89436b0abde62a f3e975828636794a9d4cc27adb14a2f66592d414 is the first bad commit commit f3e975828636794a9d4cc27adb14a2f66592d414 Author: Jiri Olsa Date: Thu Dec 15 22:44:30 2022 +0100 bpf: Remove trace_printk_lock commit e2bb9e01d589f7fa82573aedd2765ff9b277816a upstream. Both bpf_trace_printk and bpf_trace_vprintk helpers use static buffer guarded with trace_printk_lock spin lock. The spin lock contention causes issues with bpf programs attached to contention_begin tracepoint [1][2]. Andrii suggested we could get rid of the contention by using trylock, but we could actually get rid of the spinlock completely by using percpu buffers the same way as for bin_args in bpf_bprintf_prepare function. Adding new return 'buf' argument to struct bpf_bprintf_data and making bpf_bprintf_prepare to return also the buffer for printk helpers. [1] https://lore.kernel.org/bpf/CACkBjsakT_yWxnSWr4r-0TpPvbKm9-OBmVUhJb7hV3hY8fdCkw@mail.gmail.com/ [2] https://lore.kernel.org/bpf/CACkBjsaCsTovQHFfkqJKto6S4Z8d02ud1D7MPESrHa1cVNNTrw@mail.gmail.com/ Reported-by: Hao Sun Suggested-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20221215214430.1336195-4-jolsa@kernel.org Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman include/linux/bpf.h | 3 +++ kernel/bpf/helpers.c | 31 +++++++++++++++++++------------ kernel/trace/bpf_trace.c | 20 ++++++-------------- 3 files changed, 28 insertions(+), 26 deletions(-) accumulated error probability: 0.00 culprit signature: 4eaa746b5882c920ad39a6441ada1715a00bc536d604198a549f551d77b4af1a parent signature: b954b1e95073472d8db03d848059093a7caed8d2bbf097b3ac7c3a3e5c3c0f7b reproducer is flaky (0.55 repro chance estimate) revisions tested: 19, total time: 5h58m22.989753567s (build: 2h31m0.410797731s, test: 3h21m5.055386074s) first good commit: f3e975828636794a9d4cc27adb14a2f66592d414 bpf: Remove trace_printk_lock recipients (to): ["cascardo@igalia.com" "daniel@iogearbox.net" "gregkh@linuxfoundation.org" "jolsa@kernel.org" "yhs@fb.com"] recipients (cc): []