[cocci] [PATCH v1 0/1] scripts/coccinelle: Add script for using ARRAY_END()

[cocci] [PATCH v1 0/1] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

Hi!

This is a script to help find and replace uses of ARRAY_SIZE() to find
the end of an array (a pointer one past the last element).  We already
replaced some uses a few months ago, fixing some bugs while doing that,
and now I've written a coccinelle patch to do it elsewhere.

This is the first time I write a script under scripts/coccinelle/, so
take it with a grain of salt.  I've tested it, and I see no false
positives.  However, I've found several false negatives (for example,
in macros, or where the argument is a struct member).


Have a lovely night!
Alex


Alejandro Colomar (1):
  scripts/coccinelle: Add script for using ARRAY_END()

 scripts/coccinelle/misc/array_end.cocci | 93 +++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 scripts/coccinelle/misc/array_end.cocci

Range-diff against v0:
-:  -------- > 1:  f1c9dff5 scripts/coccinelle: Add script for using ARRAY_END()
-- 
2.53.0

[cocci] [PATCH v1 1/1] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

Recently, we added an ARRAY_END() macro to simplify finding a pointer
one past the last element in an array.  Such a pointer is often called
the 'end', and thus the macro name.

This script makes it easy to find more places where that macro should be
used.

See also:
436debc9cad8 ("array_size.h: add ARRAY_END()")
8118f197b7b7 ("mm: fix benign off-by-one bugs")
a9e5620c9a9e ("kernel: fix off-by-one benign bugs")
61e9210e2392 ("mm: use ARRAY_END() instead of open-coding it")

Cc: Kees Cook <kees@kernel.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Cc: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 scripts/coccinelle/misc/array_end.cocci | 93 +++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 scripts/coccinelle/misc/array_end.cocci

diff --git a/scripts/coccinelle/misc/array_end.cocci b/scripts/coccinelle/misc/array_end.cocci
new file mode 100644
index 00000000..2474b7e6
--- /dev/null
+++ b/scripts/coccinelle/misc/array_end.cocci
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Use ARRAY_END instead of an expression derived from ARRAY_SIZE
+//
+// Confidence: ???
+// Copyright: 2026, Alejandro Colomar <alx@kernel.org>
+// Comments:
+// Options: --no-includes --include-headers
+
+virtual patch
+virtual context
+virtual org
+virtual report
+
+@i@
+@@
+
+#include <linux/kernel.h>
+
+//----------------------------------------------------------
+//  For context mode
+//----------------------------------------------------------
+
+@depends on i&&context@
+type T;
+T[] a;
+expression b;
+@@
+(
+* (a + ARRAY_SIZE(a))
+|
+* (&a[0] + ARRAY_SIZE(a))
+|
+* (&a[ARRAY_SIZE(a)])
+|
+* (&a[ARRAY_SIZE(a) - b])
+)
+
+//----------------------------------------------------------
+//  For patch mode
+//----------------------------------------------------------
+
+@depends on i&&patch@
+type T;
+T[] a;
+expression b;
+@@
+(
+- (a + ARRAY_SIZE(a))
++ ARRAY_END(a)
+|
+- (&a[0] + ARRAY_SIZE(a))
++ ARRAY_END(a)
+|
+- (&a[ARRAY_SIZE(a)])
++ ARRAY_END(a)
+|
+- (&a[ARRAY_SIZE(a) - b])
++ ARRAY_END(a) - b
+)
+
+//----------------------------------------------------------
+//  For org and report mode
+//----------------------------------------------------------
+
+@r depends on (org || report)@
+type T;
+T[] a;
+expression b;
+position p;
+@@
+(
+ (a@p + ARRAY_SIZE(a))
+|
+ (&a[0]@p + ARRAY_SIZE(a))
+|
+ (&a[ARRAY_SIZE(a)]@p)
+|
+ (&a[ARRAY_SIZE(a)@p - b])
+)
+
+@script:python depends on org@
+p << r.p;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING should use ARRAY_END")
+
+@script:python depends on report@
+p << r.p;
+@@
+
+msg="WARNING: Use ARRAY_END"
+coccilib.report.print_report(p[0], msg)
+
-- 
2.53.0

Re: [cocci] [PATCH] scripts/coccinelle: Add script for using ARRAY_END()

[Markus Elfring]

…
> This script makes it easy to find more places where that macro should be
> used.

See also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc3#n94


…
> +++ b/scripts/coccinelle/misc/array_end.cocci
> @@ -0,0 +1,93 @@
…


> +// Confidence: ???

I hope that a more reasonable value can be determined for this information.


…
> +// Comments:

Please omit such an empty field.


…
> +@i@
> +@@
> +
> +#include <linux/kernel.h>

I doubt that such an SmPL rule would be required.


> +
> +//----------------------------------------------------------
> +//  For context mode
> +//----------------------------------------------------------
> +

Please omit such extra comment lines.


> +@depends on i&&context@
> +type T;
> +T[] a;
> +expression b;
> +@@
> +(
> +* (a + ARRAY_SIZE(a))
> +|
> +* (&a[0] + ARRAY_SIZE(a))
> +|
> +* (&a[ARRAY_SIZE(a)])
> +|
> +* (&a[ARRAY_SIZE(a) - b])
> +)

Extra space characters may be omitted directly after SmPL asterisks.


…
> +@r depends on (org || report)@

You may omit parentheses here.


…
> +@script:python depends on report@
> +p << r.p;
> +@@
> +
> +msg="WARNING: Use ARRAY_END"
> +coccilib.report.print_report(p[0], msg)

Would the following command variant be a bit nicer?

coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END()")



By the way:
How do you think about to omit a cover letter for a single patch?

Regards,
Markus

Re: [cocci] [PATCH] scripts/coccinelle: Add script for using ARRAY_END()

[Julia Lawall]

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On Mon, 9 Mar 2026, Markus Elfring wrote:

> …
> > This script makes it easy to find more places where that macro should be
> > used.
>
> See also:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc3#n94
>
>
> …
> > +++ b/scripts/coccinelle/misc/array_end.cocci
> > @@ -0,0 +1,93 @@
> …
>
>
> > +// Confidence: ???
>
> I hope that a more reasonable value can be determined for this information.
>
>
> …
> > +// Comments:
>
> Please omit such an empty field.
>
>
> …
> > +@i@
> > +@@
> > +
> > +#include <linux/kernel.h>
>
> I doubt that such an SmPL rule would be required.
>
>
> > +
> > +//----------------------------------------------------------
> > +//  For context mode
> > +//----------------------------------------------------------
> > +
>
> Please omit such extra comment lines.

No problem to put such comments.

>
>
> > +@depends on i&&context@
> > +type T;
> > +T[] a;
> > +expression b;
> > +@@
> > +(
> > +* (a + ARRAY_SIZE(a))
> > +|
> > +* (&a[0] + ARRAY_SIZE(a))
> > +|
> > +* (&a[ARRAY_SIZE(a)])
> > +|
> > +* (&a[ARRAY_SIZE(a) - b])
> > +)
>
> Extra space characters may be omitted directly after SmPL asterisks.

No concern about the spaces either.

>
>
> …
> > +@r depends on (org || report)@
>
> You may omit parentheses here.
>
>
> …
> > +@script:python depends on report@
> > +p << r.p;
> > +@@
> > +
> > +msg="WARNING: Use ARRAY_END"
> > +coccilib.report.print_report(p[0], msg)
>
> Would the following command variant be a bit nicer?
>
> coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END()")

Either way.

julia

Re: [cocci] [PATCH] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

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Hi Julia,

On 2026-03-09T12:59:48+0100, Julia Lawall wrote:
> > > +
> > > +//----------------------------------------------------------
> > > +//  For context mode
> > > +//----------------------------------------------------------
> > > +
> >
> > Please omit such extra comment lines.
> 
> No problem to put such comments.

Okay; thanks!  Although I tend to prefer without them, so I've removed
them.  Also, a majority of existing scripts don't have them.

