[REGRESSION] in 3.18-rc1: ppp crashes kernel

[REGRESSION] in 3.18-rc1: ppp crashes kernel

[Stefan Seyfried]

Hi all,

since 3.18-rc1, setting up a PPP interface kills my kernel with

[  163.433251] PPP generic driver version 2.4.2
[  164.452474] ------------[ cut here ]------------
[  164.453327] kernel BUG at ../mm/vmalloc.c:1316!
[  164.453327] invalid opcode: 0000 [#1] PREEMPT SMP 
[  164.453327] Modules linked in: ppp_async crc_ccitt ppp_generic slhc af_packet xfs libcrc32c coretemp kvm_intel 
snd_hda_codec_conexant iTCO_wdt snd_hda_codec_generic iTCO_vendor_support uvcvideo snd_hda_intel snd_hda_controller mac80211 videobuf2_vmalloc snd_hda_codec kvm e1000e videobuf2_memops cfg80211 videobuf2_core v4l2_common snd_hwdep i2c_i801 videodev snd_pcm pcspkr thinkpad_acpi serio_raw wmi lpc_ich snd_timer thermal snd rfkill mfd_core tpm_tis shpchp mei_me soundcore ptp mei pps_core acpi_cpufreq tpm battery processor ac dm_mod btrfs xor raid6_pq i915 i2c_algo_bit drm_kms_helper drm video button sg
[  164.453327] CPU: 0 PID: 6927 Comm: pppd Not tainted 3.18.0-rc3-3.ge706e91-desktop #1
[  164.453327] Hardware name: LENOVO 7470E36/7470E36, BIOS 6DET61WW (3.11 ) 11/10/2009

This is easy to reproduce with:

linux:~ # cat bin/crashme.sh 
----
#!/bin/bash -x
pppd local pty "netcat -l 1234" &
sleep 1
pppd local pty "netcat localhost 1234" &
sleep 1
----

3.17 works fine.
I bisected the issue multiple times and always arrived at

# first bad commit: [d6dd50e07c5bec00db2005969b1a01f8ca3d25ef] Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

which is a merge commit unfortunately.

The BUG encountered above is in:

1309 static struct vm_struct *__get_vm_area_node(unsigned long size,
1310                 unsigned long align, unsigned long flags, unsigned long start,
1311                 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1312 {
1313         struct vmap_area *va;
1314         struct vm_struct *area;
1315 
1316         BUG_ON(in_interrupt());
1317         if (flags & VM_IOREMAP)
1318                 align = 1ul << clamp(fls(size), PAGE_SHIFT, IOREMAP_MAX_ORDER);
1319 

the call trace is:
[  164.453327] Call Trace:
[  164.453327]  [<ffffffff811974bd>] __vmalloc_node_range+0x6d/0x290
[  164.453327]  [<ffffffff8119771e>] __vmalloc+0x3e/0x50
[  164.453327]  [<ffffffff81146950>] bpf_prog_alloc+0x30/0xa0
[  164.453327]  [<ffffffff8157b716>] bpf_prog_create+0x46/0xb0
[  164.453327]  [<ffffffffa07ecb90>] ppp_ioctl+0x420/0xe9a [ppp_generic]
[  164.453327]  [<ffffffff811df1c7>] do_vfs_ioctl+0x2e7/0x4c0
[  164.453327]  [<ffffffff811df421>] SyS_ioctl+0x81/0xa0
[  164.453327]  [<ffffffff8165ee2d>] system_call_fastpath+0x16/0x1b
[  164.453327]  [<00007f4502d87397>] 0x7f4502d87397

I have a crashdump of the kernel, but given this is easily reproducible, I doubt
that I need to send this to anyone :-)

Best regards,

	Stefan

-- 
Stefan Seyfried
Linux Consultant & Developer -- GPG Key: 0x731B665B

B1 Systems GmbH
Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de
GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537

Re: [REGRESSION] in 3.18-rc1: ppp crashes kernel

[Paul Bolle]

On Fri, 2014-11-07 at 12:10 +0100, Stefan Seyfried wrote:
> I bisected the issue multiple times and always arrived at
> 
> # first bad commit: [d6dd50e07c5bec00db2005969b1a01f8ca3d25ef] Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> 
> which is a merge commit unfortunately.

