From a956bd6f8583326b18348ab1452b4686778f785d Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Thu, 12 Apr 2012 16:48:01 +0200 Subject: [PATCH 1/2] 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 87a0f868830..d389e74342a 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; } From 283c1f2558ef4a4411fe908364b15b73b6ab44cf Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Thu, 12 Apr 2012 16:51:57 +0200 Subject: [PATCH 2/2] x86, microcode: Ensure that module is only loaded on supported AMD CPUs Exit early when there's no support for a particular CPU family. Also, fixup the "no support for this CPU vendor" to be issued only when the driver is attempted to be loaded on an unsupported vendor. 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 [Boris: add a commit msg because Andreas is lazy] Signed-off-by: Borislav Petkov --- arch/x86/kernel/microcode_amd.c | 12 +++++++----- arch/x86/kernel/microcode_core.c | 6 +++--- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/microcode_amd.c b/arch/x86/kernel/microcode_amd.c index 73465aab28f..8a2ce8fd41c 100644 --- a/arch/x86/kernel/microcode_amd.c +++ b/arch/x86/kernel/microcode_amd.c @@ -82,11 +82,6 @@ static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig) { struct cpuinfo_x86 *c = &cpu_data(cpu); - if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) { - pr_warning("CPU%d: family %d not supported\n", cpu, c->x86); - return -1; - } - csig->rev = c->microcode; pr_info("CPU%d: patch_level=0x%08x\n", cpu, csig->rev); @@ -380,6 +375,13 @@ static struct microcode_ops microcode_amd_ops = { struct microcode_ops * __init init_amd_microcode(void) { + struct cpuinfo_x86 *c = &cpu_data(0); + + if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) { + pr_warning("AMD CPU family 0x%x not supported\n", c->x86); + return NULL; + } + patch = (void *)get_zeroed_page(GFP_KERNEL); if (!patch) return NULL; diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c index d389e74342a..c9bda6d6035 100644 --- a/arch/x86/kernel/microcode_core.c +++ b/arch/x86/kernel/microcode_core.c @@ -526,11 +526,11 @@ static int __init microcode_init(void) microcode_ops = init_intel_microcode(); else if (c->x86_vendor == X86_VENDOR_AMD) microcode_ops = init_amd_microcode(); - - if (!microcode_ops) { + else pr_err("no support for this CPU vendor\n"); + + if (!microcode_ops) return -ENODEV; - } microcode_pdev = platform_device_register_simple("microcode", -1, NULL, 0);