> > > +@depends on i&&context@
> > > +type T;
> > > +T[] a;
> > > +expression b;
> > > +@@
> > > +(
> > > +* (a + ARRAY_SIZE(a))
> > > +|
> > > +* (&a[0] + ARRAY_SIZE(a))
> > > +|
> > > +* (&a[ARRAY_SIZE(a)])
> > > +|
> > > +* (&a[ARRAY_SIZE(a) - b])
> > > +)
> >
> > Extra space characters may be omitted directly after SmPL asterisks.
> 
> No concern about the spaces either.

Okay; I've kept them, as the majority has them.

> > …
> > > +@r depends on (org || report)@
> >
> > You may omit parentheses here.
> >
> >
> > …
> > > +@script:python depends on report@
> > > +p << r.p;
> > > +@@
> > > +
> > > +msg="WARNING: Use ARRAY_END"
> > > +coccilib.report.print_report(p[0], msg)
> >
> > Would the following command variant be a bit nicer?
> >
> > coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END()")
> 
> Either way.

I've taken the suggestion.  Thanks for the review!


Have a lovely day!
Alex

> 
> julia


-- 
<https://www.alejandro-colomar.es>

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Re: [cocci] [PATCH] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

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Hi Markus,

On 2026-03-09T12:17:00+0100, Markus Elfring wrote:
> …
> > This script makes it easy to find more places where that macro should be
> > used.
> 
> See also:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc3#n94

Thanks!

> …
> > +++ b/scripts/coccinelle/misc/array_end.cocci
> > @@ -0,0 +1,93 @@
> …
> 
> 
> > +// Confidence: ???
> 
> I hope that a more reasonable value can be determined for this information.

I don't know how the scale works.  I know the script has a few false
negatives, and AFAIK there are no false positives.  To what level of
confidence would that belong?

Is that field a keyword, or may I be explicit such as with this?:

// Confidence: no false positives, but a few false negatives

Or maybe I should write that in Comments...

> …
> > +// Comments:
> 
> Please omit such an empty field.

Ok; thanks!

$ grep -rh '^// Comments:' scripts/coccinelle/ | sort | uniq -c
     34 // Comments:
      2 // Comments: -
      1 // Comments: -I ... -all_includes can give more complete results
      1 // Comments: Comments on code can be deleted if near code that is removed.
      1 // Comments: Some false positives on empty default cases in switch statements.
      1 // Comments: requires at least Coccinelle 0.2.4, lex or parse error otherwise
$ find scripts/coccinelle/ -type f | wc -l
76


It seems around half of the existing scripts have that.  You may want to
remove those empty comments.  I added it because the scripts I looked at
do have it.

> …
> > +@i@
> > +@@
> > +
> > +#include <linux/kernel.h>
> 
> I doubt that such an SmPL rule would be required.

Okay, I'll remove it.  Thanks!

> > +
> > +//----------------------------------------------------------
> > +//  For context mode
> > +//----------------------------------------------------------
> > +
> 
> Please omit such extra comment lines.

Agree.  BTW, you may want to remove such lines from existing scripts:

$ grep -r '^//.*For context mode' scripts/coccinelle/
scripts/coccinelle/null/deref_null.cocci:// For context mode
scripts/coccinelle/misc/boolconv.cocci://  For context mode
scripts/coccinelle/misc/array_size.cocci://  For context mode
scripts/coccinelle/misc/struct_size.cocci://  For context mode
scripts/coccinelle/misc/newline_in_nl_msg.cocci://  For context mode
scripts/coccinelle/misc/badty.cocci://  For context mode
scripts/coccinelle/api/alloc/pool_zalloc-simple.cocci://  For context mode
scripts/coccinelle/api/alloc/zalloc-simple.cocci://  For context mode
scripts/coccinelle/api/alloc/alloc_cast.cocci://  For context mode
scripts/coccinelle/api/pm_runtime.cocci://  For context mode
scripts/coccinelle/api/resource_size.cocci://  For context mode
scripts/coccinelle/api/vma_pages.cocci://  For context mode

> > +@depends on i&&context@
> > +type T;
> > +T[] a;
> > +expression b;
> > +@@
> > +(
> > +* (a + ARRAY_SIZE(a))
> > +|
> > +* (&a[0] + ARRAY_SIZE(a))
> > +|
> > +* (&a[ARRAY_SIZE(a)])
> > +|
> > +* (&a[ARRAY_SIZE(a) - b])
> > +)
> 
> Extra space characters may be omitted directly after SmPL asterisks.

Good to know; thanks!

Although most scripts seem to be using white space (space (164) or
tab (26)) after the asterisk.  Please confirm if you prefer it removed
in new scripts.  Only 39 scripts don't have white space after it.

$ grep -rh '^\*' scripts/coccinelle/ | grep -o '^..' | sort | uniq -c
     26 *	
    164 * 
      4 *(
      1 *;
      1 *E
      1 *I
      1 *P
      2 *W
      1 *\
      1 *b
      1 *c
      3 *d
      1 *e
      4 *f
      1 *g
      2 *i
      1 *l
      4 *r
      2 *s
      1 *u
      2 *w
      5 *x
$ grep -rh '^\*' scripts/coccinelle/ | grep -o '^.\s' | sort | uniq -c | hd
00000000  20 20 20 20 20 32 36 20  2a 09 0a 20 20 20 20 31  |     26 *..    1|
00000010  36 34 20 2a 20 0a                                 |64 * .|
00000016
$ grep -rh '^\*' scripts/coccinelle/ | grep -o '^.\S' | wc -l
39


> …
> > +@r depends on (org || report)@
> 
> You may omit parentheses here.

Ok.

> …
> > +@script:python depends on report@
> > +p << r.p;
> > +@@
> > +
> > +msg="WARNING: Use ARRAY_END"
> > +coccilib.report.print_report(p[0], msg)
> 
> Would the following command variant be a bit nicer?
> 
> coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END()")

Sounds good.

> By the way:
> How do you think about to omit a cover letter for a single patch?

Sounds reasonable.  I like the cover letter as it holds the range-diff,
which may become a bit confusing when it's in the same email as the
patch, but maybe that's just me.

I'll send v2 in a single email.

> 
> Regards,
> Markus

Have a lovely day!
Alex

-- 
<https://www.alejandro-colomar.es>

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Re: [cocci] [PATCH] scripts/coccinelle: Add script for using ARRAY_END()

[Julia Lawall]

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On Mon, 9 Mar 2026, Alejandro Colomar wrote:

> Hi Markus,
>
> On 2026-03-09T12:17:00+0100, Markus Elfring wrote:
> > …
> > > This script makes it easy to find more places where that macro should be
> > > used.
> >
> > See also:
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc3#n94
>
> Thanks!
>
> > …
> > > +++ b/scripts/coccinelle/misc/array_end.cocci
> > > @@ -0,0 +1,93 @@
> > …
> >
> >
> > > +// Confidence: ???
> >
> > I hope that a more reasonable value can be determined for this information.
>
> I don't know how the scale works.  I know the script has a few false
> negatives, and AFAIK there are no false positives.  To what level of
> confidence would that belong?

Probably high would be fine.  The goal is mostly to indiacte whether the
results are most likely correct or whether they will require a lot of
study to know if everything is ok.

>
> Is that field a keyword, or may I be explicit such as with this?:
>
> // Confidence: no false positives, but a few false negatives
>
> Or maybe I should write that in Comments...
>
> > …
> > > +// Comments:
> >
> > Please omit such an empty field.
>
> Ok; thanks!
>
> $ grep -rh '^// Comments:' scripts/coccinelle/ | sort | uniq -c
>      34 // Comments:
>       2 // Comments: -
>       1 // Comments: -I ... -all_includes can give more complete results
>       1 // Comments: Comments on code can be deleted if near code that is removed.
>       1 // Comments: Some false positives on empty default cases in switch statements.
>       1 // Comments: requires at least Coccinelle 0.2.4, lex or parse error otherwise
> $ find scripts/coccinelle/ -type f | wc -l
> 76
>
>
> It seems around half of the existing scripts have that.  You may want to
> remove those empty comments.  I added it because the scripts I looked at
> do have it.

