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* [Cocci] [PATCH v3 0/3] Update memdup_user.cocci
@ 2020-07-20 16:22 Denis Efremov
  2020-07-20 16:22 ` [Cocci] [PATCH v3 1/3] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
                   ` (3 more replies)
  0 siblings, 4 replies; 7+ messages in thread
From: Denis Efremov @ 2020-07-20 16:22 UTC (permalink / raw)
  To: Julia Lawall; +Cc: cocci, linux-kernel

Add GFP_USER to the allocation flags and handle vmemdup_user().

Changes in v2:
 - memdup_user/vmemdup_user matching suppressed
 - PoC for selfcheck virtual rule
Changes in v3:
 - add missing '-' for patch rule in kmalloc/kzalloc call args
 - selfcheck rule dropped from patchset

Denis Efremov (3):
  coccinelle: api: extend memdup_user transformation with GFP_USER
  coccinelle: api: extend memdup_user rule with vmemdup_user()
  coccinelle: api: filter out memdup_user definitions

 scripts/coccinelle/api/memdup_user.cocci | 64 ++++++++++++++++++++++--
 1 file changed, 61 insertions(+), 3 deletions(-)

-- 
2.26.2

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Cocci] [PATCH v3 1/3] coccinelle: api: extend memdup_user transformation with GFP_USER
  2020-07-20 16:22 [Cocci] [PATCH v3 0/3] Update memdup_user.cocci Denis Efremov
@ 2020-07-20 16:22 ` Denis Efremov
  2020-07-20 16:22 ` [Cocci] [PATCH v3 2/3] coccinelle: api: extend memdup_user rule with vmemdup_user() Denis Efremov
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 7+ messages in thread
From: Denis Efremov @ 2020-07-20 16:22 UTC (permalink / raw)
  To: Julia Lawall; +Cc: cocci, linux-kernel

Match GFP_USER and optional __GFP_NOWARN allocations with
memdup_user.cocci rule.
Commit 6c2c97a24f09 ("memdup_user(): switch to GFP_USER") switched
memdup_user() from GFP_KERNEL to GFP_USER. In almost all cases it
is still a good idea to recommend memdup_user() for GFP_KERNEL
allocations. The motivation behind altering memdup_user() to GFP_USER:
https://lkml.org/lkml/2018/1/6/333

Signed-off-by: Denis Efremov <efremov@linux.com>
---
 scripts/coccinelle/api/memdup_user.cocci | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/scripts/coccinelle/api/memdup_user.cocci b/scripts/coccinelle/api/memdup_user.cocci
index c809ab10bbce..0e29d41ecab8 100644
--- a/scripts/coccinelle/api/memdup_user.cocci
+++ b/scripts/coccinelle/api/memdup_user.cocci
@@ -20,7 +20,9 @@ expression from,to,size;
 identifier l1,l2;
 @@
 
--  to = \(kmalloc\|kzalloc\)(size,GFP_KERNEL);
+-  to = \(kmalloc\|kzalloc\)
+-		(size,\(GFP_KERNEL\|GFP_USER\|
+-		      \(GFP_KERNEL\|GFP_USER\)|__GFP_NOWARN\));
 +  to = memdup_user(from,size);
    if (
 -      to==NULL
@@ -43,7 +45,9 @@ position p;
 statement S1,S2;
 @@
 
-*  to = \(kmalloc@p\|kzalloc@p\)(size,GFP_KERNEL);
+*  to = \(kmalloc@p\|kzalloc@p\)
+		(size,\(GFP_KERNEL\|GFP_USER\|
+		      \(GFP_KERNEL\|GFP_USER\)|__GFP_NOWARN\));
    if (to==NULL || ...) S1
    if (copy_from_user(to, from, size) != 0)
    S2
-- 
2.26.2

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* [Cocci] [PATCH v3 2/3] coccinelle: api: extend memdup_user rule with vmemdup_user()
  2020-07-20 16:22 [Cocci] [PATCH v3 0/3] Update memdup_user.cocci Denis Efremov
  2020-07-20 16:22 ` [Cocci] [PATCH v3 1/3] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
@ 2020-07-20 16:22 ` Denis Efremov
  2020-07-20 16:22 ` [Cocci] [PATCH v3 3/3] coccinelle: api: filter out memdup_user definitions Denis Efremov
  2020-07-24 20:02 ` [Cocci] [PATCH v3 0/3] Update memdup_user.cocci Julia Lawall
  3 siblings, 0 replies; 7+ messages in thread
From: Denis Efremov @ 2020-07-20 16:22 UTC (permalink / raw)
  To: Julia Lawall; +Cc: cocci, linux-kernel

