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* [Cocci] [PATCH v2 0/4] Update memdup_user.cocci
@ 2020-06-08 15:00 Denis Efremov
  2020-06-08 15:00 ` [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
                   ` (4 more replies)
  0 siblings, 5 replies; 11+ messages in thread
From: Denis Efremov @ 2020-06-08 15:00 UTC (permalink / raw)
  To: Julia Lawall; +Cc: linux-kernel, cocci

Add GFP_USER to the allocation flags and handle vmemdup_user().
The third patch supresses memdup_user(), vmemdup_user() functions
detection. Last patch is a proof of concept for the rule selfchecking.
Gives the ability to detect that an open-coded pattern in a function
definition that we search for in the kernel sources changed.

Denis Efremov (4):
  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
  coccinelle: api: add selfcheck for memdup_user rule

 scripts/coccinelle/api/memdup_user.cocci | 106 ++++++++++++++++++++++-
 1 file changed, 103 insertions(+), 3 deletions(-)

-- 
2.26.2

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^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER
  2020-06-08 15:00 [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
@ 2020-06-08 15:00 ` Denis Efremov
  2020-07-17 20:56   ` Julia Lawall
  2020-06-08 15:00 ` [Cocci] [PATCH v2 2/4] coccinelle: api: extend memdup_user rule with vmemdup_user() Denis Efremov
                   ` (3 subsequent siblings)
  4 siblings, 1 reply; 11+ messages in thread
From: Denis Efremov @ 2020-06-08 15:00 UTC (permalink / raw)
  To: Julia Lawall; +Cc: linux-kernel, cocci

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..cadcc2e87881 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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^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Cocci] [PATCH v2 2/4] coccinelle: api: extend memdup_user rule with vmemdup_user()
  2020-06-08 15:00 [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
  2020-06-08 15:00 ` [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
@ 2020-06-08 15:00 ` Denis Efremov
  2020-06-08 15:00 ` [Cocci] [PATCH v2 3/4] coccinelle: api: filter out memdup_user definitions Denis Efremov
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 11+ messages in thread
From: Denis Efremov @ 2020-06-08 15:00 UTC (permalink / raw)
  To: Julia Lawall; +Cc: linux-kernel, cocci

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 cadcc2e87881..d15c061a34ab 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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https://systeme.lip6.fr/mailman/listinfo/cocci

^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Cocci] [PATCH v2 3/4] coccinelle: api: filter out memdup_user definitions
  2020-06-08 15:00 [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
  2020-06-08 15:00 ` [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
  2020-06-08 15:00 ` [Cocci] [PATCH v2 2/4] coccinelle: api: extend memdup_user rule with vmemdup_user() Denis Efremov
@ 2020-06-08 15:00 ` Denis Efremov
  2020-06-08 15:00 ` [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for memdup_user rule Denis Efremov
  2020-07-17 12:01 ` [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
  4 siblings, 0 replies; 11+ messages in thread
From: Denis Efremov @ 2020-06-08 15:00 UTC (permalink / raw)
  To: Julia Lawall; +Cc: linux-kernel, cocci

Don't match original implementations.

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 d15c061a34ab..8621bd98be1e 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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https://systeme.lip6.fr/mailman/listinfo/cocci

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* [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for memdup_user rule
  2020-06-08 15:00 [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
                   ` (2 preceding siblings ...)
  2020-06-08 15:00 ` [Cocci] [PATCH v2 3/4] coccinelle: api: filter out memdup_user definitions Denis Efremov
@ 2020-06-08 15:00 ` Denis Efremov
  2020-06-09 16:22   ` Julia Lawall
  2020-07-17 12:01 ` [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
  4 siblings, 1 reply; 11+ messages in thread
From: Denis Efremov @ 2020-06-08 15:00 UTC (permalink / raw)
  To: Julia Lawall; +Cc: linux-kernel, cocci

