Re: [mainline]Kernel Warnings at kernel/bpf/syscall.c:3374

[Venkat Rao Bagalkote]

+ LKML, netdev

On 10/04/25 10:17 am, Venkat Rao Bagalkote wrote:
> Hello!!
>
>
> I am observing below kernel warnings on IBM Power9 server, while 
> running bpf selftest on mainline kernel.
>
> This issue never seen before good commit[1], and seen intermetently 
> after bad commit[2], and this is not reproducible everytime.
>
> So likely issue got introduced b/w these two commits.
>
> [1]GoodCommit: 7f2ff7b6261742ed52aa973ccdf99151b7cc3a50
> [2]Bad Commit: 08733088b566b58283f0f12fb73f5db6a9a9de30
>
>
> Traces:
>
>
> [34208.591723] ------------[ cut here ]------------
> [34208.591738] WARNING: CPU: 9 PID: 375502 at 
> kernel/bpf/syscall.c:3374 bpf_tracing_link_release+0x90/0xa0
> [34208.591750] Modules linked in: bpf_testmod(OE) 8021q(E) garp(E) 
> mrp(E) vrf(E) tun(E) rpadlpar_io(E) rpaphp(E) vfat(E) fat(E) isofs(E) 
> ext4(E) crc16(E) mbcache(E) jbd2(E) nft_masq(E) veth(E) bridge(E) 
> stp(E) llc(E) overlay(E) bonding(E) nft_fib_inet(E) nft_fib_ipv4(E) 
> nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) 
> nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) rfkill(E) 
> ip_set(E) mlx5_ib(E) ib_uverbs(E) ib_core(E) mlx5_core(E) mlxfw(E) 
> psample(E) tls(E) ibmveth(E) pseries_rng(E) sg(E) vmx_crypto(E) drm(E) 
> fuse(E) dm_mod(E) drm_panel_orientation_quirks(E) xfs(E) lpfc(E) 
> nvmet_fc(E) nvmet(E) sr_mod(E) sd_mod(E) cdrom(E) nvme_fc(E) 
> nvme_fabrics(E) ibmvscsi(E) nvme_core(E) scsi_transport_srp(E) 
> scsi_transport_fc(E) [last unloaded: bpf_test_modorder_x(OE)]
> [34208.591838] CPU: 9 UID: 0 PID: 375502 Comm: test_progs-no_a 
> Tainted: G        W  OE       6.15.0-rc1-ga24588245776 #1 VOLUNTARY
> [34208.591848] Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
> [34208.591852] Hardware name: IBM,8375-42A POWER9 (architected) 
> 0x4e0202 0xf000005 of:IBM,FW950.80 (VL950_131) hv:phyp pSeries
> [34208.591857] NIP:  c00000000049c830 LR: c00000000049c7cc CTR: 
> 0000000000000070
> [34208.591863] REGS: c00000000eb07a60 TRAP: 0700   Tainted: G        
> W  OE        (6.15.0-rc1-ga24588245776)
> [34208.591869] MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 
> 84002482  XER: 00000000
> [34208.591882] CFAR: c00000000049c7d4 IRQMASK: 0
> [34208.591882] GPR00: c00000000049c7cc c00000000eb07d00 
> c000000001da8100 fffffffffffffff2
> [34208.591882] GPR04: 0000000000014ed8 c00000103965d480 
> c0000003415ca800 c0000000b247c900
> [34208.591882] GPR08: 0000000000000000 0000000000000000 
> c0000000b247c900 0000000000002000
> [34208.591882] GPR12: c00000000eb078a8 c000000017ff5300 
> 0000000000000000 0000000000000000
> [34208.591882] GPR16: 0000000000000000 0000000000000000 
> 0000000000000000 0000000000000000
> [34208.591882] GPR20: 0000000000000000 0000000000000000 
> 0000000000000000 0000000000000000
> [34208.591882] GPR24: 0000000000000000 0000000000000000 
> 0000000000000000 c0000003893d6780
> [34208.591882] GPR28: c00000000369a6a0 0000000000000fa4 
> c00000000135d988 c0000000c224bf00
> [34208.591945] NIP [c00000000049c830] bpf_tracing_link_release+0x90/0xa0
> [34208.591953] LR [c00000000049c7cc] bpf_tracing_link_release+0x2c/0xa0
> [34208.591960] Call Trace:
> [34208.591963] [c00000000eb07d00] [c00000000049c7cc] 
> bpf_tracing_link_release+0x2c/0xa0 (unreliable)
> [34208.591973] [c00000000eb07d30] [c00000000049c614] 
> bpf_link_free+0x94/0x160
> [34208.591981] [c00000000eb07d70] [c00000000049c780] 
> bpf_link_release+0x50/0x70
> [34208.591989] [c00000000eb07d90] [c0000000006ee75c] __fput+0x11c/0x3c0
> [34208.591997] [c00000000eb07de0] [c0000000006e46bc] sys_close+0x4c/0xa0
> [34208.592003] [c00000000eb07e10] [c0000000000325a4] 
> system_call_exception+0x114/0x300
> [34208.592012] [c00000000eb07e50] [c00000000000d05c] 
> system_call_vectored_common+0x15c/0x2ec
> [34208.592020] --- interrupt: 3000 at 0x7fff9c40d8a4
> [34208.592030] NIP:  00007fff9c40d8a4 LR: 00007fff9c40d8a4 CTR: 
> 0000000000000000
> [34208.592035] REGS: c00000000eb07e80 TRAP: 3000   Tainted: G        
> W  OE        (6.15.0-rc1-ga24588245776)
> [34208.592041] MSR:  800000000280f033 
> <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE>  CR: 48002886  XER: 00000000
> [34208.592057] IRQMASK: 0
> [34208.592057] GPR00: 0000000000000006 00007fffcce2d650 
> 00007fff9c527100 0000000000000066
> [34208.592057] GPR04: 0000000000000000 0000000000000007 
> 0000000000000004 00007fff9ce5efc0
> [34208.592057] GPR08: 00007fff9ce57908 0000000000000000 
> 0000000000000000 0000000000000000
> [34208.592057] GPR12: 0000000000000000 00007fff9ce5efc0 
> 0000000000000000 0000000000000000
> [34208.592057] GPR16: 0000000000000000 0000000000000000 
> 0000000000000000 0000000000000000
> [34208.592057] GPR20: 0000000000000000 0000000000000000 
> 0000000000000000 00007fff9ce4f470
> [34208.592057] GPR24: 0000000010610b6c 00007fff9ce50000 
> 00007fffcce2e098 0000000000000001
> [34208.592057] GPR28: 00007fffcce2e250 00007fffcce2e088 
> 0000000000000000 0000000000000066
> [34208.592118] NIP [00007fff9c40d8a4] 0x7fff9c40d8a4
> [34208.592122] LR [00007fff9c40d8a4] 0x7fff9c40d8a4
> [34208.592127] --- interrupt: 3000
> [34208.592130] Code: 4bfffc28 60000000 60000000 60000000 38210030 
> e8010010 ebe1fff8 7c0803a6 4e800020 60000000 60000000 60000000 
> <0fe00000> 4bffffa4 60000000 60000000
> [34208.592152] ---[ end trace 0000000000000000 ]---
>
>
> If you happen to fix this issue, please add below tag.
>
>
> Reported-by: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxx>
>
>
> Regards,
>
> Venkat.