That merge commit actually does add some code:

git show d6dd50e07c5bec00db2005969b1a01f8ca3d25ef
[...]
diff --cc init/main.c
index 8af2f1abfe38,e3c4cdd94d5b..c5c11da6c4e1
--- a/init/main.c
+++ b/init/main.c
@@@ -583,6 -585,6 +583,7 @@@ asmlinkage __visible void __init start_
  	early_irq_init();
  	init_IRQ();
  	tick_init();
++	rcu_init_nohz();
  	init_timers();
  	hrtimers_init();
  	softirq_init();

Wild guess: is CONFIG_RCU_NOCB_CPU perhaps set in your
v3.18-rc3 .config?


Paul Bolle

Re: [REGRESSION] in 3.18-rc1: ppp crashes kernel

[Stefan Seyfried]

Hi Paul,

Am 07.11.2014 um 12:53 schrieb Paul Bolle:
> On Fri, 2014-11-07 at 12:10 +0100, Stefan Seyfried wrote:
>> I bisected the issue multiple times and always arrived at
>>
>> # first bad commit: [d6dd50e07c5bec00db2005969b1a01f8ca3d25ef] Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
>>
>> which is a merge commit unfortunately.
> 
> That merge commit actually does add some code:
> 
> git show d6dd50e07c5bec00db2005969b1a01f8ca3d25ef
> [...]
> diff --cc init/main.c
> index 8af2f1abfe38,e3c4cdd94d5b..c5c11da6c4e1
> --- a/init/main.c
> +++ b/init/main.c
> @@@ -583,6 -585,6 +583,7 @@@ asmlinkage __visible void __init start_
>   	early_irq_init();
>   	init_IRQ();
>   	tick_init();
> ++	rcu_init_nohz();
>   	init_timers();
>   	hrtimers_init();
>   	softirq_init();
> 
> Wild guess: is CONFIG_RCU_NOCB_CPU perhaps set in your
> v3.18-rc3 .config?

Yes it is:
tux@linux:~> zgrep CONFIG_RCU_NOCB_CPU /proc/config.gz
CONFIG_RCU_NOCB_CPU=y
# CONFIG_RCU_NOCB_CPU_NONE is not set
# CONFIG_RCU_NOCB_CPU_ZERO is not set
CONFIG_RCU_NOCB_CPU_ALL=y

And I'll try without it, but looking at the backtrace and the actual
BUG_ON() in the code, I cannot really believe it is the real problems.

But I'll try with the config changed and with the above line removed.

Thanks,

	Stefan
-- 
Stefan Seyfried
Linux Consultant & Developer -- GPG Key: 0x731B665B

B1 Systems GmbH
Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de
GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537

Re: [REGRESSION] in 3.18-rc1: ppp crashes kernel

[Stefan Seyfried]

Am 07.11.2014 um 12:56 schrieb Stefan Seyfried:
> Hi Paul,
> 
> Am 07.11.2014 um 12:53 schrieb Paul Bolle:
>> Wild guess: is CONFIG_RCU_NOCB_CPU perhaps set in your
>> v3.18-rc3 .config?
> 
> Yes it is:
> tux@linux:~> zgrep CONFIG_RCU_NOCB_CPU /proc/config.gz
> CONFIG_RCU_NOCB_CPU=y
> # CONFIG_RCU_NOCB_CPU_NONE is not set
> # CONFIG_RCU_NOCB_CPU_ZERO is not set
> CONFIG_RCU_NOCB_CPU_ALL=y
> 
> And I'll try without it, but looking at the backtrace and the actual
> BUG_ON() in the code, I cannot really believe it is the real problems.
> 
> But I'll try with the config changed and with the above line removed.

