Hi, With the latest net-next v6.8-5204-g237bb5f7f7f5 kernel, while running kselftest, there was this trap and stacktrace: This is a vanilla net-next tree kernel, only changes to tools/testing/sefltests Makefile make the build mark it as "dirty". The message was apparently introduced with this patch: https://lore.kernel.org/lkml/20240207185328.GEZcPRqPsNInRXyNMj@fat_crate.local/ Here is the stacktrace: Mar 18 19:46:35 defiant kernel: [ 1859.134913] ------------[ cut here ]------------ Mar 18 19:46:35 defiant kernel: [ 1859.134916] Unpatched return thunk in use. This should not happen! Mar 18 19:46:35 defiant kernel: [ 1859.134919] WARNING: CPU: 30 PID: 80103 at arch/x86/kernel/cpu/bugs.c:2935 __warn_thunk (/home/marvin/linux/kernel/net-next/arch/x86/kernel/cpu/bugs.c:2935 (discriminator 3)) Mar 18 19:46:35 defiant kernel: [ 1859.134925] Modules linked in: ir_rcmm_decoder ir_imon_decoder ir_sharp_decoder ir_rc6_decoder ir_sanyo_decoder ir_nec_decoder ir_sony_decoder ir_jvc_decoder ir_rc5_decoder rc_loopback gpio_sim macvlan act_gact cls_flower sch_ingress bridge stp llc bonding tls xfrm_user nf_tables nfnetlink nvme_fabrics binfmt_misc amd_atl intel_rapl_msr nls_iso8859_1 intel_rapl_common snd_hda_codec_realtek snd_hda_codec_generic amdgpu snd_hda_codec_hdmi snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hda_core snd_hwdep snd_pcm edac_mce_amd crct10dif_pclmul polyval_clmulni snd_seq_midi polyval_generic snd_seq_midi_event ghash_clmulni_intel sha512_ssse3 amdxcp sha256_ssse3 snd_rawmidi drm_exec sha1_ssse3 gpu_sched aesni_intel drm_buddy drm_suballoc_helper crypto_simd drm_ttm_helper cryptd snd_seq ttm joydev snd_seq_device rapl input_leds drm_display_helper snd_timer cec snd wmi_bmof drm_kms_helper k10temp ccp soundcore i2c_algo_bit mac_hid tcp_bbr sch_fq msr parport_pc ppdev lp parport fuse drm efi_pstore ip_tables Mar 18 19:46:35 defiant kernel: [ 1859.134985] x_tables autofs4 btrfs blake2b_generic xor raid6_pq libcrc32c hid_generic nvme nvme_core ahci i2c_piix4 crc32_pclmul r8169 nvme_auth xhci_pci libahci xhci_pci_renesas realtek video wmi gpio_amdpt [last unloaded: gpio_mockup] Mar 18 19:46:35 defiant kernel: [ 1859.135002] CPU: 30 PID: 80103 Comm: cpuid_test Not tainted 6.8.0-net-next-km-05204-g237bb5f7f7f5-dirty #3 Mar 18 19:46:35 defiant kernel: [ 1859.135004] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023 Mar 18 19:46:35 defiant kernel: [ 1859.135005] RIP: 0010:__warn_thunk (/home/marvin/linux/kernel/net-next/arch/x86/kernel/cpu/bugs.c:2935 (discriminator 3)) Mar 18 19:46:35 defiant kernel: [ 1859.135008] Code: 50 9b 0f 01 83 e3 01 74 0e 48 8b 5d f8 c9 31 f6 31 ff e9 0e 9f 3b 01 48 c7 c7 28 62 1d b9 c6 05 f2 d6 6b 02 01 e8 60 af 07 00 <0f> 0b 48 8b 5d f8 c9 31 f6 31 ff e9 eb 9e 3b 01 90 90 90 90 90 90 All code ======== 0: 50 push %rax 1: 9b fwait 2: 0f 01 83 e3 01 74 0e sgdt 0xe7401e3(%rbx) 9: 48 8b 5d f8 mov -0x8(%rbp),%rbx