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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 4ZWgGioYHXMmayL1ennfaKiKpA6mHfkfiAMOigIO1AzvjzVXZ7uXRCiSyiixKjLzdnWjNcf24/NmR4oV1B3ErIKsNKTFgIGw0xNKeTsqNnGD4ayGGTRUPsNttJFjnW0vrBetkWBkZ8tldCJVLeFSk6kp9CvBFg9WZkBdFkMh7Jt25VCgnKO/UY+hN1k6WE3+B/I50GFMBjugT3ni8005Mnyw95AsUGWSbFARdrEoJwdcQx2npRfFUMHg9dz2Rp+lTB9Q3zAJztuMe/pp+WgHAiV9t2JbpV30laBhw+pu6purXLDwxDELCTpYjM1HlZCr/8PvCwaaqKqcuY1u38rjf2bE+4o0kEHaTjF2iTJRGVrDkGNrPzFVeQaC/r9NH8gTNjPR/R1RzzAZMeNdciX8eT7F+r6pVZbfD0qa2D+ShbuVwljkTGZTeF6EbDf9DdDy X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Jul 2026 09:09:11.5664 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 74d7a8ba-74ad-4c4d-212c-08dee18791d1 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CO1PEPF000075F3.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB6210 Hello Qianheng, On 7/14/2026 1:29 PM, Qianheng Peng wrote: > The crash issue may occur when insmod amd_pstate_ut modules. > > amd_pstate_ut: 1 amd_pstate_ut_acpi_cpc_valid success! > amd_pstate_ut: 2 amd_pstate_ut_check_enabled success! > BUG: kernel NULL pointer dereference, address: 0000000000000080 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 0 P4D 0 > Oops: 0000 [#1] SMP NOPTI > CPU: 0 PID: 20300 Comm: modprobe > Kdump: loaded Tainted: G O 6.6.0-0010.rc1.ctl4.x86_64 #1 > Hardware name: FiberHome R2200 V5/Xeon Boards, BIOS 3.1a 02/24/2020 Is this an AMD platform? > RIP: 0010:amd_pstate_ut_check_perf+0x141/0x280 [amd_pstate_ut] > Call Trace: > > amd_pstate_ut_init+0x1b/0xff0 [amd_pstate_ut] > ? __pfx_amd_pstate_ut_init+0x10/0x10 [amd_pstate_ut] > do_one_initcall+0x42/0x2e0 > ? kmalloc_trace+0x26/0x90 > do_init_module+0x60/0x240 > __se_sys_init_module+0x185/0x1c0 > do_syscall_64+0x62/0x190 > entry_SYSCALL_64_after_hwframe+0x76/0x7e > > > Add invalidation check of cpudata in amd_pstate_ut_check_perf() and > amd_pstate_ut_check_freq() to avoid unpredicated null pointer dereference. > > Fixes: 14eb1c96e3a3 ("cpufreq: amd-pstate: Add test module for amd-pstate driver") > Suggested-by: Li Xiong > Suggested-by: Xibo Wang > Signed-off-by: Qianheng Peng > --- > drivers/cpufreq/amd-pstate-ut.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c > index 735b29f..3b24260 100644 > --- a/drivers/cpufreq/amd-pstate-ut.c > +++ b/drivers/cpufreq/amd-pstate-ut.c > @@ -157,6 +157,10 @@ static int amd_pstate_ut_check_perf(u32 index) > if (!policy) > continue; > cpudata = policy->driver_data; > + if (!cpudata) { > + pr_err("%s driver_data of %s is empty!\n", __func__, policy->kobj.name); > + return -EINVAL; > + } > > if (get_shared_mem()) { > ret = cppc_get_perf_caps(cpu, &cppc_perf); > @@ -229,6 +233,10 @@ static int amd_pstate_ut_check_freq(u32 index) > if (!policy) > continue; > cpudata = policy->driver_data; > + if (!cpudata) { > + pr_err("%s driver_data of %s is empty!\n", __func__, policy->kobj.name); > + return -EINVAL; > + } The only time I think this can happen is when the amd-pstate-ut races with a the amd_pstate.*_cpu_exit() (probably as a result of concurrent mode switch) or if you are running this without running amd-pstate as the cpufreq driver (which the ut doesn't check for beforehand) My setup fails at this exact same point when I have the driver unloaded. What is the output of following before you run into this issue: cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver cat /sys/devices/system/cpu/amd_pstate/status Are you doing any concurrent hotplug / mode switch? > > if (!((policy->cpuinfo.max_freq >= cpudata->nominal_freq) && > (cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) && > -- > 1.8.3.1 > -- Thanks and Regards, Prateek