From 6d9e28b45a1d0332fe444f348e584afd06fa7852 Mon Sep 17 00:00:00 2001 From: Xiao Liang Date: Mon, 22 Jan 2018 14:12:52 +0800 Subject: [PATCH] perf/x86/amd/power: Do not load AMD power module on !AMD platforms The AMD power module can be loaded on non AMD platforms, but unload fails with the following Oops: BUG: unable to handle kernel NULL pointer dereference at (null) IP: __list_del_entry_valid+0x29/0x90 Call Trace: perf_pmu_unregister+0x25/0xf0 amd_power_pmu_exit+0x1c/0xd23 [power] SyS_delete_module+0x1a8/0x2b0 ? exit_to_usermode_loop+0x8f/0xb0 entry_SYSCALL_64_fastpath+0x20/0x83 Return -ENODEV instead of 0 from the module init function if the CPU does not match. Fixes: 7c2df8915a37 ("perf/x86/amd/power: Add AMD accumulated power reporting mechanism") Signed-off-by: Xiao Liang Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180122061252.6394-1-xiliang@redhat.com --- arch/x86/events/amd/power.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/amd/power.c b/arch/x86/events/amd/power.c index a6eee5ac4f581..2aefacf5c5b2a 100644 --- a/arch/x86/events/amd/power.c +++ b/arch/x86/events/amd/power.c @@ -277,7 +277,7 @@ static int __init amd_power_pmu_init(void) int ret; if (!x86_match_cpu(cpu_match)) - return 0; + return -ENODEV; if (!boot_cpu_has(X86_FEATURE_ACC_POWER)) return -ENODEV; -- 2.39.5