From a956bd6f8583326b18348ab1452b4686778f785d Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Thu, 12 Apr 2012 16:48:01 +0200 Subject: [PATCH] x86, microcode: Fix sysfs warning during module unload on unsupported CPUs Loading the microcode driver on an unsupported CPU and subsequently unloading the driver causes WARNING: at fs/sysfs/group.c:138 mc_device_remove+0x5f/0x70 [microcode]() Hardware name: 01972NG sysfs group ffffffffa00013d0 not found for kobject 'cpu0' Modules linked in: snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_intel btusb snd_hda_codec bluetooth thinkpad_acpi rfkill microcode(-) [last unloaded: cfg80211] Pid: 4560, comm: modprobe Not tainted 3.4.0-rc2-00002-g258f742 #5 Call Trace: [] ? warn_slowpath_common+0x7b/0xc0 [] ? warn_slowpath_fmt+0x45/0x50 [] ? sysfs_remove_group+0x34/0x120 [] ? mc_device_remove+0x5f/0x70 [microcode] [] ? subsys_interface_unregister+0x69/0xa0 [] ? mutex_lock+0x16/0x40 [] ? microcode_exit+0x50/0x92 [microcode] [] ? sys_delete_module+0x16d/0x260 [] ? wait_iff_congested+0x45/0x110 [] ? page_fault+0x1f/0x30 [] ? system_call_fastpath+0x16/0x1b on recent kernels. This is due to commit 8a25a2fd126c ("cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem") which renders commit 6c53cbfced04 ("x86, microcode: Correct sysdev_add error path") useless. See http://marc.info/?l=linux-kernel&m=133416246406478 Avoid above warning by restoring the old driver behaviour before 6c53cbfced04 ("x86, microcode: Correct sysdev_add error path"). Cc: stable@vger.kernel.org Cc: Tigran Aivazian Signed-off-by: Andreas Herrmann Acked-by: Greg Kroah-Hartman Link: http://lkml.kernel.org/r/20120411163849.GE4794@alberich.amd.com Signed-off-by: Borislav Petkov --- arch/x86/kernel/microcode_core.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c index 87a0f86..d389e74 100644 --- a/arch/x86/kernel/microcode_core.c +++ b/arch/x86/kernel/microcode_core.c @@ -419,10 +419,8 @@ static int mc_device_add(struct device *dev, struct subsys_interface *sif) if (err) return err; - if (microcode_init_cpu(cpu) == UCODE_ERROR) { - sysfs_remove_group(&dev->kobj, &mc_attr_group); + if (microcode_init_cpu(cpu) == UCODE_ERROR) return -EINVAL; - } return err; } -- 2.7.4