Add vmemdup_user() transformations to the memdup_user.cocci rule.
Commit 50fd2f298bef ("new primitive: vmemdup_user()") introduced
vmemdup_user(). The function uses kvmalloc with GPF_USER flag.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
 scripts/coccinelle/api/memdup_user.cocci | 45 ++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/scripts/coccinelle/api/memdup_user.cocci b/scripts/coccinelle/api/memdup_user.cocci
index 0e29d41ecab8..60027e21c5e6 100644
--- a/scripts/coccinelle/api/memdup_user.cocci
+++ b/scripts/coccinelle/api/memdup_user.cocci
@@ -39,6 +39,28 @@ identifier l1,l2;
 -    ...+>
 -  }
 
+@depends on patch@
+expression from,to,size;
+identifier l1,l2;
+@@
+
+-  to = \(kvmalloc\|kvzalloc\)(size,\(GFP_KERNEL\|GFP_USER\));
++  to = vmemdup_user(from,size);
+   if (
+-      to==NULL
++      IS_ERR(to)
+                 || ...) {
+   <+... when != goto l1;
+-  -ENOMEM
++  PTR_ERR(to)
+   ...+>
+   }
+-  if (copy_from_user(to, from, size) != 0) {
+-    <+... when != goto l2;
+-    -EFAULT
+-    ...+>
+-  }
+
 @r depends on !patch@
 expression from,to,size;
 position p;
@@ -52,6 +74,17 @@ statement S1,S2;
    if (copy_from_user(to, from, size) != 0)
    S2
 
+@rv depends on !patch@
+expression from,to,size;
+position p;
+statement S1,S2;
+@@
+
+*  to = \(kvmalloc@p\|kvzalloc@p\)(size,\(GFP_KERNEL\|GFP_USER\));
+   if (to==NULL || ...) S1
+   if (copy_from_user(to, from, size) != 0)
+   S2
+
 @script:python depends on org@
 p << r.p;
 @@
@@ -63,3 +96,15 @@ p << r.p;
 @@
 
 coccilib.report.print_report(p[0], "WARNING opportunity for memdup_user")
+
+@script:python depends on org@
+p << rv.p;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING opportunity for vmemdup_user")
+
+@script:python depends on report@
+p << rv.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING opportunity for vmemdup_user")
-- 
2.26.2

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Cocci] [PATCH v3 3/3] coccinelle: api: filter out memdup_user definitions
  2020-07-20 16:22 [Cocci] [PATCH v3 0/3] Update memdup_user.cocci Denis Efremov
  2020-07-20 16:22 ` [Cocci] [PATCH v3 1/3] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
  2020-07-20 16:22 ` [Cocci] [PATCH v3 2/3] coccinelle: api: extend memdup_user rule with vmemdup_user() Denis Efremov
@ 2020-07-20 16:22 ` Denis Efremov
  2020-07-24 20:02 ` [Cocci] [PATCH v3 0/3] Update memdup_user.cocci Julia Lawall
  3 siblings, 0 replies; 7+ messages in thread
From: Denis Efremov @ 2020-07-20 16:22 UTC (permalink / raw)
  To: Julia Lawall; +Cc: cocci, linux-kernel

Don't match memdup_user/vmemdup_user.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
 scripts/coccinelle/api/memdup_user.cocci | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/scripts/coccinelle/api/memdup_user.cocci b/scripts/coccinelle/api/memdup_user.cocci
index 60027e21c5e6..e01e95108405 100644
--- a/scripts/coccinelle/api/memdup_user.cocci
+++ b/scripts/coccinelle/api/memdup_user.cocci
@@ -15,12 +15,20 @@ virtual context
 virtual org
 virtual report
 
+@initialize:python@
+@@
+filter = frozenset(['memdup_user', 'vmemdup_user'])
+
+def relevant(p):
+    return not (filter & {el.current_element for el in p})
+
 @depends on patch@
 expression from,to,size;
 identifier l1,l2;
+position p : script:python() { relevant(p) };
 @@
 
