<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/caif/caif_dev.c, branch v4.11</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>netns: make struct pernet_operations::id unsigned int</title>
<updated>2016-11-18T15:59:15+00:00</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2016-11-17T01:58:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c7d03a00b56fc23c3a01a8353789ad257363e281'/>
<id>c7d03a00b56fc23c3a01a8353789ad257363e281</id>
<content type='text'>
Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng-&gt;ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng-&gt;ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: caif: convert to using IFF_NO_QUEUE</title>
<updated>2015-08-18T18:55:07+00:00</updated>
<author>
<name>Phil Sutter</name>
<email>phil@nwl.cc</email>
</author>
<published>2015-08-18T08:30:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4676a15207e3bc5e18b7e39b934ce0e890ee54fe'/>
<id>4676a15207e3bc5e18b7e39b934ce0e890ee54fe</id>
<content type='text'>
Signed-off-by: Phil Sutter &lt;phil@nwl.cc&gt;
Cc: Dmitry Tarnyagin &lt;dmitry.tarnyagin@lockless.no&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Phil Sutter &lt;phil@nwl.cc&gt;
Cc: Dmitry Tarnyagin &lt;dmitry.tarnyagin@lockless.no&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Include appropriate header file in caif/caif_dev.c</title>
<updated>2014-02-10T01:32:49+00:00</updated>
<author>
<name>Rashika Kheria</name>
<email>rashika.kheria@gmail.com</email>
</author>
<published>2014-02-09T14:29:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8203274e1541392e8a85d4bcbcda55d62fe62469'/>
<id>8203274e1541392e8a85d4bcbcda55d62fe62469</id>
<content type='text'>
Include appropriate header file net/caif/caif_dev.h in caif/caif_dev.c
because it has prototype declarations of function defined in
caif/caif_dev.c.

This eliminates the following file in caif/caif_dev.c:
net/caif/caif_dev.c:303:6: warning: no previous prototype for ‘caif_enroll_dev’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria &lt;rashika.kheria@gmail.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Include appropriate header file net/caif/caif_dev.h in caif/caif_dev.c
because it has prototype declarations of function defined in
caif/caif_dev.c.

This eliminates the following file in caif/caif_dev.c:
net/caif/caif_dev.c:303:6: warning: no previous prototype for ‘caif_enroll_dev’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria &lt;rashika.kheria@gmail.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: pass info struct via netdevice notifier</title>
<updated>2013-05-28T20:11:01+00:00</updated>
<author>
<name>Jiri Pirko</name>
<email>jiri@resnulli.us</email>
</author>
<published>2013-05-28T01:30:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=351638e7deeed2ec8ce451b53d33921b3da68f83'/>
<id>351638e7deeed2ec8ce451b53d33921b3da68f83</id>
<content type='text'>
So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko &lt;jiri@resnulli.us&gt;

v2-&gt;v3: fix typo on simeth
	shortened dev_getter
	shortened notifier_info struct name
v1-&gt;v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko &lt;jiri@resnulli.us&gt;

v2-&gt;v3: fix typo on simeth
	shortened dev_getter
	shortened notifier_info struct name
v1-&gt;v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>caif: Remove my bouncing email address.</title>
<updated>2013-04-23T17:25:51+00:00</updated>
<author>
<name>sjur.brandeland@stericsson.com</name>
<email>sjur.brandeland@stericsson.com</email>
</author>
<published>2013-04-22T23:57:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=26ee65e680f4a2291f6258e11beceae0ad4eeba3'/>
<id>26ee65e680f4a2291f6258e11beceae0ad4eeba3</id>
<content type='text'>
Remove my soon bouncing email address.
Also remove the "Contact:" line in file header.
The MAINTAINERS file is a better place to find the
contact person anyway.

Signed-off-by: Sjur Brændeland &lt;sjur.brandeland@stericsson.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove my soon bouncing email address.
Also remove the "Contact:" line in file header.
The MAINTAINERS file is a better place to find the
contact person anyway.

Signed-off-by: Sjur Brændeland &lt;sjur.brandeland@stericsson.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>CAIF: fix indentation for function arguments</title>
<updated>2013-03-07T21:24:45+00:00</updated>
<author>
<name>Silviu-Mihai Popescu</name>
<email>silviupopescu1990@gmail.com</email>
</author>
<published>2013-03-06T19:39:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3bffc475f9995843fa23a4978a4c112d8c8f4a6e'/>
<id>3bffc475f9995843fa23a4978a4c112d8c8f4a6e</id>
<content type='text'>
This lines up function arguments on second and subsequent lines at the
first column after the openning parenthesis of the first line.

Signed-off-by: Silviu-Mihai Popescu &lt;silviupopescu1990@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This lines up function arguments on second and subsequent lines at the
first column after the openning parenthesis of the first line.

