Subject: linux-next: runtime warnings after merge of the bpf-next tree

From: Stephen Rothwell <[email-masked]>
Date: Thu, 1 Feb 2024 14:23:48 +1100

Hi all,

After merging the bpf-next tree, today's linux-next build (powerpc
pseries_le_defconfig) produced these runtime warnings in my qemu boot
tests:

  ipip: IPv4 and MPLS over IPv4 tunneling driver
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c00000000209ba3c CTR: c00000000209b9a4
  REGS: c0000000049bf960 TRAP: 0700   Not tainted  (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000482  XER: 00000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c00000000209ba3c c0000000049bfc00 c0000000015c9900 000000000000001b 
  GPR04: c0000000012bc980 000000000000019a 000000000000019a 0000000000000133 
  GPR08: c000000002969900 0000000000000001 c000000002969900 c000000002969900 
  GPR12: c00000000209b9a4 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1060 
  GPR28: 0000000000000000 0000000000000007 c0000000020c10a8 c000000002968f80 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c00000000209ba3c] cubictcp_register+0x98/0xc8
  Call Trace:
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  NET: Registered PF_INET6 protocol family
	.
	.
	.
  Running code patching self-tests ...
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c00000000204900c CTR: c000000002048fe0
  REGS: c0000000049bf970 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000482  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c00000000204900c c0000000049bfc10 c0000000015c9900 000000000000001a 
  GPR04: c000000001218fb0 0000000000000002 c0000000049bfc02 0000000035b5793c 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 000000009e3fcb99 
  GPR12: c000000002048fe0 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c000000002048fe0 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c00000000204900c] bpf_rstat_kfunc_init+0x2c/0x40
  Call Trace:
  [c0000000049bfc10] [c0000000020c10b0] 0xc0000000020c10b0 (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  registered taskstats version 1
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c000000002050fdc CTR: c000000002050fb8
  REGS: c0000000049bf970 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000482  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c000000002050fdc c0000000049bfc10 c0000000015c9900 000000000000001d 
  GPR04: c000000001223600 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000024000242 
  GPR12: c000000002050fb8 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c000000002050fb8 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c000000002050fdc] bpf_fs_kfuncs_init+0x24/0x38
  Call Trace:
  [c0000000049bfc10] [c0000000020c10b0] 0xc0000000020c10b0 (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c000000002050fa4 CTR: c000000002050f80
  REGS: c0000000049bf970 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000482  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c000000002050fa4 c0000000049bfc10 c0000000015c9900 000000000000001a 
  GPR04: c0000000012235e8 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000024000242 
  GPR12: c000000002050f80 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c000000002050f80 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c000000002050fa4] bpf_key_sig_kfuncs_init+0x24/0x38
  Call Trace:
  [c0000000049bfc10] [c0000000020c10b0] 0xc0000000020c10b0 (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c0000000020517dc CTR: c000000002051790
  REGS: c0000000049bf940 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000422  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c0000000020517dc c0000000049bfbe0 c0000000015c9900 000000000000001a 
  GPR04: c000000001227670 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000024000282 
  GPR12: c000000002051790 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c000000001227670 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c0000000020517dc] kfunc_init+0x4c/0x110
  Call Trace:
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c0000000003976c8 CTR: c00000000039769c
  REGS: c0000000049bf970 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000422  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c0000000003976c8 c0000000049bfc10 c0000000015c9900 0000000000000000 
  GPR04: c000000001228d70 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000024000282 
  GPR12: c00000000039769c c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c00000000039769c 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c0000000003976c8] init_subsystem+0x2c/0x40
  Call Trace:
  [c0000000049bfc10] [c0000000020c10b0] 0xc0000000020c10b0 (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c000000002051ed8 CTR: 0000000000000000
  REGS: c0000000049bf950 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000220  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c000000002051ed8 c0000000049bfbf0 c0000000015c9900 000000000000001a 
  GPR04: c00000000122ad08 0000000000000001 c000000004810c00 c00000007fc92c30 
  GPR08: 0000000000000017 0000000000000001 0000000000000008 0000000024000222 
