Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932878Ab1EFVbV (ORCPT ); Fri, 6 May 2011 17:31:21 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:25517 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932837Ab1EFVbU (ORCPT ); Fri, 6 May 2011 17:31:20 -0400 Message-ID: <4DC46862.3090901@oracle.com> Date: Fri, 06 May 2011 14:30:10 -0700 From: Randy Dunlap Organization: Oracle Linux Engineering User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-3.fc11 Thunderbird/3.0 MIME-Version: 1.0 To: Mike Waychison CC: linux-kernel@vger.kernel.org, Matt_Domsch@dell.com, akpm@linux-foundation.org, matthew.e.tolentino@intel.com, gregkh@suse.de Subject: Re: [PATCH v3] efivars: prevent oops on unload when efi is not enabled References: <20110506125702.2585228b.randy.dunlap@oracle.com> <1304713661-14708-1-git-send-email-mikew@google.com> In-Reply-To: <1304713661-14708-1-git-send-email-mikew@google.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: acsinet22.oracle.com [141.146.126.238] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090201.4DC46870.002C:SCFMA922111,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4935 Lines: 97 On 05/06/11 13:27, Mike Waychison wrote: > From: Randy Dunlap > > efivars_exit() should check for efi_enabled and not undo > allocations when efi is not enabled. Otherwise there is an Oops > during module unload: > > calling efivars_init+0x0/0x1000 [efivars] @ 2810 > EFI Variables Facility v0.08 2004-May-17 > initcall efivars_init+0x0/0x1000 [efivars] returned 0 after 5120 usecs > Oops: 0000 [#1] SMP DEBUG_PAGEALLOC > last sysfs file: /sys/module/firmware_class/initstate > CPU 1 > Modules linked in: efivars(-) af_packet tun nfsd lockd nfs_acl auth_rpcgss sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT xt_tcpudp nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables x_tables ipv6 cpufreq_ondemand acpi_cpufreq freq_table mperf binfmt_misc dm_mirror dm_region_hash dm_log dm_multipath scsi_dh dm_mod snd_hda_codec_analog snd_hda_intel snd_hda_codec snd_hwdep mousedev snd_seq joydev snd_seq_device mac_hid evdev snd_pcm usbkbd usbmouse usbhid snd_timer hid tg3 snd sr_mod pcspkr rtc_cmos soundcore cdrom iTCO_wdt processor sg dcdbas i2c_i801 rtc_core iTCO_vendor_support intel_agp snd_page_alloc thermal_sys rtc_lib intel_gtt 8250_pnp button hwmon unix ide_pci_generic ide_core ata_generic pata_acpi ata_piix sd_mod crc_t10dif ext3 jbd mbcache uhci_hcd ohci_hcd ssb mmc_core pcmcia pcmcia_core firmware_class ehci_hcd usbcore [last unloaded: dell_rbu] > > Pid: 2812, comm: rmmod Not tainted 2.6.39-rc6 #1 Dell Inc. OptiPlex 745 /0TY565 > RIP: 0010:[] [] unregister_efivars+0x28/0x12c [efivars] > RSP: 0018:ffff88005eedde98 EFLAGS: 00010283 > RAX: ffffffffa06a23fc RBX: ffffffffa06a44c0 RCX: ffff88007c227a50 > RDX: 0000000000000000 RSI: 00000055ac13db78 RDI: ffffffffa06a44c0 > RBP: ffff88005eeddec8 R08: 0000000000000000 R09: ffff88005eeddd78 > R10: ffffffffa06a4220 R11: ffff88005eeddd78 R12: fffffffffffff7d0 > R13: 00007fff5a3aaec0 R14: 0000000000000000 R15: ffffffffa06a4508 > FS: 00007fa8dcc4a6f0(0000) GS:ffff88007c200000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: 0000000000000000 CR3: 000000005d148000 CR4: 00000000000006e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process rmmod (pid: 2812, threadinfo ffff88005eedc000, task ffff88006754b000) > Stack: > ffff88005eeddec8 ffffffffa06a4220 0000000000000000 00007fff5a3aaec0 > 0000000000000000 0000000000000001 ffff88005eedded8 ffffffffa06a2418 > ffff88005eeddf78 ffffffff810d3598 ffffffffa06a4220 0000000000000880 > Call Trace: > [] efivars_exit+0x1c/0xc04 [efivars] > [] sys_delete_module+0x2d6/0x368 > [] ? lockdep_sys_exit_thunk+0x35/0x67 > [] ? audit_syscall_entry+0x172/0x1a5 > [] system_call_fastpath+0x16/0x1b > Code: 5c c9 c3 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 08 0f 1f 44 00 00 4c 8b 67 48 48 89 fb 4c 8d 7f 48 49 81 ec 30 08 00 00 <4d> 8b ac 24 30 08 00 00 49 81 ed 30 08 00 00 eb 59 48 89 df 48 > RIP [] unregister_efivars+0x28/0x12c [efivars] > RSP > CR2: 0000000000000000 > ---[ end trace aa99b99090f70baa ]--- > > Matt apparently removed such a check in 2004 (with no reason given): > * 17 May 2004 - Matt Domsch > * remove check for efi_enabled in exit > but there have been several changes since then. > > Signed-off-by: Randy Dunlap > Signed-off-by: Mike Waychison Tested-by: Randy Dunlap Thanks for the fix. > Cc: Matt Domsch > Cc: > Cc: Greg Kroah-Hartman > --- > v3: > - Fix typo that I forgot to commit. > v2: > - Updated to conditionally unregister efivars for real EFI in the module > unload itself -- mikew > --- > drivers/firmware/efivars.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c > index ff0c373..2934a13 100644 > --- a/drivers/firmware/efivars.c > +++ b/drivers/firmware/efivars.c > @@ -820,8 +820,10 @@ efivars_init(void) > static void __exit > efivars_exit(void) > { > - unregister_efivars(&__efivars); > - kobject_put(efi_kobj); > + if (efi_enabled) { > + unregister_efivars(&__efivars); > + kobject_put(efi_kobj); > + } > } > > module_init(efivars_init); -- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/