Check that the rule matches vmemdup_user implementation.
memdup_user is out of scope because we are not matching
kmalloc_track_caller() function.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
 scripts/coccinelle/api/memdup_user.cocci | 46 ++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/scripts/coccinelle/api/memdup_user.cocci b/scripts/coccinelle/api/memdup_user.cocci
index 8621bd98be1e..78fded83b197 100644
--- a/scripts/coccinelle/api/memdup_user.cocci
+++ b/scripts/coccinelle/api/memdup_user.cocci
@@ -14,13 +14,24 @@ virtual patch
 virtual context
 virtual org
 virtual report
+virtual selfcheck
 
 @initialize:python@
 @@
-filter = frozenset(['memdup_user', 'vmemdup_user'])
+
+definitions = {
+    'memdup_user': 'mm/util.c',
+    'vmemdup_user': 'mm/util.c',
+}
+
+filter = frozenset(definitions.keys())
+coccinelle.filtered = set()
+coccinelle.checked_files = set()
 
 def relevant(p):
-    return not (filter & {el.current_element for el in p})
+    found = filter & {el.current_element for el in p}
+    coccinelle.filtered |= found
+    return not found
 
 @depends on patch@
 expression from,to,size;
@@ -117,3 +128,34 @@ p << rv.p;
 @@
 
 coccilib.report.print_report(p[0], "WARNING opportunity for vmemdup_user")
+
+@script:python depends on selfcheck@
+@@
+coccinelle.checked_files |= set(definitions.values()) & set(cocci.files())
+
+@finalize:python depends on selfcheck@
+filtered << merge.filtered;
+checked_files << merge.checked_files;
+@@
+
+# Don't check memdup_user because the pattern is not capturing
+# kmalloc_track_caller() calls
+del definitions['memdup_user']
+
+# mapping between checked files and filtered definitions
+found_defns = {}
+for files, funcs in zip(checked_files, filtered):
+   for file in files:
+      found_defns[file] = funcs
+
+# reverse mapping of definitions
+expected_defns = {v : set() for v in definitions.values()}
+for k, v in definitions.items():
+    expected_defns[v] |= {k}
+
+for efile, efuncs in expected_defns.items():
+    if efile in found_defns:
+        not_found = efuncs - found_defns[efile]
+        if not_found:
+            print('SELF-CHECK: the pattern no longer matches ' \
+		  'definitions {} in file {}'.format(not_found, efile))
-- 
2.26.2

_______________________________________________
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Cocci@systeme.lip6.fr
https://systeme.lip6.fr/mailman/listinfo/cocci

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for memdup_user rule
  2020-06-08 15:00 ` [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for memdup_user rule Denis Efremov
@ 2020-06-09 16:22   ` Julia Lawall
  2020-06-11 21:25     ` Denis Efremov
  0 siblings, 1 reply; 11+ messages in thread
From: Julia Lawall @ 2020-06-09 16:22 UTC (permalink / raw)
  To: Denis Efremov; +Cc: linux-kernel, cocci



On Mon, 8 Jun 2020, Denis Efremov wrote:

> Check that the rule matches vmemdup_user implementation.
> memdup_user is out of scope because we are not matching
> kmalloc_track_caller() function.

Is this a bit over-enginered?  More precisely, even if it is nice to check
that the API definition has the expected behavior, does it make sense to
do it in one case but not the other?