  GPR12: 0000000000000034 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c00000000122ad08 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c000000002051ed8] cpumask_kfunc_init+0x98/0xf0
  Call Trace:
  [c0000000049bfbf0] [c000000002051e84] cpumask_kfunc_init+0x44/0xf0 (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  Loading compiled-in X.509 certificates
	.
	.
	.
  netconsole: network logging started
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c000000000f0099c CTR: c000000000f00970
  REGS: c0000000049bf970 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000282  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c000000000f0099c c0000000049bfc10 c0000000015c9900 000000000000001a 
  GPR04: c0000000012b12c0 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000000000000 
  GPR12: c000000000f00970 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c000000000f00970 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c000000000f0099c] init_subsystem+0x2c/0x40
  Call Trace:
  [c0000000049bfc10] [c0000000020c10b0] 0xc0000000020c10b0 (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c000000002094ab0 CTR: c000000002094a70
  REGS: c0000000049bf960 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000282  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c000000002094ab0 c0000000049bfc00 c0000000015c9900 0000000000000003 
  GPR04: c0000000012b1260 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000000000000 
  GPR12: c000000002094a70 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000012aef20 c0000000012b1260 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c000000002094ab0] bpf_kfunc_init+0x40/0x18c
  Call Trace:
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c000000002094ccc CTR: c000000002094ca0
  REGS: c0000000049bf970 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000282  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c000000002094ccc c0000000049bfc10 c0000000015c9900 0000000000000006 
  GPR04: c0000000012b25e0 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000000000000 
  GPR12: c000000002094ca0 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c000000002094ca0 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c000000002094ccc] xdp_metadata_init+0x2c/0x40
  Call Trace:
  [c0000000049bfc10] [c0000000020c10b0] 0xc0000000020c10b0 (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c000000002095890 CTR: c000000002095800
  REGS: c0000000049bf940 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24000282  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c000000002095890 c0000000049bfbe0 c0000000015c9900 0000000000000003 
  GPR04: c0000000012b5938 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000000000000 
  GPR12: c000000002095800 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c0000000012b5938 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c000000002095890] bpf_prog_test_run_init+0x90/0xec
  Call Trace:
  [c0000000049bfbe0] [c000000002095848] bpf_prog_test_run_init+0x48/0xec (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  modprobe (54) used greatest stack depth: 28336 bytes left
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x68/0x74
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc2-03380-gd0c0d80c1162 #2
  Hardware name: IBM pSeries (emulated by qemu) POWER8 (raw) 0x4d0200 0xf000004 of:SLOF,HEAD pSeries
  NIP:  c0000000003bfbfc LR: c00000000209bd0c CTR: c00000000209bce0
  REGS: c0000000049bf970 TRAP: 0700   Tainted: G        W           (6.8.0-rc2-03380-gd0c0d80c1162)
  MSR:  800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 24000242  XER: 20000000
  CFAR: c0000000003bfbb0 IRQMASK: 0 
  GPR00: c00000000209bd0c c0000000049bfc10 c0000000015c9900 000000000000001b 
  GPR04: c0000000012bcb28 0000000000000002 c0000000049bfc02 fffffffffffe0000 
  GPR08: 0000000000000000 0000000000000001 0000000000000000 c00000000291fb90 
  GPR12: c00000000209bce0 c000000002b60000 c0000000000110cc 0000000000000000 
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
  GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000014cd250 
  GPR24: c000000002003e6c c000000001582c78 000000000000018b c0000000020c1068 
  GPR28: 0000000000000000 0000000000000008 c0000000020c10b0 c00000000209bce0 
  NIP [c0000000003bfbfc] register_btf_kfunc_id_set+0x68/0x74
  LR [c00000000209bd0c] bpf_tcp_ca_kfunc_init+0x2c/0x74
  Call Trace:
  [c0000000049bfc10] [c0000000020c10b0] 0xc0000000020c10b0 (unreliable)
  [c0000000049bfc30] [c000000000010d58] do_one_initcall+0x80/0x2f8
  [c0000000049bfd00] [c000000002005aec] kernel_init_freeable+0x32c/0x520
  [c0000000049bfde0] [c0000000000110f8] kernel_init+0x34/0x25c
  [c0000000049bfe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
  --- interrupt: 0 at 0x0
  Code: 60420000 3d22ffc6 39290708 7d291a14 89290270 7d290774 79230020 4bfff8c0 60420000 e9240000 7d290074 7929d182 <0b090000> 3860ffea 4e800020 3c4c0121 
  ---[ end trace 0000000000000000 ]---
  Freeing unused kernel image (initmem) memory: 6464K

Exposed (and maybe caused) by commit

  6e7769e6419f ("bpf: treewide: Annotate BPF kfuncs in BTF")

-- 
Cheers,
Stephen Rothwell