* [PATCH] scripts: coccinelle: allow list_entry_is_head() to use pos
@ 2021-07-30 9:58 ` Daniel Thompson
0 siblings, 0 replies; 5+ messages in thread
From: Daniel Thompson @ 2021-07-30 9:58 UTC (permalink / raw)
To: Julia Lawall, Gilles Muller, Nicolas Palix, Michal Marek
Cc: Daniel Thompson, cocci, linux-kernel
Currently use_after_iter.cocci generates false positives for code of the
following form:
~~~
list_for_each_entry(d, &ddata->irq_list, node) {
if (irq == d->irq)
break;
}
if (list_entry_is_head(d, &ddata->irq_list, node))
return IRQ_NONE;
~~~
[This specific example comes from drivers/power/supply/cpcap-battery.c]
Most list macros use list_entry_is_head() as loop exit condition meaning it
is not unsafe to reuse pos (a.k.a. d) in the code above.
Let's avoid reporting these cases.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
Notes:
I'm pretty much a complete beginner w.r.t. SmPL. This is written
entirely by finding previous fixes and emulating them!
However I did test it by running the checker across the current kernel
tree. The changes reduced the error count by four... which was small
enough for me to eyeball each one and check they match the pattern I
was targetting.
scripts/coccinelle/iterators/use_after_iter.cocci | 2 ++
1 file changed, 2 insertions(+)
diff --git a/scripts/coccinelle/iterators/use_after_iter.cocci b/scripts/coccinelle/iterators/use_after_iter.cocci
index 9be48b520879..676edd562eef 100644
--- a/scripts/coccinelle/iterators/use_after_iter.cocci
+++ b/scripts/coccinelle/iterators/use_after_iter.cocci
@@ -123,6 +123,8 @@ hlist_for_each_entry_safe(c,...) S
|
list_remove_head(x,c,...)
|
+list_entry_is_head(c,...)
+|
sizeof(<+...c...+>)
|
&c->member
base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c
--
2.30.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* [Cocci] [PATCH] scripts: coccinelle: allow list_entry_is_head() to use pos
@ 2021-07-30 9:58 ` Daniel Thompson
0 siblings, 0 replies; 5+ messages in thread
From: Daniel Thompson @ 2021-07-30 9:58 UTC (permalink / raw)
To: Julia Lawall, Gilles Muller, Nicolas Palix, Michal Marek
Cc: Daniel Thompson, cocci, linux-kernel
Currently use_after_iter.cocci generates false positives for code of the
following form:
~~~
list_for_each_entry(d, &ddata->irq_list, node) {
if (irq == d->irq)
break;
}
if (list_entry_is_head(d, &ddata->irq_list, node))
return IRQ_NONE;
~~~
[This specific example comes from drivers/power/supply/cpcap-battery.c]
Most list macros use list_entry_is_head() as loop exit condition meaning it
is not unsafe to reuse pos (a.k.a. d) in the code above.
Let's avoid reporting these cases.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
Notes:
I'm pretty much a complete beginner w.r.t. SmPL. This is written
entirely by finding previous fixes and emulating them!
However I did test it by running the checker across the current kernel
tree. The changes reduced the error count by four... which was small
enough for me to eyeball each one and check they match the pattern I
was targetting.
scripts/coccinelle/iterators/use_after_iter.cocci | 2 ++
1 file changed, 2 insertions(+)
diff --git a/scripts/coccinelle/iterators/use_after_iter.cocci b/scripts/coccinelle/iterators/use_after_iter.cocci
index 9be48b520879..676edd562eef 100644
--- a/scripts/coccinelle/iterators/use_after_iter.cocci
+++ b/scripts/coccinelle/iterators/use_after_iter.cocci
@@ -123,6 +123,8 @@ hlist_for_each_entry_safe(c,...) S
|
list_remove_head(x,c,...)
|
+list_entry_is_head(c,...)
+|
sizeof(<+...c...+>)
|
&c->member
base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c
--
2.30.2
_______________________________________________
Cocci mailing list
Cocci@systeme.lip6.fr
https://systeme.lip6.fr/mailman/listinfo/cocci
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] scripts: coccinelle: allow list_entry_is_head() to use pos
2021-07-30 9:58 ` [Cocci] " Daniel Thompson
@ 2021-07-30 10:58 ` Julia Lawall
-1 siblings, 0 replies; 5+ messages in thread
From: Julia Lawall @ 2021-07-30 10:58 UTC (permalink / raw)
To: Daniel Thompson
Cc: Gilles Muller, Nicolas Palix, Michal Marek, cocci, linux-kernel
On Fri, 30 Jul 2021, Daniel Thompson wrote:
> Currently use_after_iter.cocci generates false positives for code of the
> following form:
> ~~~
> list_for_each_entry(d, &ddata->irq_list, node) {
> if (irq == d->irq)
> break;
> }
>
> if (list_entry_is_head(d, &ddata->irq_list, node))
> return IRQ_NONE;
> ~~~
> [This specific example comes from drivers/power/supply/cpcap-battery.c]
>
> Most list macros use list_entry_is_head() as loop exit condition meaning it
> is not unsafe to reuse pos (a.k.a. d) in the code above.
>
> Let's avoid reporting these cases.
>
> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
> ---
>
> Notes:
> I'm pretty much a complete beginner w.r.t. SmPL. This is written
> entirely by finding previous fixes and emulating them!
>
> However I did test it by running the checker across the current kernel
> tree. The changes reduced the error count by four... which was small
> enough for me to eyeball each one and check they match the pattern I
> was targetting.