--  to = \(kmalloc\|kzalloc\)
+-  to = \(kmalloc@p\|kzalloc@p\)
 -		(size,\(GFP_KERNEL\|GFP_USER\|
 -		      \(GFP_KERNEL\|GFP_USER\)|__GFP_NOWARN\));
 +  to = memdup_user(from,size);
@@ -42,9 +50,10 @@ identifier l1,l2;
 @depends on patch@
 expression from,to,size;
 identifier l1,l2;
+position p : script:python() { relevant(p) };
 @@
 
--  to = \(kvmalloc\|kvzalloc\)(size,\(GFP_KERNEL\|GFP_USER\));
+-  to = \(kvmalloc@p\|kvzalloc@p\)(size,\(GFP_KERNEL\|GFP_USER\));
 +  to = vmemdup_user(from,size);
    if (
 -      to==NULL
@@ -63,7 +72,7 @@ identifier l1,l2;
 
 @r depends on !patch@
 expression from,to,size;
-position p;
+position p : script:python() { relevant(p) };
 statement S1,S2;
 @@
 
@@ -76,7 +85,7 @@ statement S1,S2;
 
 @rv depends on !patch@
 expression from,to,size;
-position p;
+position p : script:python() { relevant(p) };
 statement S1,S2;
 @@
 
-- 
2.26.2

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [Cocci] [PATCH v3 0/3] Update memdup_user.cocci
  2020-07-20 16:22 [Cocci] [PATCH v3 0/3] Update memdup_user.cocci Denis Efremov
                   ` (2 preceding siblings ...)
  2020-07-20 16:22 ` [Cocci] [PATCH v3 3/3] coccinelle: api: filter out memdup_user definitions Denis Efremov
@ 2020-07-24 20:02 ` Julia Lawall
  3 siblings, 0 replies; 7+ messages in thread
From: Julia Lawall @ 2020-07-24 20:02 UTC (permalink / raw)
  To: Denis Efremov; +Cc: cocci, linux-kernel



On Mon, 20 Jul 2020, Denis Efremov wrote:

> Add GFP_USER to the allocation flags and handle vmemdup_user().
>
> Changes in v2:
>  - memdup_user/vmemdup_user matching suppressed
>  - PoC for selfcheck virtual rule
> Changes in v3:
>  - add missing '-' for patch rule in kmalloc/kzalloc call args
>  - selfcheck rule dropped from patchset
>
> Denis Efremov (3):
>   coccinelle: api: extend memdup_user transformation with GFP_USER
>   coccinelle: api: extend memdup_user rule with vmemdup_user()
>   coccinelle: api: filter out memdup_user definitions

All three applied.  Thanks.

julia

>
>  scripts/coccinelle/api/memdup_user.cocci | 64 ++++++++++++++++++++++--
>  1 file changed, 61 insertions(+), 3 deletions(-)
>
> --
> 2.26.2
>
>
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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [Cocci] [PATCH v3 2/3] coccinelle: api: extend memdup_user rule with vmemdup_user()
       [not found]   ` <0b326e2b-723c-3482-c0ef-5d6592a9c6cb@web.de>
@ 2020-07-22  6:02     ` Julia Lawall
  0 siblings, 0 replies; 7+ messages in thread
From: Julia Lawall @ 2020-07-22  6:02 UTC (permalink / raw)
  To: Markus Elfring
  Cc: Michal Marek, Gilles Muller, kernel-janitors, Nicolas Palix,
	linux-kernel, Coccinelle


[-- Attachment #1: Type: text/plain, Size: 1496 bytes --]



On Wed, 22 Jul 2020, Markus Elfring wrote:

> >>> +@depends on patch@
> >>> +expression from,to,size;
> >>> +identifier l1,l2;
> >>> +@@
> >>> +
> >>> +-  to = \(kvmalloc\|kvzalloc\)(size,\(GFP_KERNEL\|GFP_USER\));
> >>> ++  to = vmemdup_user(from,size);
> >>
> >> I propose to combine the desired adjustment with the previous SmPL rule
> >> by using another disjunction.
>
> How do you think about to check run time characteristics for
> the following SmPL script sketches?
>
> A)
> @R1@
> @@
> // Change something
>
> @R2@
> @@
> // Change another thing
>
>
> B)
> @Replacement_with_disjunction@
> @@
> (
> // R1: Change something
> |
> // R2: Change another thing
> )