JFTR, this did not help:
tux@linux:~/linux> zgrep CONFIG_RCU_NOCB_CPU /proc/config.gz
# CONFIG_RCU_NOCB_CPU is not set

neither did:

--- a/init/main.c
+++ b/init/main.c
@@ -583,7 +583,7 @@ asmlinkage __visible void __init start_kernel(void)
        early_irq_init();
        init_IRQ();
        tick_init();
-       rcu_init_nohz();
+//     rcu_init_nohz();
        init_timers();
        hrtimers_init();
        softirq_init();
-- 
Stefan Seyfried
Linux Consultant & Developer -- GPG Key: 0x731B665B

B1 Systems GmbH
Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de
GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537

Re: [REGRESSION] in 3.18-rc1: ppp crashes kernel

[Paul Bolle]

On Fri, 2014-11-07 at 13:54 +0100, Stefan Seyfried wrote:
> JFTR, this did not help:
> tux@linux:~/linux> zgrep CONFIG_RCU_NOCB_CPU /proc/config.gz
> # CONFIG_RCU_NOCB_CPU is not set
> 
> neither did:
> 
> --- a/init/main.c
> +++ b/init/main.c
> @@ -583,7 +583,7 @@ asmlinkage __visible void __init start_kernel(void)
>         early_irq_init();
>         init_IRQ();
>         tick_init();
> -       rcu_init_nohz();
> +//     rcu_init_nohz();
>         init_timers();
>         hrtimers_init();
>         softirq_init();

Thanks. I guess this is not my lucky day. I won't be visiting a casino
tonight...


Paul Bolle

Re: [REGRESSION] in 3.18-rc1: ppp crashes kernel

[Takashi Iwai]

At Fri, 07 Nov 2014 12:10:46 +0100,
Stefan Seyfried wrote:
> 
> Hi all,
> 
> since 3.18-rc1, setting up a PPP interface kills my kernel with
> 
> [  163.433251] PPP generic driver version 2.4.2
> [  164.452474] ------------[ cut here ]------------
> [  164.453327] kernel BUG at ../mm/vmalloc.c:1316!
> [  164.453327] invalid opcode: 0000 [#1] PREEMPT SMP 
> [  164.453327] Modules linked in: ppp_async crc_ccitt ppp_generic slhc af_packet xfs libcrc32c coretemp kvm_intel 
> snd_hda_codec_conexant iTCO_wdt snd_hda_codec_generic iTCO_vendor_support uvcvideo snd_hda_intel snd_hda_controller mac80211 videobuf2_vmalloc snd_hda_codec kvm e1000e videobuf2_memops cfg80211 videobuf2_core v4l2_common snd_hwdep i2c_i801 videodev snd_pcm pcspkr thinkpad_acpi serio_raw wmi lpc_ich snd_timer thermal snd rfkill mfd_core tpm_tis shpchp mei_me soundcore ptp mei pps_core acpi_cpufreq tpm battery processor ac dm_mod btrfs xor raid6_pq i915 i2c_algo_bit drm_kms_helper drm video button sg
> [  164.453327] CPU: 0 PID: 6927 Comm: pppd Not tainted 3.18.0-rc3-3.ge706e91-desktop #1
> [  164.453327] Hardware name: LENOVO 7470E36/7470E36, BIOS 6DET61WW (3.11 ) 11/10/2009
> 
> This is easy to reproduce with:
> 
> linux:~ # cat bin/crashme.sh 
> ----
> #!/bin/bash -x
> pppd local pty "netcat -l 1234" &
> sleep 1
> pppd local pty "netcat localhost 1234" &
> sleep 1
> ----
> 
> 3.17 works fine.
> I bisected the issue multiple times and always arrived at
> 
> # first bad commit: [d6dd50e07c5bec00db2005969b1a01f8ca3d25ef] Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> 
> which is a merge commit unfortunately.
> 
> The BUG encountered above is in:
> 
> 1309 static struct vm_struct *__get_vm_area_node(unsigned long size,
> 1310                 unsigned long align, unsigned long flags, unsigned long start,
> 1311                 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
> 1312 {
> 1313         struct vmap_area *va;
> 1314         struct vm_struct *area;
> 1315 
> 1316         BUG_ON(in_interrupt());
> 1317         if (flags & VM_IOREMAP)
> 1318                 align = 1ul << clamp(fls(size), PAGE_SHIFT, IOREMAP_MAX_ORDER);
> 1319 
> 
> the call trace is:
> [  164.453327] Call Trace:
> [  164.453327]  [<ffffffff811974bd>] __vmalloc_node_range+0x6d/0x290
> [  164.453327]  [<ffffffff8119771e>] __vmalloc+0x3e/0x50
> [  164.453327]  [<ffffffff81146950>] bpf_prog_alloc+0x30/0xa0
> [  164.453327]  [<ffffffff8157b716>] bpf_prog_create+0x46/0xb0
> [  164.453327]  [<ffffffffa07ecb90>] ppp_ioctl+0x420/0xe9a [ppp_generic]
> [  164.453327]  [<ffffffff811df1c7>] do_vfs_ioctl+0x2e7/0x4c0
> [  164.453327]  [<ffffffff811df421>] SyS_ioctl+0x81/0xa0
> [  164.453327]  [<ffffffff8165ee2d>] system_call_fastpath+0x16/0x1b
> [  164.453327]  [<00007f4502d87397>] 0x7f4502d87397