julia

>
> Signed-off-by: Denis Efremov <efremov@linux.com>
> ---
>  scripts/coccinelle/api/memdup_user.cocci | 46 ++++++++++++++++++++++--
>  1 file changed, 44 insertions(+), 2 deletions(-)
>
> diff --git a/scripts/coccinelle/api/memdup_user.cocci b/scripts/coccinelle/api/memdup_user.cocci
> index 8621bd98be1e..78fded83b197 100644
> --- a/scripts/coccinelle/api/memdup_user.cocci
> +++ b/scripts/coccinelle/api/memdup_user.cocci
> @@ -14,13 +14,24 @@ virtual patch
>  virtual context
>  virtual org
>  virtual report
> +virtual selfcheck
>
>  @initialize:python@
>  @@
> -filter = frozenset(['memdup_user', 'vmemdup_user'])
> +
> +definitions = {
> +    'memdup_user': 'mm/util.c',
> +    'vmemdup_user': 'mm/util.c',
> +}
> +
> +filter = frozenset(definitions.keys())
> +coccinelle.filtered = set()
> +coccinelle.checked_files = set()
>
>  def relevant(p):
> -    return not (filter & {el.current_element for el in p})
> +    found = filter & {el.current_element for el in p}
> +    coccinelle.filtered |= found
> +    return not found
>
>  @depends on patch@
>  expression from,to,size;
> @@ -117,3 +128,34 @@ p << rv.p;
>  @@
>
>  coccilib.report.print_report(p[0], "WARNING opportunity for vmemdup_user")
> +
> +@script:python depends on selfcheck@
> +@@
> +coccinelle.checked_files |= set(definitions.values()) & set(cocci.files())
> +
> +@finalize:python depends on selfcheck@
> +filtered << merge.filtered;
> +checked_files << merge.checked_files;
> +@@
> +
> +# Don't check memdup_user because the pattern is not capturing
> +# kmalloc_track_caller() calls
> +del definitions['memdup_user']
> +
> +# mapping between checked files and filtered definitions
> +found_defns = {}
> +for files, funcs in zip(checked_files, filtered):
> +   for file in files:
> +      found_defns[file] = funcs
> +
> +# reverse mapping of definitions
> +expected_defns = {v : set() for v in definitions.values()}
> +for k, v in definitions.items():
> +    expected_defns[v] |= {k}
> +
> +for efile, efuncs in expected_defns.items():
> +    if efile in found_defns:
> +        not_found = efuncs - found_defns[efile]
> +        if not_found:
> +            print('SELF-CHECK: the pattern no longer matches ' \
> +		  'definitions {} in file {}'.format(not_found, efile))
> --
> 2.26.2
>
> _______________________________________________
> Cocci mailing list
> Cocci@systeme.lip6.fr
> https://systeme.lip6.fr/mailman/listinfo/cocci
>
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* Re: [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for memdup_user rule
  2020-06-09 16:22   ` Julia Lawall
@ 2020-06-11 21:25     ` Denis Efremov
  0 siblings, 0 replies; 11+ messages in thread
From: Denis Efremov @ 2020-06-11 21:25 UTC (permalink / raw)
  To: Julia Lawall; +Cc: linux-kernel, cocci


On 6/9/20 7:22 PM, Julia Lawall wrote:
> 
> 
> On Mon, 8 Jun 2020, Denis Efremov wrote:
> 
>> Check that the rule matches vmemdup_user implementation.
>> memdup_user is out of scope because we are not matching
>> kmalloc_track_caller() function.
> 
> Is this a bit over-enginered?

Last patch it's just a PoC. Patches 1-3 are independent from 4.

> More precisely, even if it is nice to check
> that the API definition has the expected behavior, does it make sense to
> do it in one case but not the other?

Yes, I also don't like it. However, I doubt that we need to match
kmalloc_track_caller.

Thanks,
Denis
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* Re: [Cocci] [PATCH v2 0/4] Update memdup_user.cocci
  2020-06-08 15:00 [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
                   ` (3 preceding siblings ...)
  2020-06-08 15:00 ` [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for memdup_user rule Denis Efremov
@ 2020-07-17 12:01 ` Denis Efremov
  4 siblings, 0 replies; 11+ messages in thread
From: Denis Efremov @ 2020-07-17 12:01 UTC (permalink / raw)
  To: Julia Lawall; +Cc: linux-kernel, cocci

Ping?

