4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xiao Liang xiliang@redhat.com
commit 40d4071ce2d20840d224b4a77b5dc6f752c9ab15 upstream.
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: c7ab62bfbe0e ("perf/x86/amd/power: Add AMD accumulated power reporting mechanism") Signed-off-by: Xiao Liang xiliang@redhat.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lkml.kernel.org/r/20180122061252.6394-1-xiliang@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/events/amd/power.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- 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(voi int ret;
if (!x86_match_cpu(cpu_match)) - return 0; + return -ENODEV;
if (!boot_cpu_has(X86_FEATURE_ACC_POWER)) return -ENODEV;