I don't require taht an empty comments field be removed.

> > …
> > > +@i@
> > > +@@
> > > +
> > > +#include <linux/kernel.h>
> >
> > I doubt that such an SmPL rule would be required.
>
> Okay, I'll remove it.  Thanks!

I'm lacking context.  You maye need this if the file doesn't already have
it.  But it is hard to know if it could be include indirectly...

julia


>
> > > +
> > > +//----------------------------------------------------------
> > > +//  For context mode
> > > +//----------------------------------------------------------
> > > +
> >
> > Please omit such extra comment lines.
>
> Agree.  BTW, you may want to remove such lines from existing scripts:
>
> $ grep -r '^//.*For context mode' scripts/coccinelle/
> scripts/coccinelle/null/deref_null.cocci:// For context mode
> scripts/coccinelle/misc/boolconv.cocci://  For context mode
> scripts/coccinelle/misc/array_size.cocci://  For context mode
> scripts/coccinelle/misc/struct_size.cocci://  For context mode
> scripts/coccinelle/misc/newline_in_nl_msg.cocci://  For context mode
> scripts/coccinelle/misc/badty.cocci://  For context mode
> scripts/coccinelle/api/alloc/pool_zalloc-simple.cocci://  For context mode
> scripts/coccinelle/api/alloc/zalloc-simple.cocci://  For context mode
> scripts/coccinelle/api/alloc/alloc_cast.cocci://  For context mode
> scripts/coccinelle/api/pm_runtime.cocci://  For context mode
> scripts/coccinelle/api/resource_size.cocci://  For context mode
> scripts/coccinelle/api/vma_pages.cocci://  For context mode
>
> > > +@depends on i&&context@
> > > +type T;
> > > +T[] a;
> > > +expression b;
> > > +@@
> > > +(
> > > +* (a + ARRAY_SIZE(a))
> > > +|
> > > +* (&a[0] + ARRAY_SIZE(a))
> > > +|
> > > +* (&a[ARRAY_SIZE(a)])
> > > +|
> > > +* (&a[ARRAY_SIZE(a) - b])
> > > +)
> >
> > Extra space characters may be omitted directly after SmPL asterisks.
>
> Good to know; thanks!
>
> Although most scripts seem to be using white space (space (164) or
> tab (26)) after the asterisk.  Please confirm if you prefer it removed
> in new scripts.  Only 39 scripts don't have white space after it.
>
> $ grep -rh '^\*' scripts/coccinelle/ | grep -o '^..' | sort | uniq -c
>      26 *
>     164 *
>       4 *(
>       1 *;
>       1 *E
>       1 *I
>       1 *P
>       2 *W
>       1 *\
>       1 *b
>       1 *c
>       3 *d
>       1 *e
>       4 *f
>       1 *g
>       2 *i
>       1 *l
>       4 *r
>       2 *s
>       1 *u
>       2 *w
>       5 *x
> $ grep -rh '^\*' scripts/coccinelle/ | grep -o '^.\s' | sort | uniq -c | hd
> 00000000  20 20 20 20 20 32 36 20  2a 09 0a 20 20 20 20 31  |     26 *..    1|
> 00000010  36 34 20 2a 20 0a                                 |64 * .|
> 00000016
> $ grep -rh '^\*' scripts/coccinelle/ | grep -o '^.\S' | wc -l
> 39
>
>
> > …
> > > +@r depends on (org || report)@
> >
> > You may omit parentheses here.
>
> Ok.
>
> > …
> > > +@script:python depends on report@
> > > +p << r.p;
> > > +@@
> > > +
> > > +msg="WARNING: Use ARRAY_END"
> > > +coccilib.report.print_report(p[0], msg)
> >
> > Would the following command variant be a bit nicer?
> >
> > coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END()")
>
> Sounds good.
>
> > By the way:
> > How do you think about to omit a cover letter for a single patch?
>
> Sounds reasonable.  I like the cover letter as it holds the range-diff,
> which may become a bit confusing when it's in the same email as the
> patch, but maybe that's just me.
>
> I'll send v2 in a single email.
>
> >
> > Regards,
> > Markus
>
> Have a lovely day!
> Alex
>
> --
> <https://www.alejandro-colomar.es>
>

Re: [cocci] [PATCH] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

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Hi Julia,

On 2026-03-09T13:21:23+0100, Julia Lawall wrote:
[...]
> > > > +// Confidence: ???
> > >
> > > I hope that a more reasonable value can be determined for this information.
> >
> > I don't know how the scale works.  I know the script has a few false
> > negatives, and AFAIK there are no false positives.  To what level of
> > confidence would that belong?
> 
> Probably high would be fine.  The goal is mostly to indiacte whether the
> results are most likely correct or whether they will require a lot of
> study to know if everything is ok.

Thanks!  I've put high with a comment about the false negatives.

[...]
> > > > +// Comments:
> > >
> > > Please omit such an empty field.
> >
> > Ok; thanks!
> >
> > $ grep -rh '^// Comments:' scripts/coccinelle/ | sort | uniq -c
> >      34 // Comments:
> >       2 // Comments: -
> >       1 // Comments: -I ... -all_includes can give more complete results
> >       1 // Comments: Comments on code can be deleted if near code that is removed.
> >       1 // Comments: Some false positives on empty default cases in switch statements.
> >       1 // Comments: requires at least Coccinelle 0.2.4, lex or parse error otherwise
> > $ find scripts/coccinelle/ -type f | wc -l
> > 76
> >
> >
> > It seems around half of the existing scripts have that.  You may want to
> > remove those empty comments.  I added it because the scripts I looked at
> > do have it.
> 
> I don't require taht an empty comments field be removed.

Ok.

> > > …
> > > > +@i@
> > > > +@@
> > > > +
> > > > +#include <linux/kernel.h>
> > >
> > > I doubt that such an SmPL rule would be required.
> >
> > Okay, I'll remove it.  Thanks!
> 
> I'm lacking context.  You maye need this if the file doesn't already have
> it.  But it is hard to know if it could be include indirectly...

Hmmm, this macro is defined together with ARRAY_SIZE() in
<linux/array_size.h>.  I guess even if a file isn't including that
already (including indirectly), it would do well in including it for
using the macro, so I guess it's okay to remove it here.

The only concern would be files that *can't* possibly include it (maybe
tools/?).


> julia

Cheers,
Alex

-- 
<https://www.alejandro-colomar.es>

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[cocci] [PATCH v2] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

Recently, we added an ARRAY_END() macro to simplify finding a pointer
one past the last element in an array.  Such a pointer is often called
the 'end', and thus the macro name.

Make it easy to find more places where that macro should be used.

See also:
436debc9cad8 ("array_size.h: add ARRAY_END()")
8118f197b7b7 ("mm: fix benign off-by-one bugs")
a9e5620c9a9e ("kernel: fix off-by-one benign bugs")
61e9210e2392 ("mm: use ARRAY_END() instead of open-coding it")