bpf_prog_create() is called inside spin_lock_bh(), and the BUG_ON()
hits.  Below is a quick fix.


Takashi

-- 8< --
From: Takashi Iwai <tiwai@suse.de>
Subject: [PATCH] net: ppp: Don't call bpf_prog_create() in ppp_lock

In ppp_ioctl(), bpf_prog_create() is called inside ppp_lock, which
eventually calls vmalloc() and hits BUG_ON() in vmalloc.c.  This patch
works around the problem by moving the allocation outside the lock.

Reported-by: Stefan Seyfried <stefan.seyfried@googlemail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/net/ppp/ppp_generic.c | 40 ++++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 68c3a3f4e0ab..794a47329368 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -755,23 +755,23 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 		err = get_filter(argp, &code);
 		if (err >= 0) {
+			struct bpf_prog *pass_filter = NULL;
 			struct sock_fprog_kern fprog = {
 				.len = err,
 				.filter = code,
 			};
 
-			ppp_lock(ppp);
-			if (ppp->pass_filter) {
-				bpf_prog_destroy(ppp->pass_filter);
-				ppp->pass_filter = NULL;
+			err = 0;
+			if (fprog.filter)
+				err = bpf_prog_create(&pass_filter, &fprog);
+			if (!err) {
+				ppp_lock(ppp);
+				if (ppp->pass_filter)
+					bpf_prog_destroy(ppp->pass_filter);
+				ppp->pass_filter = pass_filter;
+				ppp_unlock(ppp);
 			}
-			if (fprog.filter != NULL)
-				err = bpf_prog_create(&ppp->pass_filter,
-						      &fprog);
-			else
-				err = 0;
 			kfree(code);
-			ppp_unlock(ppp);
 		}
 		break;
 	}
@@ -781,23 +781,23 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 		err = get_filter(argp, &code);
 		if (err >= 0) {
+			struct bpf_prog *active_filter = NULL;
 			struct sock_fprog_kern fprog = {
 				.len = err,
 				.filter = code,
 			};
 
-			ppp_lock(ppp);
-			if (ppp->active_filter) {
-				bpf_prog_destroy(ppp->active_filter);
-				ppp->active_filter = NULL;
+			err = 0;
+			if (fprog.filter)
+				err = bpf_prog_create(&active_filter, &fprog);
+			if (!err) {
+				ppp_lock(ppp);
+				if (ppp->active_filter)
+					bpf_prog_destroy(ppp->active_filter);
+				ppp->active_filter = active_filter;
+				ppp_unlock(ppp);
 			}
-			if (fprog.filter != NULL)
-				err = bpf_prog_create(&ppp->active_filter,
-						      &fprog);
-			else
-				err = 0;
 			kfree(code);
-			ppp_unlock(ppp);
 		}
 		break;
 	}
-- 
2.1.3

Re: [REGRESSION] in 3.18-rc1: ppp crashes kernel

[Stefan Seyfried]

Hi Takashi,

yes, this no longer crashes. No real-world test yet, but the obvious
crash is gone. Thanks!

