[PATCH] bug: fix warning suppressions with kunit built as module

[PATCH] bug: fix warning suppressions with kunit built as module

[Bartosz Golaszewski]

CONFIG_KUNIT is a tristate symbol but the warning suppression code in
lib/bug.c is only built if it's built-in. Use IS_ENABLE(CONFIG_KUNIT) to
enable it for a loadable kunit module as well. When using a plain #ifdef,
the suppressions only work if kunit is built-in.

Cc: stable@vger.kernel.org
Fixes: 85347718ab0d ("bug/kunit: Core support for suppressing warning backtraces")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 lib/bug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/bug.c b/lib/bug.c
index 292420f45811..b9820a0226f5 100644
--- a/lib/bug.c
+++ b/lib/bug.c
@@ -219,7 +219,7 @@ static enum bug_trap_type __report_bug(struct bug_entry *bug, unsigned long buga
 	no_cut   = bug->flags & BUGFLAG_NO_CUT_HERE;
 	has_args = bug->flags & BUGFLAG_ARGS;
 
-#ifdef CONFIG_KUNIT
+#if IS_ENABLED(CONFIG_KUNIT)
 	/*
 	 * Before the once logic so suppressed warnings do not consume
 	 * the single-fire budget of WARN_ON_ONCE().
-- 
2.47.3

Re: [PATCH] bug: fix warning suppressions with kunit built as module

[Albert Esteve]

On Tue, Jul 7, 2026 at 2:58 PM Bartosz Golaszewski
<bartosz.golaszewski@oss.qualcomm.com> wrote:
>
> CONFIG_KUNIT is a tristate symbol but the warning suppression code in
> lib/bug.c is only built if it's built-in. Use IS_ENABLE(CONFIG_KUNIT) to
> enable it for a loadable kunit module as well. When using a plain #ifdef,
> the suppressions only work if kunit is built-in.
>
> Cc: stable@vger.kernel.org
> Fixes: 85347718ab0d ("bug/kunit: Core support for suppressing warning backtraces")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> ---
>  lib/bug.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/bug.c b/lib/bug.c
> index 292420f45811..b9820a0226f5 100644
> --- a/lib/bug.c
> +++ b/lib/bug.c
> @@ -219,7 +219,7 @@ static enum bug_trap_type __report_bug(struct bug_entry *bug, unsigned long buga
>         no_cut   = bug->flags & BUGFLAG_NO_CUT_HERE;
>         has_args = bug->flags & BUGFLAG_ARGS;
>
> -#ifdef CONFIG_KUNIT
> +#if IS_ENABLED(CONFIG_KUNIT)

Hello Bartosz,

Thanks for the fix! While it is correct, I think we could just drop
the guard completely. kunit_is_suppressed_warning() already has a
correct stub in the #else branch of include/kunit/test-bug.h when
CONFIG_KUNIT is not enabled:

    static inline bool kunit_is_suppressed_warning(bool count) { return false; }

With it, the check in lib/bug.c is redundant.

BR,
Albert

>         /*
>          * Before the once logic so suppressed warnings do not consume
>          * the single-fire budget of WARN_ON_ONCE().
> --
> 2.47.3
>

Re: [PATCH] bug: fix warning suppressions with kunit built as module

[Nico Pache]

On 7/7/26 6:58 AM, Bartosz Golaszewski wrote:
> CONFIG_KUNIT is a tristate symbol but the warning suppression code in
> lib/bug.c is only built if it's built-in. Use IS_ENABLE(CONFIG_KUNIT) to
> enable it for a loadable kunit module as well. When using a plain #ifdef,
> the suppressions only work if kunit is built-in.
> 
> Cc: stable@vger.kernel.org
> Fixes: 85347718ab0d ("bug/kunit: Core support for suppressing warning backtraces")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

I ran into the same issue and found the following fix also resolved the issue.

Tested-by: Nico Pache <npache@redhat.com>
Acked-by: Nico Pache <npache@redhat.com>


> ---
>  lib/bug.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/bug.c b/lib/bug.c
> index 292420f45811..b9820a0226f5 100644
> --- a/lib/bug.c
> +++ b/lib/bug.c
> @@ -219,7 +219,7 @@ static enum bug_trap_type __report_bug(struct bug_entry *bug, unsigned long buga
>  	no_cut   = bug->flags & BUGFLAG_NO_CUT_HERE;
>  	has_args = bug->flags & BUGFLAG_ARGS;
>  
> -#ifdef CONFIG_KUNIT
> +#if IS_ENABLED(CONFIG_KUNIT)
>  	/*
>  	 * Before the once logic so suppressed warnings do not consume
>  	 * the single-fire budget of WARN_ON_ONCE().