linux-kernel - Re: [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for memdup_user rule

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Message-ID: <alpine.DEB.2.21.2006091821010.2516@hadrien>
Date:   Tue, 9 Jun 2020 18:22:05 +0200 (CEST)
From:   Julia Lawall <julia.lawall@...ia.fr>
To:     Denis Efremov <efremov@...ux.com>
cc:     linux-kernel@...r.kernel.org, cocci@...teme.lip6.fr
Subject: Re: [Cocci] [PATCH v2 4/4] coccinelle: api: add selfcheck for
 memdup_user rule

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@...ux.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")
> +
> +@...ipt:python depends on selfcheck@
> +@@
> +coccinelle.checked_files |= set(definitions.values()) & set(cocci.files())
> +
> +@...alize: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@...teme.lip6.fr
> https://systeme.lip6.fr/mailman/listinfo/cocci
>

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