Markus, you are welcome to try this since you are concerned about it.
But it doesn't matter.

julia

>
>
> >>> +@rv depends on !patch@
> >>> +expression from,to,size;
> >>> +position p;
> >>> +statement S1,S2;
> >>> +@@
> >>> +
> >>> +*  to = \(kvmalloc@p\|kvzalloc@p\)(size,\(GFP_KERNEL\|GFP_USER\));
> >>> +   if (to==NULL || ...) S1
> >>> +   if (copy_from_user(to, from, size) != 0)
> >>> +   S2
> >>
> >> * Can it be helpful to omit the SmPL asterisk functionality from
> >>   the operation modes “org” and “report”?
> >>
> >> * Should the operation mode “context” work without an extra position metavariable?
> >
> > This is fine as is in all three aspects.
>
> Is every technique from the Coccinelle software required for
> each operation mode in such data processing approaches?
>
> Regards,
> Markus
>

[-- Attachment #2: Type: text/plain, Size: 136 bytes --]

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* Re: [Cocci] [PATCH v3 2/3] coccinelle: api: extend memdup_user rule with vmemdup_user()
       [not found] <e3d2ffb9-2a47-3d77-0501-9d48845435bd@web.de>
@ 2020-07-21  9:58 ` Julia Lawall
       [not found]   ` <0b326e2b-723c-3482-c0ef-5d6592a9c6cb@web.de>
  0 siblings, 1 reply; 7+ messages in thread
From: Julia Lawall @ 2020-07-21  9:58 UTC (permalink / raw)
  To: Markus Elfring
  Cc: Michal Marek, Gilles Muller, kernel-janitors, Nicolas Palix,
	linux-kernel, Coccinelle


[-- Attachment #1: Type: text/plain, Size: 980 bytes --]



On Tue, 21 Jul 2020, Markus Elfring wrote:

> …
> > +++ b/scripts/coccinelle/api/memdup_user.cocci
> > @@ -39,6 +39,28 @@ …
> …
> > +@depends on patch@
> > +expression from,to,size;
> > +identifier l1,l2;
> > +@@
> > +
> > +-  to = \(kvmalloc\|kvzalloc\)(size,\(GFP_KERNEL\|GFP_USER\));
> > ++  to = vmemdup_user(from,size);
>
> I propose to combine the desired adjustment with the previous SmPL rule
> by using another disjunction.
>
>
> > +@rv depends on !patch@
> > +expression from,to,size;
> > +position p;
> > +statement S1,S2;
> > +@@
> > +
> > +*  to = \(kvmalloc@p\|kvzalloc@p\)(size,\(GFP_KERNEL\|GFP_USER\));
> > +   if (to==NULL || ...) S1
> > +   if (copy_from_user(to, from, size) != 0)
> > +   S2
>
> * Can it be helpful to omit the SmPL asterisk functionality from
>   the operation modes “org” and “report”?
>
> * Should the operation mode “context” work without an extra position metavariable?

This is fine as is in all three aspects.

julia

[-- Attachment #2: Type: text/plain, Size: 136 bytes --]

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Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-20 16:22 [Cocci] [PATCH v3 0/3] Update memdup_user.cocci Denis Efremov
2020-07-20 16:22 ` [Cocci] [PATCH v3 1/3] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
2020-07-20 16:22 ` [Cocci] [PATCH v3 2/3] coccinelle: api: extend memdup_user rule with vmemdup_user() Denis Efremov
2020-07-20 16:22 ` [Cocci] [PATCH v3 3/3] coccinelle: api: filter out memdup_user definitions Denis Efremov
2020-07-24 20:02 ` [Cocci] [PATCH v3 0/3] Update memdup_user.cocci Julia Lawall
     [not found] <e3d2ffb9-2a47-3d77-0501-9d48845435bd@web.de>
2020-07-21  9:58 ` [Cocci] [PATCH v3 2/3] coccinelle: api: extend memdup_user rule with vmemdup_user() Julia Lawall
     [not found]   ` <0b326e2b-723c-3482-c0ef-5d6592a9c6cb@web.de>
2020-07-22  6:02     ` Julia Lawall

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