Am 07.11.2014 um 14:22 schrieb Takashi Iwai:
> At Fri, 07 Nov 2014 12:10:46 +0100,
> Stefan Seyfried wrote:
>>
>> Hi all,
>>
>> since 3.18-rc1, setting up a PPP interface kills my kernel with
>>
>> [  163.433251] PPP generic driver version 2.4.2
>> [  164.452474] ------------[ cut here ]------------
>> [  164.453327] kernel BUG at ../mm/vmalloc.c:1316!
>> [  164.453327] invalid opcode: 0000 [#1] PREEMPT SMP 
>> [  164.453327] Modules linked in: ppp_async crc_ccitt ppp_generic slhc af_packet xfs libcrc32c coretemp kvm_intel 
>> snd_hda_codec_conexant iTCO_wdt snd_hda_codec_generic iTCO_vendor_support uvcvideo snd_hda_intel snd_hda_controller mac80211 videobuf2_vmalloc snd_hda_codec kvm e1000e videobuf2_memops cfg80211 videobuf2_core v4l2_common snd_hwdep i2c_i801 videodev snd_pcm pcspkr thinkpad_acpi serio_raw wmi lpc_ich snd_timer thermal snd rfkill mfd_core tpm_tis shpchp mei_me soundcore ptp mei pps_core acpi_cpufreq tpm battery processor ac dm_mod btrfs xor raid6_pq i915 i2c_algo_bit drm_kms_helper drm video button sg
>> [  164.453327] CPU: 0 PID: 6927 Comm: pppd Not tainted 3.18.0-rc3-3.ge706e91-desktop #1
>> [  164.453327] Hardware name: LENOVO 7470E36/7470E36, BIOS 6DET61WW (3.11 ) 11/10/2009
>>
>> This is easy to reproduce with:
>>
>> linux:~ # cat bin/crashme.sh 
>> ----
>> #!/bin/bash -x
>> pppd local pty "netcat -l 1234" &
>> sleep 1
>> pppd local pty "netcat localhost 1234" &
>> sleep 1
>> ----
>>
>> 3.17 works fine.
>> I bisected the issue multiple times and always arrived at
>>
>> # first bad commit: [d6dd50e07c5bec00db2005969b1a01f8ca3d25ef] Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
>>
>> which is a merge commit unfortunately.
>>
>> The BUG encountered above is in:
>>
>> 1309 static struct vm_struct *__get_vm_area_node(unsigned long size,
>> 1310                 unsigned long align, unsigned long flags, unsigned long start,
>> 1311                 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
>> 1312 {
>> 1313         struct vmap_area *va;
>> 1314         struct vm_struct *area;
>> 1315 
>> 1316         BUG_ON(in_interrupt());
>> 1317         if (flags & VM_IOREMAP)
>> 1318                 align = 1ul << clamp(fls(size), PAGE_SHIFT, IOREMAP_MAX_ORDER);
>> 1319 
>>
>> the call trace is:
>> [  164.453327] Call Trace:
>> [  164.453327]  [<ffffffff811974bd>] __vmalloc_node_range+0x6d/0x290
>> [  164.453327]  [<ffffffff8119771e>] __vmalloc+0x3e/0x50
>> [  164.453327]  [<ffffffff81146950>] bpf_prog_alloc+0x30/0xa0
>> [  164.453327]  [<ffffffff8157b716>] bpf_prog_create+0x46/0xb0
>> [  164.453327]  [<ffffffffa07ecb90>] ppp_ioctl+0x420/0xe9a [ppp_generic]
>> [  164.453327]  [<ffffffff811df1c7>] do_vfs_ioctl+0x2e7/0x4c0
>> [  164.453327]  [<ffffffff811df421>] SyS_ioctl+0x81/0xa0
>> [  164.453327]  [<ffffffff8165ee2d>] system_call_fastpath+0x16/0x1b
>> [  164.453327]  [<00007f4502d87397>] 0x7f4502d87397
> 
> bpf_prog_create() is called inside spin_lock_bh(), and the BUG_ON()
> hits.  Below is a quick fix.
> 
> 
> Takashi
> 
> -- 8< --
> From: Takashi Iwai <tiwai@suse.de>
> Subject: [PATCH] net: ppp: Don't call bpf_prog_create() in ppp_lock
> 
> In ppp_ioctl(), bpf_prog_create() is called inside ppp_lock, which
> eventually calls vmalloc() and hits BUG_ON() in vmalloc.c.  This patch
> works around the problem by moving the allocation outside the lock.
> 
> Reported-by: Stefan Seyfried <stefan.seyfried@googlemail.com>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>

