2011-05-06 19:57:22

by Randy Dunlap

[permalink] [raw]
Subject: [PATCH] efivars: prevent oops on unload when efi is not enabled

From: Randy Dunlap <[email protected]>

unregister_efivars() 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:[<ffffffffa06a17f6>] [<ffffffffa06a17f6>] 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:
[<ffffffffa06a2418>] efivars_exit+0x1c/0xc04 [efivars]
[<ffffffff810d3598>] sys_delete_module+0x2d6/0x368
[<ffffffff812d1db9>] ? lockdep_sys_exit_thunk+0x35/0x67
[<ffffffff810fcba1>] ? audit_syscall_entry+0x172/0x1a5
[<ffffffff81575082>] 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 [<ffffffffa06a17f6>] unregister_efivars+0x28/0x12c [efivars]
RSP <ffff88005eedde98>
CR2: 0000000000000000
---[ end trace aa99b99090f70baa ]---

Matt apparently removed such a check in 2004 (with no reason given):
* 17 May 2004 - Matt Domsch <[email protected]>
* remove check for efi_enabled in exit
but there have been several changes since then.

Signed-off-by: Randy Dunlap <[email protected]>
Cc: Matt Domsch <[email protected]>
Cc: <[email protected]>
Cc: Mike Waychison <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
---
drivers/firmware/efivars.c | 3 +++
1 file changed, 3 insertions(+)

--- lnx-2639-rc6.orig/drivers/firmware/efivars.c
+++ lnx-2639-rc6/drivers/firmware/efivars.c
@@ -688,6 +688,9 @@ void unregister_efivars(struct efivars *
{
struct efivar_entry *entry, *n;

+ if (!efi_enabled)
+ return;
+
list_for_each_entry_safe(entry, n, &efivars->list, list) {
spin_lock(&efivars->lock);
list_del(&entry->list);


2011-05-06 20:09:46

by Mike Waychison

[permalink] [raw]
Subject: Re: [PATCH] efivars: prevent oops on unload when efi is not enabled

On Fri, May 6, 2011 at 3:04 PM, Matt Domsch <[email protected]> wrote:
> On Fri, May 06, 2011 at 02:57:02PM -0500, Randy Dunlap wrote:
>> From: Randy Dunlap <[email protected]>
>>
>> unregister_efivars() should check for efi_enabled and not undo
>> allocations when efi is not enabled. ?Otherwise there is an Oops
>> during module unload:
>
> Thanks Randy.
>
> I'm not sure why the driver is still loaded at all if efi_enabled==0.
>
> static int __init
> efivars_init(void)
> {
> ...
> ? ? ? ?if (!efi_enabled)
> ? ? ? ? ? ? ? ?return 0;
>
>
>
> That return 0 should be return -ENODEV I think. ?Mike?

Ya, I changed efivars so that others could still use the
register_efivars/unregister_efivars interfaces when !efi_enabled.
They are used by the drivers/firmware/google/gsmi.c driver currently
pending in linux-next.

I think the right approach in this case would be to do

if (efi_enabled) {
unregister_efivars(&__efivars);
kobject_put(efi_kobj);
}

in efivars_exit().

>
> Thanks,
> Matt
>
> --
> Matt Domsch
> Technology Strategist
> Dell | Office of the CTO
>

2011-05-06 20:24:24

by Mike Waychison

[permalink] [raw]
Subject: [PATCH v2] efivars: prevent oops on unload when efi is not enabled

From: Randy Dunlap <[email protected]>

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:[<ffffffffa06a17f6>] [<ffffffffa06a17f6>] 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:
[<ffffffffa06a2418>] efivars_exit+0x1c/0xc04 [efivars]
[<ffffffff810d3598>] sys_delete_module+0x2d6/0x368
[<ffffffff812d1db9>] ? lockdep_sys_exit_thunk+0x35/0x67
[<ffffffff810fcba1>] ? audit_syscall_entry+0x172/0x1a5
[<ffffffff81575082>] 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 [<ffffffffa06a17f6>] unregister_efivars+0x28/0x12c [efivars]
RSP <ffff88005eedde98>
CR2: 0000000000000000
---[ end trace aa99b99090f70baa ]---

Matt apparently removed such a check in 2004 (with no reason given):
* 17 May 2004 - Matt Domsch <[email protected]>
* remove check for efi_enabled in exit
but there have been several changes since then.

Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Mike Waychison <[email protected]>
Cc: Matt Domsch <[email protected]>
Cc: <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
---
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..2ab7c0c 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_enable) {
+ unregister_efivars(&__efivars);
+ kobject_put(efi_kobj);
+ }
}

module_init(efivars_init);
--
1.7.3.1

2011-05-06 20:28:31

by Mike Waychison

[permalink] [raw]
Subject: [PATCH v3] efivars: prevent oops on unload when efi is not enabled

From: Randy Dunlap <[email protected]>

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:[<ffffffffa06a17f6>] [<ffffffffa06a17f6>] 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:
[<ffffffffa06a2418>] efivars_exit+0x1c/0xc04 [efivars]
[<ffffffff810d3598>] sys_delete_module+0x2d6/0x368
[<ffffffff812d1db9>] ? lockdep_sys_exit_thunk+0x35/0x67
[<ffffffff810fcba1>] ? audit_syscall_entry+0x172/0x1a5
[<ffffffff81575082>] 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 [<ffffffffa06a17f6>] unregister_efivars+0x28/0x12c [efivars]
RSP <ffff88005eedde98>
CR2: 0000000000000000
---[ end trace aa99b99090f70baa ]---

Matt apparently removed such a check in 2004 (with no reason given):
* 17 May 2004 - Matt Domsch <[email protected]>
* remove check for efi_enabled in exit
but there have been several changes since then.

Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Mike Waychison <[email protected]>
Cc: Matt Domsch <[email protected]>
Cc: <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
---
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);
--
1.7.3.1

2011-05-06 21:31:21

by Randy Dunlap

[permalink] [raw]
Subject: Re: [PATCH v3] efivars: prevent oops on unload when efi is not enabled

On 05/06/11 13:27, Mike Waychison wrote:
> From: Randy Dunlap <[email protected]>
>
> 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:[<ffffffffa06a17f6>] [<ffffffffa06a17f6>] 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:
> [<ffffffffa06a2418>] efivars_exit+0x1c/0xc04 [efivars]
> [<ffffffff810d3598>] sys_delete_module+0x2d6/0x368
> [<ffffffff812d1db9>] ? lockdep_sys_exit_thunk+0x35/0x67
> [<ffffffff810fcba1>] ? audit_syscall_entry+0x172/0x1a5
> [<ffffffff81575082>] 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 [<ffffffffa06a17f6>] unregister_efivars+0x28/0x12c [efivars]
> RSP <ffff88005eedde98>
> CR2: 0000000000000000
> ---[ end trace aa99b99090f70baa ]---
>
> Matt apparently removed such a check in 2004 (with no reason given):
> * 17 May 2004 - Matt Domsch <[email protected]>
> * remove check for efi_enabled in exit
> but there have been several changes since then.
>
> Signed-off-by: Randy Dunlap <[email protected]>
> Signed-off-by: Mike Waychison <[email protected]>

Tested-by: Randy Dunlap <[email protected]>

Thanks for the fix.

> Cc: Matt Domsch <[email protected]>
> Cc: <[email protected]>
> Cc: Greg Kroah-Hartman <[email protected]>
> ---
> 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 ***