* [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private()
@ 2014-09-23 17:05 Rob Jones
2014-09-23 17:46 ` Ben Hutchings
0 siblings, 1 reply; 7+ messages in thread
From: Rob Jones @ 2014-09-23 17:05 UTC (permalink / raw)
To: davem
Cc: netfilter, coreteam, netfilter-devel, netdev, linux-kernel,
linux-kernel, rob.jones
Reduce boilerplate code by using __seq_open_private() instead of seq_open()
in xt_match_open() and xt_target_open().
Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
---
This patch uses an existing variant of seq_open() to reduce the kernel code
size.
The only significant variation from the pre-existing code is the fact that
__seq_open_private() calls kzalloc() rather than kmalloc(), which could
conceivably have an impact on timing.
This version 2 incorporates a minor initialisation simplification (resulting
from kzalloc() being used) requested by netfilter-devel@vger.kernel.org
net/netfilter/x_tables.c | 31 ++++---------------------------
1 file changed, 4 insertions(+), 27 deletions(-)
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 227aa11..393f17b 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1080,7 +1080,6 @@ static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
struct nf_mttg_trav *trav = seq->private;
unsigned int j;
- trav->class = MTTG_TRAV_INIT;
for (j = 0; j < *pos; ++j)
if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
return NULL;
@@ -1137,22 +1136,11 @@ static const struct seq_operations xt_match_seq_ops = {
static int xt_match_open(struct inode *inode, struct file *file)
{
- struct seq_file *seq;
struct nf_mttg_trav *trav;
- int ret;
-
- trav = kmalloc(sizeof(*trav), GFP_KERNEL);
- if (trav == NULL)
+ trav = __seq_open_private(file, &xt_match_seq_ops, sizeof(*trav));
+ if (!trav)
return -ENOMEM;
- ret = seq_open(file, &xt_match_seq_ops);
- if (ret < 0) {
- kfree(trav);
- return ret;
- }
-
- seq = file->private_data;
- seq->private = trav;
trav->nfproto = (unsigned long)PDE_DATA(inode);
return 0;
}
@@ -1201,22 +1189,11 @@ static const struct seq_operations xt_target_seq_ops = {
static int xt_target_open(struct inode *inode, struct file *file)
{
- struct seq_file *seq;
struct nf_mttg_trav *trav;
- int ret;
-
- trav = kmalloc(sizeof(*trav), GFP_KERNEL);
- if (trav == NULL)
+ trav = __seq_open_private(file, &xt_target_seq_ops, sizeof(*trav));
+ if (!trav)
return -ENOMEM;
- ret = seq_open(file, &xt_target_seq_ops);
- if (ret < 0) {
- kfree(trav);
- return ret;
- }
-
- seq = file->private_data;
- seq->private = trav;
trav->nfproto = (unsigned long)PDE_DATA(inode);
return 0;
}
--
1.7.10.4
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [Linux-kernel] [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private()
2014-09-23 17:05 [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private() Rob Jones
@ 2014-09-23 17:46 ` Ben Hutchings
0 siblings, 0 replies; 7+ messages in thread
From: Ben Hutchings @ 2014-09-23 17:46 UTC (permalink / raw)
To: Rob Jones
Cc: davem, coreteam, netdev, linux-kernel, linux-kernel, netfilter,
netfilter-devel
On Tue, 2014-09-23 at 18:05 +0100, Rob Jones wrote:
> Reduce boilerplate code by using __seq_open_private() instead of seq_open()
> in xt_match_open() and xt_target_open().
>
> Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
> ---
>
> This patch uses an existing variant of seq_open() to reduce the kernel code
> size.
>
> The only significant variation from the pre-existing code is the fact that
> __seq_open_private() calls kzalloc() rather than kmalloc(), which could
> conceivably have an impact on timing.
>
> This version 2 incorporates a minor initialisation simplification (resulting
> from kzalloc() being used) requested by netfilter-devel@vger.kernel.org
[...]
> --- a/net/netfilter/x_tables.c
> +++ b/net/netfilter/x_tables.c
> @@ -1080,7 +1080,6 @@ static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
> struct nf_mttg_trav *trav = seq->private;
> unsigned int j;
>
> - trav->class = MTTG_TRAV_INIT;
> for (j = 0; j < *pos; ++j)
> if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
> return NULL;
[...]
I'm fairly sure this simplification is wrong, as xt_mttg_seq_start() is
potentially called multiple times on the same file handle.
Ben.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private()
@ 2014-09-23 17:46 ` Ben Hutchings
0 siblings, 0 replies; 7+ messages in thread
From: Ben Hutchings @ 2014-09-23 17:46 UTC (permalink / raw)
To: Rob Jones
Cc: davem, coreteam, netdev, linux-kernel, linux-kernel, netfilter,
netfilter-devel
On Tue, 2014-09-23 at 18:05 +0100, Rob Jones wrote:
> Reduce boilerplate code by using __seq_open_private() instead of seq_open()
> in xt_match_open() and xt_target_open().
