Bug 217765

Summary: CFI violation when reading amd_pstate/status
Product: Power Management Reporter: Jannik Glückert (jannik.glueckert)
Component: cpufreqAssignee: linux-pm (linux-pm)
Status: NEW ---    
Severity: normal CC: ndesaulniers, Perry.Yuan, sam
Priority: P3    
Hardware: AMD   
OS: Linux   
Kernel Version: Subsystem:
Regression: No Bisected commit-id:

Description Jannik Glückert 2023-08-05 08:42:32 UTC 
On kernel 6.4.7, with amd_pstate=active, with a Ryzen 7700X
I get a Clang CFI violation when reading /sys/devices/system/cpu/amd_pstate/status

This is reproduceable with every read, I have only tried with amd_pstate=active

With the following CFI and Clang configs, Clang 16.0.6
CONFIG_CFI_CLANG=y
CONFIG_CFI_PERMISSIVE=y
CONFIG_LTO_CLANG=y
CONFIG_LTO_CLANG_THIN=y

Below is the full call trace, let me know if you need a trace with debug info.

[ 4947.849350] CFI failure at dev_attr_show+0x24/0x60 (target: show_status+0x0/0x70; expected type: 0x8651b1de)
[ 4947.849358] WARNING: CPU: 2 PID: 16519 at dev_attr_show+0x24/0x60
[ 4947.849360] Modules linked in: binfmt_misc nf_conntrack_netbios_ns nf_conntrack_broadcast wireguard curve25519_x86_64 libcurve25519_generic ip6_udp_tunnel udp_tunnel snd_seq_dummy snd_hrtimer snd_seq rfcomm joydev uhid xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_nat_tftp nf_conntrack_tftp nft_fib_inet nft_fib_ipv6 nft_fib_ipv4 nft_fib nft_reject_inet nf_reject_ipv6 nf_reject_ipv4 nft_reject nft_ct nft_chain_nat bridge 8021q mrp garp stp llc nf_tables ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_raw iptable_security ip_set nfnetlink ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables bnep vfat fat amdgpu snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel mt7921e vfio_pci intel_rapl_msr mt7921_common intel_rapl_common mt76_connac_lib edac_mce_amd vfio_pci_core mt76 vfio_iommu_type1 vfio kvm_amd iommufd iommu_v2 snd_usb_audio
[ 4947.849379]  snd_intel_dspcfg gpu_sched snd_intel_sdw_acpi mac80211 drm_suballoc_helper snd_usbmidi_lib i2c_algo_bit drm_ttm_helper snd_hda_codec btusb ttm btrtl libarc4 btmtk snd_hda_core snd_rawmidi kvm snd_seq_device drm_display_helper btintel snd_hwdep mc btbcm irqbypass cfg80211 cec snd_pcm asus_nb_wmi bluetooth eeepc_wmi snd_timer asus_wmi drm_kms_helper ledtrig_audio sparse_keymap snd gpio_amdpt platform_profile gpio_generic drm_buddy rfkill soundcore rapl i2c_piix4 wmi_bmof pcspkr k10temp lm92 nct6775_core hwmon_vid fuse loop dm_crypt crct10dif_pclmul polyval_clmulni polyval_generic ghash_clmulni_intel nvme sp5100_tco ccp r8169 nvme_core nvme_common video wmi sunrpc
[ 4947.849398] CPU: 2 PID: 16519 Comm: cat Tainted: P                   6.4.7-gentoo-dist-hardened #1
[ 4947.849399] Hardware name: ASUS System Product Name/TUF GAMING B650M-PLUS WIFI, BIOS 1616 05/16/2023
[ 4947.849400] RIP: 0010:dev_attr_show+0x24/0x60