Signed-off-by: Silviu-Mihai Popescu &lt;silviupopescu1990@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>caif_dev: fix sparse warnings for caif_flow_cb</title>
<updated>2013-03-03T06:43:48+00:00</updated>
<author>
<name>Silviu-Mihai Popescu</name>
<email>silviupopescu1990@gmail.com</email>
</author>
<published>2013-03-02T09:45:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d6e89c0b7660bd725a0948126f9db1a327f48d76'/>
<id>d6e89c0b7660bd725a0948126f9db1a327f48d76</id>
<content type='text'>
This fixed the following sparse warning:
net/caif/caif_dev.c:121:6: warning: symbol 'caif_flow_cb' was not
declared. Should it be static?

Signed-off-by: Silviu-Mihai Popescu &lt;silviupopescu1990@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This fixed the following sparse warning:
net/caif/caif_dev.c:121:6: warning: symbol 'caif_flow_cb' was not
declared. Should it be static?

Signed-off-by: Silviu-Mihai Popescu &lt;silviupopescu1990@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2012-07-19T18:17:30+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2012-07-19T18:17:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=abaa72d7fd9a20a67b62e6afa0e746e27851dc33'/>
<id>abaa72d7fd9a20a67b62e6afa0e746e27851dc33</id>
<content type='text'>
Conflicts:
	drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
</pre>
</div>
</content>
</entry>
<entry>
<title>caif: Fix access to freed pernet memory</title>
<updated>2012-07-17T06:06:20+00:00</updated>
<author>
<name>Sjur Brændeland</name>
<email>sjur.brandeland@stericsson.com</email>
</author>
<published>2012-07-15T10:10:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=96f80d123eff05c3cd4701463786b87952a6c3ac'/>
<id>96f80d123eff05c3cd4701463786b87952a6c3ac</id>
<content type='text'>
unregister_netdevice_notifier() must be called before
unregister_pernet_subsys() to avoid accessing already freed
pernet memory. This fixes the following oops when doing rmmod:

Call Trace:
 [&lt;ffffffffa0f802bd&gt;] caif_device_notify+0x4d/0x5a0 [caif]
 [&lt;ffffffff81552ba9&gt;] unregister_netdevice_notifier+0xb9/0x100
 [&lt;ffffffffa0f86dcc&gt;] caif_device_exit+0x1c/0x250 [caif]
 [&lt;ffffffff810e7734&gt;] sys_delete_module+0x1a4/0x300
 [&lt;ffffffff810da82d&gt;] ? trace_hardirqs_on_caller+0x15d/0x1e0
 [&lt;ffffffff813517de&gt;] ? trace_hardirqs_on_thunk+0x3a/0x3
 [&lt;ffffffff81696bad&gt;] system_call_fastpath+0x1a/0x1f

RIP
 [&lt;ffffffffa0f7f561&gt;] caif_get+0x51/0xb0 [caif]

Signed-off-by: Sjur Brændeland &lt;sjur.brandeland@stericsson.com&gt;
Acked-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
unregister_netdevice_notifier() must be called before
unregister_pernet_subsys() to avoid accessing already freed
pernet memory. This fixes the following oops when doing rmmod:

Call Trace:
 [&lt;ffffffffa0f802bd&gt;] caif_device_notify+0x4d/0x5a0 [caif]
 [&lt;ffffffff81552ba9&gt;] unregister_netdevice_notifier+0xb9/0x100
 [&lt;ffffffffa0f86dcc&gt;] caif_device_exit+0x1c/0x250 [caif]
 [&lt;ffffffff810e7734&gt;] sys_delete_module+0x1a4/0x300
 [&lt;ffffffff810da82d&gt;] ? trace_hardirqs_on_caller+0x15d/0x1e0
 [&lt;ffffffff813517de&gt;] ? trace_hardirqs_on_thunk+0x3a/0x3
 [&lt;ffffffff81696bad&gt;] system_call_fastpath+0x1a/0x1f

RIP
 [&lt;ffffffffa0f7f561&gt;] caif_get+0x51/0xb0 [caif]

Signed-off-by: Sjur Brændeland &lt;sjur.brandeland@stericsson.com&gt;
Acked-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>caif: added check for potential null return</title>
<updated>2012-06-25T23:44:11+00:00</updated>
<author>
<name>Kim Lilliestierna XX</name>
<email>kim.xx.lilliestierna@stericsson.com</email>
</author>
<published>2012-06-25T07:49:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c95567c8035281d20ca8266cb39f8d48307a70af'/>
<id>c95567c8035281d20ca8266cb39f8d48307a70af</id>
<content type='text'>
Add check on NULL return from caif_get().

Signed-off-by: Kim Lilliestierna &lt;Kim.xx.Lilliestierna@stericsson.com&gt;
Signed-off-by: Sjur Brændeland &lt;sjur.brandeland@stericssion.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add check on NULL return from caif_get().

Signed-off-by: Kim Lilliestierna &lt;Kim.xx.Lilliestierna@stericsson.com&gt;
Signed-off-by: Sjur Brændeland &lt;sjur.brandeland@stericssion.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