>
> Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
> ---
>
> This patch uses an existing variant of seq_open() to reduce the kernel code
> size.
>
> The only significant variation from the pre-existing code is the fact that
> __seq_open_private() calls kzalloc() rather than kmalloc(), which could
> conceivably have an impact on timing.
>
> This version 2 incorporates a minor initialisation simplification (resulting
> from kzalloc() being used) requested by netfilter-devel@vger.kernel.org
[...]
> --- a/net/netfilter/x_tables.c
> +++ b/net/netfilter/x_tables.c
> @@ -1080,7 +1080,6 @@ static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
> struct nf_mttg_trav *trav = seq->private;
> unsigned int j;
>
> - trav->class = MTTG_TRAV_INIT;
> for (j = 0; j < *pos; ++j)
> if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
> return NULL;
[...]
I'm fairly sure this simplification is wrong, as xt_mttg_seq_start() is
potentially called multiple times on the same file handle.
Ben.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Linux-kernel] [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private()
2014-09-23 17:46 ` Ben Hutchings
@ 2014-09-23 21:40 ` Pablo Neira Ayuso
-1 siblings, 0 replies; 7+ messages in thread
From: Pablo Neira Ayuso @ 2014-09-23 21:40 UTC (permalink / raw)
To: Ben Hutchings
Cc: Rob Jones, davem, coreteam, netdev, linux-kernel, linux-kernel,
netfilter, netfilter-devel
On Tue, Sep 23, 2014 at 06:46:27PM +0100, Ben Hutchings wrote:
> On Tue, 2014-09-23 at 18:05 +0100, Rob Jones wrote:
> > Reduce boilerplate code by using __seq_open_private() instead of seq_open()
> > in xt_match_open() and xt_target_open().
> >
> > Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
> > ---
> >
> > This patch uses an existing variant of seq_open() to reduce the kernel code
> > size.
> >
> > The only significant variation from the pre-existing code is the fact that
> > __seq_open_private() calls kzalloc() rather than kmalloc(), which could
> > conceivably have an impact on timing.
> >
> > This version 2 incorporates a minor initialisation simplification (resulting
> > from kzalloc() being used) requested by netfilter-devel@vger.kernel.org
> [...]
> > --- a/net/netfilter/x_tables.c
> > +++ b/net/netfilter/x_tables.c
> > @@ -1080,7 +1080,6 @@ static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
> > struct nf_mttg_trav *trav = seq->private;
> > unsigned int j;
> >
> > - trav->class = MTTG_TRAV_INIT;
> > for (j = 0; j < *pos; ++j)
> > if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
> > return NULL;
> [...]
>
> I'm fairly sure this simplification is wrong, as xt_mttg_seq_start() is
> potentially called multiple times on the same file handle.
Right. I'm going to take v1 of this patch instead, sorry for the
inconvenience Rob.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private()
@ 2014-09-23 21:40 ` Pablo Neira Ayuso
0 siblings, 0 replies; 7+ messages in thread
From: Pablo Neira Ayuso @ 2014-09-23 21:40 UTC (permalink / raw)
To: Ben Hutchings
Cc: Rob Jones, davem, coreteam, netdev, linux-kernel, linux-kernel,
netfilter, netfilter-devel
On Tue, Sep 23, 2014 at 06:46:27PM +0100, Ben Hutchings wrote:
> On Tue, 2014-09-23 at 18:05 +0100, Rob Jones wrote:
> > Reduce boilerplate code by using __seq_open_private() instead of seq_open()
> > in xt_match_open() and xt_target_open().
> >
> > Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
> > ---
> >
> > This patch uses an existing variant of seq_open() to reduce the kernel code
> > size.
> >
> > The only significant variation from the pre-existing code is the fact that
> > __seq_open_private() calls kzalloc() rather than kmalloc(), which could
> > conceivably have an impact on timing.
> >
> > This version 2 incorporates a minor initialisation simplification (resulting
> > from kzalloc() being used) requested by netfilter-devel@vger.kernel.org
> [...]
> > --- a/net/netfilter/x_tables.c
> > +++ b/net/netfilter/x_tables.c
> > @@ -1080,7 +1080,6 @@ static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
> > struct nf_mttg_trav *trav = seq->private;
> > unsigned int j;
> >
> > - trav->class = MTTG_TRAV_INIT;
> > for (j = 0; j < *pos; ++j)
> > if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
> > return NULL;
> [...]
>
> I'm fairly sure this simplification is wrong, as xt_mttg_seq_start() is
> potentially called multiple times on the same file handle.