FWIW :-)
Tested-by: Stefan Seyfried <stefan.seyfried@googlemail.com>

> ---
>  drivers/net/ppp/ppp_generic.c | 40 ++++++++++++++++++++--------------------
>  1 file changed, 20 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
> index 68c3a3f4e0ab..794a47329368 100644
> --- a/drivers/net/ppp/ppp_generic.c
> +++ b/drivers/net/ppp/ppp_generic.c
> @@ -755,23 +755,23 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  
>  		err = get_filter(argp, &code);
>  		if (err >= 0) {
> +			struct bpf_prog *pass_filter = NULL;
>  			struct sock_fprog_kern fprog = {
>  				.len = err,
>  				.filter = code,
>  			};
>  
> -			ppp_lock(ppp);
> -			if (ppp->pass_filter) {
> -				bpf_prog_destroy(ppp->pass_filter);
> -				ppp->pass_filter = NULL;
> +			err = 0;
> +			if (fprog.filter)
> +				err = bpf_prog_create(&pass_filter, &fprog);
> +			if (!err) {
> +				ppp_lock(ppp);
> +				if (ppp->pass_filter)
> +					bpf_prog_destroy(ppp->pass_filter);
> +				ppp->pass_filter = pass_filter;
> +				ppp_unlock(ppp);
>  			}
> -			if (fprog.filter != NULL)
> -				err = bpf_prog_create(&ppp->pass_filter,
> -						      &fprog);
> -			else
> -				err = 0;
>  			kfree(code);
> -			ppp_unlock(ppp);
>  		}
>  		break;
>  	}
> @@ -781,23 +781,23 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  
>  		err = get_filter(argp, &code);
>  		if (err >= 0) {
> +			struct bpf_prog *active_filter = NULL;
>  			struct sock_fprog_kern fprog = {
>  				.len = err,
>  				.filter = code,
>  			};
>  
> -			ppp_lock(ppp);
> -			if (ppp->active_filter) {
> -				bpf_prog_destroy(ppp->active_filter);
> -				ppp->active_filter = NULL;
> +			err = 0;
> +			if (fprog.filter)
> +				err = bpf_prog_create(&active_filter, &fprog);
> +			if (!err) {
> +				ppp_lock(ppp);
> +				if (ppp->active_filter)
> +					bpf_prog_destroy(ppp->active_filter);
> +				ppp->active_filter = active_filter;
> +				ppp_unlock(ppp);
>  			}
> -			if (fprog.filter != NULL)
> -				err = bpf_prog_create(&ppp->active_filter,
> -						      &fprog);
> -			else
> -				err = 0;
>  			kfree(code);
> -			ppp_unlock(ppp);
>  		}
>  		break;
>  	}
> 
-- 
Stefan Seyfried
Linux Consultant & Developer -- GPG Key: 0x731B665B

B1 Systems GmbH
Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de
GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537