Cc: Kees Cook <kees@kernel.org>
Cc: Markus Elfring <Markus.Elfring@web.de>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Cc: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 scripts/coccinelle/misc/array_end.cocci | 74 +++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 scripts/coccinelle/misc/array_end.cocci

diff --git a/scripts/coccinelle/misc/array_end.cocci b/scripts/coccinelle/misc/array_end.cocci
new file mode 100644
index 00000000..fc431c4a
--- /dev/null
+++ b/scripts/coccinelle/misc/array_end.cocci
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Use ARRAY_END instead of an expression derived from ARRAY_SIZE
+//
+// Confidence: High
+// Copyright: 2026, Alejandro Colomar <alx@kernel.org>
+// Comments: No known false positives, but has a few false negatives
+// Options: --no-includes --include-headers
+
+virtual patch
+virtual context
+virtual org
+virtual report
+
+@depends on context@
+type T;
+T[] a;
+expression b;
+@@
+(
+* (a + ARRAY_SIZE(a))
+|
+* (&a[0] + ARRAY_SIZE(a))
+|
+* (&a[ARRAY_SIZE(a)])
+|
+* (&a[ARRAY_SIZE(a) - b])
+)
+
+@depends on patch@
+type T;
+T[] a;
+expression b;
+@@
+(
+- (a + ARRAY_SIZE(a))
++ ARRAY_END(a)
+|
+- (&a[0] + ARRAY_SIZE(a))
++ ARRAY_END(a)
+|
+- (&a[ARRAY_SIZE(a)])
++ ARRAY_END(a)
+|
+- (&a[ARRAY_SIZE(a) - b])
++ ARRAY_END(a) - b
+)
+
+@r depends on org || report@
+type T;
+T[] a;
+expression b;
+position p;
+@@
+(
+ (a@p + ARRAY_SIZE(a))
+|
+ (&a[0]@p + ARRAY_SIZE(a))
+|
+ (&a[ARRAY_SIZE(a)]@p)
+|
+ (&a[ARRAY_SIZE(a)@p - b])
+)
+
+@script:python depends on org@
+p << r.p;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING should use ARRAY_END")
+
+@script:python depends on report@
+p << r.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END")

Range-diff against v1:
1:  f1c9dff5 ! 1:  9fd8d3d1 scripts/coccinelle: Add script for using ARRAY_END()
    @@ Commit message
         one past the last element in an array.  Such a pointer is often called
         the 'end', and thus the macro name.
     
    -    This script makes it easy to find more places where that macro should be
    -    used.
    +    Make it easy to find more places where that macro should be used.
     
         See also:
         436debc9cad8 ("array_size.h: add ARRAY_END()")
    @@ Commit message
         61e9210e2392 ("mm: use ARRAY_END() instead of open-coding it")
     
         Cc: Kees Cook <kees@kernel.org>
    +    Cc: Markus Elfring <Markus.Elfring@web.de>
         Cc: Julia Lawall <Julia.Lawall@inria.fr>
         Cc: Nicolas Palix <nicolas.palix@imag.fr>
         Signed-off-by: Alejandro Colomar <alx@kernel.org>
    @@ scripts/coccinelle/misc/array_end.cocci (new)
     +// SPDX-License-Identifier: GPL-2.0-only
     +/// Use ARRAY_END instead of an expression derived from ARRAY_SIZE
     +//
    -+// Confidence: ???
    ++// Confidence: High
     +// Copyright: 2026, Alejandro Colomar <alx@kernel.org>
    -+// Comments:
    ++// Comments: No known false positives, but has a few false negatives
     +// Options: --no-includes --include-headers
     +
     +virtual patch
    @@ scripts/coccinelle/misc/array_end.cocci (new)
     +virtual org
     +virtual report
     +
    -+@i@
    -+@@
    -+
    -+#include <linux/kernel.h>
    -+
    -+//----------------------------------------------------------
    -+//  For context mode
    -+//----------------------------------------------------------
    -+
    -+@depends on i&&context@
    ++@depends on context@
     +type T;
     +T[] a;
     +expression b;
    @@ scripts/coccinelle/misc/array_end.cocci (new)
     +* (&a[ARRAY_SIZE(a) - b])
     +)
     +
    -+//----------------------------------------------------------
    -+//  For patch mode
    -+//----------------------------------------------------------
    -+
    -+@depends on i&&patch@
    ++@depends on patch@
     +type T;
     +T[] a;
     +expression b;
    @@ scripts/coccinelle/misc/array_end.cocci (new)
     ++ ARRAY_END(a) - b
     +)
     +
    -+//----------------------------------------------------------
    -+//  For org and report mode
    -+//----------------------------------------------------------
    -+
    -+@r depends on (org || report)@
    ++@r depends on org || report@
     +type T;
     +T[] a;
     +expression b;
    @@ scripts/coccinelle/misc/array_end.cocci (new)
     +p << r.p;
     +@@
     +
    -+msg="WARNING: Use ARRAY_END"
    -+coccilib.report.print_report(p[0], msg)
    -+
    ++coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END")
-- 
2.53.0

Re: [cocci] [PATCH v2] scripts/coccinelle: Add script for using ARRAY_END()

[Markus Elfring]

…
> ---
>  scripts/coccinelle/misc/array_end.cocci | 74 +++++++++++++++++++++++++
…

Some contributors would appreciate patch version descriptions.
https://lore.kernel.org/all/?q=%22This+looks+like+a+new+version+of+a+previously+submitted+patch%22
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc3#n310


May a subdirectory name be omitted from the subject prefix?
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/scripts/coccinelle/


…
> +// Comments: No known false positives, but has a few false negatives

Would such information motivate for any further software refinements?


…
> +@script:python depends on org@
> +p << r.p;
> +@@
> +
> +coccilib.org.print_todo(p[0], "WARNING should use ARRAY_END")
…

I suggest to reuse the message also from the SmPL report rule.

Regards,
Markus

Re: [cocci] [PATCH v2] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

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Hi Markus,

On 2026-03-09T15:05:08+0100, Markus Elfring wrote:
> …
> > ---
> >  scripts/coccinelle/misc/array_end.cocci | 74 +++++++++++++++++++++++++
> …
> 
> Some contributors would appreciate patch version descriptions.
> https://lore.kernel.org/all/?q=%22This+looks+like+a+new+version+of+a+previously+submitted+patch%22
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc3#n310

I replied to all of your comments, and said how I would address them, in
reply to v1.  This v2 is in-reply-to v1, so that that sub-thread is easy
to find.  And at the bottom is a range-diff where you can find all the
exact changes from v1 to v2.

I could have noted in plain English the changes from v1 to v2, but
I thought it might be a bit redundant.

> May a subdirectory name be omitted from the subject prefix?
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/scripts/coccinelle/

Yeah, we could do that.  Here's what I checked for writing the subject
prefix:

	$ git log --oneline --author Lawall torvalds/master scripts/coccinelle/misc/ 
	f01701ce update Coccinelle URL
	92b2dada scripts/coccinelle: drop bugon.cocci
	c3003315 scripts: coccinelle: boolinit: drop warnings on named constants
	518d8a56 scripts: coccinelle: Correct warning message
	b825b432 scripts: coccinelle: only suggest true/false in files that already use>
	937c812d coccinelle: orplus: reorganize to improve performance
	69c4907b Coccinelle: use false positive annotation
	f75621c6 coccinelle: bugon: reduce rule applicability
	c7eaa887 Coccinelle: array_size: reduce rule applicability
	8f551bef Coccinelle: reduce rule applicability
	74a8478f coccinelle: misc: move constants to the right
	932058a5 coccinelle: misc: semantic patch to delete overly complex return code >
	24f0c2d6 scripts/coccinelle: find constant additions that could be bit ors
	ad99ac2f scripts/coccinelle/misc/warn.cocci: use WARN
	2cbd0825 scripts/coccinelle: sizeof of pointer
	4619c2b8 scripts/coccinelle: address test is always true
	89910581 coccinelle: semantic patch for bool issues
	4a05f067 coccinelle: semantic patch to check for PTR_ERR after reassignment
	29a36d4d scripts/coccinelle: improve the coverage of some semantic patches
	a1087ef6 scripts/coccinelle: update for compatability with Coccinelle 0.2.4

Since the latest line and a decent amount of lines have
"scripts/coccinelle", I picked that.  I don't have a preference, so
please let me know what's the preferred one.  I tend to prefer more
explicit ones, even if slightly longer, but I'll take whatever the
maintainers' preference is.

The only one I didn't really like was the 'scripts: coccinelle:' one.
Paths are more readable if we're going to include all the
subdirectories.  But this is just my opinion.

> …
> > +// Comments: No known false positives, but has a few false negatives
> 
> Would such information motivate for any further software refinements?

Yes, if anyone here knows how to handle the false negatives and wants to
work with me on improving those, I'm very interested.