On 6/8/20 6:00 PM, Denis Efremov wrote:
> Add GFP_USER to the allocation flags and handle vmemdup_user().
> The third patch supresses memdup_user(), vmemdup_user() functions
> detection. Last patch is a proof of concept for the rule selfchecking.
> Gives the ability to detect that an open-coded pattern in a function
> definition that we search for in the kernel sources changed.
> 
> Denis Efremov (4):
>   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
>   coccinelle: api: add selfcheck for memdup_user rule
> 
>  scripts/coccinelle/api/memdup_user.cocci | 106 ++++++++++++++++++++++-
>  1 file changed, 103 insertions(+), 3 deletions(-)
> 
_______________________________________________
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Cocci@systeme.lip6.fr
https://systeme.lip6.fr/mailman/listinfo/cocci

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER
  2020-06-08 15:00 ` [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
@ 2020-07-17 20:56   ` Julia Lawall
  0 siblings, 0 replies; 11+ messages in thread
From: Julia Lawall @ 2020-07-17 20:56 UTC (permalink / raw)
  To: Denis Efremov; +Cc: linux-kernel, cocci



On Mon, 8 Jun 2020, Denis Efremov wrote:

> 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>

Applied.

> ---
>  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..cadcc2e87881 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
>
> _______________________________________________
> Cocci mailing list
> Cocci@systeme.lip6.fr
> https://systeme.lip6.fr/mailman/listinfo/cocci
>
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* Re: [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER
@ 2020-06-09 14:16 Markus Elfring
  0 siblings, 0 replies; 11+ messages in thread
From: Markus Elfring @ 2020-06-09 14:16 UTC (permalink / raw)
  To: Denis Efremov, Coccinelle, Gilles Muller, Julia Lawall,
	Masahiro Yamada, Michal Marek, Nicolas Palix
  Cc: kernel-janitors, linux-kernel

…
> +++ b/scripts/coccinelle/api/memdup_user.cocci
> @@ -20,7 +20,9 @@ expression from,to,size;
> +-  to = \(kmalloc\|kzalloc\)
> +		(size,\(GFP_KERNEL\|GFP_USER\|
> +		      \(GFP_KERNEL\|GFP_USER\)|__GFP_NOWARN\));

I got the impression that this SmPL code needs another correction also
according to the proposed SmPL disjunction.

+-to = \( kmalloc \| kzalloc \) (size, \( GFP_KERNEL \| GFP_USER \) \( | __GFP_NOWARN \| \) );


Would you like to express by any other approach that a specific flag
is an optional source code transformation parameter?

Regards,
Markus
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^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER
@ 2020-06-08 17:20 Markus Elfring
  0 siblings, 0 replies; 11+ messages in thread
From: Markus Elfring @ 2020-06-08 17:20 UTC (permalink / raw)
  To: Denis Efremov, Gilles Muller, Julia Lawall, Masahiro Yamada,
	Michal Marek, Nicolas Palix
  Cc: kernel-janitors, Coccinelle, linux-kernel

> Match GFP_USER and optional __GFP_NOWARN allocations with
> memdup_user.cocci rule.

You suggest another interesting software extension.


…
> +++ 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);

But I find the proposed change for such SmPL code inappropriate.

It was specified by the means of the semantic patch language
to replace an assignment statement for which a function call provides a value.
I would interpret your adjustment in the way that an expression list
should be preserved.
Were two minus characters forgotten for the first SmPL rule?

Further concerns should be taken into account for the SmPL rule “r”.

I would appreciate if the clarification will be continued also for
the topic “Safer source code analysis by "memdup_user.cocci"”?
https://github.com/coccinelle/coccinelle/issues/78

Regards,
Markus
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^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, back to index

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-08 15:00 [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
2020-06-08 15:00 ` [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER Denis Efremov
2020-07-17 20:56   ` Julia Lawall
2020-06-08 15:00 ` [Cocci] [PATCH v2 2/4] coccinelle: api: extend memdup_user rule with vmemdup_user() Denis Efremov
2020-06-08 15:00 ` [Cocci] [PATCH v2 3/4] coccinelle: api: filter out memdup_user definitions Denis Efremov
2020-06-08 15:00 ` [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for memdup_user rule Denis Efremov
2020-06-09 16:22   ` Julia Lawall
2020-06-11 21:25     ` Denis Efremov
2020-07-17 12:01 ` [Cocci] [PATCH v2 0/4] Update memdup_user.cocci Denis Efremov
2020-06-08 17:20 [Cocci] [PATCH v2 1/4] coccinelle: api: extend memdup_user transformation with GFP_USER Markus Elfring
2020-06-09 14:16 Markus Elfring

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