Right. I'm going to take v1 of this patch instead, sorry for the
inconvenience Rob.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Linux-kernel] [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private()
2014-09-23 21:40 ` Pablo Neira Ayuso
@ 2014-09-24 8:14 ` Rob Jones
-1 siblings, 0 replies; 7+ messages in thread
From: Rob Jones @ 2014-09-24 8:14 UTC (permalink / raw)
To: Pablo Neira Ayuso, Ben Hutchings
Cc: davem, coreteam, netdev, linux-kernel, linux-kernel, netfilter,
netfilter-devel
On 23/09/14 22:40, Pablo Neira Ayuso wrote:
> On Tue, Sep 23, 2014 at 06:46:27PM +0100, Ben Hutchings wrote:
>> On Tue, 2014-09-23 at 18:05 +0100, Rob Jones wrote:
>>> Reduce boilerplate code by using __seq_open_private() instead of seq_open()
>>> in xt_match_open() and xt_target_open().
>>>
>>> Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
>>> ---
>>>
>>> This patch uses an existing variant of seq_open() to reduce the kernel code
>>> size.
>>>
>>> The only significant variation from the pre-existing code is the fact that
>>> __seq_open_private() calls kzalloc() rather than kmalloc(), which could
>>> conceivably have an impact on timing.
>>>
>>> This version 2 incorporates a minor initialisation simplification (resulting
>>> from kzalloc() being used) requested by netfilter-devel@vger.kernel.org
>> [...]
>>> --- a/net/netfilter/x_tables.c
>>> +++ b/net/netfilter/x_tables.c
>>> @@ -1080,7 +1080,6 @@ static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
>>> struct nf_mttg_trav *trav = seq->private;
>>> unsigned int j;
>>>
>>> - trav->class = MTTG_TRAV_INIT;
>>> for (j = 0; j < *pos; ++j)
>>> if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
>>> return NULL;
>> [...]
>>
>> I'm fairly sure this simplification is wrong, as xt_mttg_seq_start() is
>> potentially called multiple times on the same file handle.
Well spotted Ben.
>
> Right. I'm going to take v1 of this patch instead, sorry for the
> inconvenience Rob.
No problem at all. It gave me something to do on the train home last
night :-)
--
Rob Jones
Codethink Ltd
mailto:rob.jones@codethink.co.uk
tel:+44 161 236 5575
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private()
@ 2014-09-24 8:14 ` Rob Jones
0 siblings, 0 replies; 7+ messages in thread
From: Rob Jones @ 2014-09-24 8:14 UTC (permalink / raw)
To: Pablo Neira Ayuso, Ben Hutchings
Cc: davem, coreteam, netdev, linux-kernel, linux-kernel, netfilter,
netfilter-devel
On 23/09/14 22:40, Pablo Neira Ayuso wrote:
> On Tue, Sep 23, 2014 at 06:46:27PM +0100, Ben Hutchings wrote:
>> On Tue, 2014-09-23 at 18:05 +0100, Rob Jones wrote:
>>> Reduce boilerplate code by using __seq_open_private() instead of seq_open()
>>> in xt_match_open() and xt_target_open().
>>>
>>> Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
>>> ---
>>>
>>> This patch uses an existing variant of seq_open() to reduce the kernel code
>>> size.
>>>
>>> The only significant variation from the pre-existing code is the fact that
>>> __seq_open_private() calls kzalloc() rather than kmalloc(), which could
>>> conceivably have an impact on timing.
>>>
>>> This version 2 incorporates a minor initialisation simplification (resulting
>>> from kzalloc() being used) requested by netfilter-devel@vger.kernel.org
>> [...]
>>> --- a/net/netfilter/x_tables.c
>>> +++ b/net/netfilter/x_tables.c
>>> @@ -1080,7 +1080,6 @@ static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
>>> struct nf_mttg_trav *trav = seq->private;
>>> unsigned int j;
>>>
>>> - trav->class = MTTG_TRAV_INIT;
>>> for (j = 0; j < *pos; ++j)
>>> if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
>>> return NULL;
>> [...]
>>
>> I'm fairly sure this simplification is wrong, as xt_mttg_seq_start() is
>> potentially called multiple times on the same file handle.
Well spotted Ben.
>
> Right. I'm going to take v1 of this patch instead, sorry for the
> inconvenience Rob.
No problem at all. It gave me something to do on the train home last
night :-)
--
Rob Jones
Codethink Ltd
mailto:rob.jones@codethink.co.uk
tel:+44 161 236 5575
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2014-09-24 8:15 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-09-23 17:05 [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private() Rob Jones
2014-09-23 17:46 ` [Linux-kernel] " Ben Hutchings
2014-09-23 17:46 ` Ben Hutchings
2014-09-23 21:40 ` [Linux-kernel] " Pablo Neira Ayuso
2014-09-23 21:40 ` Pablo Neira Ayuso
2014-09-24 8:14 ` [Linux-kernel] " Rob Jones
2014-09-24 8:14 ` Rob Jones
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