Here's one case which isn't caught, for example (which I expect will be
difficult to handle, if not impossible):

	@@ -2876,7 +2876,7 @@ static struct dentry *proc_##LSM##_attr_dir_lookup(struct 
	inode *dir, \
	 { \
		return proc_pident_lookup(dir, dentry, \
					  LSM##_attr_dir_stuff, \
	-                                 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
	+                                 ARRAY_END(LSM##_attr_dir_stuff)); \
	 } \
	 \
	 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \

I could research and find other false negatives.


Cheers,
Alex

-- 
<https://www.alejandro-colomar.es>

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Re: [cocci] [PATCH v2] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

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Hi Markus, Julia,

On 2026-03-09T15:32:24+0100, Alejandro Colomar wrote:
> > …
> > > +// Comments: No known false positives, but has a few false negatives
> > 
> > Would such information motivate for any further software refinements?
> 
> Yes, if anyone here knows how to handle the false negatives and wants to
> work with me on improving those, I'm very interested.
> 
> Here's one case which isn't caught, for example (which I expect will be
> difficult to handle, if not impossible):
> 
> 	@@ -2876,7 +2876,7 @@ static struct dentry *proc_##LSM##_attr_dir_lookup(struct 
> 	inode *dir, \
> 	 { \
> 		return proc_pident_lookup(dir, dentry, \
> 					  LSM##_attr_dir_stuff, \
> 	-                                 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
> 	+                                 ARRAY_END(LSM##_attr_dir_stuff)); \
> 	 } \
> 	 \
> 	 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
> 
> I could research and find other false negatives.

Here are more false negatives that I found manually.  The semantic patch
didn't find them.  Does anyone know how we could improve it or why it
didn't find them?

	diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
	index 8d81c1e7..d883e1bd 100644
	--- a/arch/powerpc/kernel/rtas.c
	+++ b/arch/powerpc/kernel/rtas.c
	@@ -555,10 +555,8 @@ static struct rtas_function rtas_function_table[] __ro_after_init = {
		},
	 };
	 
	-#define for_each_rtas_function(funcp)                                       \
	-       for (funcp = &rtas_function_table[0];                               \
	-            funcp < &rtas_function_table[ARRAY_SIZE(rtas_function_table)]; \
	-            ++funcp)
	+#define for_each_rtas_function(f)                                     \
	+       for (f = rtas_function_table; f < ARRAY_END(rtas_function_table); ++f)
	 
	 /*
	  * Nearly all RTAS calls need to be serialized. All uses of the
	diff --git a/arch/s390/purgatory/purgatory.c b/arch/s390/purgatory/purgatory.c
	index ecb38102..3e45056b 100644
	--- a/arch/s390/purgatory/purgatory.c
	+++ b/arch/s390/purgatory/purgatory.c
	@@ -19,7 +19,7 @@ int verify_sha256_digest(void)
		struct sha256_ctx sctx;
	 
		sha256_init(&sctx);
	-       end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions);
	+       end = ARRAY_END(purgatory_sha_regions);
	 
		for (ptr = purgatory_sha_regions; ptr < end; ptr++)
			sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len);
	diff --git a/drivers/md/bcache/util.h b/drivers/md/bcache/util.h
	index f61ab1ba..988b0773 100644
	--- a/drivers/md/bcache/util.h
	+++ b/drivers/md/bcache/util.h
	@@ -273,9 +273,7 @@ do {                                                                        \
		BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *));        \
		(array)->freelist = NULL;                                       \
										\
	-       for (_i = (array)->data;                                        \
	-            _i < (array)->data + ARRAY_SIZE((array)->data);            \
	-            _i++)                                                      \
	+       for (_i = (array)->data; _i < ARRAY_END((array)->data); _i++)   \
			array_free(array, _i);                                  \
	 } while (0)
	 
	diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
	index 6e38aa73..c0cd2d1e 100644
	--- a/drivers/net/wireless/ath/ath9k/ath9k.h
	+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
	@@ -444,9 +444,7 @@ ath_node_to_tid(struct ath_node *an, u8 tidno)
	 #define case_rtn_string(val) case val: return #val
	 
	 #define ath_for_each_chanctx(_sc, _ctx)                             \
	-       for (ctx = &sc->chanctx[0];                                 \
	-            ctx <= &sc->chanctx[ARRAY_SIZE(sc->chanctx) - 1];      \
	-            ctx++)
	+       for (ctx = &sc->chanctx[0]; ctx <= ARRAY_END(sc->chanctx) - 1; ctx++)
	 
	 void ath_chanctx_init(struct ath_softc *sc);
	 void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
	diff --git a/drivers/net/wireless/intel/iwlwifi/mei/net.c b/drivers/net/wireless/intel/iwlwifi/mei/net.c
	index eac46d1a..b0d2905d 100644
	--- a/drivers/net/wireless/intel/iwlwifi/mei/net.c
	+++ b/drivers/net/wireless/intel/iwlwifi/mei/net.c
	@@ -43,7 +43,7 @@ static bool iwl_mei_rx_filter_eth(const struct ethhdr *ethhdr,
			return false;
	 
		for (filt = &filters->eth_filters[0];
	-            filt < &filters->eth_filters[0] + ARRAY_SIZE(filters->eth_filters);
	+            filt < ARRAY_END(filters->eth_filters);
		     filt++) {
			/* Assume there are no enabled filter after a disabled one */
			if (!(filt->flags & SAP_ETH_FILTER_ENABLED))
	@@ -142,7 +142,7 @@ iwl_mei_rx_filter_tcp_udp(struct sk_buff *skb, bool  ip_match,
		const struct iwl_sap_flex_filter *filt;
	 
		for (filt = &filters->flex_filters[0];
	-            filt < &filters->flex_filters[0] + ARRAY_SIZE(filters->flex_filters);
	+            filt < ARRAY_END(filters->flex_filters);
		     filt++) {
			if (!(filt->flags & SAP_FLEX_FILTER_ENABLED))
				break;
	diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
	index f6ce6e26..a7aa3ce4 100644
	--- a/drivers/usb/core/devio.c
	+++ b/drivers/usb/core/devio.c
	@@ -1490,7 +1490,7 @@ static int proc_conninfo_ex(struct usb_dev_state *ps,
	 
		if (ci.num_ports < ARRAY_SIZE(ci.ports))
			memmove(&ci.ports[0],
	-                       &ci.ports[ARRAY_SIZE(ci.ports) - ci.num_ports],
	+                       ARRAY_END(ci.ports) - ci.num_ports,
				ci.num_ports);
	 
		if (copy_to_user(arg, &ci, min(sizeof(ci), size)))
	diff --git a/fs/smb/client/dfs.h b/fs/smb/client/dfs.h
	index e60f0a24..4977f649 100644
	--- a/fs/smb/client/dfs.h
	+++ b/fs/smb/client/dfs.h
	@@ -32,7 +32,7 @@ struct dfs_ref_walk {
	 };
	 
	 #define ref_walk_start(w)      ((w)->refs)
	-#define ref_walk_end(w)        (&(w)->refs[ARRAY_SIZE((w)->refs) - 1])
	+#define ref_walk_end(w)        (ARRAY_END((w)->refs) - 1)
	 #define ref_walk_cur(w)        ((w)->ref)
	 #define ref_walk_descend(w)    (--ref_walk_cur(w) >= ref_walk_start(w))
	 
	diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
	index 1b9b18e5..0ff49f24 100644
	--- a/kernel/bpf/core.c
	+++ b/kernel/bpf/core.c
	@@ -2298,7 +2298,7 @@ static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn
		u64 regs[MAX_BPF_EXT_REG] = {}; \
	 \
		kmsan_unpoison_memory(stack, sizeof(stack)); \
	-       FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
	+       FP = (u64) (unsigned long) ARRAY_END(stack); \
		ARG1 = (u64) (unsigned long) ctx; \
		return ___bpf_prog_run(regs, insn); \
	 }
	@@ -2312,7 +2312,7 @@ static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
		u64 regs[MAX_BPF_EXT_REG]; \
	 \
		kmsan_unpoison_memory(stack, sizeof(stack)); \
	-       FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
	+       FP = (u64) (unsigned long) ARRAY_END(stack); \
		BPF_R1 = r1; \
		BPF_R2 = r2; \
		BPF_R3 = r3; \
	diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
	index 198f8a0d..d98e42a3 100644
	--- a/net/ipv4/tcp_input.c
	+++ b/net/ipv4/tcp_input.c
	@@ -2009,7 +2009,7 @@ static struct sk_buff *tcp_maybe_skipping_dsack(struct sk_buff *skb,
	 
