Re: [PATCH v4 02/14] kunit: bug: Count suppressed warning backtraces

On Thu, 13 Mar 2025 at 19:44, Alessandro Carminati <[email protected]> wrote:
>
> From: Guenter Roeck <[email protected]>
>
> Count suppressed warning backtraces to enable code which suppresses
> warning backtraces to check if the expected backtrace(s) have been
> observed.
>
> Using atomics for the backtrace count resulted in build errors on some
> architectures due to include file recursion, so use a plain integer
> for now.
>
> Acked-by: Dan Carpenter <[email protected]>
> Reviewed-by: Kees Cook <[email protected]>
> Tested-by: Linux Kernel Functional Testing <[email protected]>
> Signed-off-by: Guenter Roeck <[email protected]>
> Reviewed-by: David Gow <[email protected]>
> Signed-off-by: Alessandro Carminati <[email protected]>
> ---

Looks good. I'd definitely prefer the atomics to work one day, but I
doubt we're likely to have backtraces from multiple threads happening
in a KUnit test, so it's definitely not urgent.

Reviewed-by: David Gow <[email protected]>

Cheers,
-- David


>  include/kunit/bug.h | 7 ++++++-
>  lib/kunit/bug.c     | 4 +++-
>  2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/include/kunit/bug.h b/include/kunit/bug.h
> index 0a8e62c1fcaf..44efa7d5c902 100644
> --- a/include/kunit/bug.h
> +++ b/include/kunit/bug.h
> @@ -20,6 +20,7 @@
>  struct __suppressed_warning {
>         struct list_head node;
>         const char *function;
> +       int counter;
>  };
>
>  void __kunit_start_suppress_warning(struct __suppressed_warning *warning);
> @@ -28,7 +29,7 @@ bool __kunit_is_suppressed_warning(const char *function);
>
>  #define DEFINE_SUPPRESSED_WARNING(func)        \
>         struct __suppressed_warning __kunit_suppress_##func = \
> -               { .function = __stringify(func) }
> +               { .function = __stringify(func), .counter = 0 }
>
>  #define KUNIT_START_SUPPRESSED_WARNING(func) \
>         __kunit_start_suppress_warning(&__kunit_suppress_##func)
> @@ -39,12 +40,16 @@ bool __kunit_is_suppressed_warning(const char *function);
>  #define KUNIT_IS_SUPPRESSED_WARNING(func) \
>         __kunit_is_suppressed_warning(func)
>
> +#define SUPPRESSED_WARNING_COUNT(func) \
> +       (__kunit_suppress_##func.counter)
> +
>  #else /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */
>
>  #define DEFINE_SUPPRESSED_WARNING(func)
>  #define KUNIT_START_SUPPRESSED_WARNING(func)
>  #define KUNIT_END_SUPPRESSED_WARNING(func)
>  #define KUNIT_IS_SUPPRESSED_WARNING(func) (false)
> +#define SUPPRESSED_WARNING_COUNT(func) (0)
>
>  #endif /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */
>  #endif /* __ASSEMBLY__ */
> diff --git a/lib/kunit/bug.c b/lib/kunit/bug.c
> index 351f9a595a71..84c05b1a9e8b 100644
> --- a/lib/kunit/bug.c
> +++ b/lib/kunit/bug.c
> @@ -32,8 +32,10 @@ bool __kunit_is_suppressed_warning(const char *function)
>                 return false;
>
>         list_for_each_entry(warning, &suppressed_warnings, node) {
> -               if (!strcmp(function, warning->function))
> +               if (!strcmp(function, warning->function)) {
> +                       warning->counter++;
>                         return true;
> +               }
>         }
>         return false;
>  }
> --
> 2.34.1
>