[ 4947.849401] Code: 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 56 53 4c 8b 5e 10 4d 85 db 74 34 49 89 f6 41 ba 22 4e ae 79 45 03 53 f1 74 02 <0f> 0b 41 ff d3 0f 1f 00 48 89 c3 48 3d 00 10 00 00 7c 19 49 8b 76
[ 4947.849403] RSP: 0018:ffffb33a03d9fd10 EFLAGS: 00010203
[ 4947.849404] RAX: ffff922f11509980 RBX: ffff9230e86f43c0 RCX: 0000000000000000
[ 4947.849404] RDX: ffff922f1746b000 RSI: ffffffffaee25f10 RDI: ffff922f0005f800
[ 4947.849405] RBP: ffff9230e86f43e8 R08: 0000000000001000 R09: ffff922f1746b000
[ 4947.849405] R10: 0000000015e419ad R11: ffffffffadda9330 R12: ffffffffae8aa188
[ 4947.849406] R13: ffff9233bbcb6fc0 R14: ffffffffaee25f10 R15: ffff922f1746b000
[ 4947.849407] FS:  00007eff007b4740(0000) GS:ffff923657e80000(0000) knlGS:0000000000000000
[ 4947.849407] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4947.849408] CR2: 00007eff0099f000 CR3: 000000010a0a2000 CR4: 0000000000750ee0
[ 4947.849409] PKRU: 55555554
[ 4947.849409] Call Trace:
[ 4947.849410]  <TASK>
[ 4947.849411]  ? __warn+0xcf/0x1c0
[ 4947.849414]  ? dev_attr_show+0x24/0x60
[ 4947.849415]  ? report_cfi_failure+0x4e/0x60
[ 4947.849417]  ? handle_cfi_failure+0x14c/0x1d0
[ 4947.849419]  ? __cfi_show_status+0x10/0x10
[ 4947.849420]  ? handle_bug+0x4f/0x90
[ 4947.849421]  ? exc_invalid_op+0x1a/0x60
[ 4947.849422]  ? asm_exc_invalid_op+0x1a/0x20
[ 4947.849424]  ? __cfi_show_status+0x10/0x10
[ 4947.849425]  ? dev_attr_show+0x24/0x60
[ 4947.849426]  sysfs_kf_seq_show+0xa6/0x110
[ 4947.849433]  seq_read_iter+0x16c/0x4b0
[ 4947.849436]  vfs_read+0x272/0x2d0
[ 4947.849438]  ksys_read+0x72/0xe0
[ 4947.849439]  do_syscall_64+0x76/0xb0
[ 4947.849440]  ? do_user_addr_fault+0x252/0x650
[ 4947.849442]  ? exc_page_fault+0x7a/0x1b0
[ 4947.849443]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
[ 4947.849444] RIP: 0033:0x7eff008b2651
[ 4947.849445] Code: b5 fe ff ff 48 8d 3d 66 42 0a 00 50 e8 68 1b 02 00 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d ad 0d 0e 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 53 48 83 ec 20 48 89
[ 4947.849446] RSP: 002b:00007ffecca23268 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 4947.849447] RAX: ffffffffffffffda RBX: 0000000000008000 RCX: 00007eff008b2651
[ 4947.849447] RDX: 0000000000020000 RSI: 00007eff009a0000 RDI: 0000000000000003
[ 4947.849448] RBP: 0000000000000003 R08: 00000000ffffffff R09: 0000000000000000
[ 4947.849448] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000
[ 4947.849449] R13: 0000000000000000 R14: 00007eff009a0000 R15: 0000000000020000
[ 4947.849450]  </TASK>
[ 4947.849450] ---[ end trace 0000000000000000 ]---
Comment 1 Nick Desaulniers 2023-08-07 16:13:34 UTC 
Thanks for the report; I've filed this in https://github.com/ClangBuiltLinux/linux/issues/1901 where we will track it.
Comment 2 Perry Yuan(AMD) 2023-08-08 06:43:23 UTC 
https://lore.kernel.org/all/20230807-amd-pstate-cfi-v1-1-0263daa13bc3@weissschuh.net/

the patch has been applied to 6.5-rc as the fix.