	 static int tcp_sack_cache_ok(const struct tcp_sock *tp, const struct tcp_sack_block *cache)
	 {
	-       return cache < tp->recv_sack_cache + ARRAY_SIZE(tp->recv_sack_cache);
	+       return cache < ARRAY_END(tp->recv_sack_cache);
	 }
	 
	 static int
	@@ -2109,7 +2109,7 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
	 
		if (!tp->sacked_out) {
			/* It's already past, so skip checking against it */
	-               cache = tp->recv_sack_cache + ARRAY_SIZE(tp->recv_sack_cache);
	+               cache = ARRAY_END(tp->recv_sack_cache);
		} else {
			cache = tp->recv_sack_cache;
			/* Skip empty blocks in at head of the cache */


Have a lovely day!
Alex

-- 
<https://www.alejandro-colomar.es>

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Re: [cocci] [PATCH v2] scripts/coccinelle: Add script for using ARRAY_END()

[Julia Lawall]

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On Sun, 15 Mar 2026, Alejandro Colomar wrote:

> Hi Markus, Julia,
>
> On 2026-03-09T15:32:24+0100, Alejandro Colomar wrote:
> > > …
> > > > +// Comments: No known false positives, but has a few false negatives
> > >
> > > Would such information motivate for any further software refinements?
> >
> > Yes, if anyone here knows how to handle the false negatives and wants to
> > work with me on improving those, I'm very interested.
> >
> > Here's one case which isn't caught, for example (which I expect will be
> > difficult to handle, if not impossible):
> >
> > 	@@ -2876,7 +2876,7 @@ static struct dentry *proc_##LSM##_attr_dir_lookup(struct
> > 	inode *dir, \
> > 	 { \
> > 		return proc_pident_lookup(dir, dentry, \
> > 					  LSM##_attr_dir_stuff, \
> > 	-                                 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
> > 	+                                 ARRAY_END(LSM##_attr_dir_stuff)); \
> > 	 } \
> > 	 \
> > 	 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
> >
> > I could research and find other false negatives.
>
> Here are more false negatives that I found manually.  The semantic patch
> didn't find them.  Does anyone know how we could improve it or why it
> didn't find them?

Typically, some things are not found when Coccinelle is not able to parse
the relevnt code.  You can see this with the --verbose-parsing option.
BUG indicates the line where the parsing problem was detected and bug
indicates the other lines that were ignored due to the parse error.

julia


>
> 	diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
> 	index 8d81c1e7..d883e1bd 100644
> 	--- a/arch/powerpc/kernel/rtas.c
> 	+++ b/arch/powerpc/kernel/rtas.c
> 	@@ -555,10 +555,8 @@ static struct rtas_function rtas_function_table[] __ro_after_init = {
> 		},
> 	 };
>
> 	-#define for_each_rtas_function(funcp)                                       \
> 	-       for (funcp = &rtas_function_table[0];                               \
> 	-            funcp < &rtas_function_table[ARRAY_SIZE(rtas_function_table)]; \
> 	-            ++funcp)
> 	+#define for_each_rtas_function(f)                                     \
> 	+       for (f = rtas_function_table; f < ARRAY_END(rtas_function_table); ++f)
>
> 	 /*
> 	  * Nearly all RTAS calls need to be serialized. All uses of the
> 	diff --git a/arch/s390/purgatory/purgatory.c b/arch/s390/purgatory/purgatory.c
> 	index ecb38102..3e45056b 100644
> 	--- a/arch/s390/purgatory/purgatory.c
> 	+++ b/arch/s390/purgatory/purgatory.c
> 	@@ -19,7 +19,7 @@ int verify_sha256_digest(void)
> 		struct sha256_ctx sctx;
>
> 		sha256_init(&sctx);
> 	-       end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions);
> 	+       end = ARRAY_END(purgatory_sha_regions);
>
> 		for (ptr = purgatory_sha_regions; ptr < end; ptr++)
> 			sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len);
> 	diff --git a/drivers/md/bcache/util.h b/drivers/md/bcache/util.h
> 	index f61ab1ba..988b0773 100644
> 	--- a/drivers/md/bcache/util.h
> 	+++ b/drivers/md/bcache/util.h
> 	@@ -273,9 +273,7 @@ do {                                                                        \
> 		BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *));        \
> 		(array)->freelist = NULL;                                       \
> 										\
> 	-       for (_i = (array)->data;                                        \
> 	-            _i < (array)->data + ARRAY_SIZE((array)->data);            \
> 	-            _i++)                                                      \
> 	+       for (_i = (array)->data; _i < ARRAY_END((array)->data); _i++)   \
> 			array_free(array, _i);                                  \
> 	 } while (0)
>
> 	diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
> 	index 6e38aa73..c0cd2d1e 100644
> 	--- a/drivers/net/wireless/ath/ath9k/ath9k.h
> 	+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
> 	@@ -444,9 +444,7 @@ ath_node_to_tid(struct ath_node *an, u8 tidno)
> 	 #define case_rtn_string(val) case val: return #val
>
> 	 #define ath_for_each_chanctx(_sc, _ctx)                             \
> 	-       for (ctx = &sc->chanctx[0];                                 \
> 	-            ctx <= &sc->chanctx[ARRAY_SIZE(sc->chanctx) - 1];      \
> 	-            ctx++)
> 	+       for (ctx = &sc->chanctx[0]; ctx <= ARRAY_END(sc->chanctx) - 1; ctx++)
>
> 	 void ath_chanctx_init(struct ath_softc *sc);
> 	 void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
> 	diff --git a/drivers/net/wireless/intel/iwlwifi/mei/net.c b/drivers/net/wireless/intel/iwlwifi/mei/net.c
> 	index eac46d1a..b0d2905d 100644
> 	--- a/drivers/net/wireless/intel/iwlwifi/mei/net.c
> 	+++ b/drivers/net/wireless/intel/iwlwifi/mei/net.c
> 	@@ -43,7 +43,7 @@ static bool iwl_mei_rx_filter_eth(const struct ethhdr *ethhdr,
> 			return false;
>
> 		for (filt = &filters->eth_filters[0];
> 	-            filt < &filters->eth_filters[0] + ARRAY_SIZE(filters->eth_filters);
> 	+            filt < ARRAY_END(filters->eth_filters);
> 		     filt++) {
> 			/* Assume there are no enabled filter after a disabled one */
> 			if (!(filt->flags & SAP_ETH_FILTER_ENABLED))
> 	@@ -142,7 +142,7 @@ iwl_mei_rx_filter_tcp_udp(struct sk_buff *skb, bool  ip_match,
> 		const struct iwl_sap_flex_filter *filt;
>
> 		for (filt = &filters->flex_filters[0];
> 	-            filt < &filters->flex_filters[0] + ARRAY_SIZE(filters->flex_filters);
> 	+            filt < ARRAY_END(filters->flex_filters);
> 		     filt++) {
> 			if (!(filt->flags & SAP_FLEX_FILTER_ENABLED))
> 				break;
> 	diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
> 	index f6ce6e26..a7aa3ce4 100644
> 	--- a/drivers/usb/core/devio.c
> 	+++ b/drivers/usb/core/devio.c
> 	@@ -1490,7 +1490,7 @@ static int proc_conninfo_ex(struct usb_dev_state *ps,
>
> 		if (ci.num_ports < ARRAY_SIZE(ci.ports))
> 			memmove(&ci.ports[0],
> 	-                       &ci.ports[ARRAY_SIZE(ci.ports) - ci.num_ports],
> 	+                       ARRAY_END(ci.ports) - ci.num_ports,
> 				ci.num_ports);
>
> 		if (copy_to_user(arg, &ci, min(sizeof(ci), size)))
> 	diff --git a/fs/smb/client/dfs.h b/fs/smb/client/dfs.h
> 	index e60f0a24..4977f649 100644
> 	--- a/fs/smb/client/dfs.h
> 	+++ b/fs/smb/client/dfs.h
> 	@@ -32,7 +32,7 @@ struct dfs_ref_walk {
> 	 };
>
> 	 #define ref_walk_start(w)      ((w)->refs)
> 	-#define ref_walk_end(w)        (&(w)->refs[ARRAY_SIZE((w)->refs) - 1])
> 	+#define ref_walk_end(w)        (ARRAY_END((w)->refs) - 1)
> 	 #define ref_walk_cur(w)        ((w)->ref)
> 	 #define ref_walk_descend(w)    (--ref_walk_cur(w) >= ref_walk_start(w))
>
> 	diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> 	index 1b9b18e5..0ff49f24 100644
> 	--- a/kernel/bpf/core.c
> 	+++ b/kernel/bpf/core.c
> 	@@ -2298,7 +2298,7 @@ static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn
> 		u64 regs[MAX_BPF_EXT_REG] = {}; \
> 	 \
> 		kmsan_unpoison_memory(stack, sizeof(stack)); \
> 	-       FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
> 	+       FP = (u64) (unsigned long) ARRAY_END(stack); \
> 		ARG1 = (u64) (unsigned long) ctx; \
> 		return ___bpf_prog_run(regs, insn); \
> 	 }
> 	@@ -2312,7 +2312,7 @@ static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
> 		u64 regs[MAX_BPF_EXT_REG]; \
> 	 \
> 		kmsan_unpoison_memory(stack, sizeof(stack)); \
> 	-       FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
> 	+       FP = (u64) (unsigned long) ARRAY_END(stack); \
> 		BPF_R1 = r1; \
> 		BPF_R2 = r2; \
> 		BPF_R3 = r3; \
> 	diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> 	index 198f8a0d..d98e42a3 100644
> 	--- a/net/ipv4/tcp_input.c
> 	+++ b/net/ipv4/tcp_input.c
> 	@@ -2009,7 +2009,7 @@ static struct sk_buff *tcp_maybe_skipping_dsack(struct sk_buff *skb,
>
> 	 static int tcp_sack_cache_ok(const struct tcp_sock *tp, const struct tcp_sack_block *cache)
> 	 {
> 	-       return cache < tp->recv_sack_cache + ARRAY_SIZE(tp->recv_sack_cache);
> 	+       return cache < ARRAY_END(tp->recv_sack_cache);
> 	 }
>
> 	 static int
> 	@@ -2109,7 +2109,7 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
>
> 		if (!tp->sacked_out) {
> 			/* It's already past, so skip checking against it */
> 	-               cache = tp->recv_sack_cache + ARRAY_SIZE(tp->recv_sack_cache);
> 	+               cache = ARRAY_END(tp->recv_sack_cache);
> 		} else {
> 			cache = tp->recv_sack_cache;
> 			/* Skip empty blocks in at head of the cache */
>
>
> Have a lovely day!
> Alex
>
> --
> <https://www.alejandro-colomar.es>
>

