From aabb6e1531b0c78423dca6a39620892249fef7f9 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 6 May 2011 13:27:41 -0700 Subject: [PATCH] efivars: prevent oops on unload when efi is not enabled 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 Cc: Matt Domsch Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/efivars.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 5d1ec6898e7c..a2d2f1f0d4f3 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -827,8 +827,10 @@ err_put: 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);