d: c9 leave e: 31 f6 xor %esi,%esi 10: 31 ff xor %edi,%edi 12: e9 0e 9f 3b 01 jmp 0x13b9f25 17: 48 c7 c7 28 62 1d b9 mov $0xffffffffb91d6228,%rdi 1e: c6 05 f2 d6 6b 02 01 movb $0x1,0x26bd6f2(%rip) # 0x26bd717 25: e8 60 af 07 00 call 0x7af8a 2a:* 0f 0b ud2 <-- trapping instruction 2c: 48 8b 5d f8 mov -0x8(%rbp),%rbx 30: c9 leave 31: 31 f6 xor %esi,%esi 33: 31 ff xor %edi,%edi 35: e9 eb 9e 3b 01 jmp 0x13b9f25 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop Code starting with the faulting instruction =========================================== 0: 0f 0b ud2 2: 48 8b 5d f8 mov -0x8(%rbp),%rbx 6: c9 leave 7: 31 f6 xor %esi,%esi 9: 31 ff xor %edi,%edi b: e9 eb 9e 3b 01 jmp 0x13b9efb 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop Mar 18 19:46:35 defiant kernel: [ 1859.135009] RSP: 0018:ffffb9f8c652bc70 EFLAGS: 00010046 Mar 18 19:46:35 defiant kernel: [ 1859.135011] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 Mar 18 19:46:35 defiant kernel: [ 1859.135012] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 Mar 18 19:46:35 defiant kernel: [ 1859.135013] RBP: ffffb9f8c652bc78 R08: 0000000000000000 R09: 0000000000000000 Mar 18 19:46:35 defiant kernel: [ 1859.135014] R10: 0000000000000000 R11: 0000000000000000 R12: ffff998e369f1c78 Mar 18 19:46:35 defiant kernel: [ 1859.135015] R13: 0000000000000000 R14: 0000000000000000 R15: ffff998e369f23f8 Mar 18 19:46:35 defiant kernel: [ 1859.135016] FS: 000071f68c680740(0000) GS:ffff999b18900000(0000) knlGS:0000000000000000 Mar 18 19:46:35 defiant kernel: [ 1859.135017] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Mar 18 19:46:35 defiant kernel: [ 1859.135018] CR2: 0000000000000000 CR3: 000000032c828000 CR4: 0000000000f50ef0 Mar 18 19:46:35 defiant kernel: [ 1859.135019] PKRU: 55555554 Mar 18 19:46:35 defiant kernel: [ 1859.135020] Call Trace: Mar 18 19:46:35 defiant kernel: [ 1859.135021] <TASK> Mar 18 19:46:35 defiant kernel: [ 1859.135022] ? show_regs (/home/marvin/linux/kernel/net-next/arch/x86/kernel/dumpstack.c:479) Mar 18 19:46:35 defiant kernel: [ 1859.135026] ? __warn_thunk (/home/marvin/linux/kernel/net-next/arch/x86/kernel/cpu/bugs.c:2935 (discriminator 3)) Mar 18 19:46:35 defiant kernel: [ 1859.135028] ? __warn (/home/marvin/linux/kernel/net-next/kernel/panic.c:677) Mar 18 19:46:35 defiant kernel: [ 1859.135030] ? __warn_thunk (/home/marvin/linux/kernel/net-next/arch/x86/kernel/cpu/bugs.c:2935 (discriminator 3)) Mar 18 19:46:35 defiant kernel: [ 1859.135032] ? report_bug (/home/marvin/linux/kernel/net-next/lib/bug.c:201 /home/marvin/linux/kernel/net-next/lib/bug.c:219) Mar 18 19:46:35 defiant kernel: [ 1859.135036] ? irq_work_queue (/home/marvin/linux/kernel/net-next/kernel/irq_work.c:119) Mar 18 19:46:35 defiant kernel: [ 1859.135040] ? handle_bug (/home/marvin/linux/kernel/net-next/arch/x86/kernel/traps.c:218) Mar 18 19:46:35 defiant kernel: [ 1859.135043] ? exc_invalid_op (/home/marvin/linux/kernel/net-next/arch/x86/kernel/traps.c:260 (discriminator 1)) Mar 18 19:46:35 defiant kernel: [ 1859.135045] ? asm_exc_invalid_op (/home/marvin/linux/kernel/net-next/./arch/x86/include/asm/idtentry.h:621) Mar 18 19:46:35 defiant kernel: [ 1859.135050] ? __warn_thunk (/home/marvin/linux/kernel/net-next/arch/x86/kernel/cpu/bugs.c:2935 (discriminator 3)) Mar 18 19:46:35 defiant kernel: [ 1859.135053] warn_thunk_thunk (/home/marvin/linux/kernel/net-next/arch/x86/entry/entry.S:48) Mar 18 19:46:35 defiant kernel: [ 1859.135057] svm_vcpu_enter_exit (/home/marvin/linux/kernel/net-next/./include/linux/kvm_host.h:543 /home/marvin/linux/kernel/net-next/arch/x86/kvm/svm/svm.c:4115) Mar 18 19:46:35 defiant kernel: [ 1859.135059] svm_vcpu_run (/home/marvin/linux/kernel/net-next/./arch/x86/include/asm/cpufeature.h:171 /home/marvin/linux/kernel/net-next/arch/x86/kvm/svm/svm.c:4182) Mar 18 19:46:35 defiant kernel: [ 1859.135062] kvm_arch_vcpu_ioctl_run (/home/marvin/linux/kernel/net-next/arch/x86/kvm/x86.c:10981 /home/marvin/linux/kernel/net-next/arch/x86/kvm/x86.c:11184 /home/marvin/linux/kernel/net-next/arch/x86/kvm/x86.c:11410) Mar 18 19:46:35 defiant kernel: [ 1859.135065] ? call_rcu (/home/marvin/linux/kernel/net-next/kernel/rcu/tree.c:2839) Mar 18 19:46:35 defiant kernel: [ 1859.135068] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135070] ? put_object (/home/marvin/linux/kernel/net-next/mm/kmemleak.c:549) Mar 18 19:46:35 defiant kernel: [ 1859.135074] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135076] ? kmemleak_free (/home/marvin/linux/kernel/net-next/mm/kmemleak.c:1109) Mar 18 19:46:35 defiant kernel: [ 1859.135078] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135080] kvm_vcpu_ioctl (/home/marvin/linux/kernel/net-next/arch/x86/kvm/../../../virt/kvm/kvm_main.c:4447) Mar 18 19:46:35 defiant kernel: [ 1859.135083] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135085] ? kvm_vcpu_ioctl (/home/marvin/linux/kernel/net-next/arch/x86/kvm/../../../virt/kvm/kvm_main.c:4610) Mar 18 19:46:35 defiant kernel: [ 1859.135087] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135089] ? do_syscall_64 (/home/marvin/linux/kernel/net-next/./arch/x86/include/asm/cpufeature.h:171 /home/marvin/linux/kernel/net-next/arch/x86/entry/common.c:98) Mar 18 19:46:35 defiant kernel: [ 1859.135092] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135093] ? trace_hardirqs_on (/home/marvin/linux/kernel/net-next/kernel/trace/trace_preemptirq.c:58) Mar 18 19:46:35 defiant kernel: [ 1859.135097] __x64_sys_ioctl (/home/marvin/linux/kernel/net-next/fs/ioctl.c:51 /home/marvin/linux/kernel/net-next/fs/ioctl.c:904 /home/marvin/linux/kernel/net-next/fs/ioctl.c:890 /home/marvin/linux/kernel/net-next/fs/ioctl.c:890) Mar 18 19:46:35 defiant kernel: [ 1859.135101] do_syscall_64 (/home/marvin/linux/kernel/net-next/arch/x86/entry/common.c:52 /home/marvin/linux/kernel/net-next/arch/x86/entry/common.c:83) Mar 18 19:46:35 defiant kernel: [ 1859.135103] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135105] ? do_syscall_64 (/home/marvin/linux/kernel/net-next/./arch/x86/include/asm/cpufeature.h:171 /home/marvin/linux/kernel/net-next/arch/x86/entry/common.c:98) Mar 18 19:46:35 defiant kernel: [ 1859.135106] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135108] ? irqentry_exit (/home/marvin/linux/kernel/net-next/kernel/entry/common.c:361) Mar 18 19:46:35 defiant kernel: [ 1859.135110] ? srso_alias_return_thunk (/home/marvin/linux/kernel/net-next/arch/x86/lib/retpoline.S:181) Mar 18 19:46:35 defiant kernel: [ 1859.135112] ? exc_page_fault (/home/marvin/linux/kernel/net-next/arch/x86/mm/fault.c:1567) Mar 18 19:46:35 defiant kernel: [ 1859.135114] entry_SYSCALL_64_after_hwframe (/home/marvin/linux/kernel/net-next/arch/x86/entry/entry_64.S:129) Mar 18 19:46:35 defiant kernel: [ 1859.135115] RIP: 0033:0x71f68c51a94f Mar 18 19:46:35 defiant kernel: [ 1859.135135] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 77 1f 48 8b 44 24 18 64 48 2b 04 25 28 00 All code ======== 0: 00 48 89 add %cl,-0x77(%rax) 3: 44 24 18 rex.R and $0x18,%al 6: 31 c0 xor %eax,%eax 8: 48 8d 44 24 60 lea 0x60(%rsp),%rax d: c7 04 24 10 00 00 00 movl $0x10,(%rsp) 14: 48 89 44 24 08 mov %rax,0x8(%rsp) 19: 48 8d 44 24 20 lea 0x20(%rsp),%rax 1e: 48 89 44 24 10 mov %rax,0x10(%rsp) 23: b8 10 00 00 00 mov $0x10,%eax 28: 0f 05 syscall 2a:* 41 89 c0 mov %eax,%r8d <-- trapping instruction 2d: 3d 00 f0 ff ff cmp $0xfffff000,%eax 32: 77 1f ja 0x53 34: 48 8b 44 24 18 mov 0x18(%rsp),%rax 39: 64 fs 3a: 48 rex.W 3b: 2b .byte 0x2b 3c: 04 25 add $0x25,%al 3e: 28 00 sub %al,(%rax) Code starting with the faulting instruction =========================================== 0: 41 89 c0 mov %eax,%r8d 3: 3d 00 f0 ff ff cmp $0xfffff000,%eax 8: 77 1f ja 0x29 a: 48 8b 44 24 18 mov 0x18(%rsp),%rax f: 64 fs 10: 48 rex.W 11: 2b .byte 0x2b 12: 04 25 add $0x25,%al 14: 28 00 sub %al,(%rax) Mar 18 19:46:35 defiant kernel: [ 1859.135137] RSP: 002b:00007ffd0f928bd0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 Mar 18 19:46:35 defiant kernel: [ 1859.135138] RAX: ffffffffffffffda RBX: 0000000028af2880 RCX: 000071f68c51a94f Mar 18 19:46:35 defiant kernel: [ 1859.135139] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000007 Mar 18 19:46:35 defiant kernel: [ 1859.135140] RBP: 000071f68c6806c0 R08: 0000000000000000 R09: 0000000000000001 Mar 18 19:46:35 defiant kernel: [ 1859.135141] R10: 000000000000001f R11: 0000000000000246 R12: 0000000028af2880 Mar 18 19:46:35 defiant kernel: [ 1859.135142] R13: 0000000000000041 R14: 0000000000427e18 R15: 000071f68c6e3040 Mar 18 19:46:35 defiant kernel: [ 1859.135146] </TASK> Mar 18 19:46:35 defiant kernel: [ 1859.135146] ---[ end trace 0000000000000000 ]--- Hope this helps. Best regards, Mirsad Todorovac