Re: [cocci] [PATCH v2] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

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Hi Julia,

On 2026-03-15T18:54:32+0100, Julia Lawall wrote:
> > Here are more false negatives that I found manually.  The semantic patch
> > didn't find them.  Does anyone know how we could improve it or why it
> > didn't find them?
> 
> Typically, some things are not found when Coccinelle is not able to parse
> the relevnt code.  You can see this with the --verbose-parsing option.
> BUG indicates the line where the parsing problem was detected and bug
> indicates the other lines that were ignored due to the parse error.

Ahhh, thanks!  It seems there were issues parsing unrelated code, so not
a problem of the semantic patch.  I'll remove the comment about false
negatives and send v3.


> julia

Have a lovely night!
Alex

-- 
<https://www.alejandro-colomar.es>

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Re: [cocci] [v2] scripts/coccinelle: Add script for using ARRAY_END()

[Markus Elfring]

> Here are more false negatives that I found manually.  The semantic patch
> didn't find them.

Thanks for your clarification approach.


>                    Does anyone know how we could improve it

The corresponding knowledge is evolving.


>                                                             or why it
> didn't find them?

I suggest to refine case distinctions.
Can further test cases help to achieve a better understanding for the affected data processing?


…
> 	+++ b/arch/powerpc/kernel/rtas.c
> 	@@ -555,10 +555,8 @@ static struct rtas_function rtas_function_table[] __ro_after_init = {
> 		},
> 	 };
> 	 
> 	-#define for_each_rtas_function(funcp)                                       \
> 	-       for (funcp = &rtas_function_table[0];                               \
> 	-            funcp < &rtas_function_table[ARRAY_SIZE(rtas_function_table)]; \
> 	-            ++funcp)
> 	+#define for_each_rtas_function(f)                                     \
> 	+       for (f = rtas_function_table; f < ARRAY_END(rtas_function_table); ++f)

Are there development challenges to reconsider for macro definitions?


…
> 	+++ b/drivers/net/wireless/intel/iwlwifi/mei/net.c
> 	@@ -43,7 +43,7 @@ static bool iwl_mei_rx_filter_eth(const struct ethhdr *ethhdr,
> 			return false;
> 	 
> 		for (filt = &filters->eth_filters[0];
> 	-            filt < &filters->eth_filters[0] + ARRAY_SIZE(filters->eth_filters);
> 	+            filt < ARRAY_END(filters->eth_filters);
> 		     filt++) {
> 			/* Assume there are no enabled filter after a disabled one */
> 			if (!(filt->flags & SAP_ETH_FILTER_ENABLED))

Will any loops become better supported?

Regards,
Markus

Re: [cocci] [v2] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

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Hi Markus,

On 2026-03-16T08:18:17+0100, Markus Elfring wrote:
[...]
> …
> > 	+++ b/arch/powerpc/kernel/rtas.c
> > 	@@ -555,10 +555,8 @@ static struct rtas_function rtas_function_table[] __ro_after_init = {
> > 		},
> > 	 };
> > 	 
> > 	-#define for_each_rtas_function(funcp)                                       \
> > 	-       for (funcp = &rtas_function_table[0];                               \
> > 	-            funcp < &rtas_function_table[ARRAY_SIZE(rtas_function_table)]; \
> > 	-            ++funcp)
> > 	+#define for_each_rtas_function(f)                                     \
> > 	+       for (f = rtas_function_table; f < ARRAY_END(rtas_function_table); ++f)
> 
> Are there development challenges to reconsider for macro definitions?

I've seen cases within macros that were correctly reported, so it's not
an issue with macros.

> …
> > 	+++ b/drivers/net/wireless/intel/iwlwifi/mei/net.c
> > 	@@ -43,7 +43,7 @@ static bool iwl_mei_rx_filter_eth(const struct ethhdr *ethhdr,
> > 			return false;
> > 	 
> > 		for (filt = &filters->eth_filters[0];
> > 	-            filt < &filters->eth_filters[0] + ARRAY_SIZE(filters->eth_filters);
> > 	+            filt < ARRAY_END(filters->eth_filters);
> > 		     filt++) {
> > 			/* Assume there are no enabled filter after a disabled one */
> > 			if (!(filt->flags & SAP_ETH_FILTER_ENABLED))
> 
> Will any loops become better supported?

I've seen cases within loops that worked correctly, so it's not an issue
with loops.

After debugging like Julia suggested, it was indeed what Julia guessed:
some files can't be parsed correctly, at places unrelated to this.
There's nothing we can do to improve the patch.


Have a lovely day!
Alex

-- 
<https://www.alejandro-colomar.es>

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Re: [cocci] [v2] scripts/coccinelle: Add script for using ARRAY_END()

[Markus Elfring]

> There's nothing we can do to improve the patch.

