From 8d31bb1451643f328db0cea0e21e63ef54b4faf2 Mon Sep 17 00:00:00 2001 From: Qianheng Peng Date: Thu, 16 Jul 2026 16:51:39 +0800 Subject: [PATCH] cpufreq: amd-pstate-ut: Skip tests when amd-pstate driver is not active The crash issue may occur when modprobe amd_pstate_ut on intel platform. 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 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 state detection to amd pstate driver to prevent amd_pstate_ut driver from testing on non-AMD platforms. 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 Reviewed-by: Zhongqiu Han Link: https://lore.kernel.org/r/1784191899-28957-1-git-send-email-pengqh1@chinatelecom.cn (ML: adjust title) Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate-ut.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c index 735b29f76438..2142838ad6cc 100644 --- a/drivers/cpufreq/amd-pstate-ut.c +++ b/drivers/cpufreq/amd-pstate-ut.c @@ -560,6 +560,11 @@ static int amd_pstate_ut_check_freq_attrs(u32 index) static int __init amd_pstate_ut_init(void) { u32 i = 0, arr_size = ARRAY_SIZE(amd_pstate_ut_cases); + enum amd_pstate_mode mode = amd_pstate_get_status(); + + /* don't test if no running amd-pstate driver */ + if (mode == AMD_PSTATE_UNDEFINED || mode == AMD_PSTATE_DISABLE) + return -EOPNOTSUPP; for (i = 0; i < arr_size; i++) { int ret;