This looks fine. Thanks for the proposal.
julia
>
> scripts/coccinelle/iterators/use_after_iter.cocci | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/scripts/coccinelle/iterators/use_after_iter.cocci b/scripts/coccinelle/iterators/use_after_iter.cocci
> index 9be48b520879..676edd562eef 100644
> --- a/scripts/coccinelle/iterators/use_after_iter.cocci
> +++ b/scripts/coccinelle/iterators/use_after_iter.cocci
> @@ -123,6 +123,8 @@ hlist_for_each_entry_safe(c,...) S
> |
> list_remove_head(x,c,...)
> |
> +list_entry_is_head(c,...)
> +|
> sizeof(<+...c...+>)
> |
> &c->member
>
> base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c
> --
> 2.30.2
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Cocci] [PATCH] scripts: coccinelle: allow list_entry_is_head() to use pos
@ 2021-07-30 10:58 ` Julia Lawall
0 siblings, 0 replies; 5+ messages in thread
From: Julia Lawall @ 2021-07-30 10:58 UTC (permalink / raw)
To: Daniel Thompson; +Cc: Michal Marek, Nicolas Palix, cocci, linux-kernel
On Fri, 30 Jul 2021, Daniel Thompson wrote:
> Currently use_after_iter.cocci generates false positives for code of the
> following form:
> ~~~
> list_for_each_entry(d, &ddata->irq_list, node) {
> if (irq == d->irq)
> break;
> }
>
> if (list_entry_is_head(d, &ddata->irq_list, node))
> return IRQ_NONE;
> ~~~
> [This specific example comes from drivers/power/supply/cpcap-battery.c]
>
> Most list macros use list_entry_is_head() as loop exit condition meaning it
> is not unsafe to reuse pos (a.k.a. d) in the code above.
>
> Let's avoid reporting these cases.
>
> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
> ---
>
> Notes:
> I'm pretty much a complete beginner w.r.t. SmPL. This is written
> entirely by finding previous fixes and emulating them!
>
> However I did test it by running the checker across the current kernel
> tree. The changes reduced the error count by four... which was small
> enough for me to eyeball each one and check they match the pattern I
> was targetting.
This looks fine. Thanks for the proposal.
julia
>
> scripts/coccinelle/iterators/use_after_iter.cocci | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/scripts/coccinelle/iterators/use_after_iter.cocci b/scripts/coccinelle/iterators/use_after_iter.cocci
> index 9be48b520879..676edd562eef 100644
> --- a/scripts/coccinelle/iterators/use_after_iter.cocci
> +++ b/scripts/coccinelle/iterators/use_after_iter.cocci
> @@ -123,6 +123,8 @@ hlist_for_each_entry_safe(c,...) S
> |
> list_remove_head(x,c,...)
> |
> +list_entry_is_head(c,...)
> +|
> sizeof(<+...c...+>)
> |
> &c->member
>
> base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c
> --
> 2.30.2
>
>
_______________________________________________
Cocci mailing list
Cocci@systeme.lip6.fr
https://systeme.lip6.fr/mailman/listinfo/cocci
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] scripts: coccinelle: allow list_entry_is_head() to use pos
2021-07-30 9:58 ` [Cocci] " Daniel Thompson
(?)
(?)
@ 2021-08-08 20:02 ` Julia Lawall
-1 siblings, 0 replies; 5+ messages in thread
From: Julia Lawall @ 2021-08-08 20:02 UTC (permalink / raw)
To: Daniel Thompson
Cc: Gilles Muller, Nicolas Palix, Michal Marek, cocci, linux-kernel
On Fri, 30 Jul 2021, Daniel Thompson wrote:
> Currently use_after_iter.cocci generates false positives for code of the
> following form:
> ~~~
> list_for_each_entry(d, &ddata->irq_list, node) {
> if (irq == d->irq)
> break;
> }
>
> if (list_entry_is_head(d, &ddata->irq_list, node))
> return IRQ_NONE;
> ~~~
> [This specific example comes from drivers/power/supply/cpcap-battery.c]
>
> Most list macros use list_entry_is_head() as loop exit condition meaning it
> is not unsafe to reuse pos (a.k.a. d) in the code above.
>
> Let's avoid reporting these cases.
Applied.
The function is really nice. The use_after_iter.cocci rule gives a lot of
false positives where people have used random variables as flags to
indicate how the loop was executed...
thanks,
julia
>
> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
> ---
>
> Notes:
> I'm pretty much a complete beginner w.r.t. SmPL. This is written
> entirely by finding previous fixes and emulating them!
>
> However I did test it by running the checker across the current kernel
> tree. The changes reduced the error count by four... which was small
> enough for me to eyeball each one and check they match the pattern I
> was targetting.
>
> scripts/coccinelle/iterators/use_after_iter.cocci | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/scripts/coccinelle/iterators/use_after_iter.cocci b/scripts/coccinelle/iterators/use_after_iter.cocci
> index 9be48b520879..676edd562eef 100644
> --- a/scripts/coccinelle/iterators/use_after_iter.cocci
> +++ b/scripts/coccinelle/iterators/use_after_iter.cocci
> @@ -123,6 +123,8 @@ hlist_for_each_entry_safe(c,...) S
> |
> list_remove_head(x,c,...)
> |
> +list_entry_is_head(c,...)
> +|
> sizeof(<+...c...+>)
> |
> &c->member
>
> base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c
> --
> 2.30.2
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-08-08 20:02 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-30 9:58 [PATCH] scripts: coccinelle: allow list_entry_is_head() to use pos Daniel Thompson
2021-07-30 9:58 ` [Cocci] " Daniel Thompson
2021-07-30 10:58 ` Julia Lawall
2021-07-30 10:58 ` [Cocci] " Julia Lawall
2021-08-08 20:02 ` Julia Lawall
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.