On Fri, May 16, 2025 at 01:22:17PM +0200, Borislav Petkov wrote: > Hi Herbert, > > one of our linux-next tests which hotplugs a CPU fails with the below splat. > > Reproducing is very easy: > > # echo 0 > /sys/devices/system/cpu/cpu1/online > # echo 1 > /sys/devices/system/cpu/cpu1/online > > Opcode bytes point to: > > 02:06:54 [ 3199.416779] Code: 65 c6 05 9a c8 ad 02 01 f7 47 2c 00 40 20 00 74 4f 65 48 c7 05 95 c8 ad 02 00 00 00 00 f6 c3 02 74 0d c7 44 24 04 80 1f 00 00 <0f> ae 54 24 04 83 e3 01 75 47 48 8b 44 24 08 65 48 2b 05 49 97 ad > All code > ======== > 0: 65 c6 05 9a c8 ad 02 movb $0x1,%gs:0x2adc89a(%rip) # 0x2adc8a2 > 7: 01 > 8: f7 47 2c 00 40 20 00 testl $0x204000,0x2c(%rdi) > f: 74 4f je 0x60 > 11: 65 48 c7 05 95 c8 ad movq $0x0,%gs:0x2adc895(%rip) # 0x2adc8b2 > 18: 02 00 00 00 00 > 1d: f6 c3 02 test $0x2,%bl > 20: 74 0d je 0x2f > 22: c7 44 24 04 80 1f 00 movl $0x1f80,0x4(%rsp) > 29: 00 > 2a:* 0f ae 54 24 04 ldmxcsr 0x4(%rsp) <-- trapping instruction > 2f: 83 e3 01 and $0x1,%ebx > 32: 75 47 jne 0x7b > 34: 48 8b 44 24 08 mov 0x8(%rsp),%rax > 39: 65 gs > 3a: 48 rex.W > 3b: 2b .byte 0x2b > 3c: 05 .byte 0x5 > 3d: 49 97 xchg %rax,%r15 > 3f: ad lods %ds:(%rsi),%eax > > Code starting with the faulting instruction > =========================================== > 0: 0f ae 54 24 04 ldmxcsr 0x4(%rsp) > 5: 83 e3 01 and $0x1,%ebx > 8: 75 47 jne 0x51 > a: 48 8b 44 24 08 mov 0x8(%rsp),%rax > f: 65 gs > 10: 48 rex.W > 11: 2b .byte 0x2b > 12: 05 .byte 0x5 > 13: 49 97 xchg %rax,%r15 > 15: ad lods %ds:(%rsi),%eax > > And LDMXCSR would #UD for a bunch of conditions. > > Reverting cryptodev from linux-next next-20250515 this way: > > $ git revert -m 1 ed18a632e45785e3392cf96b9683ca033a74b1f8 > > fixes the issue so I'm thinking it must be one of the patches you guys have > there. > > Ideas? Yes probably. So what's happened is that previously if you call sha256_update from lib/crypto it would only use the generic C code to perform the operation. This has now been changed to automatically use SIMD instructions which obviously blew up in your case. Eric, can you please take a look at this crash? It looks like crypto_simd_usable returned true, but kernel_fpu_begin still crashed for some reason. One of them must be wrong :) Thanks, > 02:05:36 [ 3129.220448] systemd[1]: systemd-timedated.service: Deactivated successfully. > 02:05:36 [ 3129.252398] systemd[1]: systemd-hostnamed.service: Deactivated successfully. > 02:06:54 [ 3199.347946] smpboot: CPU 1 is now offline > 02:06:54 [ 3199.375693] smpboot: Booting Node 0 Processor 1 APIC 0x2 > 02:06:54 [ 3199.381723] Oops: invalid opcode: 0000 [#1] SMP NOPTI > 02:06:54 [ 3199.387364] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Kdump: loaded Not tainted 6.15.0-rc6-next-20250515-484803582c77-1747374910702 #1 PREEMPT(voluntary) > 02:06:54 [ 3199.402308] Hardware name: AMD Corporation Cinnabar/Cinnabar, BIOS RCB100DB 08/09/2024 > 02:06:54 [ 3199.411140] RIP: 0010:kernel_fpu_begin_mask+0x58/0xc0 > 02:06:54 [ 3199.416779] Code: 65 c6 05 9a c8 ad 02 01 f7 47 2c 00 40 20 00 74 4f 65 48 c7 05 95 c8 ad 02 00 00 00 00 f6 c3 02 74 0d c7 44 24 04 80 1f 00 00 <0f> ae 54 24 04 83 e3 01 75 47 48 8b 44 24 08 65 48 2b 05 49 97 ad > 02:06:54 [ 3199.437736] RSP: 0000:ff3a2270c019fd98 EFLAGS: 00010002 > 02:06:54 [ 3199.443568] RAX: 0000000000000046 RBX: 0000000000000002 RCX: 0000000000000000 > 02:06:54 [ 3199.451528] RDX: 0000000000000057 RSI: ff380c5800eba000 RDI: ff380c5800eec280 > 02:06:54 [ 3199.459487] RBP: ff3a2270c019fe30 R08: 0000000000000000 R09: ff380c8684245078 > 02:06:54 [ 3199.467446] R10: 0000000000000000 R11: 0000000000000000 R12: ff380c5800eba000 > 02:06:54 [ 3199.475405] R13: 0000000000000057 R14: 00000000000015c0 R15: 00000000000015c0 > 02:06:54 [ 3199.483364] FS: 0000000000000000(0000) GS:ff380c86d4935000(0000) knlGS:0000000000000000 > 02:06:54 [ 3199.492391] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > 02:06:54 [ 3199.498801] CR2: 0000000000000000 CR3: 000000304b82a000 CR4: 00000000003318b0 > 02:06:54 [ 3199.506761] Call Trace: > 02:06:54 [ 3199.509487] <TASK> > 02:06:54 [ 3199.511825] sha256_blocks_simd+0x23/0x50 > 02:06:54 [ 3199.516303] sha256_update+0x73/0x100 > 02:06:54 [ 3199.520381] sha256+0x70/0xa0 > 02:06:54 [ 3199.523690] ? __smp_call_single_queue+0xb0/0x120 > 02:06:54 [ 3199.528939] ? srso_alias_return_thunk+0x5/0xfbef5 > 02:06:54 [ 3199.534285] ? bsearch+0x57/0x90 > 02:06:54 [ 3199.537884] ? __pfx_cmp_id+0x10/0x10 > 02:06:54 [ 3199.541968] __apply_microcode_amd+0xf1/0x1c0 > 02:06:54 [ 3199.546827] ? srso_alias_return_thunk+0x5/0xfbef5 > 02:06:54 [ 3199.552169] ? srso_alias_return_thunk+0x5/0xfbef5 > 02:06:54 [ 3199.557511] ? cpu_init_exception_handling+0x1fe/0x2c0 > 02:06:54 [ 3199.563241] ? srso_alias_return_thunk+0x5/0xfbef5 > 02:06:54 [ 3199.568584] apply_microcode_amd+0xca/0x110 > 02:06:54 [ 3199.573251] start_secondary+0x24/0x140 > 02:06:54 [ 3199.577531] ? srso_alias_return_thunk+0x5/0xfbef5 > 02:06:54 [ 3199.582872] common_startup_64+0x13e/0x141 > 02:06:54 [ 3199.587446] </TASK> > 02:06:54 [ 3199.589877] Modules linked in: iscsi_target_mod target_core_mod binfmt_misc xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nft_compat nf_nat_tftp nf_conntrack_tftp overlay snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill ip_set nf_tables nfnetlink sunrpc vfat fat amd_atl intel_rapl_msr intel_rapl_common amd64_edac edac_mce_amd kvm_amd ipmi_ssif kvm mlx5_ib irqbypass cdc_ether ib_uverbs usbnet rapl mii wmi_bmof pcspkr dax_hmem acpi_cpufreq ib_core acpi_ipmi i2c_piix4 k10temp i2c_smbus ipmi_si ipmi_devintf ipmi_msghandler i2c_designware_platform i2c_designware_core sch_fq_codel xfs ast drm_client_lib i2c_algo_bit drm_shmem_helper mlx5_core ahci drm_kms_helper libahci mlxfw tls nvme ghash_clmulni_intel sha512_ssse3 drm tg3 psample pci_hyperv_intf libata ccp nvme_core sp5100_tco wmi dm_mirror dm_region_hash dm_log -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