Can we influence the evolution any further also for components
of the Coccinelle software?

Regards,
Markus

[cocci] [PATCH v3] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

Recently, we added an ARRAY_END() macro to simplify finding a pointer
one past the last element in an array.  Such a pointer is often called
the 'end', and thus the macro name.

Make it easy to find more places where that macro should be used.

See also:
436debc9cad8 ("array_size.h: add ARRAY_END()")
8118f197b7b7 ("mm: fix benign off-by-one bugs")
a9e5620c9a9e ("kernel: fix off-by-one benign bugs")
61e9210e2392 ("mm: use ARRAY_END() instead of open-coding it")

Cc: Kees Cook <kees@kernel.org>
Cc: Markus Elfring <Markus.Elfring@web.de>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Cc: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---

Hi!

This v3 only has one change: I've removed the comment about the false
negatives.  They were due to spatch(1) not being able to correctly parse
unrelated code elsewhere.

See range-diff and interdiff at the bottom.


Have a lovely night!
Alex

 scripts/coccinelle/misc/array_end.cocci | 73 +++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 scripts/coccinelle/misc/array_end.cocci

diff --git a/scripts/coccinelle/misc/array_end.cocci b/scripts/coccinelle/misc/array_end.cocci
new file mode 100644
index 00000000..88c664de
--- /dev/null
+++ b/scripts/coccinelle/misc/array_end.cocci
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Use ARRAY_END instead of an expression derived from ARRAY_SIZE
+//
+// Confidence: High
+// Copyright: 2026, Alejandro Colomar <alx@kernel.org>
+// Options: --no-includes --include-headers
+
+virtual patch
+virtual context
+virtual org
+virtual report
+
+@depends on context@
+type T;
+T[] a;
+expression b;
+@@
+(
+* (a + ARRAY_SIZE(a))
+|
+* (&a[0] + ARRAY_SIZE(a))
+|
+* (&a[ARRAY_SIZE(a)])
+|
+* (&a[ARRAY_SIZE(a) - b])
+)
+
+@depends on patch@
+type T;
+T[] a;
+expression b;
+@@
+(
+- (a + ARRAY_SIZE(a))
++ ARRAY_END(a)
+|
+- (&a[0] + ARRAY_SIZE(a))
++ ARRAY_END(a)
+|
+- (&a[ARRAY_SIZE(a)])
++ ARRAY_END(a)
+|
+- (&a[ARRAY_SIZE(a) - b])
++ ARRAY_END(a) - b
+)
+
+@r depends on org || report@
+type T;
+T[] a;
+expression b;
+position p;
+@@
+(
+ (a@p + ARRAY_SIZE(a))
+|
+ (&a[0]@p + ARRAY_SIZE(a))
+|
+ (&a[ARRAY_SIZE(a)]@p)
+|
+ (&a[ARRAY_SIZE(a)@p - b])
+)
+
+@script:python depends on org@
+p << r.p;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING should use ARRAY_END")
+
+@script:python depends on report@
+p << r.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END")

Range-diff:
1:  9fd8d3d1 ! 1:  2ae22f8b scripts/coccinelle: Add script for using ARRAY_END()
    @@ scripts/coccinelle/misc/array_end.cocci (new)
     +//
     +// Confidence: High
     +// Copyright: 2026, Alejandro Colomar <alx@kernel.org>
    -+// Comments: No known false positives, but has a few false negatives
     +// Options: --no-includes --include-headers
     +
     +virtual patch
-- 
2.53.0

Re: [cocci] [PATCH v3] scripts/coccinelle: Add script for using ARRAY_END()

[Alejandro Colomar]

[-- Attachment #1: Type: text/plain, Size: 3400 bytes --]

On 2026-03-15T23:11:03+0100, Alejandro Colomar wrote:
> Recently, we added an ARRAY_END() macro to simplify finding a pointer
> one past the last element in an array.  Such a pointer is often called
> the 'end', and thus the macro name.
> 
> Make it easy to find more places where that macro should be used.
> 
> See also:
> 436debc9cad8 ("array_size.h: add ARRAY_END()")
> 8118f197b7b7 ("mm: fix benign off-by-one bugs")
> a9e5620c9a9e ("kernel: fix off-by-one benign bugs")
> 61e9210e2392 ("mm: use ARRAY_END() instead of open-coding it")
> 
> Cc: Kees Cook <kees@kernel.org>
> Cc: Markus Elfring <Markus.Elfring@web.de>
> Cc: Julia Lawall <Julia.Lawall@inria.fr>
> Cc: Nicolas Palix <nicolas.palix@imag.fr>
> Signed-off-by: Alejandro Colomar <alx@kernel.org>
> ---
> 
> Hi!
> 
> This v3 only has one change: I've removed the comment about the false
> negatives.  They were due to spatch(1) not being able to correctly parse
> unrelated code elsewhere.
> 
> See range-diff and interdiff at the bottom.

Oops, actually, only the range-diff.

> 
> 
> Have a lovely night!
> Alex
> 
>  scripts/coccinelle/misc/array_end.cocci | 73 +++++++++++++++++++++++++
>  1 file changed, 73 insertions(+)
>  create mode 100644 scripts/coccinelle/misc/array_end.cocci
> 
> diff --git a/scripts/coccinelle/misc/array_end.cocci b/scripts/coccinelle/misc/array_end.cocci
> new file mode 100644
> index 00000000..88c664de
> --- /dev/null
> +++ b/scripts/coccinelle/misc/array_end.cocci
> @@ -0,0 +1,73 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/// Use ARRAY_END instead of an expression derived from ARRAY_SIZE
> +//
> +// Confidence: High
> +// Copyright: 2026, Alejandro Colomar <alx@kernel.org>
> +// Options: --no-includes --include-headers
> +
> +virtual patch
> +virtual context
> +virtual org
> +virtual report
> +
> +@depends on context@
> +type T;
> +T[] a;
> +expression b;
> +@@
> +(
> +* (a + ARRAY_SIZE(a))
> +|
> +* (&a[0] + ARRAY_SIZE(a))
> +|
> +* (&a[ARRAY_SIZE(a)])
> +|
> +* (&a[ARRAY_SIZE(a) - b])
> +)
> +
> +@depends on patch@
> +type T;
> +T[] a;
> +expression b;
> +@@
> +(
> +- (a + ARRAY_SIZE(a))
> ++ ARRAY_END(a)
> +|
> +- (&a[0] + ARRAY_SIZE(a))
> ++ ARRAY_END(a)
> +|
> +- (&a[ARRAY_SIZE(a)])
> ++ ARRAY_END(a)
> +|
> +- (&a[ARRAY_SIZE(a) - b])
> ++ ARRAY_END(a) - b
> +)
> +
> +@r depends on org || report@
> +type T;
> +T[] a;
> +expression b;
> +position p;
> +@@
> +(
> + (a@p + ARRAY_SIZE(a))
> +|
> + (&a[0]@p + ARRAY_SIZE(a))
> +|
> + (&a[ARRAY_SIZE(a)]@p)
> +|
> + (&a[ARRAY_SIZE(a)@p - b])
> +)
> +
> +@script:python depends on org@
> +p << r.p;
> +@@
> +
> +coccilib.org.print_todo(p[0], "WARNING should use ARRAY_END")
> +
> +@script:python depends on report@
> +p << r.p;
> +@@
> +
> +coccilib.report.print_report(p[0], "WARNING: opportunity for ARRAY_END")
> 
> Range-diff:
> 1:  9fd8d3d1 ! 1:  2ae22f8b scripts/coccinelle: Add script for using ARRAY_END()
>     @@ scripts/coccinelle/misc/array_end.cocci (new)
>      +//
>      +// Confidence: High
>      +// Copyright: 2026, Alejandro Colomar <alx@kernel.org>
>     -+// Comments: No known false positives, but has a few false negatives
>      +// Options: --no-includes --include-headers
>      +
>      +virtual patch
> -- 
> 2.53.0
> 

-- 
<https://www.alejandro-colomar.es>

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